The effect of fire, with and without subsequent defoliation on the herbaceous layer of Burkea africana savanna.

Abstract

A back-fire applied to the herbaceous layer during September 1978 resulted in significantly less dry matter production over the following year, compared to an unburnt area. This was largely due to the significant reduction in dry matter and basal cover of the non-forage species group which had, prior to the fire, exhibited a notable accumulation of dead material. In contrast, basal cover and dry matter production of the leafier forage species group were not significantly affected by the back-fire. On plots where the burn was followed by an 8-weekly clipping treatment, a slower biomass accumulation rate of the sward as a whole was recorded than on burnt plots allowed unchecked post-fire regrowth. The lowest rate was recorded on unburnt plots allowed unchecked growth. The burn plus 8-weekly clipping reduced the biomass accumulation rate of the non-forage species compared with the same group on unburnt unclipped plots. In a similar comparison, the rate of accumulation of forage species biomass was, however, stimulated by the burn plus 8-weekly clipping.

Keywords: basal cover; biomass; burkea africana; clipping; defoliation; dry matter production; effect of fire; fire; herbaceous layer; nylsvley nature reserve; production; regrowth; savanna; south africa