HR: 1340h
AN: H53A-1227    [Abstracts]
TI: Effects of Modern Timber Harvest Practices on Suspended Sediment Concentrations in Mica Creek, Idaho
AU: * Karwan, D L
EM: diana.karwan@yale.edu
AF: Yale University School of Forestry and Environmental Studies, 210 Prospect Street, New Haven, CT 06511
AU: Gravelle, J
EM: jag@pineorchard.com
AF: University of Idaho, 1205 Pro-Mall Blvd #112, Pullman, WA 99163
AB: The concern regarding sedimentation effects from modern timber harvest practices emphasizes the necessity for a greater understanding of how both road construction and timber harvest relate to stream sediment levels. In order to investigate this, a network of seven automated stream monitoring stations was installed in the Mica Creek Experimental Study Area in north Idaho. Water samples analyzed for total suspended solids (TSS) were collected regularly since 1991 under both flow-based and stream-stage storm rise conditions from 1991 to 2003. This period of time encompasses a pre-treatment time interval from 1991 to 1997, and two treatment time intervals: post-road from 1998 to 2001 and post-road/post-harvest from 2001 to 2003. Using a paired watershed approach, treated and control catchments were statistically compared for each time interval. At this time the impacts corresponding to road construction and timber harvest using modern practices remain difficult to discern from the larger variation in the entire suspended sediment record. Continued monitoring at these sites is planned to evaluate trends over subsequent years. This analysis is part of a long-term integrated study that measures both physical change in the watershed as well as biological response to road construction and timber harvest conducted under current best management practices (BMPs). Mica Creek is believed to be one of the first comprehensive study basins which examines the effects of using modern practices on privately managed timberland.
DE: 1803 Anthropogenic effects
DE: 1815 Erosion and sedimentation
DE: 1871 Surface water quality
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting