Simulation of changes in arctic terrestrial carbon stocks under using ecosys mathematical model

Sustainable Canadian arctic terrestrial ecosystems are vital for northern communities and also for global communities. Arctic terrestrial ecosystems have huge stores of soil C and also contain plant C, all which are important for ecosystem health. However, there are large knowledge gaps concerning the current state of these northern ecosystems, which lead to huge uncertainties in quantification of how climate variables affect these ecosystems. These uncertainties are in part due to the complex nature of climate impacts on biological, physical and chemical activities in soils and plants. The major objective of the modelling effort is to develop a methodology using the ecosys mathematical model, to bring a greater understanding and quantification of ecological processes in northern ecosystems thereby reduce uncertainties of the dynamics of these ecosystems. Addressing current uncertainties associated with quantifying tundra ecosystems may improve our long - term predictions of climate impact on future sustainability of these ecosystems. This research will allow further insights of these ecosystems at several spatial scales - site/plot, landscape and regional. Study site locations include Daring Lake (mesic tundra, wet sedge and fen tundra), Churchill, Iqaluit, Cape Bounty and Ellesmere Island-Lake Hazen, Canada. Modelled results will be compared to measured soil temperature, carbon dioxide and energy exchange fluxes, nitrous oxide, methane emissions and phytomass growth. We have conducted preliminary simulations for the Daring Lake fen site - Modelled (57 g C m-2) and measured (43 g C m-2) shoot biomass were comparable for sedge however, the model underestimated the growth of the dwarf birch trees; work is in progress to determine whether the dwarf tree physiology is represented correctly in the model. Overall, the fen site resulted in a net C source with net ecosystem productivity of 13.5 g C m-2 yr-1, however this could change when the dwarf birch tree growth are better represented. The study showed the importance of using ecosys mathematical model, in conjunction with measured data to asses both short and long-term sustainability of these northern ecosystems. The research will also allow recommendations of sustainable (soil, water, air, plant and other habitat quality) best management practices (BMPs) for northern ecosystems in Canada and around the world, today and tomorrow. A healthy environment will in turn help people in northern communities e.g. food, water, economic security. This research will contribute to many other different areas e.g. quantification of carbon stocks in inventories, carbon trading, IPCC Tier III methodology for the Kyoto Protocol, policy decisions etc. We hope that the research can contribute to avoiding climate change since this may disrupt the sustainability of these ecosystems vital for northern communities, as well as affect other regions of the world more negatively such as the Tropics.