USDA Forest Service

Human Dimensions Program
Rocky Mountain Research Station

800 East Beckwith Ave
Missoula, MT 59801

(406) 542-4150

United States Department of Agriculture Forest Service.

USDA Link Forest Service Link


Climate Change Research

Climate Change
Issues are climate change and ecosystem vulnerability.
Develop models to assess the impact of climate change on ecosystems and forest sector so that managers can develop “least regret” management actions to address the potential impacts of climate change and its uncertainty.
The Impact of Climate Change on US Forests (5.5 mb pdf) National Assessment: Potential Consequences of Climate Variability and Change (web page)


For more climate change research, please visit the Climate Change Resource Center website


Research Description – The increasing concentration of carbon dioxide in the earth’s atmosphere has raised concerns about the potential changes in climate and climate variability resulting from these changes in the earth’s atmosphere and the vulnerability of ecosystems to these changes in climate. Forest and rangeland vegetation, the geographic distribution of plant and animal species, and the productivity of these ecosystems is strongly influenced by the amount of rainfall and snow, the temperatures, the length of the growing season and many other factors of the local climate. Identifying the vulnerabilities of ecosystems and economies to climate variability and change depends on an understanding of the sensitivity of those systems to climate. This research uses computer models to explore the impact of changes in climate on forest and rangeland ecosystems.

Team Lead Scientist – Linda Joyce;, 970-498-2560

Research Accomplishments and On-going –

Does spatial scale influence the estimation of climate change impacts on forest productivity? The influence of spatial aggregation on modeled forest responses to climate change was investigated by applying the process-based Terrestrial Ecosystem Model (TEM) to a fine resolution spatial grid (100 km2) and to a coarse resolution spatial grid (2500 km2). Baseline (present) climate with ambient CO2 and 2 future climates derived from the general circulation models OSU and GFDL-Q with elevated atmospheric CO2. The aggregation error of the national (U.S.) study area was very small, -0.4% (current climate). The aggregation error for the OSU climate scenarios was similar to the GFDL-Q climate scenario results and both results were similar to the aggregation error of the baseline climate in magnitude, sign, and spatial pattern. Forest-level aggregation error ranged from -1.6 to 11.8%, with the largest aggregation error occurring in boreal forest types. Aggregation errors were especially large in transition regions between temperate and boreal forest types. While aggregation error was similar across the baseline, GFDL-Q and OSU scenarios, net primary productivity (NPP) response to the climate changes in GFDL-Q and the OSU climates was an increase of 13 to 30% above the baseline NPP. Within each climate scenario, the estimated NPP response to climate change differed by less than 1% between the coarse and fine resolutions. Except for transition regions and regions with substantial variability in air temperature, these simulations indicate that the use of 0.5° resolution provides an acceptable level of aggregation error at the scale of a grid cell, a forest biome, or the national level. Improvements could be made by focusing computational intensity in heterogeneous regions and avoid computational intensity in regions that are relatively homogeneous with respect to vegetation and air temperature.
Publication: Nungesser, M.K.; Joyce, L.A.; McGuire, A.D. 1999. Effects of spatial aggregation on predictions of forest climate change response. Climate Research. 11: 109-124


Research Description – Effective public policy and stewardship of natural resources includes consideration of the projected costs and effects of different potential response strategies to manage the risks of long-term climate change. The ability to project potential future variation and changes in climate and environmental conditions, subject to assumptions about natural and human forcing, could enable resource managers to reduce damages and seize opportunities to benefit from changing conditions by adapting policy and management practices and activities. The Forest Service Assessment process utilizes computer models to analyze the potential effects of global climate change on the condition of renewable resources on the forest and rangelands of the United States. This assessment framework includes models that analyze the impact of climate change and elevated carbon dioxide on ecosystem response, and the impact on the supply and demand for timber in the forest sector. This framework offers the opportunity to assess the effects of potential response strategies on forest ecosystems and commodities, prices, incomes and welfare in the forest sector. In addition, the costs of these strategies both under potential climate change and without climate change can be evaluated. This research will explore the potential for management to address and when to address the risk and uncertainty under long-term climate change.

Team Lead Scientist – Linda Joyce;, 970-498-2560

Research Accomplishments and On-going –

Will climate change affect the forest sector in the United States? The Forest Service conducts periodic assessments of the condition of forest and rangeland resources under the authority of the Renewable Resources Planning Act (RPA). These periodic assessments synthesize and integrate the current state of scientific knowledge for policy discussions. Increasing concentration of atmospheric carbon dioxide has raised concerns about the vulnerability of forest to the elevated carbon dioxide and potential changes in climate and climate variability. The 1990 Food Protection Act, in amending the 1974 RPA, requires the Forest Service to: 1) assess the impact of climate change on the condition of renewable resources on forests and rangelands, and 2) identify the rural and urban forestry opportunities to mitigate the buildup of atmospheric carbon dioxide. Since the Amendment, RPA assessments have included an analysis of the vulnerability of U.S. forests to changes in climate. Joyce led these RPA climate change assessments in 1989, 1995, and 2000. The 2000 RPA climate change assessment (Joyce and Birdsey 2000) reviews our ability to quantify the impacts of a changing climate on vegetation communities and forest productivity, on the forest economy and land area changes, on carbon stored and its associated uncertainties in forests, in wood products, and in landfills and dumps. Current information on opportunities for increasing carbon storage in forests is also synthesized.

Joyce, L.A. 1997. Productivity of America's forests and climate change. In: U.S. Department of Agriculture, Forest Service global change research program highlights: 1991-1995. Gen. Tech. Rep. NE-237. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 97-102.
Joyce, L.A.; Birdsey, R.; Mills, J.; Heath, L. 1997. Progress toward an integrated model of the effects of global change on United States forests. In: U.S. Department of Agriculture, Forest Service Global Change Research Program Highlights: 1991-1995. Gen. Tech. Rep. NE-237. Radnor, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station: 93-96.
Joyce, L.A.; Birdsey, R., tech. eds. 2000. The impact of climate change on America’s forests: a technical document supporting the 2000 USDA Forest Service RPA Assessment. Gen. Tech. Rep. RMRS-GTR-59. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 133 p.
National Assessment Synthesis Team. 2000. Climate change impacts on the United States. the potential consequences of climate variability and change verview. Cambridge, U.K.: Cambridge University Press. 154 p.
Joyce, L.A.; Aber, J.; McNulty, S.; Dale, V.; Hansen, A.; Irland, L.; Neilson, R.; and Skog, K. 2001b. Potential consequences of climate variability and change for the forests of the United States. In: National Assessment Synthesis Team. Climate change impacts on the United States: the potential consequences of climate variability and change. Cambridge, U.K.: Cambridge University Press: 489-522.
Parson, E.A.; Corell, R.W.; Barron, E.J.; Burkett, V.; Janetos, A.; Joyce, L.A.; Karl, T.R.; MacCracken, M.C.; Melillo, J.; Granger, M. Morgan; Schimel, D.S.; Wilbanks, T. 2003. Understanding climatic impacts, vulnerabilities, and resilience in the United States: building a capacity for assessment. Climatic Change. 57: 9-42.

Will climate change affect the global forest sector? Joyce and others (1997) examined the impact of different future climate scenarios on the global forest product trade. The four climate scenarios produce consistent economic results, with expanding net primary productivity of the world's forests generally hurting timber producers and benefiting consumers. While regional changes in forest productivity strongly influence the regional economic impact, the economic results are also dependent upon whether the region is a producer or consumer of timber. Projecting out 50 years implies some knowledge about the forest sector infrastructure, particularly for countries such as Russia and China that do not currently have a fully developed forest sector. The uncertainty in the economic model appears to be at least as great as the uncertainty as in the climate scenarios. This study demonstrates the importance of examining the ecological and the economic impacts of climate change on natural resources.

How do assumptions about the path and magnitude of future changes in climate impact assessing the climate change impact on the global forest sector? The productivity and trade responses in the global forest sector may have implications for international efforts to stabilize the atmospheric concentration of carbon dioxide. Joyce in cooperation with Perez Garcia and McGuire, completed a study that takes a step toward including the role of global forest sector in integrated assessments of the global carbon cycle by linking global models of climate dynamics, ecosystem processes and forest economics to assess the potential responses of the global forest sector to different levels of greenhouse gas emissions. The results of this study indicate that assumptions within alternative climate scenarios and about trade in forest products are important factors that strongly influence the effects of climate change on the global forest sector.

Perez-Garcia, J.; Joyce, L.A.; Binkley, C.S.; McGuire, A.D. 1997. Economic impacts of climatic change on the global forest sector: an integrated ecological/economic assessment. Critical Reviews in Environmental Science and Technology. 27(Special): S123-S138.
Perez-Garcia, J.; Joyce, L.A.; McGuire, A.D. 2002. Temporal uncertainties of integrated ecological/economic assessments at the global and regional scales. Forest Ecology and Management. 162: 105-115.
Perez-Garcia, J.; Joyce, L.A.; McGuire, A.D.; Xiao, X. 2002. Impacts of climate change on the global forest sector. Climatic Change. 53: 439-461.

Will climate change influence natural disturbances such as drought, insects, disease, or fire? Early studies on the effects of climate change on forests focused on the ability of tree species to tolerate temperature and moisture changes. Many scientists are now recognizing – through modeling studies – the importance of climate changes on disturbance regimes that determine the character of forests. Trees can live for centuries, and have slowly evolved to co-exist with natural disturbances such as fire, drought, insects, diseases, and severe storm, but how will they be affected by a relatively rapid change in climate? In their article Climate Change and Forest Disturbances in the journal BioScience, a group of scientists with wide-ranging backgrounds discuss how climate change may affect forests by altering the frequency, intensity, duration, and timing of these natural disturbances, plus the relatively new phenomenon of introduced species. Some effects will be positive, some negative, and some may cancel each other out. And effects will likely vary geographically. A major problem, however, is uncertainty: we are entering uncharted waters. Thus the authors suggest a variety of strategies for coping with the possible effects of climate change:
Managing the system before the disturbance to reduce vulnerability and enhance recovery.
Managing the disturbance itself to reduce impacts.
Managing recovery to speed processes and reduce future vulnerability.
Managing to determine the impacts of disturbances and effectiveness of recovery efforts – the concept of adaptive management.

Dale, V.H.; Joyce, L.A.; McNulty, S.; Neilson, R.P; Ayres, M.P.; Flannigan, M.D.; Hanson, P.J.; Irland, L.C.; Lugo, A.E.; Peterson, C.J.; Simberloff, D.; Swanson, F.J.; Stocks, B.J.; Wotton, B.M. 2001. Forest disturbances and climate change. Bioscience. 51: 723-734.

Quantifying the impact of climate change on US forests. The objectives of this on-going research are to quantify the resource management outcomes under no climate change and climate change in the forest sector under a business as usual scenario and a scenario with a future policy instrument focused on increasing carbon sequestration above the baseline for US forests and forest products. Additionally we hope to analyze the impacts and their timing at local and regional scales in forest ecosystems and the forest sector, to identify potential research issues involved in developing a more comprehensive approach to risk assessment and management in the forest sector relative to climatic change.

Participants –
Dr. Richard Haynes, John Mills, Pacific Northwest Research Station, Portland, Oregon. This lab has maintained and developed the models used to analyze the supply and demand of timber in the United States. A publication on the use of the timber inventory model ATLAS. The recently completed assessment of the timber sector is also available from Treesearch

Dr. John Perez-Garcia, Center for International Trade in Forest Products, University of Washington. This lab maintains models used to analyze the forest trade globally. Faculty web page

Dr. Virginia Dale, Oak Ridge National Lab, Tennessee. Dr. Dale lead the effort to look at the potential impacts of climate change on natural disturbances.

Dr. Ron Neilson, Pacific Northwest Research Station, Corvallis, Oregon. This lab maintains and enhances ecological models that describe the impact of climate on biogeography and ecosystem dynamics. MAPSS


Research Description – Carbon sequestration in forests is strongly influenced by land use changes and management practices; yet until recently, ecological models examining the impact of climate change have focused on potential vegetation without land use. This omission is related to a lack of quantitative information on historical land use, such as timber harvests. The objective of this research was to develop a data set describing the area of forestland harvested and remaining in forestland (not converted to other uses) annually from 1700 at as fine a spatial resolution as possible and yet have a nationally consistent data set of timber removed from forestland on carbon sequestration patterns for U.S. forests.

Team Lead Scientist – Linda Joyce;, 970-498-2560

Research Accomplishments and On-going –
The research has developed initial estimates of the harvest rates through time. For the period from 1952 to 1997, Forest Service forest inventory data on area and volume was intermittently available. Information on acres harvested is limited and biased toward recent years--1970 to present. For the 1952 to 1997 period, we developed two approaches (statistical and analytical) to estimate acres harvested from removal and inventory volume data at the state level. To estimate harvest information further back in time, we related the harvest disturbance ratios to historical population levels and the initial recorded settlement. These estimates will be compared to recently reconstructed forestland use information at the national level. These data will also be used to describe land use change impacts on carbon sequestration from 1700 to 1997. Estimated harvest of wood will be compared to a data set we developed of historical wood product production, including fuel wood, from 1700 to 1999. Using conversion factors, this data set allows us to estimate wood removals from forests over time. Incorporating the trends in wood products through time is critical as prior to 1930 over half of the wood removed was used as fire or fuel wood. The methods we have developed provide a means of assessing uncertainty contributed by historical patterns of land use and of volume.

Participants – Dr. Dave McGuire, University of Alaska/US Geological Survey. Dr. McGuire’s lab has developed a new version of the Terrestrial Ecosystem Model that is capable of considering the role of forest disturbance on carbon and nitrogen fluxes of ecosystems, based on transient carbon dioxide concentrations and transient climate variables. Additional information can be found at Dr. Dave McGuire’s web site -

USDA Forest Service - RMRS - Project Name
Last Modified: Monday, 16 December 2013 at 14:18:30 CST

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