The Influence of Fire on Composition of Central Missouri Prairie

Abstract

Annual burning after five years resulted in a uniform cover of prairie grass with a sharp decline in broadleaved species, par- ticularly coarse composites. These effects differed most markedly with control plots on which a very evident decrease in basal area of the grass cover had occurred. The decrease in grass dominance is attri'buted to the stagnating effects of litter, possibly operating through lower light intensities at ground level. The effect of biennial burning, in contrast to annual burning, was to maintain a mixture of both grass and broad- leaved species. Fire every fifth year showed no appreciable difference from control plots, suggesting the attenuating effects of a single fire over this period of time. Lapses of two and three years after single fires showed a greater density of broadleaved species, compared to annual burning. native prairie in Missouri have been in progress since 1958. In a pre- vious paper (Kucera and Ehrenreich, 1962) the cumulative effects of annual burning on total dry matter production after three years were presented. It was shown that greater productivity of both foliage and seed stalks was maintained on fire plots during this period of time. In conjunction with these observations, composition changes result- ing from annual fire as well as other schedules are being assessed. The main features of these modifications, thus far, are the continuing vigor of the native grasses and a simultaneous decline in densities of several broadleaved species. Where burning was omitted over the past five years, with no other form of consumption and litter removal, there was a general deterioration in the native prairie community. This report summarizes initial composition changes in the prairie resulting from several selected burning schedules over the last five years as compared to prairie protected from fire.