SS3.16 Lentic-Lotic Linkages in Freshwaters: Comparisons from Different Ecosystems
Date: Monday, June 10, 2002
Time: 4:15:00 PM
Location: Colwood
 
PrepasEE, University of Alberta, Edmonton, Canada, eprepas@ualberta.ca
Burke, J, M, University of Alberta, Edmonton, Canada, burke1jm@cmich.edu
Millions, D, G, University of Alberta, Edmonton, Canada, millions@odum.biology.ualberta.ca
Serediak, M, , University of Alberta, Edmonton, Canada, mark.serediak@ualberta.ca
 
THE WESTERN BOREAL PLAIN OF CANADA: A CHALLENGING SETTING TO INTEGRATE SURFACE WATER STUDIES IN LAKES AND STREAMS
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The western Boreal Plain extends southeast from northeastern British Columbia to southwestern Manitoba. There are numerous streams and lakes on the Boreal Plain, where the dry climate (evaporation exceeds precipitation by up to 100 mm annually) results in low and variable runoff (up to 10-fold changes between years) and lakes with relatively long water residence times (5 to 7 years). An extensive dataset assembled since 1990 on streams and lakes in forested watersheds demonstrates that the small-watershed approach with a focus on low-order streams is most effective at measuring natural and disturbed (forest harvest, wildfire) nutrient (i.e., phosphorus, nitrogen) export patterns. Even shallow lakes may be stratified for much of the open-water season, thus internal ion loading may obscure impacts of watershed disturbance. However, lentic habitat variables (dissolved oxygen, cyanobacterial toxins) and biodiversity are sensitive to watershed disturbance and can be effectively used as indicators of higher external nutrient loading. Thus, the climate and physiography of the Boreal Plain necessitates an approach that combines intensive short-term nutrient studies on small streams with long-term lake monitoring programs that focus on bioindicators.