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14 CLIMATE CHANGE ALBERTAS BIODIVERSITY ALBERTAS ECOSYSTEMS Projections of the future distributions of Albertas major ecosystems indicate changes in their size and distribution under different climate change scenarios in particular an expansion of grasslands and a decline in the area of the boreal forest. The diversity of Albertas ecosystems can be represented by the provincial system of Natural Regions and Subregions Fig. 2.14 These 21 Natural Subregions nested within six Natural Regions represent unique combinations of landforms soils climate and vegetation. However the nature and boundaries of these regions are expected to change as the distribution of vegetation shifts in response to changing climate. Understanding how Albertas ecosystems will be distributed in the future provides the basic foundation for natural resource planning including for agriculture forestry and biodiversity conservation. RichardSchneider2013developedbioclimatic envelopemodelspage12todescribethecurrent distributionofAlbertasNaturalSubregions andappliedthesemodelstoclimateprojections forthe2020s2011-20402050s2041-2070 and2080s2071-2100evaluatingfivepotential futureclimatescenariosCoolMedianHot DryandWet.15 The most dramatic change projected was the expansion of Albertas grasslands at the expense of other ecosystems Fig. 2.16 Under the Cool Model the Grassland Natural Region was predicted to expand northward into the Parkland and the Parkland in turn replaced the Dry Mixedwood and Central Mixedwood. Under the Hot model the predicted expansion of grasslands was more rapid until by the end of the century that ecosystem covered almost the entire province the boreal forest was projected to disappear completely except for a remnant at higher elevations in the Caribou Mountains.17 Uncertainties remain in the types and rates of ecological transitions that will occur in response to these projected shifts in the climate envelopes of Albertas Natural Subregions. Richard Schneider and colleagues submitted predict substantial lags between changes in climate and subsequent ecosystem transitions especially in the transition from mixedwood boreal forest to aspen forest and then to parkland and grassland ecosystems. Further they predict these transitions are unlikely to occur gradually or steadily and that ecosystem components will respond to climate change at different rates. For example in upland forests natural disturbances like fire will be important for initiating ecosystem changes including the transition of mixedwood boreal forest to parkland or grassland ecosystems. But Schneider and colleagues argue that the resilience of peatlands to climate change and natural disturbance and their likely persistence on the landscape through to the end of the century will play an important role in mitigating future forest loss especially of aspen. So the future northern Alberta landscape may be comprised of a mosaic of peatlands and upland aspen forest a novel ecosystem that is not represented in Alberta today. 14 Natural Regions Committee. 2006. Natural Regions and Subregions of Alberta. Government of Alberta Edmonton AB 264 pp. Available at www.albertaparks.camedia2942026nrsrcomplete_may_06.pdf 15 These five future scenarios represent different combinations of global climate models and greenhouse gas emissions scenarios. Refer to Schneider 2013 for detailed descriptions. 16 Additional maps of projected future ecosystem distribution can be found at www.biodiversityandclimate.abmi.caresourcesmap-galleries 17 Learn more about this research by watching a presentation by Dr. Richard Schneider at www.biodiversityandclimate.abmi.cavideos