A preliminary report on the effect of Acacia karoo competition on the composition and yield of sweet grassveld

Abstract

In a large-scale experiment a dense stand of A. karoo was effectively killed by a basal bark application of 2,4,5-T at a concentration of 1.5 per cent acid equivalent in paraffin. There was no correlation between density of Acacia and either composition or basal cover of the grass component. After three years there was still no significant difference in the grass cover and composition of paddocks on which A. karoo had been cleared, and uncleared ungrazed control paddocks. There was no evidence that where grazing was precluded a dense stand of A. karoo would develop and retard improvement in botanical composition. Despite the similarity in cover and composition, uncleared paddocks yielded significantly less grass than cleared paddocks, both in dry and in wet seasons. Total costs of bush clearing averaged R6.80 per morgen.

Keywords: Cathcart|Eastern Cape Province|tree densities|basal covers|grass compositions|clearings|ungrazed habitats|bush control|bark|botanical compositions|competition|experiments|grasses|veld|grasslands|sweetveld|yields|compositional analyses|acid|bush densities