The importance of the fall, winter and spring periods to ecosystem functioning and biogeochemical cycling in tundra has only become apparent in the past two decades.  Our research group has been conducting winter climate change-related studies at a low arctic tundra site near Daring Lake, north of Yellowknife in northern Canada for the past five years.  Most of these studies have focused on the biogeochemical interactions between plants, soils, and soil microbes during fall, winter and spring, and on their responses to experimentally deepened snow.  In addition, we have measured trace gas production and isotopic nitrogen tracer distributions among plant and soil components in several vegetation-types.  The central goal has been to understand the potential importance of cold season soil N transformation processes to ecosystem-level biogeochemistry during the subsequent plant growing season, and then to develop predictions of how changes in winter climate may impact these seasonal processes.

Results/Conclusions

In this talk, I will present a synthesis of those studies. In addition, I will provide a broad conceptual framework for comparison with other tundra and temperate sites, and for highlighting future research priorities.