Vegetation sensitivity to global anthropogenic carbon dioxide emissions in a topographically complex region
Article first published online: 12 JUN 2003
Copyright 2003 by the American Geophysical Union.
Global Biogeochemical Cycles
Volume 17, Issue 2, June 2003
How to Cite
2003), Vegetation sensitivity to global anthropogenic carbon dioxide emissions in a topographically complex region, Global Biogeochem. Cycles, 17, 1067, doi:10.1029/2002GB001974, 2., , , , , , and (
- Issue published online: 12 JUN 2003
- Article first published online: 12 JUN 2003
- Manuscript Accepted: 2 APR 2003
- Manuscript Revised: 6 FEB 2003
- Manuscript Received: 21 AUG 2002
- regional climate model;
- vegetation model;
- western North America;
 Anthropogenic increases in atmospheric carbon dioxide (CO2) concentrations may affect vegetation distribution both directly through changes in photosynthesis and water-use efficiency, and indirectly through CO2-induced climate change. Using an equilibrium vegetation model (BIOME4) driven by a regional climate model (RegCM2.5), we tested the sensitivity of vegetation in the western United States, a topographically complex region, to the direct, indirect, and combined effects of doubled preindustrial atmospheric CO2 concentrations. Those sensitivities were quantified using the kappa statistic. Simulated vegetation in the western United States was sensitive to changes in atmospheric CO2 concentrations, with woody biome types replacing less woody types throughout the domain. The simulated vegetation was also sensitive to climatic effects, particularly at high elevations, due to both warming throughout the domain and decreased precipitation in key mountain regions such as the Sierra Nevada of California and the Cascade and Blue Mountains of Oregon. Significantly, when the direct effects of CO2 on vegetation were tested in combination with the indirect effects of CO2-induced climate change, new vegetation patterns were created that were not seen in either of the individual cases. This result indicates that climatic and nonclimatic effects must be considered in tandem when assessing the potential impacts of elevated CO2 levels.