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étiquettes: physical sciences, soil, vegetation, tundra ecosystems, ecological survey

Objectif(s): The goal of this research is to substantially advance the understanding of how Canadian arctic tundra ecosystems function.

Description du projet: The goal of this research is to substantially advance the understanding of how Canadian arctic tundra ecosystems function, and therefore how they are likely to be affected by perturbations such as climate change, resource development and extraction, and atmospheric pollution. Variation in soil microbial communities and their effect on biogeochemical cycling will be determined with soil samples collected from the main vegetation types at Daring Lake (heath, birch hummock, tall shrub, wet sedge). To determine the significance of biogeochemical processes during winter and spring-thaw to nitrogen cycling, snow depth and nitrogen availability will be manipulated. Long-term experiments in birch hummock tundra will investigate interactions with future climate and characterize ecosystems across the low Arctic. Shrub density increases and expansion will be characterized by measuring different aspects of ten long-term shrub monitoring plots, and also with the use of satellite images of the Daring region over the years. Tundra plant-soil microbial competition for nitrogen over the 5-10 year time scale will be determined by three experiments (single large additions; ongoing low level additions; and 15N additions). Copies of publications will be forwarded to the Aurora Research Institute and to Environment and Natural Resources in the GNWT for distribution to the communities. Researchers will participate in the Daring Lake Science Camp, if any of our groups are present at that time. At least one local student from the science camp will be recruited to help with sampling. A science synthesis meeting will probably be repeated in February 2009. Fieldwork will be conducted from near the Daring Lake Terrestrial Ecology Research Station (64.83N, 111.63W), centred on the valley to the south of an esker containing site locations 64.686N, 111.575W and 64.862N, 111.571W.