SS3.12 Large Scale Ecosystem Manipulations
Date: Thursday, June 13, 2002
Time: 3:15:00 PM
Location: Carson C
 
AllanCJ, UNC Charlotte, Charlotte, USA, cjallan@uncc.edu
Steedman, R, J, Ontario Ministry of Natural Resources, Thunder Bay, Canada, rob_steedman@mnr.gov.on.ca
 
ALTERATIONS IN THE HYDROLOGIC AND BIOGEOCHEMICAL CYCLES OF CLEARCUT BOREAL FOREST WATERSHEDS
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Three first order Precambrian Shield watersheds have been hydrochemically monitored since September 1995 to assess the hydrologic and biogeochemical effects of forest management activities in Northwestern, Ontario, Canada. The two experimental catchments WS39 and WS26 were clearcut during June-August, 1998 and all commercially valuable timber removed. Annual runoff has increased 35% (WS26) and 72% (WS39) over precut conditions. Peak stormflow discharges have also increased dramatically. Both experimental catchments exhibited increased losses of major cations, DOC, Cl, TKN and TP in relation to the reference catchment and these losses remain elevated four years after harvest. No changes in sediment transport or stream turbidity were measured although the character of the stream-borne organic material changed immediately after clearcutting. Soil moisture, soil temperature and wetland water tables remain elevated in relation to their pre disturbance state.