This dissertation research project examine how arctic plant communities may respond to global climate change, and the consequences that changes in community structure may have for ecosystem functioning. Field manipulations of community structure and temperature, combined with growth chamber experiments will be used, to determine how the competitive interactions of the major tussock tundra species change with increased temperature. Field transplants of major treeline species along with seed germination studies will be employed to determine the controls over tree migration into tundra. The student will examine how individual species affect system processes such as productivity, decomposition and nutrient cycling, and CO2 and CH4 flux, using the previously mentioned community manipulations, as well as laboratory soil incubations. The Arctic is an appropriate system for this study because the low number of species allows whole-community manipulations. Furthermore, dramatic increases in temperature are expected to occur at high latitudes in the near future. This study is significant because it links community structure with ecosystem processes. ** //
