[Senate Hearing 110-228]
[From the U.S. Government Publishing Office]
S. Hrg. 110-228
CLIMATE CHANGE ON WILDFIRE ACTIVITY
=======================================================================
HEARING
before the
COMMITTEE ON
ENERGY AND NATURAL RESOURCES
UNITED STATES SENATE
ONE HUNDRED TENTH CONGRESS
FIRST SESSION
TO
CONSIDER SCIENTIFIC ASSESSMENTS OF THE IMPACTS OF GLOBAL CLIMATE CHANGE
ON WILDFIRE ACTIVITY IN THE UNITED STATES
__________
SEPTEMBER 24, 2007
Printed for the use of the
Committee on Energy and Natural Resources
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COMMITTEE ON ENERGY AND NATURAL RESOURCES
JEFF BINGAMAN, New Mexico, Chairman
DANIEL K. AKAKA, Hawaii PETE V. DOMENICI, New Mexico
BYRON L. DORGAN, North Dakota LARRY E. CRAIG, Idaho
RON WYDEN, Oregon LISA MURKOWSKI, Alaska
TIM JOHNSON, South Dakota RICHARD BURR, North Carolina
MARY L. LANDRIEU, Louisiana JIM DeMINT, South Carolina
MARIA CANTWELL, Washington BOB CORKER, Tennessee
KEN SALAZAR, Colorado JOHN BARRASSO, Wyoming
ROBERT MENENDEZ, New Jersey JEFF SESSIONS, Alabama
BLANCHE L. LINCOLN, Arkansas GORDON H. SMITH, Oregon
BERNARD SANDERS, Vermont JIM BUNNING, Kentucky
JON TESTER, Montana MEL MARTINEZ, Florida
Robert M. Simon, Staff Director
Sam E. Fowler, Chief Counsel
Frank Macchiarola, Republican Staff Director
Judith K. Pensabene, Republican Chief Counsel
C O N T E N T S
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STATEMENTS
Page
Barrasso, Hon. John, U.S. Senator From Wyoming................... 2
Bartuska, Ann, Deputy Chief, Research and Development;
Accompanied by Susan Conard, National Program Leader, Fire
Ecology Research, Forest Service, Department of Agriculture.... 6
Bingaman, Hon. Jeff, U.S. Senator From New Mexico................ 1
Corker, Hon. Bob, U.S. Senator From Tennessee.................... 5
Craig, Hon. Larry E., U.S. Senator From Idaho.................... 5
Domenici, Hon. Pete V., U.S. Senator From New Mexico............. 3
Helms, John A., Professor Emeritus of Forestry, University of
California, Berkeley, CA....................................... 17
Salazar, Hon. Ken, U.S. Senator From Colorado.................... 3
Swetnam, Thomas W., Director, Laboratory of Tree-Ring Research,
and Professor of Dendrochronology, University of Arizona,
Tucson, AZ..................................................... 22
Tester, Hon. Jon, U.S. Senator From Montana...................... 5
Wyden, Hon. Ron, U.S. Senator From Oregon........................ 4
APPENDIXES
Appendix I
Responses to additional questions................................ 47
Appendix II
Additional material submitted for the record..................... 71
CLIMATE CHANGE ON WILDFIRE ACTIVITY
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MONDAY, SEPTEMBER 24, 2007
U.S. Senate,
Committee on Energy and Natural Resources,
Washington, DC.
The committee met, pursuant to notice, at 3:04 p.m. in room
SD-366, Dirksen Senate Office Building, Hon. Jeff Bingaman,
chairman, presiding.
OPENING STATEMENT OF HON. JEFF BINGAMAN, U.S. SENATOR FROM NEW
MEXICO
The Chairman. The hearing will come to order.
Thank you all for being here. The likelihood that global
warming would result in increased wildfire activity and fire-
suppression costs was discussed at a hearing in this committee
more than 27 years ago. Since then, we've had numerous hearings
to consider the science of climate change and also the science
related to wildfires. But this is the first hearing, I'm aware
of, to consider the impact of global warming specifically on
wildfire activity.
A report, released earlier this month by the GAO, reported
that a group of experts convened by it and by the National
Academies of Sciences, quote, ``generally agreed that the
scientific community has reached consensus that climate change
will cause forest fires to grow in size and severity,'' end
quote. That consensus is reflected in the fourth assessment of
the Intergovernmental Panel on Climate Change. It concludes
that, quote, ``An intensification and expansion of wildfires is
likely, globally, and that--with that, an extended period of
high risk--high fire risk and large increases in area burned in
North America as a result of global warming.'' Despite the
enormous efforts of firefighters, and while--wildfires have
become larger, they've become more intense, they've become more
difficult, and they've become more expensive to control in
recent years.
We've often discussed the role that past wildfire
suppression and other land uses have had on fueling wildfire
activity in some areas in recent years. It's clear, from the
science, that climate change is driving the dramatic growth in
wildfire activity, and that it is likely to get worse. A number
of studies predict that global warming will increase the number
of acres burned by wildfires in the United States by 25 to 75
percent by the middle of the century. Alaska, the Southeast,
the Southwest, and the northern Rockies appear to be at
particularly high risk. This information is important to this
committee because of our work on global warming and on wildfire
policies. For example, the wildfire situation is a stark
reminder of the enormous current and potential costs of not
acting on global warming. That's a point that was made in the
Stern report that we received earlier in the year. Along with
rising temperatures, Federal wildland fire spending has more
than tripled in less than 10 years. It's risen from 800 million
in 1996 to 3 billion this year. It also is a reminder that,
while the Forest Service's work to contain its wildland
firefighting costs is critical, those efforts will not solve
the growing budget crisis that it faces.
We have four distinguished scientists testifying before the
committee today, and let me just mention who they are and then
defer to Senator Domenici for any opening statement that he
has.
Our three witnesses today are Dr. Ann Bartuska, who is the
Forest Service's deputy chief of research and development.
Thank you very much for being here. She's accompanied by Dr.
Susan Conard, who is the Forest Service's national program
leader for fire ecology research; Dr. Thomas Swetnam, who is
the director of the Laboratory of Tree-Ring Research, and
professor of dendrochronology at the University of Arizona; and
also Dr. John A. Helms, who is professor emeritus at the
University of California, testifying on behalf of the Society
of American Foresters. So, we welcome all of you.
Now let me turn to Senator Domenici for any opening
statement he would like to make.
[The prepared statements of Senators Barrasso and Salazar
follow:]
Prepared Statement of Hon. John Barrasso, U.S. Senator From Wyoming
Wildfire and its implications for people and resources are of great
interest in Wyoming. Fires are growing increasingly larger and more
frequent in our state and across the Rocky Mountain West.
This trend raises questions of how we as a Nation should provide
for the safety of our people and the sustainability of our land.
We know that our state has sustained a drought for almost a decade
in some areas. We know wildfires are increasing in size and scope--as
they do in hot and dry years.
We know that forests continue to stockpile fuels without proper
harvesting. They suffer infestation of bark beetles and other invasive
species that increase fuel loads.
We also know an active program of harvesting and thinning forest
lands can combat these conditions.
The people of Wyoming need to see action--action that will allow
for responsible harvesting of public and private lands to reduce fire
risk.
Thinning stands and treating forests to reduce fuel loads is the
only proven method of reducing the scope and intensity of wildfire
before problems occur.
Fires ravage overgrown, hot, dry fuel loads, but thinned stands in
healthy forests withstand lightning strikes and drought years.
The right path of action is clear. We need to manage our lands
responsibly.
So, where are the Forest Service regulations implementing an active
program of forest management? Where is Congress' call to public
agencies and private citizens to manage their forests appropriately?
The citizens of Wyoming deserve an active management plan.
I will be interested to hear the witnesses testimony not in regard
to climate change, but in regard to addressing the threat of hot, dry
years by mitigating the increased wildfire risk.
We've experienced stretches of devastatingly dry years in the past.
We will see similar events in the future.
Making one issue the scapegoat for all of our woes is easy and
grabs a headline in the paper. Finding the will to make sound policy
decisions based on common sense is the challenge.
Prepared Statement of Hon. Ken Salazar, U.S. Senator From Colorado
I want to thank Chairman Bingaman and Ranking Member Domenici for
holding today's hearing on global climate change and its effects on
wildfire activity in the United States. I would also like to thank our
witnesses for taking the time to share their expertise with us today.
Climate change is a very serious problem. In June, the Senate
passed an energy bill that has the potential to curb the progression of
climate change by promoting the use of renewable energy and by reducing
the amount of greenhouse gas emission released into the atmosphere. I
look forward to working with my colleagues as this legislation is
considered by the House-Senate conference committee.
However, we are constantly learning more about the effects of
climate change. What we are learning is that we are experiencing the
impacts of climate change now, and that it is not something that will
just impact us in the future. Climate change is increasingly being
cited by scientists as the cause for our more frequent and severe
wildfires.
Today's hearing is of interest to me as studies have shown that
Western states are particularly vulnerable to more frequent and severe
wildfires due to climate change. Studies have shown that fire season
itself is even longer in the West than it was twenty years ago.
In my state of Colorado, the Hayman wildfire that began in June of
2002 was the largest wildfire in Colorado's history and burned nearly
138,000 acres over the course of three weeks. Over 40,000 people living
outside of Denver were forced to evacuate their homes, and 133 homes
were lost.
Today's hearing is critical in helping us to understand the impacts
of climate change and the increased fire danger that is now posed. It
is also important to help us understand the necessary measures we must
take to prevent further damage to our lands and communities and how we
can best serve the people of our states in the face of wildfires.
I want to thank Chairman Bingaman and Ranking Member Domenici once
again for holding this important hearing so that we can understand the
best way to address this important issue.
STATEMENT OF HON. PETE V. DOMENICI, U.S. SENATOR FROM NEW
MEXICO
Senator Domenici. Thank you, Mr. Chairman, and good
afternoon.
I doubt that much of the information we will hear today is
going to surprise most members who've participated in hearings
in this committee over the last decade. I anticipate our
witnesses today will refine our understanding of what may be
occurring, and will help us to begin to focus on the areas of
greatest risk. For that, I thank them for taking the time to
come to testify.
It seems to me that we have always had years of drought,
warm summers, early runoffs of snowpack, and when we have the
right weather conditions, we experience spectacular fires. I've
no doubt that we will see the convergence of these events again
in the future.
At least three cataclysmic fires come to mind, and they all
occurred during a period of changing climate conditions. They
are: one, the afternoon of October 8, 1871, when the township
of Peshtigo and parts of Green Bay, Wisconsin, were destroyed.
A prolonged and widespread drought and high temperatures,
capped off by a cyclonic storm, resulted in a fire covering
about 2400 square miles in Wisconsin and upper Michigan.
Between 1200 and 2400 lives were lost that afternoon, but it
didn't get much press, because it was also the day that the
city of Chicago burned.
On Sunday, September 1, 1894, a great firestorm destroyed
Hinckley, Minnesota, and five other nearby communities. The
fire covered 400 square miles, consuming nearly everything in
its path. It is estimated that between 420 and 800 people died.
Thankfully, over 500 people were evacuated from Hinckley on two
trains that happened to be in the area at the time.
Finally, the third was on August 20 and 21, 1910. Fires
raged across 3 million acres of northern Idaho and western
Montana, an area the size of Connecticut. The fires went on
runs of more than 50,000 acres, 78 square miles, and threw fire
brands 10 miles in front of the main fire. The wind blew at up
to 80 miles per hour. In this event, 86 people are known to
have perished.
I expect our witnesses today are all going to tell us that
we are in for more warming, and, therefore, more fires. They
are likely to tell us that when these fires occur, they will be
very damaging, and, yes, that these fires will result in more
carbon dioxide being released into the atmosphere, which will
impact our environment. Some of the impact may be beneficial,
and some may be damaging.
I think that we all understand that. But what we are
struggling with is this: whether anything can be done about
changes to our forests; and, if so, how much the remedial
actions may cost.
In the short run, there are only two variables that we can
influence, those being hazardous fuel removals from Federal
lands, and private development in and around our Federal
forests. I hope that Congress will address these two issues.
I'm sure today's witnesses will have more suggestions.
In closing, I very much appreciate this hearing and these
witnesses coming to testify.
Thank you very much, Mr. Chairman.
The Chairman. Thank you very much.
Let me just indicate, we have a good number of Senators
here, as well as our witnesses. Let me ask if any Senator has a
short statement they would like to put in the record, at this
time, or briefly summarize for us. Let me call on Senator
Wyden.
STATEMENT OF HON. RON WYDEN, U.S. SENATOR
FROM OREGON
Senator Wyden. Thank you very much, Mr. Chairman. I'll be
brief.
I think you've made it very clear that there is an emerging
scientific consensus that climate change and the growing number
of wildfires are related. What we're going to particularly need
to do in government is to see if we can get in front of the
trends and reduce the number of forest fires. My sense is, with
some of the practices at the land management agencies, we're
going to have to make some changes to get ahead of the problem.
For example--this'll be my last point--members of this
committee worked very, very hard in a bipartisan way on the
forest health legislation, and one of the key components there
was to get critical thinning work done in our forests in order
to prevent fires in those forests, but what has happened is,
there has been, in the administration, a--I guess you could
call it dragging their feet on completing this critical, you
know, thinning work. Until attention is turned squarely to
this, we're going to have hundreds of thousands of acres of
choked second-growth plantation forests all across the West,
and we're going to have global warming as a greater and greater
risk to these critical public resources.
So, I'd like to suggest that we get on with the bipartisan
work that's been the tradition of this committee, particularly
in the thinning area, as a way to get out in front of some of
this very, very serious problem.
Thank you, Mr. Chairman.
The Chairman. Thank you very much.
Senator Craig.
STATEMENT OF HON. LARRY E. CRAIG, U.S. SENATOR
FROM IDAHO
Senator Craig. Mr. Chairman, I'll make my comments during
the question period.
Let's put this fact on the table. We spent about 650-700
million this year in healthy forests. We've spent to date, 1.6
billion fighting fire, and probably it'll go to 1.8 or 1.9
before the snow falls. If we dedicated that much resource to
healthy forests, by the end of the decade, my guess is, we'd be
spending a lot less fighting fires.
Thank you.
The Chairman. Thank you very much.
Senator Tester.
STATEMENT OF HON. JON TESTER, U.S. SENATOR
FROM MONTANA
Senator Tester. Yes, thank you, Mr. Chairman.
I'd like to thank the panelists for being here today. You
know, about 800,000 acres--in fact, I think it's a little more
than that--burned up in the State of Montana this fire season,
and we're just about at the end of it, I hope. That, combined
with, as I read in the paper, the Northwest Passage now exists,
along with the changes in the land that my grandparents
homesteaded and we've been farming for nearly 100 years--it's
inarguable, the climate has changed.
The issue for me is figuring out what we can do to help
remedy the situation, because doing nothing is not an option,
in this case. Doing nothing, whether it's on global warming or
whether it's on the Forest Service ability to manage their
forests in a way that makes sense, is simply not a solution at
all.
So, with that, I look forward to this hearing. I want to
dovetail on something--what Senator Domenici said, you know,
that over the last decade, I believe--you guys have probably
had a lot of hearings on climate change, and maybe you hear the
same thing over and over again--but I think it's really time
that we take proactive steps to help solve the problem.
Thank you.
The Chairman. Thank you very much.
Senator Corker.
STATEMENT OF HON. BOB CORKER, U.S. SENATOR
FROM TENNESSEE
Senator Corker. Thank you. I've enjoyed my colleagues'
comments. I'm actually more interested in the panel, no offense
to anybody, and I think we'll move on with them.
So, thank you.
[Laughter.]
The Chairman. That's a great example for us all.
Senator Domenici. You mean everybody?
[Laughter.]
The Chairman. He----
Senator Domenici. ``All of us.''
The Chairman [continuing]. He meant your comments, as well
as mine.
Senator Domenici. Yours, too?
The Chairman. I think he did.
Senator Domenici. Oh, well, then we'll all shut up.
[Laughter.]
The Chairman. Dr. Bartuska, please go right ahead.
STATEMENT OF ANN BARTUSKA, DEPUTY CHIEF, RESEARCH AND
DEVELOPMENT; ACCOMPANIED BY SUSAN CONARD, NATIONAL PROGRAM
LEADER, FIRE ECOLOGY RESEARCH, FOREST SERVICE, DEPARTMENT OF
AGRICULTURE
Ms. Bartuska. Mr. Chairman and members of the committee,
thank you very much for the opportunity to talk with you today
about climate change and wildfires.
As you've mentioned, I'm accompanied by Dr. Conard, who is
our national fire ecologist, who will be providing the details
on the science of the interactions of climate change and
wildfire. But I wanted to provide some context, in the sense of
describing what the overall R&D program is for Forest Service
research, and to provide that background.
In 1908, we established our very first experimental
watershed in Colorado. That became the basis for, now, nearly
100 years of forestry research within our organization, and we
are all about the science of trees, forests, and forest
ecosystem, and all the interactions associated with that. So,
our ability to look at climate change and wildfire and the
interactions in forest ecosystems has a very long history, and
it's something that we are very proud of.
Our climate change research priorities currently involve
three areas. One is adaptation; that's providing options to
increase forest resilience, to reduce threats, and to provide
managers tools associated with that. The second is in
mitigation: increasing options through carbon sequestration and
soils--and forest soils, and forest biomass itself. Then, the
third is in decision support for practitioners and
policymakers. We think all three of those are essential for a
healthy research program.
To do this, we're relying on our extensive network, the
infrastructure of our research laboratories that are
nationwide, our long-term research studies, building upon the
80 experimental forests and ranges that we have--and, again,
the first one in--from 1908, soon to have our centennial of
that effort. But we also have our rich and nationwide forest
surveys. Some of you are aware of our Forest Inventory and
Analysis Program. We also call it the Nation's Forest Census.
We're coming up on 75 years of continuous survey of forests.
So, we have a very large data set to work from.
In addition to that, we have over two decades of focused
climate change research, three decades of air pollution
research, and long experience with scientific assessments which
provide a basis for making decisions about climate change and
forest management. We are integrating that piece of climate
change upon a solid foundation of our traditional disciplines--
entomology, pathology, silviculture--but we're also integrating
our climate change research with fire ecology, with wildland
fire research, as well as the complex interactions of dealing
with fuels research, which are some of our strongest programs.
So, all of those, together, provide, again, a very solid
foundation from which to operate.
We have been active--our scientists have been active with
the U.S. Climate Change Science Program, as well as have
participated in the assessments of the recent IPCC, the
Intergovernmental Panel on Climate Change.
Finally, I just have to point out, Forest Service R&D can't
do the work alone. We rely on our associations and partnerships
with many universities, represented here, as well as elsewhere;
other Federal agencies that deal with science and management;
as well as nongovernmental organizations. We believe, all
together we really have--to get a very important science
together.
But we also know that we have more work to do. Just last
week, about 75 of our scientists came together with several
scientists from other communities to revise and look at what
gaps we have in our climate change portfolio, and to develop a
new research and development strategy. So, we believe, again,
we're turning the corner on that.
But I think the other aspect that is critically important
for us is, How do we get our science into the hands of the
practitioners? If we just do--if we're just about science and
doing research, then we're really not meeting our obligation in
providing the tools that are needed to take the science and
translate it into practice, working with our managers to come
up with more options that they can use, build into their
planning activities, build into their management strategies, so
that they can really integrate the linkage between climate
change and wildland fire into their overall programs. This is
something that we are increasingly going to be spending our
time on. It is a critical strength of the Forest Service that
we have our research entity--or research enterprise embedded
within a management agency, and it really creates for a very
good integration of those two.
There are science-based adaptative management approaches
that we are taking now that we believe will help reduce the
impact of wildfires on climate change and mitigate the impacts
of climate change on our Nation's forests and grasslands. For
example, specifically, as has been referenced here, increasing
our fuel reduction work over the past several years can lead to
reducing the threat of large wildfires and may increase the
resilience of forests to the effects of climate change. We
intend to build upon that and continue to study those
interactions.
Mr. Chairman, thank you for being able to make a few
remarks. I'd like to now turn it over to Dr. Conard to provide
some of the technical details about our program.
Mr. Conard. Thank you.
The Chairman. Go right ahead, Dr. Conard.
Mr. Conard. Mr. Chairman and members of the committee,
thank you for the opportunity to discuss with you what
scientific research tells us about the potential interplay of
climate change and wildfire.
According to data from the National Interagency Fire
Center, annual burned areas have exceeded 7 million acres only
seven times since 1960; six of those have been in the past 20
years. In recent years, we have seen particularly severe
droughts in the western United States, Alaska, and Florida. Not
coincidentally, these regions have accounted for a majority of
increased wildfire activity in the United States.
The IPCC has reported clear patterns of temperature
increase and long-term trends in precipitation changes since
1900. For North America, the greatest future increases in
winter temperatures are projected for boreal and Arctic zones,
with summer temperature increases the greatest across the lower
48 States.
Precipitation is projected to decrease in the southwestern
United States. We can expect these changes to lead to longer
and more severe fire seasons in many areas.
The frequency and severity of fires vary greatly due to
differences in weather, topography, and fuels. For example, in
Ponderosa Pine and Loblolly Pine Forests, which historically
had high-frequency, low-severity fires, reduced fire frequency
beginning in the late 19th century has led to substantial fuel
accumulation. These fuels increase fire hazard, a condition
that can be exacerbated by warming climate and longer fire
seasons. Fuel treatments and active forest management can help
to mitigate such increases in fire hazard.
A number of studies indicate that variations in cyclic
weather patterns and in climate over time are factors in how
fire patterns change from year to year. The extent and severity
of wildland fires correlate with drought patterns, timing of
spring snowmelt, and changes in ocean circulation patterns, as
I'm sure you will hear more about from Dr. Swetnam.
Research indicates that a warming climate will increase
fire hazard, likely leading to increases in the annual area
burned, as well as in the severity of fires. We expect such
changes in fire regimes to affect geographic distributions of
trees, other plant species, and animals.
Global general circulation models provide coarse scale
projections of changes in temperature, precipitation, and other
factors as greenhouse gas increases. These models project
varying trends in climate patterns across the country.
Scientists are developing tools that adjust these model outputs
for local variations in terrain, temperatures, precipitation,
and vegetation.
A number of these models developed by Forest Service
researchers and their collaborators predict large changes in
fire regimes and vegetation patterns across North America and
in many regions of the country. Other models project potential
future distribution of suitable habitat for tree species and
for animal species. Improved models will help us to better
project and anticipate the potential effects of changing
climate on vegetation and species distributions, and on
interactions with fire and other disturbances. The higher
resolution provided by these types of models provides essential
information for site-specific planning and decisionmaking.
I would now like to talk briefly about effects of fire on
climate and carbon. As long as the incidence and severity of
wildfires remains constant, the removal of carbon through the
atmosphere through--from the atmosphere through a regrowth of
vegetation in burned areas equals the carbon emitted through
fires. There is growing scientific concurrence, however, that
climate change will increase burned areas and fire severity,
resulting in increased wildfire emissions.
Fire produces many emissions besides carbon dioxide. Some
of these compounds trap more radiation than CO2,
while others reflect heat and light. Impacts of fire-induced
vegetation changes on how the surface of the Earth reflects or
absorbs the sun's rays will also influence the effects of fire
on climate.
Research has shown that hazardous fuel-reduction treatments
in the appropriate type of fire regime are often effective at
decreasing the severity of subsequent fires. If the fuels that
are removed are used for bioenergy or in wood products, they
also provide benefits by offsetting the use of fossil fuels or
entering carbon into semi-permanent storage. Subsequent lower-
severity wildfires will emit less carbon to the atmosphere than
would occur in untreated stands. Forest Service scientists are
working with partners to develop better estimates of various
components of the forest carbon cycle that include these
alternate uses of materials and account for the various
processes involved as forests are harvested or burned and as
they regrow.
In summary, the net effect of changing fire regimes on
climate and carbon storage will be influenced by many factors.
Changing emissions, carbon dioxide uptake by regrowing
vegetation, the use of potential fuels for bioenergy or in wood
products, and changes in vegetation will all play a role.
In the United States, the magnitude and effects of climate
change and its impact on fire regimes will vary in different
regions of the country. We need to understand more about fuels,
about the effects of changing burn severity on carbon release,
and about how these effects will vary regionally.
I'd now like to turn to Dr. Bartuska for concluding
remarks.
Ms. Bartuska. So, just a few key points--sorry--a few key
points, to reiterate.
One is that we have made an investment, in the Forest
Service, for over--nearly 100 years, rather--in understanding
forest and rangeland science, and we believe this is foundation
upon which we can look at our climate change processes.
We also believe that we should be taking that into account
looking at adaptation strategies, mitigation options, but also
the decision-support tools that are needed to address the issue
of climate change and wildland fire.
But, finally, it doesn't make sense, if we're just going to
do the science, if we don't put it in a form and in a way that
is available to practitioners and helping managers make better
decisions. That really is the foundation of the work that we're
moving into.
Mr. Chairman and members of the committee, thank you for
the opportunity to discuss the science of the interactions of
climate change and wildfire. Dr. Conard and I will be available
for questions at the end of the panel.
Thank you.
[The prepared statement of Ms. Bartuska follows:]
Prepared Statement of Ann Bartuska, Deputy Chief, Research and
Development; Accompanied by Susan Conard, National Program Leader, Fire
Ecology Research, Forest Service, Department of Agriculture
Mr. Chairman and members of the Committee, thank you for the
opportunity to talk with you today about the interactions of climate
change and wildfire. I will give you a brief description of the Forest
Service research programs in climate change and wildfire. I am
accompanied today by Dr. Susan Conard, our scientist who leads the
national fire ecology research program, and she will discuss the
science of the interactions between climate change and wildfire.
The Earth's climate is changing and will continue to change for
many decades. Decisions being made today by policymakers and public and
private sector resource managers will have implications through the
next century. Forest Service Research and Development provides long-
term research, scientific information, and tools that can be used by
managers and policymakers to address climate change impacts to forests
and rangelands.
Forest Service climate change research priorities involve three
areas: adaptation (increase forest stress resilience); mitigation
(increasing carbon sequestration through storage in soils, living
plants and wood products); and decision support for practioners and
policymakers. To do this, we maintain an extensive infrastructure of
research laboratories, long-term research studies, and continuous data
from nationwide forest surveys and experimental forests. Several long-
term data sets--the Nation's Forest Census (Forest Inventory and
Analysis) and the Experimental Forests--provide several decades worth
of information on forest and rangeland trends. Over two decades of
focused climate change research, three decades of air pollution
research, and long experience with scientific assessments provide a
firm foundation for addressing climate change and forest management.
The Forest Service climate change research program is supported by
strengths of its more traditional research in areas such as
ecophysiology, landscape ecology, watershed hydrology, vegetation
modeling, nutrient cycling, and forest management. Further support
comes from partnerships with universities, federal and state agencies,
non-governental organizations, and the forest industry here and abroad.
Scientists from the Forest Service are active in the United States
Climate Change Science Program (CCSP) and participate in CCSP and
Intergovernmental Panel on Climate Change (IPCC) assessment activities.
In addition, the Forest Service climate change research, fire ecology,
wildland fire, and fuels research programs combine to provide a rich
source of information, data, and scientific discoveries. The science is
essential to underpin predictive models and adaptation and mitigation
techniques. Important aspects of the research are the effects of fire
on carbon storage, atmospheric chemistry and warming potential, water
supply, and ecosystem health and resilency. Forest Service scientists
and colleagues funded by the National Fire Plan and the Joint Fire
Science program--managed jointly by the Forest Service, US Geological
Survey, Bureau of Land Management, National Park Service, US Fish and
Wildlife Service, and the Bureau of Indian Affairs--are studying
wildfire and climate interactions, predicting and monitoring wildfire
emissions, and looking at factors that affect fire behavior and fuel
consumption. This research allows us to better understand fire and
water supply issues, perhaps two of the most critical issues for
western states.
I would like to say a few words about the scientific process.
Science can describe the connections between human and ecological
systems, develop methods to forecast the occurrence of damaging fire
events and other disturbances, and characterize the possible outcomes
of alternative management options. Scientists can help managers
interpret what they are seeing on the ground and can help evaluate the
environmental effects, social and economic costs and benefits, and
effectiveness of potential management programs towards reaching
management objectives. This scientific information can help managers
and policymakers to decide the most appropriate management strategies
for specific situations.
As scientists, we know that the scientific basis for understanding
fire and climate change interactions is more complete for some
interactions than for others. We have important knowledge gaps that we
must address. For example, current estimates of fire emissions vary
widely. While we have information for a few systems, we do not have
good information broadly on burn severity or on how burn severity will
cause emissions to fluctuate. We also do not know how much we can
increase carbon storage without causing unacceptable increases in fire
hazard in fire-dominated ecosystems.
The interaction of climate change with ecosystems is also the
subject of the Synthesis and Assessment Report (SAP) 4.3, The Effects
of Climate Change on Agriculture, Land Resources, Water Resources, and
Biodiversity, is one of 21 synthesis and assessment products being
produced by the CCSP. These reports summarize scientific understanding
of various aspects of climate change for government and private sector
decision-makers. USDA participates in CCSP and is the lead agency for
SAP 4.3. The direct and indirect climate effects on wildfires is one
topic addressed by SAP 4.3, and when the report is finalized, will help
to provide the necessary scientific basis for assisting decision and
policy makers.
As we continue to integrate results from various scientific
studies, we increase our understanding of where and why results differ,
as well as where results can be generalized. Scientists' ability to
provide this kind of information will aid decision-makers.
Although policy questions may often be framed as science questions,
many non-scientific considerations must be part of the answer to these
policy questions. While science can provide a foundation for management
and policy decisions, science alone is not sufficient to determine
policy. Adaptive management by land managers is a useful tool that
combines emerging research with evaluation of management practices.
This approach enables managers to modify practices as our understanding
of management impacts improves. This is an important concept in dealing
with active application of science by practitioners and policymakers.
While we still have much to learn about the interactions among
climate change, carbon emissions, and wildfire, there are science-based
adaptive management approaches we are taking today that can help reduce
the impact of wildfires on climate change and mitigate the impacts of
climate change on our nation's forest and grasslands. For example, the
Forest Service has increased our fuel reduction work over the past
several years, which reduces the threat of large wildfires and may
increase resilience of forests to the effects of climate change.
Mr. Chairman, Dr. Susan Conard will now address in greater detail
the science of the interactions between climate change and wildfire
activity. Following her testimony and my concluding remarks, we would
be happy to answer any questions you might have.
scientific research on the impacts of climate change on wildfire
activity
Mr. Chairman and Members of the Committee, thank you for the
opportunity to discuss with you today what scientific research tells us
about the potential interplay of climate change and wildfire. Today I
will talk about the current scientific understanding of historical
interactions of climate and wildfire, how climate is changing fire
regimes, how wildfire affects climate change, some of the research-
based knowledge and tools being developed that help us understand how
climate change is likely to affect wildfires, and ways in which this
knowledge can help support managers and policymakers.
background
A number of recent scientific studies indicate that variations in
cyclic weather patterns and climate over time are factors in the
increase in large, severe fires and how fire patterns change from year
to year. According to data from the National Interagency Fire Center
(NIFC), annual burned areas have exceeded 7 million acres only 7 times
since 1960; 6 of those have been in the past twenty years. One possible
outcome of climate change is an increase in the incidence and severity
of wildland fire in some parts of the continent and in Alaska. Fuel
treatments and active forest management have reduced fire hazard and
can help to mitigate these increases in fire hazard.
Recent data and projections from the Intergovernmental Panel on
Climate Change (IPCC) provide some context for this discussion. IPCC
reports (IPCC 2007) show that there have been clear patterns of
temperature increase and long-term trends in precipitation change
around the world since 1900. Results from over 20 different global
models project strongly increasing temperatures for much of the globe,
with the greatest increases generally projected for northern latitudes.
For North America the greatest increases in winter temperatures are in
the boreal and arctic zones, with summer temperature increases the
greatest across the lower 48 states in the United States. Precipitation
is projected to decrease in the southwestern United States, and
increase in some areas of the northeast. We can expect these
temperature and precipitation patterns to lead to longer and more
severe fire seasons in many areas of the United States and Canada,
which underscores the need to continue to engage in active forest
management as a mitigation measure.
historical wildfire
Natural disturbance--whether by fire, insects, disease, hurricanes,
ice storms, floods, or tornadoes--is a fact of life for all ecosystems.
For most forests and rangelands, fire is a relatively regular
occurrence, although the typical frequency, behavior, and severity of
the fires (the fire regime) vary greatly from one forest type to
another. This difference in fire regimes is a function of the
combination of weather, topography, stand structure (fuels), and
occurrence of ignitions that characterize specific ecosystems (e.g.
Pyne et al. 1996). For example, many prairies and grasslands
historically burned every few years, or even annually. Dry pine forests
burned primarily in frequent, low intensity surface fires. Cool, moist
conifer forests, such as coastal Douglas-fir in the Pacific Northwest
of the United States have burned in high intensity stand replacement
fires only every few hundred years (Heinselman 1978, Heyerdahl et al.
2001, Leenhouts 1998, Schmidt et al. 2002). While each ecosystem has a
typical fire regime, the characteristics of individual fires may vary
widely as a function of specific fuel structure, weather conditions
during the fire, and weather and climate patterns in the weeks (and
even years) before a fire occurs (Leenhouts 1998, White et al. 1996).
In forest systems, the highest severity fires (where severity
refers to the level of ecological impact) are in fire regimes with
stand replacing fires, which typically kill all or most of the living
vegetation, and burn deeply into surface litter and duff layers.
Ecosystem recovery is generally slow (100 to 300 years) as is the
return to pre-fire levels of fuel loadings and fire frequency. In some
forest and shrub systems, as well as in perennial grasslands and
savannas, fires may top-kill most of the above-ground biomass, but
native species are adapted to recover through re-growth from live
roots, basal sprouting or regeneration from seed. Such systems recover
rapidly--and typically undergo shorter interval between fires.
The lowest severity fires in forest systems burn only surface fuels
and low-growing vegetation, and have little impact on overstory trees.
These surface fire regimes are most typical of forest types on dry
sites or with fairly open canopies, and with grassy or shrubby
understories, such as ponderosa pine and loblolly pine. Such surface
fires typically occur much more frequently (every 3 to 30 years) than
stand replacement fires.
In mixed severity fire regimes, there may be a pattern of
relatively frequent surface fires, with less frequent stand replacement
fires, or patches of high fire severity, that are a function of either
unusually severe weather or reduced fire frequency that leads to
greater than normal fuel accumulation. This appears to be the pattern
in many conifer forests in the west and can also occur in some of the
Southeast.
In some systems in North America (such as ponderosa pine and
loblolly pine forests which historically had high frequency, low
severity fires) reduced fire frequency beginning in the late 19th
century has led to substantial fuel accumulation. These fuels increase
fire hazard and burn severity, a condition that can be exacerbated by a
warming climate and longer fire seasons (e.g Westerling et al, 2006).
effects of climate on fire regimes
While climate has always been variable, the suite of climate models
evaluated by IPCC project an increased frequency and intensity of
drought and high-intensity rainfall events, particularly in the boreal
and temperate zones of the northern hemisphere. These predictions take
into consideration the larger land mass in the northern hemisphere as
compared to the southern hemisphere. The largest changes in temperature
are projected for high latitudes in both the northern and southern
hemispheres; however, water has a moderating effect on changes in
temperature and precipitation; hence the northern hemisphere, with its
relatively larger land mass, will likely see more frequent and intense
weather patterns (IPCC 2007).
Historically, the extent and severity of drought, timing of spring
snowmelt, and changes in ocean circulation patterns have all correlated
with the extent and severity of wildfire on forests and rangelands. The
impacts of climate change may be most noticeable in the short-term on
fire regimes typified by low or mixed severity fires because fuel
structure in these systems reacts more rapidly to fire exclusion and
drought is more frequent.
Warmer winters also exacerbate summer drought because of reductions
in winter snow pack depth and duration that alter both the timing and
volume of runoff, leading to longer summer droughts, larger water
deficits, and more severe fire seasons (e.g. Westerling et al. 2006).
Wet years of climatic cycles lead to high rates of vegetative growth
(fuel production), often in the forest understory. Drought stresses
trees and other vegetation, causing increased flammability of live and
dead fuels and increased susceptibility to a number of insects (most
notably bark beetles) and some pathogens. Warmer winter temperatures
can increase the reproductive rates of insects, resulting in a second
generation in one year. In addition, warmer temperatures can extend the
ranges of some insect populations, as has happened with the mountain
pine beetle in the western United States (Logan et al, 2003). Recent
research shows clear relationships between warmer temperatures and
drought on extensive insect outbreaks in southwestern forests and
Alaska.
A number of studies published over the past two decades suggest
that a warming climate will cause increases in fire hazard, likely
leading to increases in the annual area burned as well as in the
severity of fires (Brown and Smith 2000, Flannigan et al. 1998, Fosberg
et al 1996, Lenihan et al. 1998, Stocks et al. 1998, Wotton and
Flannigan 1993). These studies in general do not take into account
mitigating measures such as fuel reduction. These projections are
supported by numerous studies that relate inter-annual or multi-year
changes in fire patterns to regional patterns of climate variability
(e.g. Swetnam and Betancourt 1990, 1998; Fauria and Johnson 2006;
Kitzberger et al. 2007; Murdiyarso and Adiningsih, 2007; Swetnam and
Baisan 1996; Westerling et al 2006).
As climate warms and becomes more variable, some of the greatest
effects on fire regimes are expected to occur in the boreal zones of
North America (primarily Alaska and Canada) and in Eurasia (Fosberg et
al. 1998, Flannigan et al. 1998, Fauria and Johnson 2006). The effects
of climate on fire regimes in systems with deep organic layers such as
peat bogs, are predicted to be large but are poorly understood
(Morrisey et al 2000, Turetsky et al. 2006). This is tremendously
important because of the large carbon stores that can be released from
these ecosystems if fire frequency and the depth of burn increase.
In recent years, we have seen particularly severe periodic seasonal
droughts in the western United States, Alaska, and Florida. Not
coincidentally, these regions have accounted for a majority of
increased wildfire activity in the United States. Climate models, which
I will speak more of later, project increased drought in the southwest
United States. The same models project increased rainfall in the upper
Midwest, Great Lakes and New England.
Changes in fire regimes and in wildfire occurrence and severity
have implications for atmospheric chemistry, the influence of smoke on
air quality, the quality of our drinking water, and the ability of
forests and grasslands to store carbon. These changes could both
facilitate and force changes in the structure and composition of
ecosystems, with feedback loops that are largely unknown. Ultimately,
changes in fire regime can be expected to result in substantial
alterations to the geographic distribution of trees, other plant
species, and animals (e.g. Heinselman 1978).
circulation patterns and wildfires
The severity of fire seasons in different parts of North America
has been shown to be highly correlated with annual and multi-year
weather patterns (such as those resulting from changes in El Nino, La
Nina or other ocean circulation patterns). (e.g. Swetnam and Betancourt
1998, Kitzberger et al. 2007). In mountainous areas of the western
United States, one of the key factors associated with severe fire
seasons is the timing of snow melt in the spring, with earlier snow
melt often being a precursor to longer summer drought periods (e.g.
Westerling et al. 2006). High temperatures and low rainfall (or longer
dry seasons) together produce increases in area burned and numbers of
large, intense fires.
The El Nino-Southern Oscillation provides the south and
southwestern United States with abundant winter rains every 3-7 years,
supporting luxuriant growth of grasses and forbs the following growing
season. If this season in turn is followed by drought, the abundant
surface fuels increase the probability of stand-replacing fires to
develop in open woodlands, parklands and dry pine (ponderosa) forests
(Swetnam and Baisan, 1990). Recent research indicates that the warm
phase of the Atlantic Multidecadal Oscillation has coincided with 40-60
year periods of increased fire frequencies throughout the western
United States, and that the West appears to be entering such a period
now (Kitzberger et al., 2007).
The effects of these multi-year weather patterns may well amplify
climate change-induced effects to forests and grasslands. Seager et al
(2007) recently projected severe drought conditions for much of the
21st century in the southwestern United States. This supports
projections of multiple models for decreased summer rain and increased
temperatures in this region (IPCC 2007).
tools for assessing interactions between climate change and wildfire
Scientists are developing and using a number of tools to assess the
interaction of climate change and fire. Under a changing climate, fire
occurrence and patterns of ecosystem recovery after a fire may also
change, leading to changes in vegetation structure and composition and
in the ability of those ecosystems to store carbon. Global General
Circulation Models (GCMs) are used to project climate effects on
temperature, precipitation and other factors and generally do not
incorporate disturbances such as wildfire except in a very coarse way.
Their predictions are primarily useful for long-range and large-scale
(e.g. national or broad regional) thinking and planning. Even at a
coarse scale, however, it is clear that the mechanisms and expected
magnitude of impacts of changing climate will vary greatly across the
country.
To develop landscape-scale projections of impacts of climate change
on ecosystems or on fire that are useful for management and planning,
scientists adjust General Circulation Model outputs for local
variations in terrain, temperatures, precipitation, and vegetation.
While Forest Service scientists are not generally involved in
developing General Circulation Models (this being largely the realm of
physicists and atmospheric chemists), they use General Circulation
Model outputs to project changes in vegetation, fire hazard, wildlife
habitat and water supply both at coarse scale and at scales more
appropriate to local and regional resource management planning.
Information from field studies and landscape-level models can also be
used by General Circulation Model developers to help make their models
more realistic, especially in terms of incorporating major landscape
processes such as fire.
There are several types of vegetation models that are useful for
assessing the potential interactions among climate change, vegetation,
and wildfire. These range from global to regional or landscape-scale,
and they take a range of approaches (See Keane et al. 2004 for an
extended discussion). Some models are based on biogeochemical processes
and focus on overall plant productivity in a given climate, but often
without regard to the likely presence or absence of vegetation, or of
individual species (e.g., Neilson et al, 2005). Other models use
detailed knowledge about how individual species grow currently to
project viability, and growth, and changes in species composition
(Bugmann and Solomon, 2000; Busing et al, in press). Still other types
of models evaluate current climatic limits of species or ecosystems and
use that information to project areas where habitat may be suitable in
the future (Iverson et al, 2004; Rehfeldt et al, 2006). Further, some
of these models are landscape-level models (Mlandnoff and Liu, 2003)
and others model individual stands and use statistical information on
distribution of forest types to develop projections.
Models give us projections of species environmental potential but
not actual capability to move on the landscape. Scientists are working
hard to realistically represent vegetation change and species migration
given that the capability of many long-lived plant species to migrate
may be slower than the projected rate of change in distribution of
suitable habitat (Neilson et al. 2005).
One example of a biogeochemical model that looks at fire, which is
under development by Forest Service researchers, is the Mapped
Atmosphere-Plant-Soil System. The MAPSS simulates potential impacts of
changes in the physical environment on vegetation dynamics for major
ecosystems (Bachelet et al. 2003). The fire module predicts substantial
increases in burned area and emissions from wildfires, particularly in
the boreal zones and in the western United States (e.g. Lenihan et al.
2003).
Keane et al. (2004) discuss and compare over 40 landscape fire
models from around the world that are able to incorporate climate into
their simulations. A number of landscape-scale models developed by
Forest Service researchers and their collaborators predict large
changes in fire regimes and vegetation patterns in areas as diverse as
Glacier National Park, California, the Ozark Plateau, and the North-
Central United States. Landscape vegetation fire models have been
developed for nearly every region of the United States, including
Alaska. However, these models vary greatly in design and in sensitivity
to climate, terrain, and other parameters (Cary et al. 2006), and in
general they are still being evaluated for use in predicting effects of
changing climate on vegetation and fire. Many of these models are
currently in use to support forest management decisions and the
development of planning alternatives.
Other kinds of models combine current distribution of individual
tree species based on data from the Forest Service Forest Inventory and
Analysis program (FIA) with climate model outputs to project potential
future distribution of suitable habitat for tree species (Iverson et
al, in press, for the eastern US; Rehfeldt et al. 2006, for the western
United States) or for bird species (Matthews et al. 2004 for the east).
The outputs from such models have potential to help managers as they
make decisions about appropriate approaches to reforestation under a
changing climate.
Depending on the landscape model, the potential effects of fire,
insects, other disturbance regimes, fuel treatments, or other
management practices over time or at multiple scales can be evaluated.
The interactions of disturbance (primarily fire in the western United
States) with vegetation and climate can be incorporated into landscape
models such as LANDIS, SIMMPLE, and MC-FIRE to compare effects under
different management scenarios. Most of these models are currently
operating at regional levels, and are not yet in nationwide
application. Forest Service researchers are currently examining how
best to incorporate climate change effects on tree growth into the
Forest Vegetation Simulator (FVS), which is currently used by
silviculturists and planners to simulate forest growth and dynamics, as
well as responses to fire and fuel treatments and to insect and
disease, at a stand level (http://www.fs.fed.us/fmsc/fvs/).
The large assortment of models mentioned above give scientists a
wide range of important information to compare and evaluate. Models
need to be tested at the local level and strengths and weaknesses
sorted out. Cushman et al. (2006) discuss the future needs for
improving the capabilities and utility of landscape models. Improved
landscape models will enable us to better project and anticipate the
potential effects of changing climate on vegetation and its
interactions with fire and other disturbances such as insects and
diseases. The resolution provided by these types of models provides
essential information for site-specific planning and decisions.
the interaction of fire, fire behavior, and climate change
While current fire behavior modeling tools do not explicitly
incorporate climate change, they all use data on weather and fuel
condition to develop predictions. Thus fire behavior modeling tools can
be used to evaluate multiple scenarios, such as the effects of extreme
drought or higher temperatures that might be expected in a changing
climate. Our knowledge of how fire behavior affects forests and
rangelands comes from a combination of experimental studies (often
using prescribed fire) and observations before, during and after
wildfires. Such observations can occur at a range of scales from
satellite remote sensing of fires and burned areas, to aircraft-based
remote sensing or smoke sampling, to measurements of fluxes or changes
in ecosystem properties made on the ground. Each year, seasonal
severity projections include expected weather patterns over the fire
season, including the known influences of changes in atmospheric
circulation patterns, temperatures, and rainfall brought about by El
Nino or La Nina, and other ocean oscillation patterns.
Good data on current and past fuel conditions as well as patterns
of fire on the landscape provide a foundation to better understand the
interactions between fire and climate. Ongoing monitoring is also
essential. Two recent national projects being implemented under the
auspices of the interagency Wildland Fire Leadership Council will help
to provide this foundation. The LANDFIRE project (http://
www.landfire.gov/index.php), a collaboration with the US Geological
Survey and the Nature Conservancy, is mapping at the 15 meter
resolution for fuels, vegetation, fire regime, condition class,
terrain, and other important parameters. The Monitoring Trends in Burn
Severity Project (http://svinetfc4.fs.fed.us/mtbs/) is mapping burn
severity and perimeters for all large fires in the United States (over
the past 20 years and into the future). Information from the burn
severity project will eventually be integrated with LANDFIRE as part of
the mechanism for updating LANDFIRE for fire and other disturbances.
The two projects will provide essential baseline data layers which can
be used for improved monitoring as well as modeling of changing fire
regimes, effects of fuel treatments, fire behavior, fuel consumption
and emissions, and potential interactions with climate.
feedbacks between fire and climate change
There is growing scientific concurrence that climate change will
increase areas burned, which will result in increased emissions of
carbon dioxide and other greenhouse gases from wildfires--both through
increases in area burned and through increased emissions. Mitigation
measures such as hazardous fuel reduction can help to reduce these
effects (e.g. Johnson et al. 2007). Fire produces many emissions
besides CO2 (including methane, particulates, and other
aerosols; Andreae and Merlet 2001). Some of these compounds are much
more efficient at trapping radiation than CO2 while others
reflect heat and light. In addition, there are great variations among
ecosystems in how fires affect the release of CO2 from soil
which normally stores about twice as much carbon as above ground parts
of forests. In some systems, post-fire emissions from soil respiration
are greatly reduced, while in others they may increase or remain
relatively unchanged (Amiro et al.2003). Another factor that will
affect the regional and perhaps global effects of fire on climate is
the magnitude of the impacts of fire-induced vegetation changes on how
the surface of the earth reflects or absorbs the sun's rays.
A number of recent papers have addressed this issue, but it is
extremely complex, and current data are not adequate to evaluate the
potential net affects. Smoke from wildfires can also cause severe local
and regional air pollution. Smoke from large fires often travels great
distances, and may affect local temperatures and air quality thousands
of miles from its origin (e.g. Colarco et al. 2004, Damoah et al.
2004). While it is clear that increases in burn area and fire severity
will increase greenhouse gas emissions, it is the balance among the
influences of these various emission changes, the uptake of
CO2 by regrowing vegetation, the utilization of potential
wildfire fuels for bioenergy or in wood products, and changes in
vegetation composition, albedo and other factors that will determine
the net effect of changing fire regimes on carbon storage and on
climate.
implications of changing fire regimes for carbon storage
There is increasing attention being paid by scientists to the
significant role that wildfire plays in the global carbon cycle
(Schimel and Baker 2002). As long as the incidence and severity of
wildfires remains constant, removal of carbon from the atmosphere
through regrowth of vegetation in burned areas equals the wildfire
carbon products emitted. An increase in wildfire will increase
emissions of carbon gases and particulates and other greenhouse gases
(IPCC 2007). Many forest management techniques, such as prescribed
burning or thinning dense vegetation in appropriate fire regimes, can
be used to make forests more resilient to wildfire, particularly in
ecosystems typified by short intervals between fires or mixed severity
fire regimes.
Research has shown that hazardous fuel reduction treatments in the
appropriate type of fire regime are often effective at decreasing the
severity of subsequent fires (e.g. Johnson et al. 2007). If the fuels
that are removed are used either for bioenergy or in wood products,
they are providing benefits in terms of overall carbon balance, either
by offsetting use of fossil fuels or entering carbon into semi-
permanent storage. Subsequent lower severity wildfires fires will emit
less carbon to the atmosphere than would occur in untreated stands.
Forest Service scientists are working with partners to develop better
estimates of various components of the forest carbon cycle that include
these alternate uses of materials (Smith et al. 2006) and account for
the various processes involved as forests are harvested or burned, and
as they regrow.
In the United States, the magnitude and effects of climate change,
and its impact on fire regimes will vary in different regions of the
country. We need to understand more about fuels, the effects of
changing burn severity on carbon release, and how these effects will
vary regionally.
I would like to turn to Dr. Bartuska for a discussion of science in
support of managers and policymakers.
science in support of managers and policymakers
Scientists can assist managers and policymakers by providing
knowledge and tools that support adaptive management in response to our
changing climate. Adaptive management combines emerging research with
evaluation of management practices. This enables managers to modify
practices as our understanding of the science of these complex systems
improves.
Research, such as that mentioned earlier, tells us that fire
regimes are changing and will continue to change across North America,
and that some of this change is due to changing climate, although
measures such as fuel reduction can help to mitigate these effects.
These changes may complicate fire management activities and suppression
operations, alter ecosystem characteristics and increase potential fire
risk and other losses to communities and infrastructure. We can also
expect that new vegetation communities will develop over time as a
reflection of the tolerances and adaptations of individual species.
Changes in vegetation and fire regimes will affect our ability to
store carbon in forests and rangelands, and will affect atmospheric
chemistry and climate. Scientists across the United States and around
the world are developing new knowledge and new approaches to
quantifying these impacts and improved methods of adaptation and
mitigation to lessen the impacts of these changes.
There is good scientific basis for vegetation treatments in
appropriate fire regimes to reduce wildfire severity; treatments will
reduce stress and crowding of vegetation and increase resistance to
severe drought and to bark insects. Because climate in many areas will
change more rapidly than long-lived plant species can migrate, moderate
to severe fires can be seen as opportunities to facilitate migration,
either by planting a mix of species that may be better adapted to
current and future climates, or by selecting seed from trees that grow
in warmer seed zones or at lower elevations.
Because we can not predict precisely what species or genotypes will
be best able to tolerate changing environments, managers may want to
ensure a diverse mix of species on the landscape. Forest biomass from
fuels reduction can be used for bioenergy and wood products--this will
decrease the net effective emissions from wildfires, offset fossil fuel
emissions, and help to increase carbon storage. Scientists are
evaluating options for incorporation of organic matter from forest
fuels into the soil, where it will decompose slowly, and not add to
fire hazard as much as if left on the surface. While wildfire is a part
of the problem of climate change and carbon storage, management of fire
and fuels and thoughtful restoration of burned areas can be a part of
the solution.
conclusion
As we have presented, science can describe the connections between
human and ecological systems. Scientists can help policymakers and
managers evaluate options and interpret the effectiveness of potential
management alternatives. Science can provide a solid foundation for the
many non-scientific considerations that managers and policymakers must
take into consideration. I hope the information we have provided has
been helpful.
Mr. Chairman and members of the Committee, thank you for the
opportunity to discuss the science of interactions of climate change
and wildfire. Dr. Conard and I would be happy to answer any questions
you might have.
The Chairman. Thank you very much.
Dr. Helms, why don't you go right ahead.
STATEMENT OF JOHN A. HELMS, PROFESSOR EMERITUS OF FORESTRY,
UNIVERSITY OF CALIFORNIA, BERKELEY, CA
Mr. Helms. Thank you, Chairman Bingaman and Ranking Member
Domenici, for--and members of the committee--for the
opportunity to come and talk to you this afternoon on this
topic.
But the first remark I'd like to make is that it must be
remembered that forests have responded to climate change
throughout the last millennia, and they adapt very strongly.
They have moved in species distribution, they have evolved, and
they've also suffered from extermination as the climate has
changed. So, this is something that is ongoing. What we are
concerned about is the increased rate at which this is
happening.
But I might also comment that the forests are adaptable,
and one can see that, when you look at forests that grow both
on a north slope and a south slope in an area. They are
obviously growing well, even though the climate might be
different by several degrees.
The projections are--vegetation change, in precise, has
been mentioned earlier, due to differences in model assumptions
on temperature change, temporal patterns of rainfall, et
cetera; but, in general, it can be summarized that the changes
most likely to be seen in the northern latitudes, where there
will be loss of meadows, a conversion of forests to grasslands,
and probably tree invasion into areas that previously were too
cold. Forests are expected to move northwards in latitude and
upwards in elevation, and probably this indicates that the pine
forests are mostly subject to change. The shift in boundaries
are--can be quite large. It has been estimated that a
temperature change of about 3 and a half degrees in the Rocky
Mountain area is equivalent to the vegetation habitat moving
upwards: 2,000 feet upslope or 200 miles further north.
Climate change will also have an effect on growth, which
may increase or decrease, depending upon the way in which the
climate changes, and the particular species, the tree ages, et
cetera.
Within a given forest, there will be changes in ecosystem
structure due to changes in species interaction and
competitiveness. But, in general, climate change is expected to
lower productivity in some forests, such as in parts of the
West, and higher productivity may occur in the Northeast, lake
States, and parts of the Southeast.
But we also must remember that carbon dioxide may also
enhance growth. Experimentally, it's been demonstrated that, if
you increase levels of CO2, it's been commonly shown
that tree growth can increase by around about 20 percent if the
site is fertile, but that this increase is then subjected to
other limiting factors in the environment, such as water supply
or other nutrients. Interestingly, as a consequence of
industrial pollution, it's being demonstrated, in many parts of
the world, that the forests are increasing in growth. So, when
we come to the point of examining the way in which climate
change is affecting growth, there are complications that will
require quite sophisticated analysis.
But as forests are placed under increasing stress, the most
observable characteristic will be loss of vigor and increased
mortality. Some of the species will no longer be able to grow
or compete. This decline in health and vigor will be resulting
in increased carbon to the atmosphere, and, in some cases, this
will be quite substantial. It may be equivalent to what might
happen under deforestation. As these species die, it exposes
the soil, and, as you are aware, there are substantial
quantities of carbon in the soil, which, as it becomes exposed,
subjected to increased temperature, it will again be a source
of release of carbon to the atmosphere, compounding the effects
of climate change.
So, already in North America, forests are showing evidence
of stress. A prime example is that of the mountain pine beetle
epidemic in British Columbia. Although the beetle is endemic
and a natural part of the ecosystem, and, indeed, and important
component in the functioning of the system, once the
populations develop to a great extent, you end up with
increased mortality. The B.C. Ministry of Forests reports that
about 23 million acres have been subject to increased beetle
attack. Of particular concern is that, as the winter conditions
are made more mild, this insect may move into other provinces
and attack other species.
A second example is that in the Southwest, where some
States have experienced a die-off of pinyon pine of about 90
percent. The Forest Service has estimated that about--almost 4
million acres over six States have been affected. Here again,
the precipitous decline in pinyon pine is associated with
climate change, particularly reduced temperatures in the
wintertime.
So, again, evaluating the effects of climate change on
forests is made difficult. It appears that the impact on
insects may, indeed, be greater than the impact on potential
wildfire.
Now, in evaluating the effect of climate on wildfires, I
would like to mention that there are three issues that are
important. One is the levels of prehistoric burning by Native
Americans. The second is the importance of human ignitions in--
as sources of wildfire. The third is the changed forest
structures that have occurred over time.
It's well documented that Native Americans have used fire
extensively. One example is in California, that prior to the
1800s it's estimated that they burned about 400--4 and a half
million acres annually. In the period of the 1800s, 1825 to the
very early 1900s, it's estimated by the Interagency Fire Center
that there's about seven fires that were 1 to 3 million acres
in extent. Although these fires are--both Native American and
in the early 1800s--were large in extent, it's probable that
the modern fires are much more destructive because of their
intensity.
I'd like to comment on the role that humans have played in
fire. Again, the Interagency Fire Center reports that in 2006
there were over 96,000 fires nationwide, of which 83 percent
were human-caused, and that, if you divide the country up into
11 regions, that human ignitions exceeded lightning ignition in
five out of those 11. So, clearly, it's difficult to separate
out the effects of climate change from other factors such as
human ignitions and fire conditions.
So, finally, I'd like to comment on what role mitigation
might play. Since the severity of wildfires are, to a large
extent, influenced by human ignitions and changed forest
conditions, it's important to consider the extent to which the
social sciences and forest management could contribute to both
understanding and mitigation.
Monitoring climate change and forest conditions should be
aimed at separating out all these complex factors and
interactions that result in wildfires. Since growth and
mortality on national forests greatly exceeds that from removal
from harvest in the building up of fuels, it would be prudent
to consider treatments and incentives aimed at fuel reduction
and, where possible, using that excess biomass for socially
needed products and energy production.
So, the aim of treatments on forests would be to create, as
far as possible, conditions in the forest that are suited to
current and future uses by society so that these forests can
better withstand what will inevitably be an increase in
wildfires that will be enhanced through climate change.
Mr. Chairman, thank you very much for the opportunity to
comment.
[The prepared statement of Mr. Helms follows:]
Prepared Statement of John A. Helms, Professor Emeritus of Forestry,
University of California, Berkeley, CA
introduction
Chairman Bingaman, Ranking Member Domenici, and members of the
Senate Committee on Energy and Natural Resources. Thank you for the
opportunity to give testimony on scientific assessments of the impacts
of global climate change on wildfire activity in the United States. My
name is John A. Helms, Professor Emeritus of Forestry at the University
of California Berkeley where I served as Head of the Department of
Forestry and Resource Management. I am here today representing the
Society of American Foresters for which I served as President in 2005.
The Society has 15,000 members who are forest managers, consultants,
academics, and researchers and promotes sustainable forest management
for balanced and diverse values.
likely magnitude of climate change
This topic has been discussed at previous hearings, so I will not
elaborate here. However, since there is a direct relation between
climate and forests, and between the structure of forests and wildfire,
it is important to understand the likely magnitude of changed climate.
Due to the complexity of General Circulation Models there is
considerable uncertainty regarding the precise changes in climate.
However, there is general agreement that temperatures will increase 1-
4C in the next century resulting in less snow, more heat-absorbing
exposed ground and sea water, which lead to less reflectance or albedo
and provide positive feedback. On the other hand, there is continuing
uncertainty regarding the extent to which changes in clouds and
precipitation patterns may ameliorate increased temperatures. Average
temperatures have already changed several degrees especially in
northern latitudes. Maritime climates are already becoming wetter and
interior of continents drier. Glaciers and ice sheets are diminishing.
effect of climate change on forest ecosystems
Throughout millennia, climate has been the principle determinant of
vegetation distribution throughout the world. Animal and plant species
are in a constant state of flux--continuously adapting, changing
distribution, evolving, and becoming extinct. At a finer scale, forests
have considerable adaptive capacity and can, for example, grow well on
both north-and south-facing slopes that have several degrees difference
in climate.
Scientific literature clearly documents changes in growing season,
phenology, and modified distribution of animals, plants, and insects.
Of particular concern is the extent to which likely increases in
temperature will cause changes in species distribution, how much
climate changes are being affected by human activities, and whether the
rate of change can be mitigated.
Projections of vegetation response to climate change are imprecise
due to differences in model assumptions on temperature change, temporal
patterns of rainfall, and likely responses of species to these changes.
However, in general, effects of climate change are more likely to be
seen in northern latitudes with loss of meadows, conversion of forest
to grassland, and tree invasion into areas that were previously too
cold. Forests are expected to move north in latitude and upward in
elevation. Pine forests at low elevation are likely to be replaced by
woodlands and grasslands. These shifts in biome boundaries are expected
to be large. It has been estimated that a temperature change of +3.5C
in the Rocky Mountain zone is equivalent to vegetation habitat moving
2,000 feet up slope or 200 miles further north (Ryan 2003).
Climate change will have considerable effects on forest growth,
which may increase or decrease depending on tree age, species, site
quality, and location. Within a given forest there will be changes in
ecosystem structure due to changes in species interaction and
competitiveness. In general, climate change is expected to lower
productivity in the west, and Alaska with higher productivity in the
Northeast, Lake States, and parts of the Southeast.
Carbon dioxide in the atmosphere can also limit growth.
Experimentally increasing atmospheric levels of CO2 have
commonly shown that tree growth increases up to 20 percent on fertile
sites. Growth declines over time since other factors such as nutrient
availability or water then become limiting. Interestingly, forest
growth has increased in many areas of the world due to added nitrogen
from industrial pollution, which further complicates analyses of tree
growth responses to climate change.
As forests are placed under increased temperature and water stress
the most observable feature will be loss of vigor and increased
mortality as species are no longer able to survive in the changed
climate. This decline in health and increased mortality and decay will
add substantially to carbon emissions--equivalent in some instances to
that due to deforestation. As species die and are replaced, soils will
be exposed, become warmer and subject to erosion, again releasing
substantial amounts of carbon to the atmosphere and compounding climate
change effects.
Already North American forests are showing evidence of stress and
apparent effects of climate change. A prime example is the mountain
pine beetle epidemic in lodgepole pine forests of British Columbia.
Although this beetle is endemic and, overall, is a positive and useful
component in the functioning of natural ecosystems, it appears that
unusually hot, dry summers and mild winters have increased beetle
attacks and in 2006 about 23 million acres were affected (BC Ministry
of Forests and Range 2007). Of particular concern is that, due to
climate change, the mountain pine beetle is likely to spread to Jack
pine forests in Alberta thus causing potential for increased wildfire.
A second example is pinyon pine in the Southwest where in some
states dieoff has reached 90 percent. The USDA Forest Service estimated
in 2003 that about 3.8 million acres over six states were affected.
Here again, the precipitous decline in pinyon pine is associated with
climate change and drought. It seems that the winters have not been
sufficiently cold to restrict build-up in bark beetle populations. In
addition, the extensive tree mortality has been accompanied by a major
decline of pinyon jays and other ecosystem changes. In evaluating the
effects of climate change on forests, therefore, it appears that the
area impacted by insects are greater than that affected by wildfire.
A third cause of catastrophic change in forest ecosystems is
hurricanes. Increasing sea water temperature in the Gulf of Mexico is
expected to cause increased hurricane frequency and severity. Again, in
the context of climate change, the sudden removal of forests by
hurricanes is likely to increase opportunities for species to invade
that are more adapted to warmer conditions.
effect of climate change on wildfires
Lightning-caused fires have always been a major component of forest
ecosystems in the West. In addition, it is well documented that Native
Americans used fire extensively in controlling game, regenerating
desired plants, and for preventing surprise attacks from enemies. Prior
to the 1800s, it has been estimated that Native Americans in California
burned about 4.5 million acres of wildlands annually (Stephens et al.
2007). The National Interagency Fire Center estimates that during the
period 1825-1918 there were seven fires that were 1-3 million acres in
extent. Although these historic fires were very large, they probably
differed from contemporary fires which are more intense, crown fires
that result in stand replacement. This difference is primarily due to
past harvesting, regeneration, and fire suppression practices that have
resulted, especially on national forests, in stands having a high
proportion of shade-tolerant species, younger age classes, and higher
density of smaller trees than were characteristic of forests prior to
settlement. Similarly, major changes have occurred in plant species and
structure of the nation's grasslands due to grazing.
The National Interagency Fire Center also reports that humans have
had a major role in fire ignitions. In 2006, there were 96,380
wildfires of which 83 percent were human-caused and human ignitions
exceeded lightning ignition in five out of 11 regions. Expressed in
terms of area, 9.8 million acres burned in 2006 of which 45 percent
were human-caused with human ignitions exceeding lightning ignitions in
eight out of 11 regions.
Clearly, then, it will be difficult to separate the effects of
climate change on wildfire occurrence from the effects of rapidly
increasing human populations in forested areas and the change in forest
conditions due to past forestry, urbanization, and other activities.
Never-the-less, weather is fundamentally important in influencing
the incidence and severity of wildfires, which due to climate change
are expected to increase in frequency and intensity (Keene et al. 1997,
USFS PNW 2004). One estimate is that wildfires will increase 50 percent
by 2050 and double by 2100, with estimates varying depending on the
climate models used (Liu et al. 2004).
Higher temperatures and low humidity are important because they
increase the drying rate of fuels and increase the likelihood of
drought and length of fire seasons. Increased wind increases the rate
of fire spread. And climate change will likely increase the incidence
of thunderstorms and lighting. However, some areas will no doubt
experience decreased fire frequency. Areas of increased precipitation
may moderate fire behavior, but greater vegetation growth may also add
to wildfire potential. Further complicating predictions is that
wildfires emit considerable quantities of particulates that result in
short-term cooling by reducing solar heating. At the same time,
wildfires exacerbate climate change by emitting greenhouse gases to the
atmosphere. In 2005, wildfires in the U.S. resulted in 126.4 Tg
CO2 (140 million tons) being emitted to the atmosphere (EPA
2007).
Although interactions among climate change, vegetation, human
actions, forest conditions, and insect and disease vectors are highly
complex and uncertain, wildfires will certainly be a major factor
accelerating species change and changes in plant distribution.
responsibility to mitigate through forest management
Since incidence and severity of wildfires are to a large extent
influenced by human ignitions and forest conditions, it is important to
consider the extent to which social sciences and forest management can
contribute to both understanding and mitigating wildfire occurrence and
intensity.
Monitoring climate change and forest conditions should be aimed at
separating out the complex factors and interactions that result in
wildfires. Since both growth and mortality on national forests greatly
exceeds harvest resulting in a build-up of fuels, it would be prudent
to consider treatments and incentives aimed at fuel reduction and using
excess biomass for societally-needed products and energy production.
The aim of such treatments on national forests would be to create, as
far as practicable, forest densities more suited to current societal
usage so that forests can better withstand the inevitable increase in
wildfires that climate change will cause.
The Chairman. Thank you very much for your testimony.
Dr. Swetnam, we're glad to have you here. Please go right
ahead.
Mr. Swetnam. OK.
STATEMENT OF THOMAS SWETNAM, DIRECTOR, LABORATORY OF TREE-RING
RESEARCH, AND PROFESSOR OF DENDROCHRONOLOGY, UNIVERSITY OF
ARIZONA, TUCSON, AZ
Mr. Swetnam. Chairman Bingaman, thank you so much for
inviting me, and thanks to the ranking member, Senator
Domenici.
By way of a little further introduction, I'm a professor of
dendrochronology, which is the use of tree rings. We use the
tree rings to study all kinds of history--climate history and
ecological history and human history. Just a little personal
note, also, I just want to say I--in addition to being a
scientist for the last 20 years, I was a firefighter before
that for several years. My father was a district ranger with
the U.S. Forest Service for 35 years in New Mexico, and he
taught me quite a lot about fire. He's been on my mind
recently. He passed away a year ago, and, last night, watching
Ken Burns's new war documentary, he came to mind, also.
Key points of my presentation here. I think you may have
some handouts here, where you can see these graphics* a little
more detailed. The first key point is that warming temperatures
clearly have begun to influence fire activity in the western
United States, with increasing numbers of large fires well
correlated with both the interannual and the decadal changes
that we see in temperature throughout the western United
States. Now, we also see--we know that there are many other
factors involved, including forest changes, increasing fuels,
and also things like invasive species; cheatgrass in the Great
Basin, for example, have also been involved. We also know that
more people have been moving into these environments. So, all
of these things are coming together in a kind of perfect
firestorm.
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* Graphics have been retained in committee files.
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That's the main point I'm going to make, and I'm going to
hold that til the end of my presentation.
I'm going to talk a little bit about the historical
perspective of fire--using tree rings and other records, we've
been able to look far back in time--and to see what the role of
fire has been in forest ecosystems over centuries and
millennia. Several things that we see right off is that there's
a lot of variability, historically, with some ecosystems not
burning very frequently in the past, and some ecosystems having
burned very frequently, until recent century. About 100 years
ago, with the beginning of livestock grazing and then fire
suppression, the fire regimes were disrupted in some forest
types. We also see, from the historical record, that fire and
climate were very well correlated going way back in time, so
warming temperatures and droughts have been related to big
fires for a long time.
I'm also going to talk a little bit about some natural
climate factors that control forests and also fire activity,
particularly the El Nino southern oscillation and these other
two major ocean and atmosphere patterns of Pacific decadal
oscillation and the Atlantic multidecadal oscillation.
Fire-scarred trees are one of the main ways that we get
these long histories of fire from our paleoecological records.
One of the main things we see on these scars--there are
injuries at the bases of trees, and what we see is that, very
commonly, there are many fire scars right until about 1890, and
then a lack of fire scars for about 100 years. The last fire
scar typically occurs when livestock grazing began--that's when
the sheep and cattle begin to eat the grasses which were
carrying fires--and then fire suppression by government
agencies.
We also have been able to use long records, like charcoal
in lake sediments and bogs. This is an interesting example of a
core sediment--core sample from a bog at Valles Caldera
National Preserve, which Senator Bingaman knows well. This bog
shows charcoal presence all the way down 9,000 years, and it's
only the top 20 centimeters of this core has no charcoal on it.
That's the last century. So, it's a truly extraordinary change
in the last 9,000 or 10,000 years, with lack of fire relation
to fire suppression.
We also see from these records that there's a lot of
variability, as I said. In some forest types--the wetter,
cooler, higher-elevation forests, like spruce and fir and
lodgepole pine, in Idaho and Montana--typically, the fires only
occurred every 100 years to 400 years in those forest types
before this century. You move over to the Ponderosa pine-
dominated ecosystems, and there you had surface fires burning
once or twice per decade, in some cases, in the Southwest. So,
very different kinds of fire histories. It's likely that fire
suppression has had much less effect in the wetter, cooler
types, because they were longer intervals anyway, so fire
suppression has had less influence there.
We have a long history of fire from giant sequoias, more
than 3,000 years of fire-scar record from the Sequoia National
Park and King's Canyon. We are able to get fire-scar records
there and compare them with our tree-ring records of
temperature. So, here we have a fire-scar-based history from
these trees, and then we have ring-width patterns from
bristlecone pine and foxtail pine. These are trees growing
right at tree line, and their growth is controlled by how warm
the growing season is. So, if it's a very warm year, you get a
thick ring; if it's a cold year, you get a narrow ring. When we
compared the foxtail pine and bristlecone records, you see this
match--a pretty good match between the fire-history record and
the temperature record over the last 1500 years.
One thing I'd point out is, about at the very end of the
record, you see that the fire-scar record drops off, with very
few fires after about 1850. That's when fire suppression began.
But you see the temperatures rising up in the tree-ring record.
My colleagues and many other dendrochronologists have put
together records like this from around the northern hemisphere,
and they show that this warming episode in the last decade or
so is warmer than the temperatures over at least the last 1,000
years, including this medieval warm period here, which was
quite warm, and there was a lot of fire.
Now, the El Nino and these other ocean atmosphere patterns
are also important to climate and fire. I'm not going to go
into detail on this. There's quite a bit more of this in the
written testimony, of how they're important. We know a lot more
about the El Nino and La Nina than we do this Pacific decadal
oscillation or the Atlantic multidecadal oscillation. But we
are learning that they control interannual to decadal-scale
climate patterns. One of the things we see when we look at the
El Nino record relative to our tree-ring, fire-history, and
also documentary records, is that there's a strong relationship
in the Southwest with the El Nino. Typically, El Ninos bring
more moisture to the Southwest and also to the Southeastern
United States, and there's less fire. But, at the same time,
there is an inverse relationship in the Northwest--so, the
northern Rockies and the Pacific Northwest is usually dry
during El Ninos, and there's more fire--and that the converse
is true of La Ninas. The pattern tends to switch back and
forth. This is of some use, actually, for potential predictive
uses, is--are these patterns over the long term.
The other thing I would say is, this Pacific decadal
oscillation has some effect on climate in the West and also
fire activity, and it's shifted to a state that's more typical
of drought; that is, colder ocean temperatures. At the same
time, the Atlantic--North Atlantic has shifted to warmer
temperatures, which is also more conducive to drought. So,
there are some changes that are not good right now with regards
to fire.
But these don't seem to explain the big fires that we're
occurring--we're seeing. Over the western United States, we've
had more and more of these recordbreaking fires, over 100,000
acres--one in Oregon, you know, the Biscuit Fire Complex in
2002, a half a million acres, and Rodeo-Chediski, in Arizona.
This year, actually, we may be breaking records, I believe, in
Idaho, Utah, Nevada, and maybe California, as the year goes on,
with more large fires that are really extraordinary.
When we look at the total record of fire over this past 30-
some-odd years, this is the paper we published last year with
my colleague Tony Westerling in Science, where we looked at
numbers of large fires over the whole West. We were focusing on
forest landscapes on Federal lands, primarily. You can see a
clear trend of rising numbers of large fires. In fact, a 300-
percent increase in the last decade and a half or so, relative
to the prior period.
If you go to lower elevations, there's not such a clear
trend. The lower elevations, below 5,000, 4,000 feet, there's
not such a clear trend of increasing numbers of large fires,
except maybe, in the recent years, there may be more and more
of those large fires since 2003.
You can see a real shift here, if you look at the size of
these pie charts*. Since 1986, there's 6.7 times more area
burning. Notice that the size of the red portion, which is area
above 5,500 feet, there's more high-elevation forest burning,
which is leading us to this conclusion that this is not just
fire suppression, this is also climate variability. Remember,
it's those high-elevation forests that only burn at long
intervals and have less of a fire-suppression effect.
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* Charts have been retained in committee files.
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The trends are very similar. When you look at temperature
in relationship to the area-burned record, there's a very good
correlation there, the interannual. Then, there's a nonlinear
relationship, as well, perhaps, as temperature is rising,
numbers of fires is increasing faster and faster.
Then, last, there's--when we look at the record, there's
many more of these early snowmelt years. That is, spring is
arriving earlier. There's many more of these early snowmelt
years in the last decade than in the previous two decades. If
you sort out when the big fires are occurring, they're
occurring in those years when there's early snowmelt.
Finally, I don't mean to simplify this at all. There's many
different factors involved, besides climate. There's changing
fuels in forest structures, and invasive species are very
important--cheatgrass in the Great Basin. In southern Arizona,
we have a problem with this African buffel grass that's
burning, and now causing more wildfire in the Sonoran Desert.
On top of that, we have the warming conditions and people--more
people moving into these landscapes. So, there's a whole suite
of problems coming together for our fire problems.
Thank you.
[The prepared statement of Mr. Swetnam follows:]
Prepared Statement of Thomas Swetnam, Director, Laboratory of Tree-Ring
Research, and Professor of Dendrochronology, University of Arizona,
Tucson, AZ, and Anthony L. Westerling, Assistant Professor,
Environmental Engineering and Geography, University of California
Chairman Bingaman, ranking member Domenici, and members of the
Committee, I thank you for the opportunity to be here and testify on
the matter of climate change and wildfires. My name is Tom Swetnam, and
I am Professor of Dendrochronology (which is the study of tree rings)
and Watershed Management at the University of Arizona. I am also
Director of the Laboratory of Tree-Ring Research. Please note that my
co-author of the written testimony is Dr. Anthony Westerling of the
University of California, Merced. Tony is Assistant Professor of
Environmental Engineering and Geography.
Senators Bingaman and Domenici may recall that we met and talked
some years ago when I was appointed by President Clinton to the first
Board of Trustees of the Valles Caldera National Preserve in New
Mexico. Part of the reason I was appointed to that Board was because I
was raised in northern New Mexico and I know that landscape very well.
I have spent a great deal of time studying forests and fires in New
Mexico and elsewhere in the West--originally as a fire fighter, and for
the past 27 years as a scientist.
executive summary
Fire is a natural and necessary part of most terrestrial
ecosystems. Prior to Euro-American settlement of North America,
enormous areas burned as a consequence of lightning and Native
American-set fires. The largest areas burned during the warmest and
driest years. However, recent fires and damages caused by them are
often outside the historical range of variability, and in some cases
these impacts are ecologically unsustainable. This is particularly the
case in many ponderosa pine-dominated forests and drier mixed conifer
forests that formerly sustained primarily frequent, low-severity
surface fires. The changes we see in some of these areas now are a
consequence of a ``perfect fire storm''--the combination of a number of
causes contributing to catastrophic fire. The ecological and watershed
damages caused by some of these fires are extreme and probably
irreversible. The threats to human lives and properties are increasing.
The key points of our testimony are:
Increasing numbers of large forest fires and total area
burned in the western United States are significantly
correlated with warming and drying trends.
Historical land uses and management practices disrupted
natural fire patterns in many western forests about a century
ago, and these changes have led to dense forests and fuel
accumulations that are also contributing to unusually large and
severe fires in some places.
Natural climate oscillations (for example the El Nino-
Southern Oscillation) have also affected fire activity, but
they do not fully explain the recent surge in burning.
Studies using coupled global circulation and wildfire models
consistently predict increased burning under scenarios of
future increased greenhouse gas concentrations.
long-term perspectives of wildfire and climate history
From many detailed studies of fire scars in tree rings, sampled in
ponderosa pine-dominated forests across the West, we have learned that
low severity forest fires used to burn through the understory of these
forests at intervals of about 5 to 30 years. This pattern of repeated
burning continued for centuries until the late 1800s, when Native
American burning practices were eliminated, large herds of sheep and
cattle were introduced, and government-sponsored fire suppression
began. My colleagues and I have developed very similar histories of
frequent, low severity forest fires from fire scars and tree rings in
giant sequoia trees in California, extending back to 3,000 years before
the present (Figure 1)*. Other scientists and colleagues have drilled
core samples from wet meadows, bogs and lake bottoms in many places in
the west. They have reconstructed more than 10,000 years of fire
history by carbon-14 dating and counting the number of charcoal
particles of various sizes deposited in the sediments.
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* Figures 1-6 have been retained in committee files.
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Fire history studies typically find a broad range of past fire
frequencies in different forest types and elevations. As you might
expect, the relatively wet forests of high elevations and more
northerly latitudes generally show much longer intervals between past
fires (on the order of 100s of years) than the relatively dry, lower
elevations where ponderosa pine dominates. Although the frequencies of
past fire varied substantially from one ecosystem type to another, a
general finding has been that the changes in past fire activity were
well-correlated with independent reconstructions of climate history. In
particular, increased fire occurrence corresponded with warming and
drying conditions. Our studies of giant sequoia fire scars and
comparison with temperature-responsive tree-ring width chronologies
shows that these long-term associations have existed for many centuries
(Figure 1).
Warmer, drier conditions are likely to promote drier fuels, which
may be more readily ignited by lightning or people. Drier fuels also
carry fire more rapidly across the landscape. Another general pattern
of wildfires is that, the longer the typical interval between fires,
the more severe and intense the fire when it occurs. For example,
lodgepole pine and spruce-fir forests of high elevations in the
Northern Rockies typically burned only once per 150 to 400 years. When
they did burn, they burned intensely during hot, dry years. Recall the
1988 Yellowstone fires, for example. In contrast, Southwestern
ponderosa pine and relative dry mixed conifer forests (like giant
sequoia groves) usually burned once or twice per decade for thousands
of years, and these fires were typically of low severity. The key
factor here is fire frequency. At low fire frequencies fuels accumulate
in increasingly dense forests over long periods, while at high fire
frequencies the fuels are consumed and open forests with little fuel
accumulation are maintained. Hence, suppression of the frequent, low
severity fires in forests where this type of fire regime predominated
has led to unusually high fuel accumulations and increasingly large and
severe wildfires.
Although warm and dry conditions were important to increased fire
occurrence, another aspect of climatic control was also important,
especially in the drier, lower-productivity forests. That is the role
of prior wet conditions, which served to reduce fire activity and allow
fuel accumulation. Our paleoecological and modern studies have
indicated that wet/dry lagging patterns are important to regional fire
patterns in some parts of the West, both in the past and today.
Based on these findings, it is evident that both climate variations
and human land uses in the past have directly and indirectly affected
forest fuels and fire frequencies. Despite local and sub-regional
differences among ecosystems with different land-use histories, at the
broadest-scale of the western states, including Alaska, increasing
numbers of large forest fires in recent years are significantly
correlated with warming and drying. I will come back to this key point
about recent broad-scale trends in a moment, but first, I will briefly
review what else we have learned about historical and natural climate
and fire patterns from tree rings and documentary records.
multiyear to multi-decadal climate variations: enso/pdo/amo
Just about everyone has heard of ``El Nino'' since the very large
event in 1982 and 1983 resulted in worldwide climate effects. This
general awareness marks a revolution in climatology that has occurred
in the past few decades. Thanks to many observations of ocean and
atmosphere patterns and computer models, we have increasing knowledge
that ocean surface temperatures, related atmospheric pressure patterns,
and the jet streams have tremendous effects on climatic patterns over
the continents. These patterns go through changing ``cycles'', or
oscillations. The word ``oscillation'' is used because the intervals
between the highs and lows, and the magnitudes of the highs and lows
are highly variable, and not fixed like the cycle of a pendulum clock.
The El Nino/La Nina pattern is also known as the El Nino-Southern
Oscillation--or ENSO, for short. ENSO is the best known of the ocean-
atmosphere oscillations, and it operates over variable periods of about
2 to 7 years. ENSO appears to most strongly affect rainfall and forest
fire patterns in the West and Southeast, but two other ocean-atmosphere
oscillations have also been identified in recent years that appear to
be quite important: The Pacific Decadal Oscillation (PDO), and the
Atlantic Multi-decadal Oscillation (AMO). As implied by the names,
these last two oscillations operate on decadal time spans, that is, the
high and low parts of the oscillations persist for 10 years or longer.
From a combination of centuries-long tree-ring records, and careful
analyses of modern climate histories and documentary records of forest
fires from government agencies, a number of studies have revealed the
following key findings:
The ENSO has important effects on wildfire occurrence,
especially in the Southwest and Southeast. In these regions, El
Nino typically brings increased cool season rainfall, and
forest fire activity is reduced in the subsequent fire season.
Conversely, during La Nina events conditions are generally
drier and wildfire activity is increased. These patterns have
some predictability to them months in advance of the fire
season. Consequently, the state of the ENSO is now being used
by the Predictive Services group at the National Interagency
Fire Center for developing seasonal wildfire ``outlooks''.
The Pacific Northwest and northern Rocky Mountains (in the
U.S.) typically have an opposite, though weaker response to
ENSO relative to the Southwest and Southeast. This means that
during El Nino events it is typically drier in these regions
and more fires occur, and during La Nina events it is wetter
and fewer fires occur. However, it appears that during some
strong La Nina events, it is generally dry throughout the West
and Southeast. The typical inverse pattern of ENSO response
between the Northwest/Northern Rockies and the Southwest/
Southeast has potential strategic applications in the
allocation and pre-positioning of fire fighting forces, and/or
emphasis on prescribed fire use in the different regions.
The Pacific Decadal Oscillation was first noted, in part,
because of its important effects on salmon fisheries in the
Northwest. The pattern itself is measured by sea surface
temperatures in the Pacific Ocean, especially the northern
part. Recent studies indicate the most pronounced sub-regional
effect of the PDO is in the Pacific Northwest and northern
California, both in terms of rainfall patterns and forest
fires. However, there are interesting interactions of the PDO
and ENSO affecting fire and climate across the West, as might
be expected because both oscillations are based on changes in
the Pacific Ocean. For example, drought conditions and more
wildfires appear to occur in parts of the West during
combinations of positive (warm) phases of the PDO and negative
(cool, La Nina) phases of the ENSO. Again, there may be some
predictive utility of these patterns for long-term ``outlooks''
and forecasting wildfire hazard.
Findings to date suggest that the positive phase of the
Atlantic Multi-Decadal Oscillation (AMO), generally corresponds
with more widespread droughts and wildfires in the western US
than during the negative phase. These associations are less
well understood than the ENSO and PDO patterns.
Finally, an important implication of the PDO and AMO
patterns described above is that both of these ocean-atmosphere
patterns appear to have shifted to states that favor more
drought and wildfire in some sub-regions of the western US
(i.e., cool PDO, warm AMO phases). These climate patterns may
have contributed to the recent surge in area burned and
increased numbers of large fires in the west, but it is
unlikely that they are primarily responsible. A chief reason
for this conclusion is that fire-promoting decadal phases of
the PDO and AMO occurred before in the past century (e.g., the
1950s and 60s), but we did not see the magnitude of increases
in burning that we have witnessed recently accompanying the
warming.
modern climate and fire trends
Most of the climate-wildfire patterns I have just described have
been studied extensively using a combination of paleoecological,
paleoclimatic, and modern documentary records. Although the paleo-
records are insightful, and are the best data we have for long-term
perspectives on climate and wildfire, the recent several decades is the
period of time when we have the most comprehensive records for
assessing climate and fire patterns. Government agencies have been
keeping records on wildfire statistics since the early 1900s, but
unfortunately, these records are often lacking in completeness and
reliability before the 1970s. Nevertheless, this recent period has
proven useful for assessing contemporary changes.
Our current understanding of recent wildfire changes in North
America derive from a set of studies in Canada, Alaska, and the Western
US. First, I am going to summarize the findings of the study led by my
colleague Tony Westerling that we published in July of last year in the
journal Science, along with our co-authors Drs. Dan Cayan and Hugo
Hidalgo from Scripps Institution of Oceanography, University of
California, San Diego. Next, I will briefly mention the published
findings on climate change and wildfire in Canada, Alaska, and
elsewhere.
The Westerling et al. (2006) study utilized fire occurrence records
for the period 1970-2003 from federal lands in the western US, and the
time series used was the number of large wildfires (i.e., exceeding 400
hectares, or about 1,000 acres). Most of the area (80%) included in
this database was above 4,500 feet elevation. Hence, these data
primarily reflect forested landscapes across the western US. It is
important to note that these data do not necessarily reflect general
wildfire patterns in the many lower elevation, non-forest ecosystem
types.
The main findings are as follows:
There is a clear upward trend in the area burned and numbers
of large forest fires in the western US, especially since the
mid 1980s (Figure 2, Figure 3, upper two plots). The area
burned by large forest fires is 6.7 times higher in the latter
period 1987 to 2003 than in the earlier period from 1970 to
1986 (Figure 4). Note, however, in a separate compilation of
lower elevation, non-forest fire occurrence data that no clear
trend through 2003 shows in these data (Figure 3, lower two
plots). It is particularly notable that the largest wildfires
in 50 to 100 years have occurred in a number of states in the
past five years (i.e., Arizona, Colorado and Oregon in 2002,
Texas 2006, Idaho and Utah 2007).
The trend and year-to-year variation in numbers of large
forest fires is well-correlated with spring and summer
temperatures over the same time period (Figure 5).
The trend and year-to-year changes in number of large forest
fires generally matches changes in the timing of spring onset,
as indicated by the timing of peak runoff from extensive
streamflow data in the western US. Many more large fires
occurred during years in which spring arrived relatively early
than during years when spring arrived relatively later (Figure
6). Additionally, there are significantly more early spring
occurring years after 1986 than before that time.
The largest increase in numbers of large wildfires has
occurred at middle elevations, with much of the increase above
5,500 feet (Figure 4). About 60% of the large fires in the
recent period occurred in the Northern Rockies and another 18%
in the Oregon Cascades, Sierra Nevada, and northern California.
This concentration of many large fire events in northern
mountain areas in relatively wet forest types suggests that
forest structure changes because of past land management may be
less important in these areas than the effect of warming and
earlier springs. That is because these northern, wetter areas
contain a large proportion of spruce-fir, lodgepole pine, and
other forest types where natural fire intervals were already
quite long (centuries), and so fire suppression has had less
effect there on changing fuel accumulation patterns.
In addition to the Westerling et al. study, several other recently
published studies point to the importance of warming temperatures in
observed trends of increasing fire occurrence in the western US
including Alaska (McKenzie et al. 2004, Duffy et al. 2005, Kasischke
and Turetsky 2006), Canada (Flannigan et al. 2005, Gillett et al.
2004), ), and possibly Russia (Goldammer 2006). Furthermore, a number
of these studies have employed global circulation model (GCM)
simulations of future climate under increasing greenhouse gas scenarios
as input to wildfire response models. The GCM-fire studies have
consistently concluded that increasing areas burned are to be expected
in coming years and decades (Brown et al. 2004, Fried et al. 2004,
Gillett et al. 2004, McKenzie et al. 2004, Flannigan et al. 2005,
Westerling and Bryant 2006).
Finally, both the Arctic Climate Impacts Assessment (http://
www.acia.uaf.edu/), and the ecosystem impacts assessment of the 2007
Intergovernmental Panel on Climate Change Report identified increasing
wildfire occurrence as a likely response to global warming. The 1,000-
plus member Association for Fire Ecology (composed of fire scientists,
students, and fire managers) recently issued a declaration on climate
change and wildfire, strongly expressing their professional and
scientific concern over current and anticipated wildfire responses to
regional and global warming http://www.fireecology.net/pdfs/san--
diego--declaration--final--29--nov--2006.pdf).
conclusion
Increasing wildfire problems are related to an interacting set of
causes, including (1) increased forest density and fuels because of a
century of fire exclusion, (2) warming climate and increasing frequency
and magnitudes of droughts, (3) invasive species, such as cheat grass
and African buffel grass allowing fires to spread more readily across
elevation gradients, and (4) the increasing presence of people and
built structures in these areas that are fire prone (i.e., the
wildland-urban-interface).
Although the combination of causes listed above exist together on
some landscapes, it should be emphasized that there is tremendous
variability across the US, and not all of these causes and problems are
present everywhere. Indeed, there are some landscapes where warming
trends apparently have had little effect, so far, on fire activity.
Some forests and other ecosystem types have been unaffected or little
affected by fire suppression. Moreover, the importance of invasive
grasses (or other non-native species), urbanization and its
consequences to habitat fragmentation, and increasing ignitions by
humans are paramount in some areas, and these factors may exceed the
effects of climate change now and the foreseeable future.
``Natural'' oscillations of the climate system, such as ENSO, PDO,
and AMO will continue to operate and have important effects on drought
and wildfire in the US. These ocean-atmosphere patterns impart some
degree of predictability to climate and wildfire hazard months in
advance of fire seasons. For example, the most recent National Oceanic
and Atmospheric Administration reports on the ENSO status indicate an
increasing trend toward La Nina conditions, which could spell increased
drought and wildfire problems next summer, especially in the Southwest
and Southeast. The effects of long-term warming trends caused by
greenhouse gases on ocean-atmosphere oscillations are not well
understood. Some modeling studies addressing these questions are not
encouraging, suggesting that increased amplitude of ENSO might occur.
Alternatively, ocean and atmospheric patterns might lock into states
promoting more-or-less permanent ``dust bowl'' like conditions in the
Southwest (Seager et al 2007).
A recent influence of warming climates and increasing drought is
apparently manifest in the rising areas burned and occurrences of
``megafires'' (>100,000 acre burns) in many places across North America
and elsewhere. Under increasing greenhouse gas scenarios, the available
evidence points to a likely continuation of rising areas burned, more
megafires, greater damages and costs incurred, and additional human
lives lost. Not least of the mounting concerns about these trends is
the likely effect of releasing more carbon into the atmosphere, and the
possibility of shifting temperate and boreal forests from a net carbon
sink to a net source.
The Chairman. Thank you very much, all of you, for your
testimony.
Let me start, and we'll do 5-minute rounds of questions
here.
Dr. Swetnam, let me start with you. It would seem that,
based on the charts--and I didn't pick up all of the
information on each of these charts that you put up, but maybe
you could interpret it a little bit for us. To what extent can
we make policy about which ecosystems we ought to be
concentrating our forest restoration dollars on----
Mr. Swetnam. Right.
The Chairman [continuing]. As a result of the research
you've done? I don't know all the factors that go into deciding
where we put that forest restoration money, but if we were
going to try to put it where it would do the most good, based
on your research, what would you conclude?
Mr. Swetnam. I think it is very important to be cognizant
of the different kinds of fire regimes that occurred in the
past, and, indeed, we see in these higher- elevation forests,
that they only burned at very long intervals in the past, and
there's likely to be less changes in those places because of
fire suppression. So, the really big problems with regards to
forest structure and ecosystem changes are in those forest
types and other ecosystem types that burn frequently in the
past, but then those fire regimes have been disrupted. So,
commonly it's Ponderosa pine--Ponderosa-pine-dominated
ecosystems in the West, and other dry mixed-conifer forest
types--as where there's been the greatest structural changes
and the greatest shifts in fire behavior and fire risk, I
think.
So, those have a real key, I think, priority for treatment.
Of course, it's also where people have moved in and--people
have, you know, moved into harm's way--are a lot of these same
landscapes. So, I think there is some basis of using the fire
history, our understanding of these different fire-regime
types, to focus the energies and the efforts where the
ecosystems have changed the most, and where the fire behavior
has shifted outside of its historical range of variability the
most.
The Chairman. To your knowledge, is that kind of a
calculation being factored in to decisions about forest
restoration priorities, at this point, or not?
Mr. Swetnam. To some extent. I believe some of the mapping
work that's being done--for example, LANDFIRE, which perhaps
Dr. Conard could talk about a little bit more--there are some
large-scale mapping efforts for the whole United States that
are aimed at identifying which ecosystems have changed the
most, and which ones--which--where are the fuels located? I
think that is one approach to getting at this, is understanding
where the high priorities are. But there is a need for more
work on this, I think, and more use of historical information,
to try to zero in on where the changes have been most severe.
The Chairman. Because where those changes have been most
severe is where you believe the forest restoration work would
do the most good?
Mr. Swetnam. That's right.
The Chairman. That's what----
Mr. Swetnam. That's right.
The Chairman [continuing]. I'm taking you to say.
An issue that I've raised with some other witnesses in
earlier hearings is this whole business--you know, one of our
policies here in Washington is that we budget fire suppression
funds on the basis of the average over the last 10 years.
Whatever was required over the last 10 years, we take the
average, and that's what we budget for the next year. When I
look at your charts, it seems like there is a fairly clear
pattern of increased fire activity. I think Dr. Conard talked
about how--I think you said six of the seven worst fire seasons
were--since what year was it?
Mr. Conard. Since 1980. Oh, I'm sorry--actually, a high
percentage of them have been in the past 10 years, so I have
another graph here that shows that in the past 10 years we've
had 5--well, we've actually had, now, 7 years, over 7 million
acres a year burning.
The Chairman. I guess the obvious question is, Does it make
any sense, given this pattern of increased fire activity that
we've experienced and are continuing to experience, to continue
budgeting, on the assumption that an average over the last 10
years will get us where we need to be? I don't know, is that
something you've looked at, Dr. Swetnam?
Mr. Swetnam. I haven't really looked at the economics of
this. I would defer to Dr. Conard and----
The Chairman. All right.
Mr. Swetnam [continuing]. Dr. Bartuska.
The Chairman. Dr. Bartuska, did you have any thoughts on
that?
Ms. Bartuska. I think you've hit one of our more
significant challenges--budgeting based on the increasing level
of fire suppression is really eating into our overall programs.
What we're trying to look at is different types of approaches,
risk-based management approaches, being able to reduce our
costs, being able to put our efforts into greater priority so
that we have--where we have the greatest risk, where we have
the greatest probability of success. But the escalating cost is
something that we're very concerned about, and, I know, has
been talked about in various hearings in the last several
months.
The Chairman. All right. My time is up.
Senator Craig.
Senator Craig. Mr. Chairman, based on what Dr. Helms said,
with fires moving north, I would suggest we invest in Idaho and
not in New Mexico.
[Laughter.]
The Chairman. Based on what Dr. Swetnam said----
[Laughter.]
The Chairman [continuing]. I think he said it's a waste of
money up in Idaho, and----
[Laughter.]
The Chairman [continuing]. We really should concentrate in
the Southwest.
Senator Craig. All right.
The Chairman. That's what I thought I heard.
Senator Craig. I was just trying to put it in the context
of those who've testified today.
Let me thank all of you very much for your testimony. I
read a great deal of what you do, and spend a good deal of time
with this issue. Thank you for these reports, coming out, and
the University of Arizona, their work.
What I said earlier--and let me do this now--I want to make
a statement, because, you know, I think it's very consistent,
but it takes us to a slightly different dimension, Mr.
Chairman, as it relates to how we look at what we're doing, or
not doing.
I say that in this context. Earlier this year, we had a
hearing to discuss wildfire management and preparedness. During
that hearing, I discussed the Angora fire at Lake Tahoe. The
reason this was a significant time to discuss it, Mr. Chairman,
was because, about a decade ago, this committee, along with
Senator Reid and others and I, looked at the dead and dying
problem of Tahoe, and we put the resources into the budget, but
we were denied activity in that watershed by certain interests,
who simply said, ``No, you're not going to come in and thin and
clean and change the character of that forest.'' That was then.
So, what happened this year was, 254 homes in the biggest
travesty--that was potentially preventable. Dr. Swetnam
continually talks about adding man to the ecosystem. Those
large homes that we're seeing spread across the West right now
definitely change things.
It's estimated that 90 percent of the trees in that fire
scenario, in Tahoe, burned. Now, that's a--3,100 acres. It
released 190,000 tons of carbon dioxide. Right now, there are
two fires burning in Idaho that are 100 times the size of that
fire. The Cascade Complex still burns, at 300,000 acres. The
East Zone Complex still burns, at 300,000 acres. It's an
unimaginable release of those two release that is phenomenal in
carbon into the atmosphere.
So, where do we stand now? Mr. Chairman, over a century
ago, to intervene on behalf of nature, we decided to make a
stand against wildfire. Many folks here today have testified to
that. We took fire out of the equation, whether it was with
man's presence or with grazing, or a variety of other
activities that were human-induced, and we replaced it with
land management.
Now that we are not able to actively manage our public
lands, we have taken both out of the equation. But the problem
is, man has more intensively come to the land by his presence,
and those--and so, to simply step back and say, ``Let it
burn,'' is no longer possible. We spent $130 million in Idaho
alone this year on fire. Part of it was to save a great
nationally known resort, called Sun Valley. We had to save it,
or we would have lost tens of billions of dollars worth of
property. Seems to me that we've rejected land management, and
nature is replacing it with fire in this scenario.
I don't know about the folks in your State, Mr. Chairman,
but I know that the folks in my State got a very bitter lesson
this year. Here's why they got the lesson. In 2004, Idaho was
one of the cleanest States in the Nation. We released 15,000--
15.56 million metric tons of CO2 in Idaho in 2004.
This year alone, by fire, we released 12 million metric tons of
CO2. So, for all of the commercial and industrial
and residential and transportation and electrical power, it was
minuscule. My State was nearly gray all summer, because its
skies were filled with smoke and with carbon.
Let me go on, just a little more. Fires are lending--are
leading producers of CO2 in the environment. On
average, 6 million tons of CO2 are released for
every acre burned. Up to 100--excuse me, 6 tons--up to a 100
tons of CO2 per acre can be released, depending on
the intensity of the fire, the number of trees per acre and so
on and so forth. To date, roughly 8.4 million acres have burned
in the United States, meaning a--at least 50 million tons of
CO2 have been released due to catastrophic fire.
Last year alone, 10 million acres. We've had that debate
about what was the bigger year. I was out in Idaho in August,
saying, ``It's one of the greatest fire years ever,'' and a
prominent person in the Forest Service called me and said,
``Larry, you're wrong. We had much bigger burns before the turn
of the century than we have today, but it's the decade that
we're in, where we're having the largest burns of recent
memory.'' It's of recent memory that we're talking about. Dr.
Conard just talked about the last decade and these acreages.
But we were burning at, or above that, before the turn of the
century.
Here is the point I want to get to. If you stop burning in
the forest today, if you stopped at the 8 or 10 million burned,
and backed it off substantially--and I'm talking about climate
change now, Mr. Chairman, your struggle, and others, to look at
comprehensive climate change legislation that might produce a
result--that would be roughly the equivalent of removing 12
million automobiles from the roads. If we stopped the forests
from burning today, it would be equivalent to removing 12
million automobiles.
Now, you and I both know we can't remove 12 million
automobiles. But if we decided to engage fire once again, both
in stopping it, where we can, and creating a healthy forest
environment where we could--if we were dedicating way more than
we are now to healthy forests--my guess is, we would come
closer to removing those automobiles from the road, in a sense
of pollution, than ever before.
Now, I've gone on beyond my time. I'll add the rest to the
record.
Senator Craig. But we know the triangle of fire, Mr.
Chairman. We know that it's oxygen, we know that it's heat, and
we know that it's fuel. We have great scientists out there
working on it. But our hands are tied today because we do not
have the political will to change the equation necessary to do
one of those three things in the triangle, and that's to remove
the fuel. If we had the political will to intervene and engage
active management again to remove the fuel, we change the
equation dramatically as it relates to fire, we change the
equation to a healthy forest coming earlier than 2035, we
change the style of sink that brings us back to a much more
positive sink for our healthy forests than a negative sink.
In 2000, I was at The Hague stopping the Clinton
administration--and this just isn't politics, this is reality
of climate change at that time--from trading off our ability to
use our national forests as sinks. We stopped 'em. We said,
``No, you don't go there.'' It's one of our great options in
climate change, is to re-create a healthy forest environment,
and to do so that it can once again sink.
I'll close by saying this. As we work, as you struggle, you
and Senator Specter, to--and you've been thoughtful and
workable; and, potentially, the work you're doing has some
application--but when? Would you like to move 12 million
automobiles off the roads? You do that by stopping our forests
from burning, short term. But, long term, you create a much
healthier environment in which those forests begin to sink and
grab up the carbon in the atmosphere and become a positive
force instead of a negative force. I think that makes good
sense. We ought to be at that business.
Thank you.
The Chairman. Senator Wyden.
Senator Wyden. Thank you.
I thank all the panel. It's been an excellent afternoon.
I think it's obvious that Senators understand that we are
dealing with a worsening spiral. We've got these hundreds of
thousands of acres, in the West, of, you know, choked second-
growth plantation forests. This leads to more fires. That
increases global warming, which, in turn, worsens the fires.
So, we have this spiral that we're dealing with.
I'm interested in hearing your thoughts about what the
barriers are to active management. Now, that's what we have
worked very hard on, as a part of the forest health
legislation, to address. I've heard litigation is always cited.
As far as I can tell, most of the litigation involves issues
relating to old growth and various matters involving, you know,
timber sales, and not barriers with respect to getting thinning
projects off the ground.
But I'd like to go right down the line and get a sense of
what each of you thinks are the barriers to active management.
That's what we want, that's what we think is critical to get on
top of this issue of cleaning out overstocked plantations.
So, Dr. Bartuska--let's just go down the row--barriers to
active management?
Ms. Bartuska. Speaking, of course, as the head of our
research organization, our real focus is on, How do we make
sure we have the right tools in the hands of the managers to
make the best decisions they have? The subject of wildland fire
and its interaction with climate change, what we're hearing
from the people on the ground is, they need to know, What are
adaptation options? What can they do about these changes that
are taking place? What do they need to do to be able to manage
for a resilient forest that allows for multiple stresses? Then,
what are the mitigation options they have with regard to carbon
and carbon management? So, what are the tools, and how do they
get there with----
Senator Wyden. What is the----
Ms. Bartuska [continuing]. In their context?
Senator Wyden [continuing]. The backlog on those thinning
projects? Because what I hear, at home, is that there's a huge
backlog on the very, kind of, of thinning projects that you're
talking about. Do you have information on that?
Ms. Bartuska. I do not know what our backlog on thinning
projects is. We could certainly get that to you and provide it
at a later time.
Senator Wyden. Would ya? That would be very helpful.
Would your colleague like to add anything on this point?
Barriers to active management, and the very projects that your
colleague was talking about.
Mr. Conard. I don't think I have anything specific to add,
except just to emphasize that, while research is providing
managers with some tools that they can use in making decisions
on how best to manage, certainly the more we can understand,
regionally and locally, the impacts of fire and better ways of
managing fire and managing carbon, that that will certainly
improve the manager's ability to do a good job.
Senator Wyden. Doctor.
Mr. Helms. Senator Wyden, I think the issue is not a matter
of lack of knowledge or lack of technology. In my view, the
issue is one of--it's a sociopolitical issue. It's lack of
trust. It's different agenda of different parts of society. I
think one of the solutions is to--we have to increase the
amount of information that's available, and understanding of
the natural processes so that society at large can better
understand the issues that it faces. It's basically a matter of
choice among very difficult and competing values. What--the job
we have in front of us, I think, is to seek some sort of
sensible balance that seeks to find some middle ground among
the people who different views on the way in which the problem
should be addressed.
Senator Wyden. You're being too logical. We got 80 votes
for the forest health legislation because we were trying to
achieve exactly the kind of balance you're talking about, and
it was built around the idea that we would get the resources
for the thinning projects that Dr. Bartuska is correctly
identifying. Those resources have not been forthcoming from the
administration. I want to get the bipartisan spirit of the
forest health bill back on track.
Dr. Helms.
Mr. Swetnam. I----
Senator Wyden. Excuse me--Dr.--excuse me--I got my
``Dr.'s'' mixed up.
Mr. Swetnam. Yes.
Senator Wyden. Thank you.
Mr. Swetnam. I would echo some previous comments. I would
point, sort of, what's lacking and needed more is more
collaboration. I'll say a little bit more about that. We need
more funding, obviously, to do a lot of this work. Ultimately,
we need to begin working at broader scales. I, personally,
don't think that we can thin our way out of this problem in the
western United States. I don't think there's either enough
funding or time necessarily to thin enough of the landscape
actually to prevent the losses that we're worried about. So,
one of the things we need to do----
Senator Wyden. But you don't think thinning is unimportant.
Mr. Swetnam. Thinning is important, especially smaller-
diameter trees, focusing on the dense forests, the forests that
have changed the most. Strategically, we can focus those in
particular areas to protect communities. But, ultimately, we
need to think, and start working at the landscape scales. By
that, I mean watersheds and mountain ranges, tens of thousands
to hundreds of thousands of acres. When you get to that scale,
I think you're also talking about other kinds of treatments
besides thinning. You've got--we've got to move back toward
using fire as a tool in these landscapes, using prescribed
fire. There is risk and there is smoke involved in doing that,
but it is a less expensive alternative, and it's a more
realistic one, an appropriate, ecologically. So, collaboration
is how we're going to get there, is working with communities--
--
Senator Wyden. No----
Mr. Swetnam [continuing]. I think----
Senator Wyden. No question about it.
Thank you, Mr. Chairman.
The Chairman. Thank you.
Senator Domenici.
Senator Domenici. Mr. Chairman, I went back to my office
for a minute--and, you know, it's quite unique to go all the
way back to my office, try to, all the way, walk back, but I
watched you all, and you were so--it's so exciting that I came
back.
[Laughter.]
Senator Domenici. I want you to know.
The Chairman. We appreciate it.
Senator Domenici. If anybody was watching the television,
they would all have been watching, today.
The Chairman. They had to either watch us or Ahmadinejad,
and we made it.
[Laughter.]
Senator Domenici. Good. Don't close me off too quick, here,
because I really have come with a purpose, and I don't know
that I can put it together here.
I'm directing my attention at you two ladies, because you,
presumably, can go back to the Department and get information,
and that's what I'm looking for.
Could you find out, and furnish the committee with,
information, first, about the number of acres of forestland
that are infested by bark beetles? Like in New Mexico, and up
in Alaska? Could you get us information as to how many
thousands of acres, or whatever, are infested? Could you get
that for us?
Ms. Bartuska. Absolutely, we could provide that.
Senator Domenici. Second, could you get us information as
to how much infested forest has been removed--over any
increment of time--last year, for 12 months? Could you get us
that information?
Ms. Bartuska. I believe so.
Senator Domenici. Could you do that? We'd like to have
that.
Third, could you get us information as to how much of that
kind of forest was sought to be cleaned, and was prevented by
some kind of court action? Could you get that for us?
Ms. Bartuska. I can bring it back to the office and see
what is available, certainly.
Senator Domenici. OK. Try that, if you would. OK.
Now, the Doctor mentioned cleaning the forests. Of course,
he's a good environmentalist, so he's right on the ball. He
knows what kind you ought to cut. He mentioned the right one so
they wouldn't hook him for cutting the forest. What size are
they supposed to be?
Mr. Swetnam. Smaller-diameter stems we need to focus on in
many forests, but not always, not in all cases.
Senator Domenici. What is the diameter? Tell me, so we'll
have it, it'll be in the record. You stated it a while ago.
Mr. Swetnam. This is also an issue. Should we fix on a
particular fixed diameter? I don't think that's----
Senator Domenici. Didn't you, a while ago, use it, just as
you spoke? You said----
Mr. Swetnam. No. No. ``Small diameter.''
Senator Domenici [continuing]. Small diameter? Is that good
enough?
Mr. Swetnam. That's the--that should be the main focus of--
--
Senator Domenici. OK, small diameter.
Mr. Swetnam. Yes.
Senator Domenici. Can you get that down, normally, when you
have an argument, where you stop arguing and agree that ``small
diameter'' means something? Will that normally happen?
Mr. Swetnam. That's when the argument begins again, is,
``Well, what do you mean by `small'?''
Senator Domenici. I understand.
Mr. Swetnam. Of course, it's--a small tree in Sierra Nevada
is a huge tree in the Southwest.
Senator Domenici. Yes. Now, here's the point. Either you
or--you don't work for the government, do you?
Mr. Swetnam. No, sir. I work for the State of Arizona.
Senator Domenici. Yes, that's right. Used to go up there
and take care of that ranch a little bit, and then got up there
in northern New Mexico.
Mr. Swetnam. The Valles Caldera National Preserve, yes,
sir.
Senator Domenici. Yes. Then you stopped that and----
Mr. Swetnam. Yes, I'm no longer on the board.
Senator Domenici. Right, we were just----
Mr. Swetnam. I was on the first board that you--both you
and Senator Bingaman appointed me to, and----
Senator Domenici. Yes, that's right. Then you didn't get
appointed the second time. I don't want to talk too much about
that.
[Laughter.]
Senator Domenici. Now, let me come back over here to you
ladies for the last question.
Now, you know, you're supposed to be able to clean up the
forest, I assume. We've even passed bills that focused on
cleaning up the forest that is close to housing and buildings,
and all you remember that. What was--we called it Happy Forests
or something--Healthy and Happy--I named it ``Happy,'' and you
all called it ``Healthy.''
[Laughter.]
Senator Domenici. I said, why couldn't it be happy? When it
burns and has a place to go, it's very happy forest.
But, anyway, what I'm trying get, along with these facts,
is a set of facts that has to do with how much forestland do we
clean up? Because I'm firmly of the opinion that the answer is:
for the money we put out, and for what Congress says we should
be doing, we're doing far too little cleanup of the heavy-
laden--and I don't know how to define it for you to bring me
back something, so let me try. How much forest acreage do we
clean up in a period of time, using whatever prescribed means
are legal and appropriate? Can you try to get me that?
Ms. Bartuska. Let me clarify ``cleanup.'' Your first
question had to do with insect or----
Senator Domenici. Yes, you're right.
Ms. Bartuska [continuing]. I would say, the bark beetle
issues in the West. We certainly can lay out where those
forests are that have been affected by beetle, and where we
have the management. Then I'm also assuming where--we could
provide--acres on where we have done fuels reduction projects
associated with the Healthy Forest Restoration Act or, in
general, where we have hazardous fuels. That, I think, is also
very available.
Senator Domenici. Right.
Ms. Bartuska. Is that sufficient, sir?
Senator Domenici. Now, this last one----
Ms. Bartuska. OK.
Senator Domenici. Did you define the last one, about just
cleanup?
Ms. Bartuska. I'm--what I'm--I was--or assuming that you
were referring to both the insect disease issue and then fire
issues as being a priority for our active management.
Senator Domenici. OK. If you can give us that, where it's
understandable to us--what some of us would just like to know--
is our sensitivity, that not much is going on, right or wrong,
with reference to beetle-infected forests and with reference to
forests that are overladen and going to burn, just as sure as
we're sitting there?
Ms. Bartuska. I can say that we--since the beginning of the
National Fire Plan, we have treated 200 million acres with
hazardous fuels reduction, so we--we feel like we have had some
accomplishment.
Senator Domenici. Great.
Ms. Bartuska. We believe that we have been showing some
good progress. But we can get you the data that supports the
larger acreage.
Senator Domenici. Very good, thank you.
The Chairman. Senator Tester.
Senator Tester. Thank you, Mr. Chairman.
I want to thank the panelists that are here today. A lot of
my questions revolve around forest management. That's probably
not your bailiwick, but we'll see if we can get through it.
First of all, I want to thank all your comments, but
especially when we were talking about what some of the problems
were when you have competing interests that want to have it
done one way, and another group wants to have it done another
way, when you try to achieve common ground, and balance, and
exchange information. I can just tell you, from my perspective,
I think what's happened in the past is that there's been a ``my
way or the highway'' kind of attitude. That is not how you get
things done. You get things done by finding common ground.
But I want to talk about thinning versus fire prevention,
first of all. I'll ask Dr. Bartuska this question, and that
is--what I've read--and, make no mistake about it, we've got to
do some thinning--but from what I've read, thinning isn't going
to eliminate the fire problem. It may help, but is it going to
eliminate it?
Ms. Bartuska. I think what was mentioned earlier is that
we--it is really a complex set of competing issues and
competing of stresses that need to be addressed. So, certainly,
management for wildfire is one piece of that. But I think there
is clearly--within the climate change context, we have other
issues that we are working toward.
Senator Tester. I mean, because you can thin a forest, and,
if you have a big undergrowth of grass, your fire potential is
going to go through the roof, is that not correct?
Ms. Bartuska. In fact, I believe Dr. Swetnam pointed to the
buffalo grass issue--or buffalo grass, rather--that is a
problem in some of the southwestern areas. Cheatgrass is
another one.
Senator Tester. Yes.
Ms. Bartuska. That is certainly--invasive species is part
of this equation, and how you manage that, and whether or not
you can address some of that problem--has to also be taken into
account.
Senator Tester. But even grass species that are native to
the area--if you get heavy rains in the spring, and it grows
up, it doesn't have to be cheatgrass, it could be any kind of
grass. You're going to have a fuel there that is going to be
easily touched off by a lightning strike or somebody careless
with a campfire or whatever.
Ms. Bartuska. Actually, I'd like to see if Dr. Conard could
respond to that.
Senator Tester. Sure.
Mr. Conard. I think what I'd like to do is back up a little
bit and----
Senator Tester. Sure.
Mr. Conard [continuing]. Maybe talk about different ways in
which fires burn in different ecosystems. The kinds of systems
that Dr. Swetnam was talking about--the Ponderosa pine, for
example; loblolly pine in the East--were historically typified
by these fairly frequent fires that burned the low-growing
fuels, but didn't damage the trees. As you get into cooler and
wetter kinds of tree systems, those were historically
characterized by crown fires that had very long intervals in
between them.
I think that's where we're beginning to see some of these
effects in the northern forests, in forests that are crown-fire
systems, but where more often you're getting those severe
conditions, where those fires can occur. Now, thinning in those
systems has--would have the effect of essentially changing the
ecosystems, because these are ecosystems with closed-canopy
forests. If you begin to open it up enough to prevent crown
fire across the landscape, which I think would probably not be
feasible, what you begin to do is change it to an ecosystem
where those shade-tolerant species, which normally would be
regenerating, can't regenerate, and other species would start
to come in. So, you'd be changing the system.
Senator Tester. OK. I want to rip over to Dr. Swetnam,
because you talked about thinning the large-diameter trees, and
I don't want to be too specific, but we did talk about the pine
beetle in B.C., which also happens to be in Montana, that that
dies when it gets into small-diameter trees, because the
winters get cold enough it can still kill it in the small
diameter trees. In the bigger diameters, we don't get cold
enough winters to kill it, so it infects the bigger trees.
So, in those kind of situations, isn't it fair to look at a
more global way of--I mean, if you cut all your small-diameter
trees, you're not going to have a forest left, the big ones are
dead.
Mr. Swetnam. That's right. You need to have a balanced
design. If you're going to do thinning or forestry treatments,
you have to be considerate of the age structures of the
forests, and how the forests regenerate naturally. With regards
to beetle outbreaks, something that we might be able to do is
to break up the landscape into a more heterogenous type of
landscape, with different ages and different species, might be
helpful. When you've got these really expansive areas of one
species, and they're all being stressed by climate change, then
you're set up for these really enormous kinds of events.
Senator Tester. OK. I've got more questions, but I'll wait
for the next round, Mr. Chairman.
The Chairman. Senator Salazar.
Senator Salazar. Thank you very much, Senator Bingaman, for
holding this hearing on this very important issue.
A comment, first, and that is, I think it is very important
for us to keep moving forward with our energy legislation that
we crafted out of this committee, also working with the Finance
Committee; because, at the end of the day, if we can move
forward with biofuels, with efficiency, with carbon
sequestration in the way that we fashioned our legislation out
of this committee, I think it'll help us move forward in a
significant way on the global warming issue. So, I appreciate
what you've done there, and I appreciate you also putting a
focus here on our forests and what's happening with fire danger
in the West.
I Dr. Swetnam, thank you for including, in your two--in
your megafires in the Western United States, a picture of the
Hayman Fire that burned in my State with 138,000 acres, back in
July 2002. I actually was the attorney general of the State at
that time, and was very involved in the criminal aspects of
that case for a period of time, and saw the disaster that
occurred out there with the burning of over 100,000 acres.
I have a question for you, Dr. Helms, with respect to a
part of your testimony where you say that, since both growth
and mortality on national forests greatly exceeds harvest,
resulting in a buildup of fuels, it would be prudent to
consider treatments and incentives aimed at fuel reduction and
using excess biomass for societally needed products and energy
production.
My question--starting with you, Dr. Helms, and to all of
you, is--as we look at what's happening in the West and in my
State, we have, in Colorado, approximately 2 million acres of
forests that have been infected by bark beetles. So, you can
travel through hundreds of miles, and you see the disaster
that's about ready to happen. I've often referred to that as
the Katrina of the West ready to happen with some of these
forests ready to go up like a tinderbox. So, my question to
you, Dr. Helms--if you look at the possibility of biomass,
bioenergy coming off with some of these forests, what kinds of
policy changes would you recommend to us to further that goal?
I would ask the same question of you, Dr. Bartuska, in terms of
what the Department of Agriculture might be recommending to us.
Dr. Helms.
Mr. Helms. The policy direction should be oriented toward
trying to secure ways and means by which these forests can,
indeed, be treated, because it--the way in which beetles attack
is primarily through those stands which are the densest. So, we
understand that, ecologically. The issue how to effect ways in
which to do that--not technologically, but through social and
political means.
Senator Salazar. OK. Dr. Bartuska, how would you respond to
that question?
Ms. Bartuska. Actually, first, I'd like to take a moment to
correct the record. I got enthusiastic and forgot the decimal
point on my million acres of treatment. We're at 20 million
acres. I think I overstated that a bit.
But, also, with regard to biomass-to-energy, I'm not sure
that a policy change is needed, so much as we have some really
fundamental scientific breakthroughs that are needed for an
effective woody biomass-to-energy portfolio. Our group and the
Forest Products Lab has been working on several of the enzymes
that are needed to really move us into a true biorefinery,
bioenergy context, and are part of a--the recent DOE-funded
projects at University of Wisconsin. So, we think that is the
big breakthrough that's needed. The billion-ton report speaks
to that woody biomass can provide up to 30 percent of the
bioenergy of this country currently in use as a substitution
for fossil fuel. So, being able to have biomass as a principal
starting point for the energy program is absolutely critical.
That's what I think we need to be----
Senator Salazar. Is it mostly, though, a technological
breakthrough that is needed for woody biomass, or do we
already--have we already developed some of the technology? Are
we putting enough money into the research and development of--
for woody biomass? What more could we do to try to get us there
faster?
Ms. Bartuska. There are several different pathways of
biomass to energy, some in the ethanol production is--we
probably have the technology and the ability to move in that
pathway. But some of the big breakthroughs in the cellulosic
ethanol, really using wood in a more effective way, require,
still, several enzyme paths that have not been worked out. That
is where we just need to have the community working much more
effectively together. I think that is actually happening right
now.
But you also have the biomass into just fuel use. That, I
think, has also been developing more technologies. The Fuel for
School program, for example, where you have biogenerators
locally placed, and it--whether it be schools, hospitals--so,
you have this balanced portfolio, and those are multiple steps.
I just believe wood has to be part of the solution, and I
think that's what we're all trying to identify, is that
pathway.
Senator Salazar. I'll only make this--my time is up, but
I'll make this comment. I think, in Colorado, we struggle with
the opportunity, and try to figure--trying to figure out the
pathway forward. There are a number of different demonstration
projects where we are trying to use woody biomass in a good way
with respect to pellets, and even a high school in one county
that wants to become the first energy-independent county in my
State, Jackson County, through using woody biomass. But I think
we're searching for the pathway to make--so that we can have
effective programs with respect to using woody biomass.
Thank you, Mr. Chairman.
The Chairman. Thank you very much.
Why don't we go ahead with any additional questions in a
second round.
Senator Craig.
Senator Craig. I'll be very brief.
A couple of comments and observations based on some of my
colleagues' questioning and response from the--our panelists.
Obviously, thinning and changing the structure of a forest
as it relates to fuel loading, whether you get laddering
effects from small trees getting to big trees, or whether it's
grass and certain types of grass--and Senator Tester mentioned
that--I'm sitting here looking at a scenario that was--is
somewhat historic. Probably in the State of Montana and Idaho,
we graze our land 50 to 60 percent less than we did a decade or
two or three ago, so that fuel buildup on the floor, if it's
just grass and some forbes and small bushes, is now rapidly
growing, in part because we no longer graze the land, or we
graze it substantially less. I flew over a fire complex in
Idaho this year unlike any I have ever experienced. I've been
fighting fires, or on fires, since I was 15 years of age, in
the back of our ranch, on BLM lands. This was a 600,000-acre
piece of black land. Now, that's all of Connecticut and
probably Rhode Island together. It had burned, 2 years before.
A lot of it had been rehab'd and seeded, but it had not been
grazed because of a variety of reasons, and decisions and
lawsuits that would disallow even the lightest of grazing. We
talk about cheatgrass as an invasive species that is very fire
prone, but is very graze-able, early. If you hit it early and
thin it and get it down, and then get your livestock off from
it, you change the whole fire equation. But slick-spot pepper
grass and a fear for the spike-tail grouse disallows that in a
lawsuit that denies the grazing of that area. A problem. Now
it's a 600,000-acre burn, once again. Four ranchers wiped out,
and grazing and some livestock. The great tragedy was the
canyons--this is high country, high plateau country--beautiful
canyon lands filled with trees and water and wildlife--gone,
gutted, like a torch gone through--in some instances, not all,
and in some.
So, when we look at reality, believe it or not, as hostile
as public policy has been to grazing over the last five
decades, in the scenario that the Doctor started talking about,
in the late 1800s, when we began to change things, grazing,
properly managed, also became a fuel reducer in some instances.
I found that, really, very intriguing. You're right, Dr.
Bartuska, I've done a couple of Fuels to Schools projects.
We've got one on the Payette Forest, in Council, Idaho. The
Payette Forest has got dead-and-dying. It's a very fire-prone
forest in some instances, but it's now suggesting it just may
not be able to find the fuels for the school. It's ironic that
they were the promoters of it, but now, policywise, doesn't
quite allow us to get to where we need to get, to get the hog
fuels, to get to the burners, and so on and so forth. Policy
begets policy, and it must work together. We, here in
Washington, have dramatically tied the hands of our land
managers into some scenarios that are a lot more political than
they are scientific, I suspect. I guess that's my frustration.
We'll work our way through that. Woody biomass and cellulosic
ethanol and, you're right, a few more works at the lab table,
and maybe we've got a stand-up commercial operation that could
significantly, as Senator Salazar mentioned, help us change
some of those equations. But it really needs to be a broadbrush
picture, narrowed, specified as it relates to the situations
we're all dealing with. My guess is, here, we try to get it too
broad at times, and we tie the hands of those who have the wise
science behind them in the management.
Anyway, Mr. Chairman, thank you very much for, I hope, a
valuable hearing coming out of a very bad fire season.
In Idaho, while the rains are coming and the snow is coming
in the high country, we're still burning. We're now--we've
knocked off about 2 million acres of land, most of it in the
timbered areas. It's a great tragedy. Now the mudslides, and
the water quality in those regions is beginning to rapidly
decline as we get into our wet season, and that's going to be
the next step and problem we deal with.
Thank you.
The Chairman. Senator Tester.
Senator Tester. Thank you, Mr. Chairman.
Dr. Bartuska, if we do nothing, if we don't do any
thinning, if we don't do anything different than we're doing
now, and climate change continues along the same upward ramp,
as one of the charts showed, have you done any projections on
what the Forest Service budgetary needs are going to be over
the next 10 or 20 years, just to fight fire, alone?
Ms. Bartuska. No, I have not done that, and I don't believe
our agency has done that, based on the climate change
projections.
Senator Tester. OK. I know it would just be projections,
but do you think it would be wise to do that? Just over the
short term, it might give us, as policymakers, some sort of
idea on what to expect if policies aren't put in place that
could help impact the forest.
Ms. Bartuska. We actually have just began looking at, what
are the management activities that are needed in response to
climate change, based on the science that we've done. So, we
believe we'll be improving our estimates over time. I can't
tell you when that will----
Senator Tester. OK.
Ms. Bartuska [continuing]. Happen, but we have----
Senator Tester. OK.
Ms. Bartuska [continuing]. Our very first documentation of
our strategy right now.
Senator Tester. That's good.
Dr. Helms, you talked some on invasive species. We have
invasive weed species that are incredible problem in our
forests and in the grassland, too, in the State of Montana. I
guess the question I have is that--Is there a connection
between the invasive species in our forests, and global
warming? Or is the invasive-species issue due to something
else?
Now, let me give you an example. I live in north central
Montana. It's flat as this table, right up here. If I overgraze
my ground, cheatgrass will come in. If I don't overgraze my
ground, if I treat it in a way that's sustainable, I'll never
have a problem with cheatgrass. Is that the same thing that's
happened in the forestland, or is it because of global warming
or some other issue, that we find invasive grasses and invasive
species--more along the line of invasive grasses, because the
invasive weeds are a whole 'nother animal?
Mr. Helms. When you have a change in vegetation, any kind
of disturbance, the--you know, nature abhors a vacuum. So, what
plants come in there are those plants that have a competitive
advantage.
Senator Tester. Gotcha. So it does have a----
Mr. Helms. It's often the invasive, testimony those exotic
plants aren't accompanied by other organisms, insects or
whatever, that hold them in check. So, once you create change,
it's the pioneering species that have the advantage. In the
context of climate change, it's going to exacerbate that, and
it will give, perhaps, invasive exotics an advantage over the
native plants.
Senator Tester. OK, good to know.
You talked a little bit about forest lands turning to
grasslands, and I didn't hear what you said at the beginning.
What happens to the grasslands with climate change?
Mr. Helms. The grasslands could move into desert.
Senator Tester. Really? That's a nice thought. You also
talked about the fact that they take off the forested
vegetation, for whatever reason, and you have higher soil
temperatures and----
Mr. Helms. Yes.
Senator Tester [continuing]. A greater potential for the
CO2 to----
Mr. Helms. Yes.
Senator. Tester [continuing]. Come out of the ground. Is
there anything being done to address that issue--and that can
be either you, Dr. Helms, or to Dr. Conard, or anybody on the
panel, I don't care--to deal with the issue of exposed ground,
higher temperatures, more CO2 potentially coming out
of the ground? Because it's going to happen.
Mr. Helms. Yes. In the context of forest management, given
that likelihood, the response would be to reduce the amount of
cutting such that there is canopy--shade--so that you don't
raise the temperature of the soil.
Senator Tester. OK.
Mr. Helms. So, it would be prudent, then, to recognize that
the soil, in the highest sites, have about 40 percent of the
total carbon content. So, you need to be prudent about how you
handle that.
Senator Tester. OK. I just want your opinion on this,
because, like I said before, a lot of these questions revolve
around forest management, and I'm not a forester, I'm a farmer.
But the question about low or no snowpack and a let-it-burn
policy is an issue that comes up a lot in Montana, where we
have a lot of acres that burned this year. What is your
perspective on a year that has very low snowpack, so we know
it's going to be a dry summer and, for the most part, the heat
comes with it--what is your perspective on the let-it-burn
policy on a fire that starts in June, per se, when you have
snowpack that's way below normal? Any of you can answer it. If
none of you want to answer it, I understand, because it's kind
of a political hot button.
Mr. Helms. If I can initiate a comment.
Senator Tester. Sure.
Mr. Helms. Where the precipitation comes in the form of
snow, the forest does two things. One, the canopy itself
collects that snow and prevents it from getting to the ground,
and it oblates and moves back to the atmosphere. But if the
forest canopy is not closed, and the trees provide partial
cover, then the trees play a crucial role in protecting that
snow that's on the ground from melt. So, I think one of the
issues that face our concerns around the forest, whether it be
through climate change or insects or disease, is to recognize
the extreme importance of the Nation's forests in relationship
to water supply, because water is going to be a particularly
critical factor, and, in the context of climate change, we need
to be very concerned about the important role that forests play
in protecting our watersheds.
Senator Tester. OK.
Do you have any comment on that, Doctor?
Ms. Bartuska. Actually, I think Dr. Helms has done a very
good job at----
Senator Tester. Yes.
Ms. Bartuska [continuing]. At summarizing where we are.
Senator Tester. Yes. Thank you very much.
I appreciate your guys's perspective, and I know that
there's questions about forest management, and there's been
head-knocking. But from my perspective, nothing's ever going to
change in the forests until we get together and find common
ground. Nothing's ever going to change. There is common ground
to be found, and we can manage the forests right, and we can
take care of our watersheds, and we can take care of the
invasive species. But, if we continue to kick people out of our
offices that differ with us in opinion, it's never going to
happen.
Thank you guys very much for your comments.
The Chairman. I think it's been useful testimony. We
appreciate you all being here. I think we will try to gain some
lessons from what you've said and put them into application.
That'll end our hearing.
[Whereupon, at 4:37 p.m., the hearing was adjourned.]
APPENDIXES
----------
Appendix I
Responses to Additional Questions
----------
Department of Agriculture,
Forest Service,
Washington, DC, December 3, 2007.
Hon. Jeff Bingaman,
Chairman, Committee on Energy and Natural Resources, 304 Dirksen Senate
Office Building, Washington, DC.
Dear Senator Bingaman: Thank you for your letter of September 28,
2007, in which you provided the questions submitted for the record by
the Committee for the September 24, 2007, hearing on Scientific
Assessments of Global Climate Change on Wildfire Activity in the United
States. The responses to the questions are enclosed.
Sincerely,
Douglas W. Crandall
Director, Legislative Affairs.
[Enclosure.]
Responses of Ann Bartuska and Susan Conard to Questions From
Senator Bingaman
Question 1. Can you summarize the available science regarding which
particular regions in the country are likely to see the most
significant increases in wildfire activity resulting from global
warming?
Answer. The recent report of the Intergovernmental Panel on Climate
Change (IPCC 2007) developed projections of the most likely future
changes in temperature and precipitation for different regions around
the world. These projections were based on the outputs of 21 different
global climate models. For North America the largest increases in
summer temperatures are projected for the western and central US, and
the largest increases in winter temperatures for the boreal zones of
Canada and Alaska, and to a lesser extent the northeastern US. Winter
precipitation is expected to decrease in the southwestern US and in
Florida, and summer precipitation is projected to decrease across much
of North America (with greatest decreases perhaps in the northwest and
in Florida), and to decrease along the eastern seaboard and in the
north (Alaska and Canada).
These data suggest that increased fire hazard may occur in many
regions of the US, primarily the western US, Florida, and the boreal
forests. Projections based on regionalized climate models (Brown et al.
2004) suggest that in the western US the greatest impacts on fire
hazard will be in the northern Rockies, Great Basin and the Southwest,
with less impact the on Front Range of the Rockies and the High Plains
regions.
Question 2. Your testimony indicates that the Forest Inventory and
Analysis program is an important program when it comes to monitoring
and understanding the impacts of global climate change on our forests.
Can you give me a better idea of the role and importance of the FIA
program in the Forest Service's global warming and other research?
Answer. The Forest Inventory and Analysis program (FIA) uses a
scientifically sound monitoring design to provide forest resource
baselines and trends. The program makes use of remote-sensing data and
field-based data to monitor forests and provide an inventory in every
State every year. The FIA program provides critical information for
interdisciplinary ecosystem research including climate change. Since
1930, FIA has collected, analyzed, and reported information on the
status and trends of America's forests by tracking how much forest
exists, where it exists, who owns it, how it is being managed, and how
it is changing, as well as how the trees and other forest vegetation
are growing and how much has died or been removed. This long term data
set is important to tracking changes in forest and tree species
distribution as well as determining the amount of carbon sequestered in
forests.
Question 3. Your testimony repeatedly mentions that vegetation
treatments ``in appropriate fire regimes'' may reduce wildfire
severity. Would you expand on which fire regimes are appropriate for
such a treatment strategy?
Answer. Fire regimes describe the general relationships between a
given ecosystem and its expected disturbance in terms of average return
interval, burn intensity and severity. Treatments are most appropriate
in those ecosystems that have historically burned frequently with low
intensity and little mortality to the overstory species. This type of
fire regime is found in dry ponderosa pine forests and dry mixed
conifer ecosystems of the west and southwest, as well as the frequent
burning pine ecosystems of the southeastern United States.
In addition, other ecosystems may benefit from appropriately
designed treatments even though fire has historically been less
frequent. The need for treatments in these areas might be to reduce
hazardous fuels in the wildland urban interface, protect wildlife
habitat, control insect and disease outbreaks, create a mosaic of age
classes across the landscape, or for other reasons related to ecosystem
restoration.
Question 4. Would you please provide a list of all of the Forest
Service projects over the last ten years that were designed to reduce
hazardous fuels within the area burned by the Angora Fire and that were
appealed or litigated? Please include the name and a brief description
of each such project; whether it was appealed, litigated, or both; the
outcome of the appeal or litigation; and the length of time between
when the appeal was filed and when it was decided by the Forest
Service.
Answer. No fuel treatment projects within the Angora Fire were
appealed or litigated within the last ten years. Over the last ten
years, seventeen fuel treatments were implemented in and adjacent to
the Angora Fire on National Forest System lands (excluding the urban
lot treatments). One of these treatment units (unit 20) was partially
complete (trees thinned and hand piles created but not burned).
Please see the chart and map* on the following pages for specific
information.
---------------------------------------------------------------------------
* Map has been retained in committee files.
ANGORA FIRE AREA PRE-FIRE TREATMENT UNIT PRESCRIPTIONS
--------------------------------------------------------------------------------------------------------------------------------------------------------
Unit Acres Treated Year Completed* Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
6 78 1995 Pre-commercial Thinning/Activity Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
7 33 2007 Commercial and Pre-commercial Thinning/Salvage/Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
8 91 2007 Commercial and Pre-commercial Thinning/Activity Fuels
Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
11 14 1997 Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
12 12 2006 Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
13 8 2007 Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
14 17 2007 Pre-commercial Thinning/Activity Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
16 27 2006 Pre-commercial Thinning/Activity Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
17 18 2006 Commercial and Pre-commercial Thinning / Activity Fuels
Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
18 11 2006 Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
19 25 2006 Pre-commercial Thinning/Activity Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
20 60 ** Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
21 87 2005 Pre-commercial Thinning/Salvage/ Activity Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
22 123 2005 Commercial Thinning/Salvage/ Activity Fuels Jackpot Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
28 21 2006 Pre-commercial Thinning/Activity Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
29 26 2005 Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
30 35 2005 Commercial and Pre-commercial Thinning/Salvage/ Activity
Fuels Pile Burn
--------------------------------------------------------------------------------------------------------------------------------------------------------
* This year represents the year the burning was completed. Thinning was completed in previous years.
** All activities completed except pile burning.
Question 5/6. A recent Forest Service assessment of the fire
behavior during the Angora Fire indicated that slash piles left behind
after fuels reduction projects burned during the fire. What is your
best estimate of the number of slash piles that burned during the
Angora fire?
a) When were those piles made?
b) Did the project decisions or descriptions specify a time-frame
for the treatment of those piles?
c) Does the Forest Service have any general guidance regarding
removal of slash piles, and, if so, was the guidance followed in the
area burned during that fire?
Answer. More than 850 acres of hand piles\1\ were burned within
Lake Tahoe Basin Management Unit (LTBMU) last fall, winter, and spring.
However, there were not enough available burn opportunities due to a
short, dry winter and air quality concerns to burn all ``cured'' hand
piles within the Basin. Opportunities to burn are dictated by the
presence of appropriate weather and fuel conditions for meeting burn
controllability and smoke management objectives.
---------------------------------------------------------------------------
\1\ The piles that burned on the Angora Fire were hand piles,
created after hand thinning and piling of much smaller amounts of
material than would be found in a typical slash pile. Slash piles refer
to machine-generated by-products, often from timber operations or
large-scale thinning.
---------------------------------------------------------------------------
The hand piles within unit 20 were among those that were not
burned. Hand piles within treatment units are not counted. However,
estimates indicate that hand pile units within the Basin average about
15-20 piles per acre. Treatment unit 20 totaled sixty acres.
a) The hand piles in treatment unit 20 were created in 2005.
b) No.
c) The Forest Service has no general guidance regarding removal of
hand piles.
Responses of Ann Bartuska and Susan Conard to Questions From
Senator Cantwell
We are observing serious wildland fire conditions such as an
increasing number of large and severe wildfires, lengthened wildfire
seasons, increased areas burned, and increasing numbers of large
wildfires in fire-sensitive ecosystems. The annual number of acres
burned on public lands has been increasing over the last couple of
decades. Recent research suggests that these trends are, in part,
related to shifts in climate. For example, a warming climate is
contributing to longer wildland fire seasons with more extreme wildland
fire events, which greatly increase the risk to human lives and
infrastructures, particularly within the wildland urban interface.
Without taking action to manage fire-dependant ecosystems today and in
the absence of thoughtful preparation and planning for the future,
wildland fires are likely to become increasingly difficult to manage.
To this extent, I have the following questions:
Question 7. The San Diego Declaration on Climate Change and Fire
Management was ratified at the Association for Fire Ecology's Third
International Fire Ecology and Management Congress, a gathering
attended by 1,200 delegates from 26 different countries across six
continents, and represents the broadest agreement to date among
wildland fire scientists and managers of the effects of global warming
on wildfires and fire regimes. What is the Bush Administration's and
the U.S. Forest Service's position on the San Diego Declaration? What
has the Administration and agency been doing to incorporate the
document's scientific conclusions and action items into land and fire
management?
Answer. We are familiar with the San Diego Declaration on Climate
Change, which was developed by the Association for Fire Ecology and
endorsed by the membership and other signatories at the 3rd
International Fire Ecology and Management Conference in Sand Diego in
November, 2006. In general, the Declaration addresses the role that
climate and weather patterns play in shaping fire regimes and the
potential for changing climate to significantly alter future fire
patterns, and encourages managers to consider these potential impacts
as they develop and implement management strategies for fire affected
ecosystems.
In the recently issued Forest Service Strategic Plan for 2007-2012,
climate change is recognized as an important factor that ``will impact
forest, range, and human well-being by potentially altering the ability
of ecosystems to provide life-supporting goods and services. The
implication for natural resource management is to be flexible and adapt
management strategies to help mitigate the effects of climate change.
In short, we need to develop new knowledge so that we can manage for
future change, ensuring the continued provision of goods, services, and
values from forests and rangelands.''
Question 8. One of the key findings of the San Diego Declaration is
that wildfire seasons are lengthening and wildfire size is growing. In
the absence of thoughtful planning and preparation for future changes
in climate and weather, wildland fires will likely be increasingly
difficult to manage---a point apparently verified by the current
wildfire season. What is the Forest Service doing to incorporate
climate change projections and mitigations into Land and Resource
Management Plans and Fire Management Plans?
Answer. The Forest Service is developing a strategic approach to
address climate change in forests and rangelands. By developing and
implementing this strategy, we anticipate that field managers will
address the effects of climate change by managing for healthy,
resilient ecosystems.
Question 9. The San Diego Declaration proposes several action items
for management, research, and education to help adapt public land
management to cope with wildland fire in a changing climate, including
holding conferences and symposia to enhance communication among
managers and researchers, and engage the general public. What is the
Administration and Forest Service doing to educate citizens about the
effects of climate change on wildland fire? What is the Administration
and Forest Service doing to enhance communication and collaboration
among fire and climate scientists, fire and land managers?
Answer. The Chief of the Forest Service has identified climate
change as one of three key themes for the agency to address, along with
water issues and encouraging children to get outdoors. Chief Kimbell
has delivered several recent speeches that have addressed climate
change and has been interviewed on numerous occasions on the subject.
The themes are spotlighted on the Forest Service webpage (http://
www.fs.fed.us/ ), and climate change is further highlighted by Research
and Development (http://www.fs.fed.us/research/fsgc/climate-
change.shtml).
Within Research and Development, fire and climate scientists
collaborate closely on an ongoing basis. Over 75 Forest Service
scientists, with several colleagues from other agencies and academia,
met in September to identify gaps in the Forest Service Research and
Development program in climate change. The results will be used to
develop an updated Climate Change Research and Development Strategy.
In addition, the Forest Service research community provides peer-
reviewed science for application on the national forests and
grasslands, including extensive research on climate change effects on
those ecosystems. This information is provided to land managers through
training, conferences and other technology transfer efforts.
Responses of Ann Bartuska and Susan Conard to Questions From
Senator Salazar
Question 10. What types of adaptation management strategies have
been found to best deal with managing the expected increased threat of
wildfires?
Answer. The most effective measures for dealing with an increased
threat of wildland fire are:
Homeowner utilization of Firewise and other guidance to:
Ensure house and deck construction material is fire
resistant.
Ensure vegetation adjacent to houses and other structures is
either removed or exhibits low flammability characteristics
(e.g.: broadleaf versus conifer trees).
Ensure combustibles are kept away from structures (needle
litter, firewood, scrap lumber, etc.).
Ensure adjacent fuel within the wildland-urban interface is
maintained in a low hazard condition, through a combination of
mechanical treatments and prescribed fire.
Maintain a high percentage of lands outside the wildland-urban
interface in a resilient, sustainable fashion, through the use of
prescribed fire, wildland fire use, and mechanical treatments.
Question 11. One of the most enduring ad campaigns in our country's
history are the Smokey the Bear public service announcements. There
probably isn't a person in the room who hasn't heard the slogan ``Only
you can prevent forest fires.'' Given that the majority of wildfires
are caused by human activity, are there plans to increase efforts to
reach the public on climate change and expected increased wildfire
activity, and ways to prevent wildfires?
Answer. The Cooperative Forest Fire Prevention (CFFP) Program,
commonly known as the Smokey Bear Program, was created to maintain
public awareness of the need to prevent human-caused wildfires. In
cooperation with the Advertising Council and the National Association
of State Foresters, new campaigns are developed every few years. In
calendar year 2008, a new campaign will be launched to spread Smokey's
message of reducing human-caused wildfires.
Fire and Aviation Management is actively involved with Forest
Service Research and other staff groups to educate the public in the
reasons for wildfire causes and increases in severity.
Question 12. The link between climate change and fire is clearly
strong, but since this linkage has come to light, some people suggest
that climate is more critical than fuel as a driver of fire behavior,
and there is no reason to treat fuels to protect communities or restore
ecosystems. What are the implications of climate change for fuel
treatment and forest restoration?
Answer. Both field observations and fire behavior models
demonstrate the central importance of fuel loads, fuel structure (the
vertical and horizontal distribution of fine fuels, in particular), and
fuel moisture as important determinants of fire behavior. Weather
patterns during and preceding a fire also have strong effects on fire
behavior, as does terrain. In general, decreased fire intensity and
ecosystem impacts will occur as fine fuel loads decrease, fuel moisture
increases, and where wind speeds are low, humidity is low, and slopes
are more shallow.
In situations where fuels are overly dense, or where understory
vegetation development has led to fuel continuity from the ground to
tree crowns, a number of studies have shown that fuel treatments can
effectively modify fire behavior, increase the effectiveness of
suppression actions, and decrease the likelihood of crown fire.
Warming climate, as it increases intensity of droughts and length
of fire seasons, is expected to lead to higher fire hazard in many
parts of the country. Maintenance of healthy forests and rangelands,
control of invasive species such as cheat grass, and fuel reduction
treatments all can play a part in reducing this threat and in improving
the ability to manage wildfires across the landscape. Recent papers
also suggest that severe fires can be seen as opportunities to
facilitate ecosystem adaptation to changing climate. For example, by
planting tree species or genotypes more adapted to warmer climates, or
by adjusting planting densities, forests recovering after a fire may be
made more resilient to future changes in climate (e.g. Spittlehouse et
al. 2003).
Question 13. Fires are becoming increasingly harder to fight and
are releasing huge quantities of carbon dioxide. Wildland Fire Use, the
practice of allowing some lightning-ignited fires to burn under less
extreme conditions, has been suggested as a way to mitigate fires and
ensure they release less carbon dioxide. Do you see a role for Wildland
Fire Use in changing future fire behavior so it is less extreme,
thereby releasing fewer greenhouse gases?
Answer. Careful use of unplanned ignitions (Wildland Fire Use) has
great potential to reduce severity and intensity of future wildfires by
creating patterns of vegetation which are less prone to large, high
severity fire events. In these areas, reduced burn severity and
emissions occur through reduced consumption of fuel, thus enabling the
site to retain material which in a severe wildfire would have otherwise
been released as carbon dioxide and other emissions.
Withholding fire from fire-adapted ecosystems increases the
potential for severe, high intensity fires. In some parts of central
Idaho wilderness areas, there is evidence that the previous
implementation of wildland fire use (1972-2006) resulted in reduced
burn severity and emissions from the fires of 2007.
Question 14. It has been suggested that because young forests grow
fast and older forests grow slowly, we can cut down old forests and
replace them with fast-growing plantations to maximize the uptake of
carbon dioxide and reduce global warming. What is the current
scientific understanding of the effects of logging older forests on the
uptake or release of greenhouse gases?
Answer. Answering this question requires consideration of the net
greenhouse gas outcome of the options in the question--it requires
thinking about what the atmosphere sees rather than thinking only in
terms of carbon on a particular acre.
Actively managing rapidly growing forests and converting the wood
to long-lived products, substitutions for fossil-fuel intensive
products, and biofuels provides substantial greenhouse gas benefits.
Older forests can be significant pools of carbon, but the pool size is
neither increasing nor decreasing when considered across time and
disturbance cycles (fire, insect, disease, wind events). In the systems
studied, a life cycle analysis shows that substantially more carbon can
be sequestered and greater greenhouse gas benefit realized by actively
managing the stand and using the wood over multiple rotations than is
sequestered by older stands of the same type.
A mosaic of ages and stand types across the landscape can be
important depending on the goals and objectives of the landowners or
managers. Old forest stands that may be important with regard to other
environmental values often do not help in overall greenhouse gas
reductions. The relative value of desired outcomes must be considered.
Responses of Ann Bartuska and Susan Conard to Questions From
Senator Domenici
Question 15/16. Dr. Conard, near the end of your written testimony
you said: ``Because climate in many areas will change more rapidly than
long-lived plant species can migrate, moderate to severe fires can be
seen as opportunities to facilitate migration, either by planting . . .
or by selecting seed from trees that grow in warmer seed zones or at
lower elevations.'' What is the current reforestation backlog facing
the Forest Service?
Answer. At the end of fiscal year 2006, the Forest Service declared
a total of approximately 1.1 million acres needing reforestation. These
needs will be updated with new information following the end of fiscal
year 2007.
Question 17. How much of that backlog was the result of fires and
insect outbreaks and how much was caused by past harvesting?
Answer. We estimate that the 1.1 million acres of reforestation
needs consist of approximately 704,000 acres resulting from wildfires,
33,000 acres caused by insect and disease, and 120,000 acres from
previous harvest treatments. Reforestation after a timber harvest is a
legal requirement that is paid for through the timber sale, whereas no
funding source outside of appropriated funds is available following a
fire unless there is a salvage sale.
Question 18. In the absence of a dramatic increase in reforestation
funding, what are the other ways the Forest Service has to pay for the
work needed to address the reforestation backlog?
Answer. Partnerships with external organizations are a way that the
Forest Service uses to provide additional funding for reforestation
work. For example, the Forest Service receives contributions from
organizations such as American Forests, The Arbor Day Foundation,
National Forest Foundation, the National Association of Garden Clubs,
the Batesville Casket Company, and the Forest Service Plant-a-Tree
programs. These contributions currently provide less than 5% of the
annual reforestation accomplishments but we are working with the
partners to increase the program.
Question 19. Given current funding availability and the projected
increase in fires that you've suggested could happen, is it realistic
to believe the Forest Service has the capability of undertaking the
kind of work you suggested in your testimony? If not, what changes
would have to occur to facilitate that kind of work?
Answer. As with all decisions regarding expenditures of funds, this
would be a matter of evaluating priorities among many competing needs.
Question 20. Dr. Conard, I have been reading a Pacific Northwest
Research Station publication from January 2004 titled Western Forests,
Fire Risk, and Climate Change. The author of the paper was Ron Neilson.
I found a number of the statements in that document quite interesting.
In the summary, Mr. Neilson said, ``In six of seven future scenarios
run through one model, the Western United States gets wetter winters
and warmer summers throughout the 21st century (as compared to current
climate), with expanded woody growth across the West and thus,
increasing fire risk.'' Several of the witnesses today told us that
early spring run-off followed by a dry summer leads to severe fire
seasons. In fact, the paper I am talking about said: ``Large fires
associated with climate patterns including the 1910 Idaho fires, 1988
Yellowstone fires, and 2002 Biscuit Fires in Southwest Oregon'' were
strongly related to climate variability. Are Forest Service researchers
suggesting we will be more likely to experience dry springs followed by
warmer summers and therefore more fires due to climate change? Or are
the models suggesting that increased forest vegetation over a larger
landscape will make more acres susceptible to forest fires?
I am also interested in another comment in this paper, which said:
``Computer models can forecast the likely effects of different
scenarios, giving people a chance to compare outcomes. Computer models
cannot predict specific events.'' We heard lots of dire predictions,
most based on computer models at our Climate Change and Wildfire
hearing. Yet, the authors of this Forest Service report are warning us
that these models have limited capabilities.
Answer. Current global change models, and regional analyses based
on these models, suggest that much of the US will experience warmer
summers, earlier snowmelt, and longer, more severe summer drought. As
shown in recent papers, such as that by Westerling (2006) in Science,
these factors can be associated with the occurrence of severe fire
seasons and more large fires in the West over the past several decades.
Fire patterns in Florida and other areas of the country have also been
associated with severe drought and other factors related to multi-year
climate variability.
Based on model projections, the environmental conditions associated
with high fire hazard are likely to increase in many regions. The
effects of climate and fire/climate interactions on vegetation are more
difficult to predict. Newer model projections (IPCC 2007) suggest that
the southwestern US will be both drier and warmer, as opposed to
earlier projections that suggested the area would be wetter and warmer.
If the new projections are correct, we might expect fewer trees in
these regions, with a transition from forest to savanna to desert
grasslands. Because projections of individual models vary, the IPCC
uses ensemble forecasts (developed by comparing the results from over
20 different global models) to increase the robustness of their
projections. Climate models are improving greatly, and generally are
much more capable at reproducing past events than they were even 5
years ago. This calibration to past events provides higher confidence
in the accuracy of projections of future changes.
Question 21. Understanding these limitations, is the Forest Service
suggesting that we should predicate future forest policy on these
predictive models?
Answer. Clearly we believe climate change has serious implications
for the long-term health and sustainability of the nation's forests.
But, as we have already noted, predictive models have their limits when
it comes to developing long-term forest policy. In the near term,
modeling results will be useful in informing management strategies
developed in forest plans. In the longer term, as the real world
effects of climate change become more apparent, other environmental
policy changes may be needed to protect the national forests. Adaptive
management strategies are being used, but will be even more important
and useful as more information comes in and models improve.
Question 22. I gather from the past testimony of Chiefs Dale
Bosworth, and Abigail Kimbell, and Undersecretary Mark Rey that the
Forest Service believes we must manage for change, including increased
management of forest vegetation. Is that correct?
Answer. We are already starting to see the impacts of climate
change on forests with fires burning hotter and bigger, larger insect
outbreaks, and warmer winters with smaller snowpacks. The agency is
working to increase the resilience of National Forests and Grasslands
by adapting to changing ecosystem conditions, and working to mitigate
future effects of climate change. Management of forest vegetation and
disturbance processes are the essential tools we use to adapt to a
changing climate and mitigate further impacts to the forests and
grasslands.
Question 23. Dr. Bartuska, I have a data set provided by the Forest
Service that shows the number of acres burned by year from 1916 through
2006. When I look at that data set, I see that 2006 is only the 37th
worst year in the 90-year data set. Two years (1931 and 1933) showed
more than 5 times the number of acres burned than we had in 2006. Four
other years (1928, 1929, 1933 and 1934) showed more than 4 times the
number of acres burned than we had in 2006. What do you think caused
the number of acres burned each year between 1916 and 1954?
Answer. First, we would like to frame the data in question. Several
years ago the Forest Service compiled available historical federal and
state wildfire occurrence data back to the early 1900's. However, the
Agency cannot provide a full accounting for field methods used to
collect the data, so the accuracy of the data during this time period
cannot be verified.
The data do indicate that significant acres were burned during the
1920's through the 1940's; the maximum number of burned acres reported
in a single year was 52 million acres in 1930. The data further
indicate that the acres burned were predominantly in the southern and
eastern US (states of VA, WV, NC, SC, TN, GA, FL, AL, LA, MS, TX, AR, &
OK) with most of the burned acres occurring on unprotected forested and
non-forested lands, for example:
------------------------------------------------------------------------
Acres Burned
Year Total Acres within States
Burned Above
------------------------------------------------------------------------
1927.................................. 38 million 34 million
1930.................................. 52 million 47 million
1933.................................. 44 million 41 million
1947.................................. 24 million 21 million
------------------------------------------------------------------------
As to the general cause of the acres burned, there appears to be a
combination of factors including climatic conditions on a national
scale such as the ``dust bowl'' of the 30's combined with a tradition
of woods and field burning and fire reporting protocols which
contributed to the high number of acres reported. The Agency has
initiated an effort to better understand and interpret the historical
data and would be willing to provide a follow-up report at conclusion
of that effort.
Question 24. I know you heard my opening statement when I mentioned
the 1871 Peshtigo fire, the 1894 fire in Hinckley, Minnesota, and the
1910 fires in Montana and Idaho. What do you think primarily caused any
of those fires?
Answer. The primary underlying factors for the fires in question
appear to be the accumulation of fuels, management practices, drought,
and wind and weather conditions. An account of the specific incidents
follows:
Peshtigo Fire.--Many months of extreme drought combined with the
land-clearing practices of the time (``slash and burn'') caused many
small fires to be whipped into a huge forest fire when a cyclonic storm
blew up on the night of October 8, 1871.
One example from survivor accounts is that railroad workers
clearing land for tracks that Sunday evening started a brush fire which
somehow became an inferno. It had been an unusually dry summer and the
fire moved fast. Some survivors said it moved so fast it was ``like a
tornado.''
Hinckley Fire.--The fire occurred on September 1, 1894 and was
centered at Hinckley, Minnesota. After a two-month drought, several
fires started in the pine forests of Pine County, Minnesota. The main
contributor to the fire was apparently the then common method of lumber
harvesting, which involved stripping trees of their branches, littering
the ground with such detritus. Another contributing factor was a
temperature inversion that trapped the gases from the fires.
1910 Fires.--1910 was the driest year in memory. Snows melted early
and the spring rains were lacking. An electrical storm the night of
July 15 touched off more than 3,000 fires. Then, on August 20,
hurricane-force winds roared into Idaho and Montana dry forests. In a
matter of hours, fires became firestorms.
Question 25. Do your models suggest that we will have more years
with the specific causal agents that occurred in these mega fire
incidents?
Answer. The primary causal agents of the incidents described above
were rooted in land management practices, such as relatively
uncontrolled burning of logging slash, and burning for land clearing.
Today, these practices are much more closely managed. Widespread
burning without knowledge of impending weather changes (such as high
winds) was often the critical confluence of events that led to these
megafires of the past. Once the fires started, often in many places at
once, there was little capability in place to suppress them. We utilize
fire behavior science and fire weather forecasting to manage fire
effects and maintain controllability of our prescribed fires. In
addition, fire weather predictive services allow for better preparation
for weather changes and identification of long-term weather trends.
As climate changes, the weather conditions that lead to increased
fire hazard are likely to become more frequent, and the annual burned
areas are likely to continue increasing, at least in the short-term.
Current land management practices, including reduction in hazardous
fuels and the existence of extensive fire suppression capabilities,
should help to mitigate these effects of changing climate on fire
regimes.
Question 26. If the low elevation and southern ponderosa pine
forests are likely to migrate to higher elevations and to the north, as
suggested by Dr. Swetnam, do you believe it would be wise to ignore the
fires at higher elevations in the northern Intermountain States?
Answer. Our policy is never to ``ignore'' fires regardless of the
location. Each fire receives an appropriate management response that
balances resources at risk, potential fire behavior and effects, cost,
and potential resource benefits from the fire (in areas where the use
of fire to achieve resource benefits is permitted by the Land and
Resource Management Plan) to determine the best management approach
while always providing for the safety of our firefighters and the
public. As climates change and conditions favor species that may be
better adapted to dry, warm conditions, our appropriate management
response approach will not change. The specific actions taken to ensure
our approach is appropriate will be determined based on risk,
probability, safety, cost, and benefits (where appropriate).
Question 27. Do you know of any research that examines the ability
of tree species to invade and reforest lands that have been heavily
impacted by fires, including how various species respond to the loss of
soil and the changes in moisture regimes after high intensity fires?
Answer. There are multiple research studies that have looked at
recovery after individual fires in a wide range of vegetation types.
Each ecosystem type has different characteristic patterns of recovery
after fires, and both the rate of recovery and the species composition
after a fire can vary as a function of fire adaptation of individual
species, the availability of seed, the size and severity of the burn,
and the weather patterns in the seasons after the fire.
The rate of regeneration of tree species after a fire is a case in
point. Some tree species, such as aspen, oaks, and maples, have the
capacity to sprout from roots or living stem bases following even
fairly severe fires. Most conifer species, on the other hand, must
reproduce from seed. Some conifer species are well-adapted to
reproducing after high-intensity fires, while others, such as ponderosa
pine in the west and loblolly pine in the east, may have their seeds
burned up in a severe fire. These species will need to reinvade from
living trees within the burn or at the edge; a process that can take
decades depending on local conditions.
There are a number of studies that have evaluated the geographic
changes in habitat suitability that might be expected for various tree
species based on various climate change scenarios. The Climate Change
Tree Atlas provides maps of potential changes in habitat suitability
for over 100 tree species in the eastern US. Models developed by Forest
Service researchers provide similar projections for key tree species in
the western US. Such information can be used by managers to help them
make decisions about appropriate strategies for regeneration following
severe disturbances, including wildfires.
Responses of Ann Bartuska and Susan Conard to Questions From
Senator Corker
Question 28. I understand that a number of models predict that the
Southeast is likely to experience the greatest increases in wildfires
in the continental United States. Will you please describe why this is
the case and describe what changes are predicted to occur and how they
will increase the risk of wildfires?
Answer. In general the eastern seaboard is projected to experience
less warming than the rest of the country, and is projected to
experience similar or higher precipitation than what we have today. The
exception is Florida, where models suggest that temperatures will warm
slightly and rainfall may decrease substantially. This pattern is
likely to lead to increased frequency of periods of high fire hazard.
We are not aware of published models that predict large increase in
wildfires in the rest of the Southeast.
Question 29. Do we need to reconsider forest management policies or
other mitigation activities?
Answer. We believe the Forest Service currently has forest
management policies and authorities that allow the agency to mitigate
and adapt to the impacts of climate change. For example, we currently
conduct thinning treatments in conifer forests to improve forest health
and make the forest more resistant to insect attacks.
Question 30. Are there currently obstacles to forest management
that could significantly reduce the damage caused by fires that will
only continue to compound the problem if temperatures continue?
Answer. The Healthy Forests Initiative, launched in 2002, has
helped to reduce the time it takes to administratively plan and
implement projects that reduce the impact of wildfire on the landscape.
The Forest Service received additional assistance in removing
administrative barriers through the Healthy Forest Restoration Act,
which improved the procedures and processes for planning and
implementing fuel reduction projects, especially near at-risk
communities. The Forest Service continues to work to streamline
planning processes and remove administrative barriers to accomplish
fuel reduction work as quickly and efficiently as possible.
Responses of Ann Bartuska and Susan Conard to Questions From
Senator Barrasso
Question 31/32. Doctors, your testimony mentions the importance of
forest treatments to reduce stress and crowding. Your research details
the opportunity for positive results presented to forest managers by
these methods. What is your agency's approach to implementing your
findings? What steps have been taken to put these findings into
practice to actively meet forest management needs?
Answer. The Forest Service research community provides peer-
reviewed science for application on the national forests and
grasslands, including extensive research on climate change effects on
those ecosystems. Among other applications, Forest Service research is
used to plan and visualize stand level vegetation treatments and
evaluate forest plan strategies for promoting healthy forests. The
computer models used for these purposes are being retooled to account
for the latest climate change research. The latest research information
is also disseminated through publications, conferences, and the ongoing
collaboration between national forests and the regionally based
research stations.
Question 33. When will we see results on the ground?
Answer. The Forest Service approach to vegetation management
already promotes the resilience of forest ecosystems in the face of
climate change. Under the National Fire Plan, the Forest Service has
accomplished 11.9 million acres of hazardous fuels and restoration
treatments from 2001 through 2006. This includes 6 million acres in the
wildland-urban interface and 2.1 million acres of restoration
treatments. Final numbers for FY07 are still being compiled, however,
an estimated 2.9 million acres of hazardous fuels and restoration work
was accomplished. The Forest Service will continue its work on fuel
reduction projects and insect treatments in FY 2008.
______
Responses of John A. Helms to Questions From Senator Salazar
Question 1. What types of adaptation management strategies have
been found to best deal with managing the expected increased threat of
wildfires?
Answer. Wildfires require a combination of fuel, temperature, and
oxygen. Of these, the only factor that can be managed is the presence
and distribution of fuels. Given that the most intense and catastrophic
fires occur in dense forests, and since experience has shown that when
wildfires encounter less dense and more open stands fire intensity
commonly drops (USDA PSW 2007), it seems clear that increased efforts
must be made to thin overly-dense stands. In doing so, irregular
mosaics of stand density should be created that remove ladder fuels to
reduce opportunities for fire to burn into tree crowns.
Since it is clearly impossible to rapidly treat all 180 million
acres the Forest Service estimates are in hazardous condition, current
efforts to create ``Defensible Fuel Profile Zones'' (DFPZs--Quincy
Library Group/USDA FS, California), ``shaded fuelbreaks'' (Agee et al.
2000) and ``Strategically Placed Landscape Area Treatments'' (SPLATS or
SPOTS in California's Sierra Nevada--USDA FS) are all worthwhile
exploring. These are areas 1/4-1/2 mile wide, usually along roads or
strategically placed in which fuel loadings are reduced to reduce
potential for crown fires, interrupt fire spread, and to provide
defensible space to fight the fires.
Although not free from criticism, these efforts are initial steps
in the right direction. More adaptive management and pilot studies
(such as the Fuels Management National Pilot Project 2007 funded by the
Forest Service) are needed to demonstrate efficacy and cost
effectiveness and to communicate lessons learned from these and other
projects and forest treatments (Wildland Fire Lessons Learned Center
2007).
Question 2. One of the most enduring ad campaigns in our country's
history are the Smokey the Bear public service announcements. There
probably isn't a person in the room who hasn't heard the slogan ``Only
you can prevent forest fires.'' Given that the majority of wildfires
are caused by human activity, are there plans to increase efforts to
reach the public on climate change and expected increased wildfire
activity, and ways to prevent wildfires?
Answer. There is considerable current effort aimed at providing the
public with information regarding wildfires, hazardous fuels, and the
need to provide defensible space around homes. Some of these are the
Fire Safe Council, Firewise, Rural Fire Assistance, and Landfire.
National programs are coordinated through the National Fire Plan. Fire-
prone states such as California have aggressive programs of public
information.
However, the fact that catastrophic wildfires are due to hazardous
fuel loadings and over-dense public forests and thus can be addressed
by forest management seems to be either little understood or rejected.
Increased effort in technology transfer and outreach is needed,
particularly at K-12 education levels where perceptions are formed, to
provide the public with science-based information regarding the need to
restore public forests to densities that do not support catastrophic,
stand-replacing fires or insect outbreaks. It is generally not
appreciated, for example, that current mature mixed conifer stands in
the Sierra Nevada of California are carrying over 1,000 trees per acre;
by comparison, natural forests in which low-intensity fires were common
carried only about 40 mature trees per acre.
Priorities to move forward are: 1) enhance collaboration among
federal and state agencies in partnership with industrial, tribal, and
non-industrial family forest owners, 2) streamline legal and regulatory
frameworks to encourage restoration of forest health and responsible
stewardship of the nation's forest lands, and 3) provide better
communication to the public and decision makers indicating that
restoring and maintaining forest health is key to mitigating likely
effects of climate change.
Question 3. The link between climate change and fire is clearly
strong, but since this linkage has come to light, some people suggest
that climate is more critical than fuel as a driver of fire behavior,
and there is no reason to treat fuels to protect communities or restore
ecosystems. What are the implications of climate change for fuel
treatment and forest restoration?
Answer. Wildfires are driven by both fuel and temperature and are
made particularly devastating when combined with low humidity and high
winds. Modeling shows that, in general, changing climate will likely
result in more wildfires. However, fires won't burn without fuel, and
fire intensity increases with fuel loading. A prudent steward of forest
lands would therefore reduce hazardous fuel loads and remove a portion
of trees that provide ladder fuels that enable flames to reach the
canopy.
The amount of fuels in a forest can reach 15-70 tons per acre
(Sampson 2004) and this fuel loading cannot be removed by prescribed
burning without incurring substantial risk. Therefore some preliminary
mechanical treatment is required. This could be cost-effective if the
smaller-dimension biomass could be used for cellulosic ethanol
production and the larger material converted into wood products that
store carbon. A major hurdle on public lands is to make this material
available through long-term contracts that provide a sufficiently
stable investment climate that will enable industry to construct the
necessary processing plants for both ethanol and wood products.
Question 4. Fires are becoming increasingly harder to fight and are
releasing huge quantities of carbon dioxide. Wildland Fire Use, the
practice of allowing some lightning-ignited fires to burn under less
extreme conditions, has been suggested as a way to mitigate fires and
ensure they release less carbon dioxide. Do you see a role for Wildland
Fire Use in changing future fire behavior so it is less extreme,
thereby releasing fewer greenhouse gases?
Answer. Yes, the Wildland Fire Use system in which lightning fires
are managed to achieve resource benefits is a worthwhile approach to
reintroducing natural fire into forest ecosystems. Wildfires are indeed
increasingly hard to fight and release 75-80 tons CO2 or
more per acre (Sampson 2004). Fires that can be several hundred
thousand acres in size are clearly emitting millions of tons of
CO2 and other greenhouse gases into the atmosphere. Once
forest stands are restored to more natural density levels, prescribed
fires can be used which emit about 18-20 tons CO2 per acre
(Sampson 2004).
Decisions to permit natural fires to burn are based on diverse
criteria that assess the risk to private property, ecological systems,
and societal values. The Wildland Fire Use approach is commendable,
however one must accept the likelihood that, initially at least, some
ecological and societal values will be damaged and air quality will be
affected. This points to the importance of providing the public with
quality information regarding the goals, risks, and benefits of the
program.
Question 5. It has been suggested that because young forests grow
fast and older forests grow slowly we can cut down old forests and
replace them with fast-growing plantations to maximize the uptake of
carbon dioxide and reduce global warming. What is the current
scientific understanding of the effects of logging older forests on the
uptake or release of greenhouse gases?
Answer. It is true that fast-growing, younger forests sequester
carbon at a higher rate than slower growing, older forests. When older
forests become mature or over-mature, the rate of carbon accumulation
may become zero or negative due to loss of vigor, tree mortality and
decay of organic matter. The total accumulation of carbon in older
forests is greater than in younger forests.
It is well documented, however, that young forests managed by
utilizing a series of harvests will, in time, sequester or store more
carbon than unmanaged forests left for several hundred years (Birdsey
and Lewis 2002, Krankina and Harmon 2006, IPCCa 2007). This is because,
over successive rotations or cutting cycles, managed forests maintain
high rates of CO2 uptake. The superiority of managed forests
in sequestering carbon is especially evident when the harvested wood is
used for both energy production and wood products that store carbon for
long periods. The situation is made even more compelling when renewable
wood products are used instead of alternative materials such as
concrete, steel, aluminum, and plastic that are non-renewable and have
been shown by life cycle analyses to consume far higher amounts of
energy in manufacture (Perez-Garcia et al. 2005). In this context it
should be mentioned that ``managed forests'' are not necessarily
single-species, uniformly-spaced ``plantations''. They could be if this
was desired, but they could also be managed to have multiple species,
several age classes, and understory vegetation such that are
indistinguishable from naturally-occurring forests.
The following figure* from the IPCCa 2007 report illustrates the
principle.
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* Figure has been retained in committee files.
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Forests and forest management have an important role in mitigating
climate change. As reported by the Intergovernmental Panel on Climate
Change (IPCC 2007b):
Forestry can make a very significant contribution to a low-
cost mitigation portfolio that provides synergies with
adaptation and sustainable development. However this
opportunity is being lost in the current institutional context
and lack of political will and has resulted in only a small
portion of this potential being realized at present (high
agreement, much evidence).
Responses of John A. Helms to Questions From Senator Domenici
You have testified that ``. . . in general, effects of climate
change are more likely to be seen in northern latitudes with loss of
meadows, conversion of forest to grassland, and tree invasion into
areas that were previously too cold. Forests are expected to move north
in latitude and upward in elevation. Pine forests at low elevation are
likely to be replaced by woodlands and grasslands.'' Dr. Swetnam
suggested that it might be too late to manage in high-elevation long
fire rotation stands and that it might be wiser to focus management in
the Ponderosa Pine forests of the Southwest.
Question 6. If the low elevation and southern Ponderosa Pine
forests are likely to migrate to higher elevations and to the north, as
suggested by Dr. Swetnam, do you believe it would be wise to ignore the
fires at higher elevations in the northern Intermountain States?
Answer. Decisions on when and how to deploy fire suppression
resources depend on professional analyses of potential fire behavior,
duration, cost, and risk to ecological, environmental, and societal
values, life, and property. This approach is appropriate when
considering fires within any ecosystem or biome. The mountain tops of
the Southwest are especially at risk to climate-induced vegetation
changes and replacement by species that are more adapted to hotter and
drier conditions. Thus these unique ecosystems may warrant special
attention to reduce the likelihood and severity of wildfires.
Question 7. What does the field of forestry tell us about the
ability of tree species to invade and reforest lands that have been
heavily impacted by fires, including the loss of soil and the changes
in moisture regimes after high intensity fires?
Answer. In general, rates of germination, establishment, and growth
of trees after wildfires are slower than those of shrubs and grasses--
in particular sprouting shrubs and hardwoods. It is therefore common
for pioneering shrubs and grasses to rapidly colonize and dominate
burned areas for many decades. This is less true for the ``fire-type''
conifers such as lodgepole pine that have serotinous cones evolved to
open from the heat of fires. Forestry research and experience shows
that vegetation growth after fires varies from brushfields to
successful tree regeneration depending on such factors as the
availability of seed. Surveys in California's Sierra Nevada have shown
that mature true fir forests having no shrubs in the understory can
have 2 million viable seeds of shrub species per acre that remain
dormant in the soil until heat from fires cracks their seed coats and
stimulates germination. In contrast, tree seeds do not commonly remain
viable in the soil after two years and seed crops have periodicity from
one to seven years.
After a wildfire, a prompt assessment is needed of post burn
conditions to determine the likelihood that desired vegetation of
diverse species will become established. The desired mix of vegetation
cover needs to be defined and the timeframe in which preferred
conditions of tree cover, habitat, and soil cover should be attained
needs to be identified. Experience has shown that those areas likely to
become brushfields or have high potential for erosion need to be
promptly planted to return them to forest conditions. Brushfields often
have conifer seedlings underneath them, but it can take 50-100 years
for the trees to overtop the brush and form a forest canopy. Burned
areas that may regenerate satisfactorily to the desired species mix
without treatment or are ecological reserves not needing treatment
should be identified in the post-burn assessment.
In all cases, the post-burn analysis should identify the costs,
benefits, and risks associated with action or no action. Decisions
should ensure that society is best served by using treatments where
necessary to rapidly restore the preburn mix of forest values,
habitats, uses, and watershed protection.
Question 8. Dr. Helms, you have also testified that `` . . . since
both growth and mortality on national forests greatly exceeds harvest
resulting in a build-up of fuels, it would be prudent to consider
treatments and incentives aimed at fuel reduction and using excess
biomass . . .'' In your estimation, what type of effort would it take
to mitigate the potential impacts of the change to our forests that you
and the other witnesses have suggested could happen? That is, how can
we prepare those forests for the changes that may occur?
Answer. Efforts are already being made by agencies within Interior
and Agriculture under existing programs and policies such as the
Healthy Forests Restoration Act of 2003 to reduce fuels that have built
up in over-dense federal forests. However, current efforts are small
relative to the magnitude of the problem. The main impediment to
progress is that segments of the public distrust and challenge analyses
and plans to thin forests. To prepare forests for climate changes,
emphasis must be placed on identifying ways and means by which high-
risk stands and forests can be thinned and fuel reduction carried out
to restore and maintain forest health and vigor in a societally-
acceptable manner.
The Forest Service estimates that 180 million acres of national
forests are in need of treatment and all this area cannot be readily
treated in a short timeframe. However, the spread of catastrophic
wildfires can be limited by shaded fuel breaks such as described in my
response to Question 1.
In 2006 a joint agency comprehensive fuels treatment strategy was
initiated aimed at reducing fuels buildup in forests in an efficient
and effective manner (USDA and USDI 2006). This mix of policy and
management approaches is an important step and warrants enhanced
support and further development.
Question 9. Do you recommend we start now, or do we have time to
fight and fuss over what environmental protections and analysis must be
completed before we begin to take action?
Answer. Because wildfires are increasingly devastating and costly
there is an urgent need to address forest condition problems and
societal impediments to mitigation. This task has already commenced and
excellent programs are beginning to reduce fuels on public lands (e.g.,
USDA and USDI 2006, National Fire Plan 2007). About 20 million acres
have already been treated under the Healthy Forest Restoration Act,
with special emphasis on the wildland/urban interface. But
accomplishments to date represent only a small fraction of the 180
million acres of national forests needing attention, thus losses to
catastrophic wildfire and costs of suppression are increasing. Overly-
dense national forests need to be thinned, which would not only reduce
hazards of wildfire but would also enhance wildlife habitat and water
yields.
National forests are owned by the people who necessarily must have
a say in how their forests are managed. In addition, treatments under
any policy or plan must conform with current laws and regulations. To
address controversy and opposition by some segments of the public to
thinning public forests, increased efforts are needed to provide
factual information through technology transfer such that children,
adults, and decision makers have adequate science-based information to
help shape opinion regarding the balance that needs to be struck
between competing uses and values of forests. This is especially
important in the context of climate change because the likely increases
in forest mortality and wildfires are undoubtedly going to negatively
impact the diverse benefits that forests provide society.
Moving forward will require policies and incentives aimed at
increasing collaboration among landowners and stakeholders such that
sustained thinning projects can be developed at the scale and duration
necessary to effectively address the wildfire problem.
Question 10. Dr. Helms, during questions by Senator Tester, you
suggested that timber management could help to maintain sufficient
crown cover to help hold the accumulated snow pack in place for longer
than in open areas. If trees sometimes have a more difficult time
regenerating after high intensity fires and water retention and run off
are negatively impacted in the absence of tree cover; and we do
experience higher temperatures, are we more likely to see brush fields,
or stands of new trees as species have to migrate up in elevation and
to the north through these heavily burned lands?
Answer. Maintaining and enhancing the nation's water supply for
residential, agricultural, and environmental needs is a critical
priority. The nation's future supply of water is in jeopardy in the
context of changed climate and precipitation patterns, particularly in
the Southwest. Most of the nation's water comes directly from forested
watersheds or indirectly through recharged ground water systems. It is
imperative, therefore, that forests be evaluated in terms of how their
structure and composition affect hydrological cycles and the extent to
which management can enhance the supply and quality of water and the
timing of distribution to streams.
Where precipitation is in the form of snow, forest cover is
critical in enhancing water yields by providing shade over snow,
delaying snow melt, and preventing erosion. These effects are enhanced
where the forest has a discontinuous canopy cover, a condition that may
have to be maintained by thinning.
Given likely higher temperatures, uncertain precipitation patterns,
and possible species change, it would be prudent to examine whether
thinning treatments can maintain forest health, delay transition to
better-adapted vegetation such as shrubs, and thus help ensure adequate
water yields for environmental and societal needs.
The potential of forests to revert to brushfields, either following
wildfire or as the result of climate change, is important because once
an area is dominated by brush it often takes many decades before trees
can break through and the area returns to forest. As brushfields
commonly reburn, the area can remain dominated by brush indefinitely.
The importance of considering ecological succession and forest/brush
dynamics in any management strategy is mentioned in my response to
Question 7.
Response of John A. Helms to Question From Senator Barrasso
Question 11. I notice that your testimony includes an emphasis on
our ``responsibility to mitigate through forest management.'' Could you
elaborate on that point, specifically fuels treatment?
Answer. Healthy forests and their associated wildlife habitats and
watersheds are priceless assets providing the nation with critical
values and uses. The sustainable management and conservation of forests
is crucial to societal welfare. When forests are allowed to become
overly dense the trees lose vigor and become susceptible to insects,
disease, mortality, and fire. This is exacerbated under conditions of
overall rise in temperature, drought, and storms. It is therefore in
society's best interest that, apart from ecological reserves,
wilderness or similar areas, forests be sustainably managed to maintain
forest health and provide the balance and diversity of values and uses
that society needs.
The argument that forests, especially national forests, should be
left unmanaged and that ``nature knows best'' is understandably
appealing. However it does not recognize that the condition of our
national forests is far from ``natural''. People are an integral and
often dominant part of ecosystems and rapidly increasing human
populations have drastically changed forest structure and composition
through harvesting, development, infrastructure, and wildfire
suppression policies. Forests could be allowed to ``develop
naturally'', but nature's way of reducing stand density is through tree
mortality through competition, suppression, insect/disease attacks, and
wildfire. Natural forests start as tens to hundreds of thousands of
seedlings per acre and at maturity may only have fifty dominants. The
natural process of forest succession is therefore characterized by
natural agents continually causing tree mortality. However, in today's
context, these forest successional processes represent loss of critical
forest values, risk to life and property, and are most certainly
societally unacceptable. The difficulty is that human timeframes of
what is important and acceptable are far shorter than nature's long-
term cycles of ecological succession. Actually, our only realistic
option is to manage our forests to reduce risks and to sustain the
values and uses upon which we are dependent.
The challenge is how to accomplish this in a socially acceptable
and economically feasible way. Societal acceptance can probably only be
achieved through a combination of Congressional leadership and science-
based information outreach. In particular, decision-making processes
are needed that emphasize stakeholder common interests in restoring
healthy forests to reduce wildfires, mitigating the effects of climate
change, and striking a balance among competing values and viewpoints.
The overall policy goal should be to restore and sustainably manage the
nation's forests for the welfare of society at large. Since fuels
treatments and thinning are costly, it is critical to explore ways and
means by which these costs can be offset by utilizing the biomass in
the form of energy or renewable wood products. The desirability of this
option becomes apparent when one appreciates that using wood can reduce
carbon emissions where it is used in place of alternative materials
that life cycle analyses show have higher energy requirements in
manufacture.
I used the word ``responsible'' in my testimony in the context that
failure to restore forest health and reduce impacts of wildfire and
insects on wood supply, wildlife habitat, and water supply is to
abdicate current society's responsibilities to present and future
generations.
Response of John A. Helms to Question From Senator Corker
Question 12. Do we need to reconsider forest management policies or
other mitigation activities? Are there currently obstacles to forest
management that could significantly reduce the damage caused by fires
that will only continue to compound the problem if temperatures
continue to rise?
Answer. Forests are a critical national resource. They are owned by
state and federal agencies, industries, tribal groups, and non-
industrial family owners having diverse goals and objectives. Issues of
climate change transcend property boundaries. It is important,
therefore, to examine current laws and regulations to determine
opportunities for coordinated policies and cooperative management at
the landscape level. Flexible policies, regulations, and incentives are
needed to readily accommodate mitigation opportunities that are time-
sensitive and likely to be ownership-, location- and forest-specific.
The major obstacle to forest management on national forest lands is
the strong perception by some that no trees should be cut to provide
wood products needed by society. It seems imperative that society
understand and support the need to reduce the density of trees on
national forests that are so susceptible to mortality, fuel build-up,
wildfires, and insect attack. This situation will be exacerbated as
temperatures rise, storms increase in frequency, and changed
precipitation patterns lead to droughts. Society must recognize that
the enormous funding needed to address the problem and to thin the
national forests is simply not available and that it is in society's
best interests to carry out the needed thinning treatments through the
sale of biomass for energy and for wood products that store carbon. It
is important that the public and decision makers consider whether it is
environmentally, ethically, or strategically appropriate that the US,
although having the capacity to be self-sufficient in wood, imports 36
percent of wood consumed and that California, for example, imports 80
percent of its wood needs from other states or countries.
______
Responses of Thomas Swetnam to Questions From Senator Bingaman
Question 1. A number of the witnesses mentioned that logging and
grazing have contributed to the accumulation of fuels that are
contributing to these fires. Can you briefly explain the process by
which logging and grazing results in the accumulation of fuels?
Answer. Intensive livestock grazing was an important cause of
reduction in surface fire occurrence in many Western forests. This
effect occurred primarily during the late 1800s and early decades of
the 1900s. Very large herds of sheep, goats, cattle and horses removed
the grass cover in under stories of ponderosa pine and mixed conifer
forests. In 1890, for example, there were more than 5 million sheep and
1.5 million cattle in New Mexico! Prior to this intensive livestock
grazing era, more-or-less continuous grass cover promoted fire
ignitions by lightning and people, and extensive spread of these fires.
Grazing and the creation of livestock trails and ``driveways''
effectively disrupted the fire ignition and spread process. The sheep
industry declined after the First World War, and after 1910 the U.S.
Forest Service also began to fight forest fires aggressively, and to
reduce overgrazing on federal forest lands. During the subsequent
century, lack of frequent surface fires in ponderosa pine and mixed
conifer forests allowed many trees to establish and dead fuels (tree
needles, branches, logs, and snags) to accumulate. This general history
did not occur everywhere in the West, but it was fairly typical in the
Southwest and in many pine-dominant and mixed conifer forests of the
Sierra Nevada, and inter-mountain regions (Swetnam and Baisan 2003).
This effect of livestock grazing, fire suppression, and subsequent fuel
accumulation was generally not important in relatively higher
elevation, wetter forests, such as spruce-fir and lodgepole pine
forests. Grass cover was much less extensive in these forest types, and
typically large fires only occurred at long intervals (>100 years), so
fire suppression has had less or no effect here in lengthening the
intervals between fires (Schoennagel et al. 2004).
Logging (tree harvesting) has a highly variable effect on fire
activity. Again, the effects depend on forest type, region, and the
kind of management practices employed. It is generally thought that
extensive, unregulated logging practices in the late 19th century and
early 20th century were a contributing factor to the enormous and
destructive wildfires that occurred during this part of the settlement
era in the Lake States and West. Some of these massive, historic
conflagrations were noted by Senator Domenici in his statement at the
beginning of the hearing (for example the Peshtigo Fire of 1871). The
unregulated 19th century harvesting, and some modern harvesting in the
20th century, produced massive quantities of surface fuels, deriving
from untreated residual branches, tree leaves/needles and boles. These
fuels contribute to fire ignition, spread, and unusual fire severity.
Although this type of logging--where residual fuels are generated and
untreated--has contributed to increased fire extent and severity in
some places and times, logging (and thinning) practices can lead to
reduced fire hazards when the residual fuels are treated, e.g., by
hauling them away or burning in situ in piles or by broadcast burning.
There is a building body of scientific evidence supporting the general
strategy of forest thinning and prescribed fire as a means of reducing
wildfire severity and damaging effects in some western forests (e.g.,
Schoennagle et al. 2004, Finney et al. 2005, Cram et al. 2006, Omi et
al. 2007). The recent Omi et al. study, in particular emphasized the
importance of treating surface fuels, and not just reducing overstory
tree densities. Again, I would emphasize that such fuels treatments
(e.g., thinning) are ecologically appropriate in forests that formerly
sustained frequent surface fires, had relatively low tree densities and
low accumulated surface fuels, but now have much higher tree densities
and accumulated dead fuels. From an ecological perspective, however,
such treatments are not justified in wetter, higher elevations forests
where frequent surface fires were not a natural occurrence (Schoennagle
et al. 2004).
Another effect of logging on fire activity is related to the
extensive road building associated with logging. Vast networks of roads
built to accommodate logging have allowed many more people to travel
into remote areas, and it is likely that this greater access has
allowed more human-set fires to occur in these places.
Question 2. You mentioned at the hearing that you believe that
thinning should generally focus on small-diameter trees. What is the
scientific rationale for focusing on small diameter trees?
Answer. To reduce fire hazards in forests that previously sustained
frequent surface fires (i.e., before intensive livestock grazing and
active fire suppression began) the primary emphasis should be on
thinning relatively smaller diameter (often younger) trees (Allen et
al. 2002). This emphasis is a rather obvious and logical strategy in
most of these forest types where past management practices have led to
extreme forest structure changes and hazardous fuel accumulations. For
example, many ponderosa pine and mixed conifer forests in the Southwest
and elsewhere in the West have extraordinarily dense ``thickets'' of
relatively small diameter trees. It has been shown in studies that the
vast majority of these small diameter (and often stunted) trees
established in these forests as a consequence of and following the
disruption of frequent fire regimes by land use practices (e.g.,
livestock grazing and active fire fighting) (e.g., Fule et al. 2002).
In some cases the stem densities of these stunted tree thickets exceed
5,000 stems per acre (Falk 2004). Moreover, it is clear from fire
behavior modeling and observational studies that these dense thickets
are an important contributing factor in generating unnaturally severe
crown fire behavior in some forests (Cram et al. 2006, Cruz et al.
2006, Allen 2007). It is also generally the case that larger diameter,
older trees, are relatively rare in most forest types as a consequence
of natural mortality patterns, and because of extensive harvesting of
large trees in the past century. Hence, there are ecological,
silvicultural, esthetic, and scientific reasons to focus primarily on
thinning smaller diameter trees, and to thin (or harvest) larger
diameter, older trees sparingly and judiciously (if at all) in these
forest types I am referring to.
In my view, it is an unnecessary and counter-productive point of
contention for federal agencies, timber industry interests, or forest
scientists to insist that specific diameter caps should never be
imposed in thinning treatments. It is quite clear that a focus on
thinning of the relatively small diameter stems will often and
substantially reduce the risk of unnaturally severe fires in these
forest types. Importantly, focus on the smaller diameter trees will
also reduce contention and challenge of such treatments by concerned
citizens and non-governmental organizations. Moreover, it is critical
that resulting fuels generated by such thinning be treated by removal
(by burning or hauling off site) (Omi et al. 2007). It is important to
note here that I use the phrase ``small diameter'' trees in a relative
sense, and specific to forests where natural surface fire regimes were
disrupted. The diameter range of trees in high density groups in
productive Sierra Nevada forests may be considerably larger than the
diameter range of thickets in lower productivity Southwestern forests.
I would also clarify that I am not opposed to traditional forestry
practices that involve either even aged or uneven-aged management or
rotation-based silvicultural designs in appropriate areas and
circumstances. I am trained as a forester myself, and my father was a
District Ranger with the U.S. Forest Service for 35 years. However, I
believe that in the context of reducing fire hazard in forests where
thickets of small diameter trees are a primary cause of increased
hazards (i.e., a substantial part of the problem in the West), a focus
on small diameter trees makes eminent sense.
Question 3. Your testimony mentions the possibility that global
warming could result in ``more-or-less permanent `dust bowl'-like
conditions in the Southwest.'' Are there any indications in the
historical or pre-historical records of what that might mean for
wildfire activity in New Mexico?
Answer. My reference to the potential for a transition to ``more-
or-less permanent `dust bowl'-like conditions in the Southwest'' was
based on the recent paper published in the journal Science by Seager et
al (2007). They hypothesized this potential under a scenario of
increasing greenhouse gases and continued global warming, and the
modeled and observed effects of ocean-atmosphere patterns on regional
climate. The most extreme droughts in the past century in New Mexico
were the ``turn of the century drought'' (1890s), the ``Dust Bowl
drought'' of the 1930s, the ``1950s drought'' (late 1940s to about
1957), and the current drought (since about 1998). The tree-ring record
of drought in the Southwest is very extensive, and perhaps the best
documented drought history of this type for anywhere in the world. Good
quality tree-ring-based drought reconstructions cover all of New Mexico
and the broader Southwest over the period from about AD 1500 to
present, and some locations have histories extending back nearly 2,000
years (Ni et al. 2002, Cook et al. 2004). These long-term histories
show that some pre-20th century droughts exceeded in magnitude and
duration any drought experienced during the 20th century. Notable
examples include the so-called ``megadroughts'' of the mid 1100s, and
the 1580s. Many of these droughts undoubtedly had profound impacts on
human populations and ecosystems. For example, a ``Great Drought'' at
the end of the 13th century AD was a contributing factor in the Anasazi
abandonment of the Colorado Plateau, and the migration of many of the
ancestors of modern New Mexico Pueblo peoples to the Rio Grande valley.
We have limited knowledge about the impacts of past megadroughts on
ecosystems and fire. However, it is likely that some past droughts led
to very large wildfires, bark beetle outbreaks, and direct drought-
induced mortality of trees and other plants--much as recent drought
effects. Moreover, extreme amplitude ``switching'' of wet years and dry
years during the late 1700s apparently led to many widespread fires in
the Southwest (Swetnam and Betancourt 1998). We think the 1580s
megadrought probably caused widespread burning and drought/bark beetle-
related tree dieoff. This interpretation is based on observations that
very few living or dead trees can be found in the Southwest that pre-
date this major event. Hence, it appears that a major forest and
woodland dieoff occurred, followed by extensive regeneration during a
wetter and cooler period in the early 1600s (Swetnam and Betancourt
1998).
During the 20th century, the 1950s drought stands out as the most
severe event. Notably, a number of very large forest fires erupted in
Southwestern forests during this period. Also, a very extensive bark
beetle outbreak and tree mortality occurred in parts of New Mexico
during the 1950s drought (Swetnam and Betancourt 1998, Breshears et al.
2005, Allen 2007). However, even though the 1950s drought was more
extreme in some areas of the Southwest than the recent drought, both
forest fires and bark beetle outbreaks were considerably smaller in
extent than during the recent drought. For example, the largest recent
fires (i.e., the Rodeo-Chediski in Arizona, 467,000 acres) were almost
an order of magnitude larger in size than the largest forest fires
during the 1950s in this region. The extraordinary size of both bark
beetle outbreaks and wildfires in the recent decade in the Western US
(including Alaska) and Canada is a chief reason that I and many of my
colleagues have concluded that recent warming temperatures and earlier
springs are likely a key factor in these patterns, and not just reduced
rainfall (Breshears et al. 2005, Westerling et al. 2006).
Responses of Thomas Swetnam to Questions From Senator Senator Salazar
Question 4. What types of adaptation management strategies have
been found to best deal with managing the expected increased threat of
wildfires?
Answer. Fuels treatments using mechanical thinning and prescribed
fires are appropriate and effective in some forest types, particularly
forests that formerly sustained frequent surface fires in the 19th
century and earlier. Climate change increases the urgency to get on
with these treatments at much larger scales than has been accomplished
so far. A general goal should be to increase the resiliency of these
forests to the coming climate ``shocks'', i.e., drought-induced
wildfires, insect outbreaks, and other disturbances. By ``resiliency''
I mean the ability of ecosystems to resist damaging effects and to
recover from disturbances. I would emphasize a need to act at broader
spatial scales, and especially to increase the use of fire as a
management tool and a key element of ecological restoration. We can not
hope to keep fire out of our forests. Fires will happen; the question
is: Will they be fires that we have planned for and managed, and are
ecologically beneficial, or will they be unplanned, uncontrolled and
destructive to ecosystems and human values?
One adaptive strategy I have advocated is utilizing recently burned
landscape ``mosaics'' as an opportunity to engage in landscape-scale
follow-up treatments. Most recent, large wildfires have resulted in
complex mosaic patterns of high, moderate, and low severity burned
areas (proportions of overstory trees killed), and unburned patches.
These large mosaics of burned/unburned areas provide an excellent
opportunity to engage in large-scale forest restoration/fire use
treatment programs. The high severity burned patches and fire lines
constructed during the suppression efforts offer safety zones and
control features for use of prescribed surface fires. Local communities
are energized in these areas and ready to move forward with proactive
restoration efforts at improving sustainability and resiliency of
forests surrounding their homes. A partnership of federal agencies,
community groups, and University scientists are currently engaged in
planning such an effort in southern Arizona, where I live and work.
Question 5. One of the most enduring ad campaigns in our country's
history are the Smokey the Bear public service announcements. There
probably isn't a person in the room who hasn't heard the slogan ``Only
you can prevent forest fires.'' Given that the majority of wildfires
are caused by human activity, are there plans to increase efforts to
reach the public on climate change and expected increased wildfire
activity, and ways to prevent wildfires?
Answer. I understand that the U.S. Forest Service is planning to
engage in a new effort to reach out to children to help them understand
climate change effects and the importance of forests and natural
resources. I am unaware of other specific plans by federal agencies to
focus on public communication/education on the wildfire and climate
change issue.
Although it is true that the majority of fires are ignited by
people nationally, in most mountain and forest regions of the West
there are more lightning ignited fires than human ignited fires.
Moreover, lightning ignited fires dominate the total area burned in
most forest landscapes of the West. In general, more than 95% of total
area burned is accounted for by fewer than 5 percent of the fires.
Hence, total area burned (or numbers of the very large fires) is a much
more relevant statistical factor to consider in terms of wildfire
trends, impacts and costs than total numbers of fires ignited.
Ignitions by people are important, particularly in some sub-regions,
and in some ecosystem types. But the effect of high numbers of human
set fires in some sub-regions does not outweigh the dominant role of
lightning, fuels and climate change at the scale of the entire Western
United States.
I do not mean to imply, however, that there isn't a strong need for
public education and fire prevention programs. Careless ignition of
fires by people can be extremely destructive, and is a part of the fire
problem. Smokey Bear's message is still needed. At the same time,
however, I believe we need to greatly increase the public's
understanding that not all fire is bad, and in fact, the use of fire as
a tool by knowledgeable managers (e.g., prescribed fire and wildland
fire use) is essential to maintain the functioning of some ecosystems.
Landscape-scale fire use will also be necessary to maintain fuels at
safe levels. This is one of the great challenges of land management, I
believe, in the coming century: How can we restore fire-dependent
ecosystems using fire as an ecological restoration and management tool,
while also protecting human property and lives? How can we use fire as
a management tool, while also managing smoke and carbon dynamics?
Question 6. The link between climate change and fire is clearly
strong, but since this linkage has come to light, some people suggest
that climate is more critical than fuel as a driver of fire behavior,
and there is no reason to treat fuels to protect communities or restore
ecosystems. What are the implications of climate change for fuel
treatment and forest restoration?
Answer. The implications are twofold. First, warming temperatures,
earlier springs, and increasing severity and duration of droughts--and
related wildfire responses--increases the urgency of forest restoration
and appropriate fire management. Forest and fuel changes because of
land uses are very important in some forests (and not in others).
Furthermore, invasive species and expanding human populations all point
to the necessity to better manage our forests to reduce fire hazards
where feasible and ecologically justifiable. Second, there are some
forest areas where forest and fuel changes are not outside the
historical range of variability, and human land uses have had
relatively little effect on the fire regimes or fire severity occurring
in these types. In these places fuels treatments (thinning or
prescribed surface fires) may or may not mitigate current or future
fire hazards, and there is little or no ecological justifications for
such treatments. In these cases, development and implementation of land
use policies (e.g., wildland fire use, land use zoning, fire fighting
and post-fire remediation policies) may be more appropriate local
responses than fuels treatments.
Question 7. Fires are becoming increasingly harder to fight and are
releasing huge quantities of carbon dioxide. Wildland Fire Use, the
practice of allowing some lightning-ignited fires to burn under less
extreme conditions, has been suggested as a way to mitigate fires and
ensure they release less carbon dioxide. Do you see a role for Wildland
Fire Use in changing future fire behavior so it is less extreme,
thereby releasing fewer greenhouse gases?
Answer. Smart, effective wildland fire use will be essential in
managing carbon dynamics in our forests in coming years. The issue is
not whether we will generate smoke and carbon inputs to the atmosphere
via fire, but how much, and to what extent can we manage such inputs? A
general hypothesis is that planned, frequent low severity fires (in
appropriate ecosystems) will result in less smoke and carbon input than
uncontrolled, high severity wildfires. I am not very familiar with
published literature on this topic, but my impression is that there is
limited information on the short and long-term effects of fire use
practices versus wildfires, particularly at the scales of landscapes
(i.e., multiple watersheds and mountain ranges). I think more research
is needed on this subject.
Question 8. It has been suggested that because young forests grow
fast and older forests grow slowly we can cut down old forests and
replace them with fast-growing plantations to maximize the uptake of
carbon dioxide and reduce global warming. What is the current
scientific understanding of the effects of logging older forests on the
uptake or release of greenhouse gases?
Answer. The specific role of older forests versus younger forests
in sequestering carbon is beyond my knowledge and expertise. I suspect
that there is some scientific literature on this topic, but I doubt
that there is a scientific basis for such a drastic step as removing
old forests for this purpose. In general, old growth forests are a
quite small proportion of the remaining forests in U.S., and so
harvesting them for the purpose of planting young trees would unlikely
be a significant benefit to carbon sequestration. The losses of the
special values of old growth forests would also be great (e.g.,
wildlife habitat, esthetic, and scientific values). On the other hand,
it may well be that expanding plantations in some previously harvested
lands, or perhaps converting grasslands or other ecosystem types (where
feasible) to forests for carbon sequestration may be a useful approach
in the future.
Responses of Thomas Swetnam to Questions From Senator Domenici
Dr. Swetnam you suggested that it might be too late to manage in
high-elevation long fire rotation stands and that it might be wiser to
focus management in the Ponderosa Pine forests of the Southwest.
Question 9. If the low elevation and southern Ponderosa Pine
forests are likely to have to migrate to higher elevations and to the
north, do you believe it would be wise to ignore the fires at higher
elevations in the northern Intermountain States?
Answer. During the hearing I stated that prioritization of
management treatments, such as forest thinning and prescribed burning,
should be focused in areas where forest structures and fuel levels have
changed the most as a consequence of past land use practices (e.g.,
livestock grazing and fire suppression). High severity fires are a much
larger problem--from an ecological and sustainability perspective--in
these forests (e.g., ponderosa pine dominated and drier mixed conifer
forests) than in some higher elevation, northern forests (e.g., spruce-
fir and lodgepole pine forests). Also, there are extensive areas of
ponderosa pine and mixed conifer outside of the Southwest that have
experienced disrupted surface fire regimes, increased forest densities
and fuel accumulations, and are in need of fuels treatments to reduce
risk of large unnaturally high severity fires. Current federal agency
approaches and tools for mapping, and assessing fire hazards and
treatment prioritization (e.g.., LANDFIRE and Fire Regime Condition
Class assessments) do in fact consider such historical and natural
aspects of fire and forest changes.
Perhaps climate change (e.g., warming) will eventually establish
more landscape areas in the higher elevations and northern Western
states suitable for ponderosa pine. If this happens on a large-scale
there will probably be many negative repercussions that will outweigh
concerns about whether or not ponderosa pine can migrate to or grow in
these places. For example, what will we do if the vast forests of
spruce-fir, lodgepole pine, western hemlock, Douglas-fir etc. in the
northern, Western states convert en masse to other ecosystem types as a
consequence of extraordinarily large fires, forest insect outbreaks,
and direct drought-induced mortality? Extreme watershed impacts, such
as reduced water quality and rapid sedimentation of municipal
reservoirs will likely occur in this scenario, as well as loss of
critical wildlife habitat, and loss of human lives and built structures
in the wildland urban-interface.
Given this worrisome potential scenario, I do not at all believe we
should ``ignore'' the changes occurring in high elevations, or northern
forests. The key question is what can we do about these changes, if
anything? It is possible that some kind of forest management might
mitigate future changes in these forests. However, broad-scale forest
thinning or the use of prescribed surface fires within these forests
(i.e., long-interval fire regime types), has much less (or no)
ecological basis or justification. Open, low-density forests and
frequent surface fires were generally not a historical, ecological
condition of most of these forests in the past; they are not
evolutionarily adapted to this type of fire regime or forest condition.
It is not at all clear that thinning treatments or surface fire use
will help maintain or sustain these forests in the face of climate
changes. It is possible that high severity fires, which are occurring
more frequently in the recent decade, will begin to ``self limit'' the
extent of future high severity fires. By ``self-limit'', I mean that
formerly burned areas (n previous years and decades) may begin to limit
the spread and extent of future fires.
In the near-term, and at the much broader global-scale, I believe
the most important thing we can do to reduce future negative impacts in
our high elevation and northern forests is to proceed rapidly to
significantly reduce our greenhouse gas emissions.
Question 10. What does the field of forestry tell us about the
ability of tree species to invade and reforest lands that have been
heavily impacted by fires, including the loss of soil and the changes
in moisture regimes after high intensity fires?
Answer. There is a considerable scientific literature on post-fire
responses of vegetation and soils. I am not an expert in these areas,
or very familiar with all of the recent literature. However, I will
comment on the case of ponderosa pine in the Southwest, which I know
best. A recent published study of post-fire forest recovery in
Southwestern ponderosa pine landscapes (Savage and Mast 2005) found
that re-establishment of forests in high severity burned areas was
highly variable. In some cases trees did re-establish, and in other
areas, burned areas have not recovered to forest--even 50+ years after
the fire. Ponderosa pine produces large seed crops only erratically,
and the seeds are heavy and do not travel very far by wind. Hence,
large canopy holes created by severe fire may not recover for
centuries. Where seedlings do establish following severe fires, Savage
and Mast found that sometimes very dense stands regenerated. If these
dense stands are not subsequently thinning by surface fires or
mechanical treatments, they may create conditions that will generate
additional high severity fires in the future.
Regarding soil effects, it has been observed that soil loss and
erosion is sometimes extreme following high severity crown fires in the
Southwest. For example, a recent crown fire in the Chiricahua Mountain
of Southern Arizona resulted in a 30 foot deep, 60 foot wide gully at
about 9000 feet elevation in this mountain (personal observation).
Sheet erosion of soils, flooding and debris flows have occurred widely
in Southwestern mountain ranges following recent fires (Allen 2007). In
some cases, thin ancient soils in some burned areas in Southwestern
Mountain ranges have been completely eroded away, and it is unlikely
that soils or trees will re-establish on these sites for centuries, and
possibly millennia.
Question 11. If trees sometimes have a more difficult time
regenerating after high intensity fires and water retention and run off
are negatively impacted in the absence of tree cover; and we do
experience higher temperatures, are we more likely to see brush fields,
or stands of new trees as species have to migrate up in elevation and
to the north through these heavily burned lands?
Answer. We are already seeing some ecosystem-type conversions as a
consequence of high severity fire and erosion in some Southwestern
forests, as I described in response to the previous question. An
example that Senator Domenici is familiar with is the Bandelier-Los
Alamos area in the Jemez Mountains of northern New Mexico. A series of
high severity crown fires in this landscape (including the 1977 La Mesa
Fire and the 2000 Cerro Grande Fire) has resulted in conversion of
ponderosa pine and mixed conifer landscapes to grasslands and shrub
fields over significant areas (Allen 2007). At this point, it seems
that grasslands and shrub fields are likely to be the most common
ecosystem type replacing forests in the Southwest, and perhaps
elsewhere in the West.
Question 12. Dr. Swetnam, much of your testimony was focused on the
Pacific Southwest and Southwest, yet many of the climate change models
suggest that in the short and middle term the tree species composition
in the upper Great Lakes and the Southeast are likely to see the
largest changes, while the Western U.S. could even see an expansion of
forests due to wetter winters. If one assumes that increased global
temperatures will result in drier climates in these areas and that
these areas may also experience increased fire activity, what steps can
the land managers in these states take to mitigate the changes, or to
prepare for the changes?
Answer. It is only relatively recently that down-scaled, regional
climate models have become sufficiently accurate to assess with some
confidence what may occur climatically in regions of U.S. under
different scenarios of increasing greenhouse gases in the atmosphere. I
am not familiar with results of forecasts in most U.S. regions, but
information on the Southwestern U.S. (e.g., Seager et al. 2007,
Hoerling 2007) are not encouraging. Precipitation forecasts are still
much less consistent and reliable that temperature estimates. However,
even in models showing some increases in winter precipitation, warming
temperatures and consequent increased evaporation and
evapotranspiration are likely to override rainfall increases, resulting
in a net decrease in soil moisture and river flows (Hoerling 2007).
Regarding what to do to mitigate and prepare for these changes, I
would refer to my answer to a similar question (#6) by Senator Salazar.
In summary, I think climate changes (warming and increased droughts, in
particular), increase the urgency of forest restoration and fuels
treatments, but these should be focused in landscapes where forests
have changed the most and have become more conducive to crown fires
because of past management actions, and where large, high severity
fires are generally outside the historical range of variability. It
also makes sense to focus fuels treatments at the wildland-urban-
interface, but not exclusively.
Question 13. Dr. Swetnam, in the most aggressive models of
increased temperature and moisture changes can you describe where
forests might exist in Arizona and New Mexico, as well as what the
species composition might be at various altitudes say 50 years from
now? And in 100 years?
Answer. This is a critically important question, not only for
Arizona and New Mexico, but also for the rest of the U.S., and the
globe, i.e., what forest and ecosystem changes will occur due to
warming and drought trends, when and where? I frankly do not think
anyone has reliable answers to these questions yet. As I pointed out in
the previous question (#12) there are improved regional climate change
model results that are useful in addressing this question. There are
also dynamic vegetation models that are beginning to address these
questions (e.g., Bachelet et al. 2001). Some of the vegetation models
do contain wildfire-climate sub-models, and some include insect
outbreak dynamics. However, I don't think the important combined
effects of fires and insect outbreaks have been addressed, and I know
of no such results for Arizona and New Mexico in particular. I do think
this is an important topical area needing much further research.
Response of Thomas Swetnam to Question From Senator Corker
Question 14. Do we need to reconsider forest management policies or
other mitigation activities? Are there currently obstacles to forest
management that could significantly reduce the damage caused by fires
that will only continue to compound the problem if temperatures
continue to rise?
Answer. As I have articulated in response to previous questions by
Senator Salazar (#4, 6, 7) and Senator Domenici (#9, 12), I believe we
need to increase our forest restoration and fuels treatments
substantially in forest types that have undergone major changes in tree
density and fuel loads because of past management activities. We
especially need to re-introduce surface fires as an ecological process
in many of these forests. This will require planning and implementation
at landscape-scales (i.e., watersheds to mountain ranges), and it will
especially require collaboration with local communities. As I describe
in response to Senator Salazar's question (#4), I think utilization of
recently burned landscape ``mosaics'' is an outstanding opportunity to
carryout much larger treatments, especially using prescribed fire.
Moreover, there is urgency in quickly moving to landscape-scale
treatments in these areas because it has been demonstrated in recent
studies (Finney et al. 2005, Omi et al. 2007) that there is a fairly
short window of time (10 years or less) that these treatments can
effectively mitigate the effects of future wildfires.
There are many obstacles to carrying out ecological restoration and
mitigating/adapting to climate change and future wildfires using
thinning and prescribed fire treatments. A few examples include smoke
emissions, risk of escaped prescribed fires, liabilities in the use of
fire as a management tool, public/agency conflicts over goals and means
of carrying out restoration programs, etc. Dealing with all of these
obstacles is daunting, but doable, I think, so long as collaborative
approaches involving all concerned are a central part of the process.
I would mention one obstacle in particular at this point: The
professional capacity for fire management must be increased
substantially within the federal agencies if we are to meet the
challenge of creating more resilient and sustainable ecosystems in the
face of coming climate changes. By this I mean that we need a much
larger corps of well-trained, experienced, year-round fuels and fire
managers. The task of fire fighting must not continue to overwhelm the
ability to manage fuels and forests. An investment in much greater
personnel capacity and expertise to plan and implement thinning and
prescribed burning in the context of building ecological resiliency is
essential to move beyond the current reactive mode of management in
response to increasingly severe wildfire seasons (see the recent GAO
report, 2007).
Appendix II
Additional Material Submitted for the Record
----------
Statement of the National Association of Conservation Districts
On behalf of the nation's 3,000 conservation districts, the
National Association of Conservation Districts (NACD) is pleased to
provide comments to the Committee on climate change and wildfires.
Established under state law, conservation districts are local units of
government charged with carrying out programs for the protection and
management of natural resources at the local level.
In carrying out their mission, districts work closely with the
USDA's Forest Service and Natural Resources Conservation Service and
the Interior Department's Bureau of Land Management to provide the
technical and other help private landowners need to plan and apply
complex conservation treatments on forest, range and other working
lands.
Conservation Districts play an important role in the areas of
hazardous fuels reduction, woody biomass utilization and forest
planning.
Though changing climate may have an effect many agree that because
of past management practices and fire suppression, many of our forests
administered by Federal agencies have accumulated fuel loads and
developed stand structures susceptible to catastrophic fires that
destroy the stands and increase the risk of insect and disease attack.
Silvicultural practices such as prescribed fire, density control and
harvest of commercial forest products can reduce the frequency and
intensity of extreme fire events, while benefiting local, regional, and
national economies.
Conservation districts across the country are actively involved in
implementing the National Fire Plan that was developed in 2000.
Conservation Districts:
Serve as a catalyst to assemble major stakeholders to work
together to solve wildfire and any other environmental problems
on a community or watershed level.
Provide education and information about critical local
natural resource issues.
Play a direct role in implementing wildfire protection plans
such as hazardous fuel reduction and prevent a catastrophic
fire or in restoration plans to stabilize a site after a
wildfire has occurred.
Conservation districts applaud Congress for passing the Healthy
Forests Restoration Act (HFRA) in 2003. The funding for HFRA and
implementation through the National Fire Plan provide opportunities for
local communities and organizations, including conservation districts,
to become engaged in community wildfire protection projects, fuels
reduction projects, and state and local Firewise education efforts.
Continued commitment from Congress and the administration to this end
is crucial to if we are to make our forests more healthy and our
communities safer places to live and work.
Conservation districts and resource conservation and development
councils (RC&Ds) already have in place a number of cooperative
agreements with federal land management agencies to promote, and
improve the utilization of woody biomass in order to reduce the build-
up of hazardous fuels, lessen the threat of catastrophic wildland fires
and restore forest, woodland, and rangeland health.
Conservation districts' efforts offer tremendous opportunities to
reduce catastrophic wildland fires and restore forest, woodland, and
rangeland health. In recognition of these opportunities, NACD entered
into a cooperative agreement with the Bureau of Land Management and
Forest Service to develop, promote, and improve woody biomass
utilization.
Other partners in this effort include the Interior Department's
Bureau of Indian Affairs, National Park Service, Fish and Wildlife
Service, the National Association of Resource Conservation &
Development Councils, and State Forestry Agencies.
Under this agreement, NACD is providing resource materials and
information to local conservation districts to educate landowners and
others on the issue. The goal of this initiative is to help increase
public understanding of the social, economic, environmental and
aesthetic benefits gained by using woody biomass as a means of reducing
the buildup of hazardous fuels.
We believe more cooperative efforts such as this are needed.
Involving local communities and landowners is the ideal way to ensure
the success of the Healthy Forests Restoration Act, the National Fire
Plan and other efforts in wildland fire management.
Conservation districts also support other collaborative efforts of
the Interior and Agriculture Departments in conducting fuel reduction
treatments in the urban wildland interface on federal lands that are at
risk from wildfire. To maximize their effectiveness, we believe these
collaborative hazardous fuel reduction efforts should include:
A landscape scale approach with the support and involvement
of local constituents;
Cross boundary mitigation;
Coordination of Federal, state and local government
priorities, project design and implementation strategies to
maximize effectiveness and minimize costs; and
Project designs that consider restoration of ecosystem
structure, native composition and natural fire regimes.
The drought, which is expected to continue unabated for several
more years--especially in the West--adds to the wildland fire issue by
contributing to insect and disease problems on our Nation's National
Forests, BLM lands and private woodlands, as well. Not only is the
damage costly to timber, but it also adds to the fuel load and
endangers lives, homes, and entire communities as we have recently seen
in South Lake Tahoe.
The nation's conservation districts believe that there are many
more opportunities to develop the potential to use woody biomass and
turn hazardous fuels into useful and valuable products such as
renewable energy. We look forward to continuing our partnerships with
the various federal agencies that are responsible for managing the
nation's public forests and rangelands.
NACD encourages support for policies and programs that prevent the
buildup of hazardous fuels and rehabilitate those lands damaged by
wildfire. Such efforts should be coordinated with biomass utilization
projects and include criteria for enhancing watershed health. We look
forward to continuing to work with the Committee on these issues and
working at the state and local level to explore opportunities to
partner with federal, state and local emergency response agencies to
address natural resources recovery.
______
Statement of Laura McCarthy, Interim Co-Director, Global Fire
Initiative, The Nature Conservancy
The Nature Conservancy is providing written testimony to add to the
record of the Energy and Natural Resources full committee held
September 24, 2007. This written testimony summarizes work by The
Nature Conservancy's Global Fire Initiative and Global Climate Change
Initiative to understand the impacts of climate change on fire
management at a global scale and to work with public land managers in
the Western U.S. to adapt to changing climate and fire regimes in
specific landscapes.
The Nature Conservancy is an international, nonprofit organization
dedicated to the conservation of biological diversity. Our mission is
to preserve the plants, animals and natural communities that represent
the diversity of life on Earth by protecting the lands and waters they
need to survive. Our on-the-ground conservation work is carried out in
all 50 states and in more than 30 foreign countries and is supported by
approximately one million individual members. The Nature Conservancy
has protected more than 117 million acres of land and 5,000 miles of
river around the world. Our work also includes more than 100 marine
conservation projects in 21 countries and 22 U.S. states.
The Conservancy owns and manages approximately 1,400 preserves
throughout the United States--the largest private system of nature
sanctuaries in the world. We recognize, however, that our mission
cannot be achieved by core protected areas alone. Therefore, our
projects increasingly seek to accommodate compatible human uses, and
especially in the developing world, to address sustained human well-
being in a changing world.
Climate change and altered fire regimes pose serious long-term
threats to healthy ecosystems that support people, plants, and animals.
Prompt action is needed to address these threats to minimize future
harm to nature and to the social and economic fabric of our society.
The effects of a changed climate, including increases in global average
air and ocean temperatures, increased precipitation in some areas and
more frequent and severe droughts in others, an increase in the
occurrence of intense weather events and a change in wildfire patterns
and intensity, are already evident. This testimony will focus on
adaptation strategies, in order to avert the most extreme effects.
impacts of climate change on fire management and forest health
Fire is a key process in many ecosystems around the world\1\ and in
the majority of U.S. ecosystems.\2\ The Nature Conservancy's recent
global fire assessment found that over half of global lands have
degraded fire regimes from urban development, livestock ranching,
agriculture and mining.\3\ The alternation of these natural fire
regimes through excessive wildfire suppression or, at the other
extreme, catastrophic wildfire, can impair ecosystem function, emit
greenhouse gases above natural levels, open pathways for invasive
species, and place biodiversity conservation and human life and
property at risk.
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\1\ Agee, J.K. 1993. Fire Ecology of Pacific Northwest Forests.
Island Press. Wash., D.C.; Hardesty, J., R.L. Myers and W. Fulks.2005.
Fire, ecosystems, and people: a preliminary assessment of fire as a
global conservation issue. The George Wright Forum 22:78-87; Myers,
R.L.2006. Living with fire: sustaining ecosystems and livelihoods
through Integrated Fire Management. The Nature Conservancy.
Tallahassee, FL; Pyne, S.J., P.L. Andrews and R.D. Laven, 1996.
Introduction to Wildland Fire. 2nd edition. John Wiley and Sons, New
York, NY.
\2\ Shlisky, A.,J. Waugh, P. Gonzalez, M. Gonazlez, M. Manta, H.
Santos. E. Alvarado, A. Ainuddin Nuruddin, D.A. Rodriguez-Rejo, R.
Swaty, D.Schmidt, M.Kaufmann, R.Myers, A.Alencar,F.Kearns,D.Johnson,
J.Smith, D.Zollner and W.Fulks.2007.Fire, Ecosystems and People:
Threats and Strategies for Global Biodiversity Conservation. GFI
Technical Report 2007-2.The Nature Conservancy. Arlington, VA.
\3\ Shlisky,A.,J. Waugh,P. Gonzalez, M. Gonazlez, M. Manta,
H.Santos. E. Alvardo, A. Ainuddin Nuruddin, D.A.Rodriguez-Trejo,
R.Swaty, D.Schmidt, M.Kaufmann, R.Myers, A.Alencar, F.Kearns,
D.Johnson,J .Smith, D.Zollner and W.Fulks. 2007. Fire, Ecosystems and
People: Threats and Strategies for Global Biodiversity Conservation.
GFI Technical Report 2007-2. The Nature Conservancy. Arlington, VA.
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Climate change is also altering key factors that control wildfire:
temperature, precipitation, humidity, wind, biomass, vegetation species
composition and structure, and soil moisture. Human activities have
increased atmospheric concentrations of carbon dioxide and other
greenhouse gases, causing global mean temperature to increase
0.7[degree] C in the 20th Century.\4\
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\4\ Intergovernmental Panel on Climate Change (IPCC). 2007. Climate
Change 2007: The Physical Science Basis. Cambridge University Press.
Cambridge, U.K.
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Projections of future climate predict that natural fire frequencies
will increase around the world,\5\ although fire may decrease in areas
of higher precipitation. Warmer temperatures, decreased precipitation
over land, increased convective activity, increased fuels from dying
vegetation, and large-scale vegetation shifts may increase fire
globally.
---------------------------------------------------------------------------
\5\ Intergovernmental Panel on Climate Change (IPCC). 2007. Climate
Change 2007: The Physical Science Basis. Cambridge University Press.
Cambridge, U.K.
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Wildfires may create a positive feedback for global warming through
significant emissions of greenhouse gases. Wildfires currently
contribute approximately 7% of global greenhouse emissions.\6\ Global
fire data indicate that carbon emissions from fire increased
significantly in the last century--from 1.5-2.7 billion tons C
y-1 in 1900 to 2.7-3.3 billion tons y-1 in 2000--
mainly as a result of tropical deforestation.\7\
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\6\ Intergovernmental Panel on Climate Change (IPCC). 2007. Climate
Change 2007: The Physical Science Basis. Cambridge University Press.
Cambridge, U.K.
\7\ Mouillet, F.,A. Narasimha, Y.Balkanski, J.F. Lamarque, and C.B.
Field. 2006. Global carbon emissions from biomass burning in the 20th
century. Geophysical Research Letters 33:L01801.doi10.1029/
2005GL024704.
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In mid-altitude conifer forests of the western U.S., an increase in
spring and summer temperatures of 1C since 1970, earlier snowmelt, and
longer summers increased fire frequency 400% and burned area levels
650% from 1970 to 2003.\8\ Low levels of human activity in those
forests, however, suggest that climate change may cause different
impacts where there are high levels of human intervention.
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\8\ Westerling.A., H.G. Hidalgo, D.R. Cayan, and T.W. Swetnam.
2006. Warming and earlier spring increase western U.S. forest fire
activity. Science 313: 940-943.
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Across much of North America, fire suppression during the 20th
Century depressed fire frequencies below natural levels. In these
areas, prescribed burning and wildland fire use could return ecosystems
to an ecologically-appropriate fire regime, particularly if favored by
future climate. Although prescribed burning may release greenhouse
gases in the short-term, re-growth in biomass results in no net loss of
carbon. Prescribed burning can also increase numbers of large-diameter
old-growth trees (and standing biomass per unit area), thus reducing
net greenhouse gas emissions in the long term.
land treatments to improve resilience in fire-dependent ecosystems
Questions to witnesses on September 24 revealed some of the
Committee members' interest in the role of mechanical fuels reduction
treatments to increase forest resilience to large-scale fires triggered
by climate change (specifically less snowpack and higher summer
temperatures). During the question and answer period, Dr. Thomas
Swetnam made a point that was captured by the press as, ``We can't thin
our way out of this.'' However, Dr. Swetnam's answer was actually much
longer, as he explained how thinning is a necessary part of a landscape
approach that addresses forest health at a scale of 100,000 acres or
more. Specifically, Dr. Swetnam suggested that entire landscapes may
not need to be mechanically thinned, but rather that such treatments
could be strategically placed in the landscape, and fuels on the rest
of the lands treated with prescribed burning and wildland fire use.
The Nature Conservancy is already applying this landscape approach
through a partnership program called the Fire Learning Network carried
out with the Department of the Interior and USDA Forest Service. The
Fire Learning Network consists of 76 multi-jurisdictional landscapes in
36 states, ranging in size from 1,200 to 12 million acres. The
landscapes are organized into regional networks that generally use
collaborative approaches to large scale ecological restoration, and the
four Western networks include several examples of the strategic
approach discussed by Dr. Swetnam.
The lessons learned from the Fire Learning Network experience with
collaborative landscape restoration indicate that land managers and
partners in some places are successfully developing strategies to
restore forest health in fire-dependent ecosystems impacted by climate
change. These land managers are developing landscape restoration plans
before they begin treatments. The landscape restoration plans are based
on a collaboratively developed vision of the desired future landscape
condition, expressed quantitatively with data derived from LANDFIRE and
related sources. The plans include an assessment of current ecological
conditions and the treatments necessary to move toward the desired
future condition. As a result, most implementation fits the description
offered by Dr. Swetnam--that is strategically placed mechanical
treatments and a program of prescribed burning and wildland fire use to
restore ecological conditions across a large landscape.
summary and recommendations
Two conclusions emerge from the above summary of climate change
impacts on fire management at a global scale that are important to
incorporate into forest and fire management policy:
1. Attempts to exclude fire from forests that are adapted to
low-intensity, frequent fire can result in a net increase in
carbon release because eventually, unnaturally severe, damaging
fires can occur as a result of a build-up of vegetation.
2. The ecologically appropriate use of prescribed burning and
wildland fire use in fire-dependent ecosystems does not
contribute to increased carbon emissions in the long run.
The Nature Conservancy recommends that the Senate Energy and
Natural Resources Committee steer the agencies to develop climate
change adaptation strategies through existing agency land and resource
management planning, research programs, and new initiatives that may be
launched to address climate change.
______
Statement of Thomas R. Armstrong, Senior Advisor, Global Change
Programs, Geological Survey, Department of the Interior
Mr. Chairman and Members of the Committee, thank you for the
opportunity to provide this statement for the record on climate change
and its impacts on wildfire activity in the United States. My name is
Thomas R. Armstrong, and I am the senior advisor for global change
programs at the U.S. Geological Survey (USGS). I also represent USGS
and the Department of the Interior (DOI) as a member of the U.S.
Climate Change Science Program (CCSP).
Climate change is perhaps the most complex and multi-faceted
challenge facing public land managers. Although climate change is a
natural, continuous Earth process, changes to the Earth's climate are
related to human activities as well. Whether the causes are natural or
from human influence, the USGS climate change focus is on understanding
its impacts and the potential adaptive strategies for managing natural
resources and ecosystems in the face of these changes.
Climate change affects biota, water, ecosystems, cultures, and
economies. To effectively manage its public lands and trust resources,
the DOI, working within the broader U.S. interagency climate change
science framework, must advance the scientific understanding of climate
change processes and impacts. The USGS, a DOI bureau, has a long and
distinguished history of conducting research, monitoring and modeling
of climate change and its physical and biological impacts. The USGS
conducts scientific research to understand the likely consequences of
climate change, especially by studying how climate has changed in the
past and using the past to forecast responses to shifting climate
conditions in the future; distinguishing between natural and human-
influenced changes; and recognizing ecological and physical responses
to changes in climate. For example, USGS scientists and colleagues have
created sophisticated models that relate wildland fire patterns to
decadal climatic variability (Swetnam and Betancourt 1998). USGS
researchers have also investigated plant, animal, soil, and water
responses to fire through field-based empirical investigations for more
than 40 years (Van Wagtendonk 1983, 1994; Keeley 2004). These
capabilities and strengths allow the USGS to play a critical role in
conducting climate change science across the Nation's terrestrial,
freshwater, and coastal systems and in providing objective science to
assist decision makers.
The DOI has taken bold steps to coordinate and focus its efforts in
climate change. Secretary Kempthorne has convened a Climate Change Task
Force to address the land management and stewardship challenges
presented by a changing climate. The task force includes three
subcommittees--one on legal and policy issues; a second on land and
water management issues; and a third, which I chair, dealing with
climate change scientific issues specifically related to the DOI's
responsibilities. This latter subcommittee is exploring development of
regional scale models to better forecast location-specific changes to
the landscapes we manage. In addition, it is evaluating information
needs to determine whether more extensive and integrated monitoring
might strengthen the understanding of on-the-ground trends in the
forces of climate and how they influence water availability, vegetative
patterns (including proliferation of invasive species and the health
and integrity of native plant communities), wildlife habitat, the
future viability of threatened and endangered species, and wildfires.
A changing climate may profoundly shape future impacts of wildfires
throughout the United States, North America, and the rest of the planet
(Westerling et al. 2006). A changing climate is expected to produce
major shifts in the timing and magnitude of local to regional
precipitation patterns, the types and distribution of vegetation,
including invasive species, and the types and volumes of fire fuel
loads-and thus fire frequency, severity, and intensity. For example, as
precipitation patterns in desert ecosystems change, opportunistic
species such as red brome and cheatgrass invade. USGS research shows
that these invasive species alter the natural ecosystems and fire
regimes, leading to hotter burning fires that further alter soils and
ecosystems (Whisenant 1990; Knapp 1996; Young and Evans 1978; Brooks
and Pyke 2001; Suring et al. 2005; Miller and Tausch 2001).
While DOI bureaus have management responsibility for both forest
and rangeland habitat, a large portion of that habitat is in rangeland.
Natural and human-caused disturbances have interacted over the past
several decades to change rangelands and pinyon-juniper ecosystems
across as much as one half of the Great Basin's one hundred million
acres (McIver et al. 2004). Protracted drought coupled with invasive
species, altered fire regimes, grazing, human settlement and
recreation, and energy exploration and development have yielded suites
of vegetation that often cannot support wildlife species. Increasing
annual temperature and decreasing precipitation regimes have
exacerbated these ecological changes, and climate change will continue
to interact with plant and animal dynamics on dry lands. As a result of
these rapid and widespread changes, the sagebrush biome is becoming
widely recognized as among North America's most ``at-risk ecosystems''
(Noss 1995).
Encroachment of native conifers such as juniper on the more mesic
or moisture-balanced lands of the sage biome has shifted fire regimes
from frequent, low-and mixed-severity fires to infrequent, high-
severity fires. Fuel loads have increased as much as six-fold (McIver
et al. 2004). Changes in the size and severity of wildfires and in the
type and patterns of precipitation, whether snow or rain, falling on
burned areas may have significant effects on the biological and
hydrological response of large areas of the landscape (Omi 2005). One
unknown is the impact of climate change on the distribution of State or
federal listed noxious weed species.
Expansion of some invasive species, particularly cheatgrass and red
brome which can serve as highly flammable fuels, have changed fire
return intervals on the more xeric or dry interior rangelands from more
than 50 years to less than 10 years (Miller and Tausch 2001). Another
recent study found that cheatgrass biomass increases are stimulated by
increasing carbon dioxide levels (Ziska et al. 2005). This study also
found that cheatgrass will become more coarse (e.g., lignin content
will increase) in the future, reducing the time that it is palatable to
livestock and wildlife and causing fuel loads to accumulate due to
reduced decomposition rates.
USGS research supports land-management agencies by working to
discover the site-specific conditions where management actions, such as
fire suppression and mechanical treatments, can restore rangeland
vegetation to habitat suitable for critical wildlife species such as
the sage grouse. Better decision making tools mean better management of
land resources, and they provide the support necessary to manage
wildland fuels and wildfires through more cost-effective means.
The USGS, in some cases in collaboration with universities or
management agencies and with the support of the Joint Fire Science
Program, conducts fire-related research to meet the varied needs of
resource managers and to understand the role of fire on the landscape.
This research includes fire management support, studies of post-fire
effects and habitat restoration, and a wide range of studies on fire
history and ecology. The ongoing mountain pine beetle epidemic, a
consequence of long-term drought, perhaps related to climate change,
has devastated forests throughout the West, thus creating a potential
for catastrophic wildfires that may affect the natural ecosystems,
homes and communities, including municipal water supplies, and local
economies. The USGS is involved in multi-agency efforts to identify the
bark beetle spread, tree mortality, and the potential for post-fire
debris flows and water-quality effects. These efforts include the
Colorado Front Range Fuels Treatment Partnership and the Northern
Colorado Bark Beetle Cooperative, partnerships that include not only
USGS but also the U.S. Forest Service, the National Park Service, the
Bureau of Land Management, the U.S. Fish and Wildlife Service, and
other State and local agencies.
To better understand the interaction between climate change and
fire, and provide the science needed by resource managers and decision
makers, the USGS is working to develop:
A better understanding of fire's ecological role over the
full range of biophysical settings and ecosystems. Basic fire
ecology identifies biological sensitivities and dependencies,
guiding management in prediction of post-fire consequences and
in engineering the proper application of fire for long-term
management. This understanding extends to physical processes
within burned watersheds that affect restoration, runoff,
erosion, sedimentation, debris-flow generation and water-
quality issues. Recent USGS research efforts include collection
and analysis of samples from the June 2007 Angora Fire on the
shores of Lake Tahoe to determine potential water-quality and
health effects of ash. Additionally, models developed by USGS
scientists can be used to predict the probability and quantity
of debris flows after wildfire.
Means for securing better and more timely empirical data on
fire effects and responses. This includes the development of
new methodologies, technologies such as remote sensing, or
approaches for quantifying and mapping active fires and post-
fire effects, as well as standardizing field sampling.
A better scientific understanding of the factors that
influence fire regimes and post-fire effects, such as climate,
precipitation, change in vegetation type and pattern, fuel, and
insect and pathogen invasions.
Methods to integrate the preceding topics to address
emergency response, treatments and prescriptions, priority
setting, fuel reduction, risk assessment, safety, public
information, and cost effectiveness.
Also, in partnership with the USDA Forest Service and the Nature
Conservancy, USGS continues to provide a pivotal role in developing the
LANDFIRE project--mapping and modeling of vegetation, fuel conditions,
and a suite of other data. These products benefit landowners and land
managers throughout the country.
In summary, wildfires are a serious and growing hazard over much of
the United States. They threaten life and property, particularly when
they move from forest or rangeland into developed areas. This situation
may be exacerbated by a changing climate. USGS fire-related research
that includes fire management support, studies of post-fire effects,
and studies of fire history and ecology are essential to understanding
and forecasting the impacts of climate change on forest and rangeland
ecosystems. An improved understanding and the ability to forecast
future impacts can serve as the scientific foundation upon which fire
management and land management decisions can be based.
Mr. Chairman, we appreciate your continued interest in this
challenging land management issue, and we thank you for the opportunity
to present this statement.