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

PPS Arctic Canada is a team of more than 170 researchers including 23 co-investigators, 3 post-doctoral fellows, 80 students from high school to graduate level and more than 70 northern residents and elders. Training and northern community involvement have been key components of our research project. Together with international researchers we developed common protocols and collected data during IPY to examine change at the tree line. Our multidisciplinary research team is developing methods for integrating data from a wide range of quantitative, qualitative and anecdotal data on change across tree line, or the Arctic delimitation zone. By actively interweaving research themes from ecological, environmental, and social sciences with northern cultural perspectives and community priorities, we are framing environmental change research in new ways, adopting new approaches to doing science in partnership with northerners, and developing new methods of cross-scale enquiry. We also integrate this research with northern priorities at specific sites to create opportunities for hands-on involvement by scientists from diverse disciplines, Elders, local knowledge holders, community people, youth and agents from multiple sectors. In the summers of 2007-09, we collected data at over a dozen locations in the Yukon, Northwest Territories, Nunavut, northern Manitoba, northern Québec and Labrador. Data were collected regarding the impacts of changes in climatic conditions on tree line and their consequences on ecosystems and communities. Other data were collected on trees of all ages, seeds, vegetation, snow and ice, microclimate, spatial pattern, soil and socioeconomic indicators across the forest tundra ecotone at sites across northern Canada. Our key finding continues to be the large amount of variability in tree growth, regeneration and spatial pattern among tree species, regions across Canada and even sites within the same region. Evidence of change in and movement of the forest-tundra ecotone is evident in some sites but not in others despite increasing temperatures. Seed viability or seedling recruitment may be hindering tree line movement at these sites. This variation in tree line response may be extremely challenging to outline general strategies for climate change adaptation in Arctic environments.