Location: Watershed Management ResearchTitle: Cattle use patterns of riparian pastures in northeastern Oregon Author
|Clark, Patrick - Pat|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2009
Publication Date: 2/10/2010
Citation: Wilson, M.A., Clark, P., Wilson, K.D., Larson, L.L., Johnson, M.D., Williams, J., Johnson, D.E. 2010. Cattle use patterns of riparian pastures in northeastern Oregon. Society for Range Management Meeting Abstracts. Interpretive Summary:
Technical Abstract: Livestock use of riparian areas has been fraught with controversy, with some arguing that livestock should be excluded while others emphasize the benefits of controlled grazing. Our study was designed to 1) characterize the nature of cattle grazing in riparian pastures, 2) determine intensity and spatial pattern of use (grazing and resting) especially along the stream banks, 3) determine ecological site preference by animals and 4) determine daily travel distances and routes. Three riparian pastures in northeastern Oregon were selected for study. Each riparian pasture was aerially photographed at high resolution (20 cm ground pixel size). Images were corrected for lens curvature and a mosaic created via edge matching. Composited images were geographically registered. These images were used to identify and digitize stream channels and banks, as well as vegetative communities. Distance from the stream wetted edges to all 1 m2 cells in the pasture was calculated, as was distance from the thalweg. Ten cows were collared with GPS units that recorded positions at 1-second intervals for 6 days. Two trials were run in each pasture. Livestock positions were divided into stationary and moving categories using GPS velocity so that resting and grazing could be independently analyzed. Cattle travel distance per day was calculated by computing displacement from each position with a velocity greater than 0. Each location where animals were stationary for more than 10 minutes was identified and the time the animal entered the position, left the position and duration of occupancy was computed. A minimum convex polygon was drawn around all locations in the stationary set and saved as a shapefile. Cattle stationary and moving positions were mapped in relation to stream banks and stream channels.