PARENT SESSION
Organized Oral Session 34: Incorporating ecological processes at many scales into biogeochemical and global climate change models
Organizer(s): WM Post, JS Olson, and C Peng
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 510b, Level 5, Palais des congrès de Montréal

Modeling responses of high latitude terrestrial ecosystems to global change.

McGuire, Anthony ^*,1, ¹ U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, Fairbanks, AK, USA

ABSTRACT- While it is clear that changes in high latitude regions have consequences for the climate system via a number of possible pathways, we do not completely understand whether the net effect of changes will enhance or mitigate warming. Responses of water, energy, and trace gas exchange may result in either positive or negative feedbacks to both regional and global warming. Of particular concern is whether the net response of high latitude ecosystems could lead to positive feedbacks that greatly enhance the rate of regional and global warming. While the responses of carbon storage in high latitude ecosystems have important implications for the rate of CO2 accumulation in the atmosphere and international efforts to stabilize the atmospheric concentration of CO2, it is important to understand how simultaneous changes in other trace gas exchanges and albedo of high latitude ecosystems also influence regional and global energy balance. Also, current responses of fire regimes to climate change suggest that fire is likely to increase in frequency and severity in the future, which has implications for both carbon storage and albedo of high latitude ecosystems. Analyses of how the global change responses of high latitude ecosystems will influence the climate system require an integrated understanding of how the response will manifest themselves at a spectrum of spatial and temporal scales. Incorporation of this integrated understanding into earth system models is important for identifying the implications for how the responses of high latitude ecosystems will influence global climate change. Examples of progress that has been made along these lines are provided, challenges that need to be met are identified.

Key words: Global Change, Ecosystem Modeling, Arctic, Boreal Forest