PARENT SESSION
Poster Session #66: Landscape Ecology II.
Friday, August 9. Presentation from 8:00 AM to 9:30 AM. Exhibit Hall B & C, TCC
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A spatial hierarchy of factors influencing bison (Bos bison) grazing patterns at Konza Prairie Biological Station.
BROCK, BRENT*,1, JOHNSON, LORETTA1, HOCH, GREG1, WASSBERG, THOMAS1, 1 Kansas State Univeristy, Manhattan, KS
ABSTRACT- Understanding factors determining spatial and temporal patterns of bison grazing in tallgrass prairie is important for predicting patterns of ecosystem responses to this keystone species. We used semiweekly observations of bison locations mapped to 260m x 260m grid cells collected over two growing seasons to explore the influence of burning and topography on bison movements. Bison were observed with greatest frequency on upland sites (P<.0001) within burned areas (P<.0001) compared with lowland, sloped, or unburned areas. There was a trend toward more bison observations in burned areas with the longest fire return intervals (FRI) indicating that bison discriminate based upon fire history. An exception to this trend occurred in 2000 where bison avoided a burned area with a 2-year FRI. Number of observations in this area were not significantly different from unburned areas (P=.49). We used GIS to analyze differences in topography among burn treatments and explore potential mechanisms for this avoidance of this area. The 2-year FRI area had the lowest total area and mean patch size of uplands among all burned areas. Bison may have avoided this area due to unsuitable topography for grazing. In addition the observed preference for upland sites was not detectable when topography was aggregated over 260m x 260m grid cells to match the spatial resolution of observations. These results indicate that topography may supercede influences of burning but bison respond to topography at finer spatial scales than burning.
KEY WORDS: Konza Prairie, bison, grazing, landscape