The Spatial Ecology of the Ground Beetle Evarthus alternans (Casey 1920) in Burned and Unburned Grasslands
Roberta R. Rader* and Mark W. McKelvey
Dr. Jonathan C. Gering and Dr. Dean DeCock, Faculty Mentors
Disturbance often influences the spatial patterns of species by altering the structure of resources within an ecosystem. We investigated the effect of recent burning on the spatial pattern of the ground beetle Evarthus alternans in adjacent burned and unburned grassland plots in Adair County, Missouri. We collected beetles using 440 pitfall traps during two 7-day periods in July and August 2005. Each plot had two trapping grids of 110 traps. Variation across the burn line was investigated with two 50m transect lines of 25 traps each. Evarthus alternans accounted for 82% of the total beetle capture with an average of 3.9 E. alternans per trap in the unburned plot and an average of 1.3 E. alternans per trap in the burned plot. Evarthus alternans also exhibited a clustered spatial pattern in the unburned plot and a random spatial pattern in the burned plot. Burning reduces spatial structure and abundance of the E. alternans population.
Keywords: ground beetle, spatial structure, pitfall traps
Topic(s):Mathematical Biology
Presentation Type: Oral Paper
Session: 13-2
Location: OP 2210
Time: 8:30