Return to CIG

Search

View All Publications

Go To Publication by Year:

View Publications by Topic:

Adaptation

Agriculture

Air Quality

Aquatic Ecosystems and Fisheries

Background Papers

Climate: Atmospheric Modeling

Climate: Coupled Atmosphere-Ocean Modeling

Climate: Diagnostics

Climate: Global Climate

Climate: Ocean Modeling

Climate: PNW Climate

Climate: Regional Climate Modeling

Coastal Ecosystems

Coastal Environments

Conservation Biology

Data Analysis and Sharing

Energy

Fact Sheets

Forecasts and Applications

Forest Ecosystems

Human Health

Hydrology and Water Resources

Infrastructure

Integrated Assessment

Ocean Acidification

Oceanography

Program Documents

Science Advisory Reports

Societal Dimensions

Special Reports

Theses and Dissertations

View Publications by Author:

Search the Publication Abstracts:


Other CSES Links:

About CSES

CSES Personnel

Data / Links

Publications

Welcome to the publications directory for the Climate Impacts Group and the Climate Dynamics Group. Please contact the web administrator for assistance with any of these publications.


View: Abstract

Global warming and stress complexes in forests of western North America

McKenzie, D., D.L. Peterson, and J.S. Littell. 2009. Global warming and stress complexes in forests of western North America. pp. 319-337. In S. V. Krupa (series editor), Developments in Environmental Science, Vol. 8, Wild Land Fires and Air Pollution, A. Bytnerowicz, M. Arbaugh, A. Riebau, and C. Anderson (eds.). Amsterdam, The Netherlands: Elsevier Science, Ltd.

Abstract

A warmer climate in western North America will likely affect forests directly through soil moisture stress and indirectly through increased extent and severity of disturbances. We propose that stress complexes, combinations of biotic and abiotic stresses, compromise the vigor and ultimate sustainability of forest ecosystems. Across western North America, increased water deficit will accelerate the normal stress complex experienced in forests, which typically involves some combination of multi-year drought, insects, and fire. Four examples suggest how stress complexes are region-specific.

Symptoms of prolonged drought and insects are currently manifested in extensive dieback of pine species in the pinyon-juniper forest of the American Southwest, an area where only a few tree species can survive. Air pollution and high stand densities from fire exclusion have compromised mixed-conifer forests of the Sierra Nevada. Bark beetles are proliferating and killing millions of hectares of dry forest in the northern interior of western North America, setting up the prospect of large and intense fires. Fire and insect mortality have also exceeded previously recorded levels in both interior and south-central Alaska, possibly precipitating extensive ecosystem changes, while extensive permafrost degradation is causing other changes.

Increases in fire disturbance superimposed on forests with increased stress from drought and insects may have significant effects on growth, regeneration, long-term distribution and abundance of forest species, and short- and long-term carbon sequestration. The effects of stress complexes will be magnified given a warming climate.