Richards, C. Natural Resources Research Institute, University of Minnesota - Duluth, crichard@sage.nrri.umn.edu
Johnson, L. Natural Resources Research Institute, University of Minnesota - Duluth,, ljohnson@sage.nrri.umn.edu
Host, G. Natural Resources Research Institute, University of Minnesota - Duluth, ghost@sage.nrri.umn.edu

 
RELATIVE INFLUENCES OF LOCAL AND LARGE SCALE WATERSHED FEATURES ON STREAM ECOSYSTEMS
 
Understanding the relative influence of regional versus local landscape characteristics is essential for developing effective watershed remediation and assessment strategies. Water quality and biological communities within watersheds are influenced by factors such as landuse patterns, surficial geology, and landscape structure, all of which may occur at different spatial scales. Landuse is controlled by anthropogenic activities which may be altered through land management at local scales. In contrast, many geological factors (e.g. soils) and other aspects of landscape structure (e.g. slope, elevation) are fixed and occur at larger scales. In a study of 65 Midwestern watersheds, we found that relative influences of local and regional landscape factors varied depending on the watershed function of interest. For example, water quality (e.g. nitrogen conc.) and the presence of woody debris was more influenced by local landuse, whereas, biological communities were strongly influenced by both regional and local landscape factors. The influence of several landscape elements (e.g. wetlands) was disproportionate to their areal extent. In subsequent study designs, watersheds were selected with respect to landuse and geology to determine underlying mechanisms controlling watershed function. A GIS based model indicated that hydrologic patterns between lacustrine and morainal regions accounted for many observed differences in water quality and community structure.
 
Day: Wednesday, Feb. 3
Time: 11:45 - 12:00pm
Location: Sweeney Center
 
Code: CS59WE1145S