2002 ARCSS All-Hands Workshop

Tundra carbon loss during winter: temporal, landscape and geographic variability

Jace T. Fahnestock¹, Jeffrey M. Welker^2
1Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523, USA, Phone 970-491-5262, jace@nrel.colostate.edu
²Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523, USA

For the past six winters we have documented patterns of carbon loss during the long non-growing season in various arctic and subarctic plant communities and under various experimental treatments. These studies, along with those of other arctic research scientists, have shown that there is significant loss of carbon from tundra ecosystems during winter and that these effluxes can represent a considerable percentage of the annual carbon budget in some systems, even changing some ecosystems from net annual carbon sinks to sources. These studies have also shown that there is considerable variation in efflux patterns during the winter period and from one year to the next. We have also found that both wintertime and summertime conditions, experimental or otherwise, can dramatically change the magnitude of C efflux during the non-growing season. We present a review of published and unpublished data from wintertime carbon efflux studies and show temporal, landscape, and geographic patterns of variability. Variation in C efflux at a site is often as great as or even greater than variation across large geographic areas.

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