SS3.12 Large Scale Ecosystem Manipulations
Date: Thursday, June 13, 2002
Location: Poster Session - VCC
 
CameronDA, Canadian Forest Service, Sault Ste. Marie, Canada, alcam@nrcan.gc.ca
Kreutzweiser, D, P, Canadian Forest Service, Sault Ste. Marie, Canada, dkreutzw@nrcan.gc.ca
Beall, F, D, Canadian Forest Service, Sault Ste. Marie, Canada, fbeall@nrcan.gc.ca
 
LARGE-SCALE ECOSYSTEM MANIPULATIONS AT THE TURKEY LAKES WATERSHED
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The Turkey Lakes Watershed, a 10.5 sq. km forested watershed at the south-eastern edge of Lake Superior, is one of the longest-standing environmental research and monitoring sites in Canada. Numerous multi-agency research and monitoring projects have focused on environmental impacts of airborne pollutants, forest productivity, biogeochemistry, ecosystem processes, and fisheries dynamics. Recently, a large-scale manipulative experiment was conducted to determine the effects of differential hardwood harvesting on forest structure and function, succession pathways and processes, soil nutrient cycling and productivity, and the yield, quality and fauna of headwater streams draining harvested catchments. Effects on headwater streams are reported here. Harvesting was conducted under a randomised block design with treatments ranging from selection (40% canopy removal) to diameter-limit (85% canopy removal) levels of intensity. Treatment block sizes ranged from 4 ha to 66 ha. Early results indicate that the intensive diameter-limit harvesting significantly altered water and nutrient yield, DOC fluxes, organic matter inputs, benthic woody debris, and sediment deposition. Most of these effects were negated at the selection harvest sites at up to 50% canopy removal, even without riparian buffer zones.