PPS Arctic Canada (Present processes, Past changes, Spatio-temporal variability in the Arctic delimitation zone, Canada)

PPS Arctic Canada (Present processes, Past changes, Spatio-temporal variability in the Arctic delimitation zone, Canada) is PPS Arctic's Canadian component, an International Polar Year-endorsed research program on the causes and consequences of change of the tree line. Recent research has noted latitudinal and altitudinal shifts in tree line that might be attributed to northern hemisphere warming. Predictions are that these changes will continue and that they can amplify warming at high latitudes. However, sparse empirical data on recent tree line dynamics has left considerable uncertainty as to the rate, magnitude and mechanisms of tree line responses to shifts in climate. Our research is ground-breaking because it begins with an expectation that there are important new relationships involving climate, environmental change, human health and well-being that we need to understand. The results from these studies contribute to our short-term objectives: 1) an analysis of recent change in tree and shrub distributions; 2) the collection of environmental and microclimate data to accompany tree line change; 3) an investigation of the mechanisms of vegetation change at tree line; 4) the mapping of the spatial pattern of tree and non-tree species at tree line and in tundra islands within the boreal forest to predict future changes as tree line migrates; 5) an assessment of the role of disturbance; and 6) the development of models of the long-term relationship between environmental change, resource availability and human health and well-being in the forest-tundra ecotone. We use methods familiar to natural and social science in order to understand change in the northern landscape as well as its meaning from ecological, social and cultural perspectives. This provides policy-relevant knowledge about environmental change and its human dimension in the tundra-taiga transition zone. Our long-term objectives are: 1) to model temporal and spatial tree line dynamics and to situate these processes within a comprehensive conceptual framework of environmental change that addresses ecological, social and cultural factors; 2) to assess the impact of climate change on processes within the tree line ecotone; 3) to determine ecosystem services of the tree line ecotone and their vulnerability with climate change and land use impacts; and 4) to develop conceptual models of the long term relationship of environmental change and human health and well-being in the Arctic and Sub-Arctic.