Botanical data were collected for the period 1970 to 1985 from the experimental farm unit at Massakloutjie in the Kalahari duneveld of the north-western Cape Province (Veld type no. 16a4, Acocks, 1975). Rainfall during the trial period varied between 111 mm (1982-83) and 593 mm (1973-74). The total plant basal cover ranged from 2, 39% (1983) to 6, 17% (1977). The cyclical nature of the rainfall, with a sequence of wet and dry cycles, was reflected in the botanical composition of the duneveld. Group A of the rainfall, with a sequence of wet and dry cycles, was reflected in the botanical composition of the duneveld. Group A species (highly desirable decreaser species) form the dominant component (up to 90%) during dry cycles because of their drought tolerance. During wet cycles the group B, C and D species (less useful to poor increaser species) increase more rapidly than do the decreaser species and may comprise as much as 50% of the botanical composition. Because of this cyclical pattern in botanical composition (or relative cover), absolute cover provides a more reliable index of relative veld condition than botanical composition.
Keywords: basal cover; botanical composition; botany; cape province; decreaser species; drought; drought tolerance; increaser species; kalahari; net income; north-western cape; production; rainfall; south africa; stocking rate; veld condition