Effects of climatic and biotic factors on the ecology and nutrient dynamics of marshes and shallow open waters in natural and disturbed regions

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Wetlands in western Canada have been disappearing rapidly due to agricultural/urban expansion and industrial land development, and are further stressed by climate warming. Most locations in the central Prairie Provinces already have temperatures 2-3 degrees warmer than in the mid 20th century and many wetlands are exhibiting decreased water levels; and temperatures are projected to continue rising during the 21st century. The processes controlling trophic state and wetland quality are complex and are further complicated by anthropogenic disturbance and climate warming. As a result of cumulative disturbances, wetland ecosystem function and water quality are being degraded. My goal is to examine the effects of climatic/physical and biotic factors on the ecology and nutrient dynamics of northern marshes and shallow open waters in natural and disturbed regions. One component of my research will be to investigate the role of top-down vs. bottom-up control of algal productivity in shallow wetland lakes in the undisturbed western boreal forest and the disturbed boreal transition/aspen parkland regions. Under Alberta's new wetland policies, wetlands facing development will be either protected, developed with modifications, or new wetlands constructed to replace destroyed wetlands. The challenge for wetland managers is determining wetland health in disturbed and restored wetlands because there is no ecosystem evaluation system in Alberta. In other regions, bioassessments have been successful in quantifying degradation and restoration success, but bioassessments are regionally specific. In western Canadian wetlands, the development of wetland health indicators has not been done. I will measure the biotic, chemical and physical factors in natural reference marshes and shallow open lakes and contrast them to disturbed wetlands. Biotic responses of emergent and submersed vegetation, macroinvertebrates, and zooplankton to different chemical and physical conditions will be quantified and developed into specific metrics and indices of wetland health. My research will increase the understanding of ecological processes in shallow wetlands and develop the necessary tools to evaluate wetland health for ecosystem management.