The Effect of Early Spring Burning on Vegetation in Buffalo Wallows

Abstract

COLLINS, S. L. AND G. E. UNO (Dept. Botany and Microbiology, Univ. Oklahoma, Norman, OK 73019). The effect of fire on vegetation in buffalo wallows. Bull. Torrey Bot. Club 110: 474-481. 1983.-Buffalo wallows are patchily distributed disturbances in grassland vegetation initiated by male buffalo during the spring rutting season. During the rainy season in spring and early summer, wallows hold water resulting in greater soil moisture than in adjacent grasslands. We examined the effects of early spring burning on wallow vegetation in a wildlife refuge containing about 700 buffalo. Ordinations indicated two vegetation gradients. The first ordination axis was a moisture gradient separating vegetation located outside wallows from that within wallows. The second axis separated samples from the burned and unburned sites. Diversity and richness values were higher outside than inside the wallows. Evenness values, were greatest inside the wallows. Richness was significantly lower in burned than in unburned wallows. Ruderal species such as winter annuals were more abundant in unburned wallows. Overall, wallows contain vegetation different from that of surrounding prairie, which increases regional species diversity in southern mixed grasslands. Also, fire alters the composition of vegetation within wallows to a greater extent than adjacent vegetation. Finally, we suggest that wallows serve as safe-sites for ruderal species within mature grassland vegetation.