Physical impact of grazing by sheep in the Nama Karoo subshrub/grass rangeland of South Africa on litter and dung distribution (Short communication)

Abstract

The direct short-term impact of three rates of stocking (4, 8 and 16 Small Stock Units/ha) on arid Nama Karoo vegetation (shrub/grass) was quantified in terms of dung distribution and trampling. Grazing, by mature Merino wethers took place for one month at a time over a period of two years (1995 and 1996). As expected, the quantity of litter and dung significantly increased with an increase in stocking rate. When litter and dung are expressed in terms of loss and excretion per animal, both decreased with increased stocking rate. On average 80% of the dung was excreted on only 10% of the camp area, which mostly took place at the watering and sleeping places. These findings demonstrate the complex interaction between grazing and soil parameters.

Keywords: Karoo bushes, Merino wethers, soil parameters, stocking rate, trampling

South African Journal of Animal Science Vol. 38 (4) 2008: pp. 326-330