SS3.07 Headwater Ecosystems in Forested Landscapes and Beyond
Date: Wednesday, June 12, 2002
Time: 10:00:00 AM
Location: View Royal
 
KiffneyPM, Northwest Fisheries Science Center, Seattle, USA, peter.kiffney@noaa.gov
Richardson, J, S, University of British Columbia, Vancouver, Canada, jrichard@interchg.ubc.ca
Edmonds, R, , University of Washington, Seattle, USA, bobe@u.washington.edu
 
FACTORS LIMITING PERIPHYTON AND PRIMARY CONSUMERS IN HEADWATER STREAMS OF THE PACIFIC NORTHWEST: EXPERIMENTS AT MULTIPLE SCALES
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Headwater streams constitute the majority of stream length in most watersheds in the Pacific Northwest and elsewhere. However, little is known about the ecology of these channels. In this research, we present data from experiments that examine the response of algae and primary consumers to various perturbations at different spatial and temporal scales. These include a natural experiment where we observed increased primary and secondary productivity in a headwater streams after a debris flow; a riparian management experiment, where algal biomass and insect consumer abundances increased, as riparian buffer width narrowed; in-situ nutrient addition experiments that showed N or P did not limit algal biomass and insect abundance until light was removed as a limiting factor; and experimental mesocosm studies where light and nutrients limited algal biomass and consumer abundance, but this depended on time since disturbance.