Linkages between climate, hydrology and ecology of lakes in northern thermokarst landscapes: past, present and future

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The impact of climate warming on water resources in northern Canada is a pressing concern, because water plays a key role in maintaining the ecological integrity of landscapes, economic development and traditional use by First Nations communities. The proposed research will improve understanding of how lakes in thermokarst landscapes of the Old Crow Flats (N. Yukon) and Hudson Bay Lowlands (N. Manitoba) respond to climatic changes. Both landscapes are recognized internationally as ecologically and culturally significant, but changes in lake and river hydrology challenge the ability of agencies to maintain integrity of their natural resources because existing data are insufficient to develop effective policies and practices. The proposed program will integrate 3 research components to provide information over a sufficient range of spatial and temporal (years to centuries) scales to quantify the roles of influential hydrological processes on ecological conditions of lakes in thermokarst landscapes; including: 1) use of spatial lake surveys of water, biota and stable isotopes to understand how hydrological processes regulate contemporary lake conditions; 2) use of spatial surveys of aquatic biota (algae) preserved in surficial lake sediments and which grow on experimental substrate stations to develop a scientifically robust ability to interpret eco-hydrological changes from analysis of biota preserved in sediment cores; and 3) analyses of sediment cores from selected lakes spanning the past millennium to quantify ecological responses to past hydrological changes. These thermokarst landscapes have been identified as very vulnerable to global warming, but their freshwater ecosystems remain the least studied and most poorly understood in North America. Thus, the proposed program will provide basic research on these systems and promote development of methodologies for long-term monitoring by agencies in the north. It will increase capacity of government agencies (Parks Canada, Vuntut Gwitchin First Nation) to fulfill their mandates to steward the landscapes effectively, and it will train 4 PhD, 2 MSc and 10 undergraduate research students in highly-sought fields of environmental assessment.