HR: 16:45h
AN: NB14A-06    [Abstracts]
TI: Effects of Clearcut Logging on Export of Invertebrates, Fine Particulate Organic Matter and Dissolved Organic Carbon From Headwater Streams.
AU: * Mackay, C A
EM: GREENHA@UNBC.CA
AF: University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 Canada
AU: Heise, B A
EM: heise@cariboo.bc.ca
AF: University College of the Cariboo, P.O. Box 3010, Kamloops, BC V2C 5N3 Canada
AB: We compared the export of aquatic invertebrates (drift) and fine particulate organic matter (FPOM) from headwater streams directly affected by logging to that of control streams. Thirty subalpine streams were sampled in the southern interior of BC within two watersheds, Bone and Damfino, in 2003 and 2004. Streams were categorized into three treatment types: new clearcuts logged 1-3 years previous, old clearcuts logged 5-7 years previous, and controls. Discharge rates ranged from 0.0142 to 11.329 L sec^-1 and drift densities ranged from 0.0132 to 30.139 individuals L^-1. Paired sites were positioned above and below disturbance in clearcuts, and equivalent elevation gradients in control streams. At Damfino, FPOM and drift densities of both clearcut treatments increased in downstream pairs, opposite to differences between control pairs (p=0.004, 0.003). Old clearcuts showed increases of Ephemeroptera (p=0.029), and both clearcut treatments displayed increases of Diptera (p=0.027) compared with controls.
DE: 1803 Anthropogenic effects
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly