The influence of rainfall on vegetation composition in different conditional states

The impact of ecological factors such as changes in rainfall could lead to large compositional changes in the diverse indigenous flora of southern Africa. A study was therefore initiated to determine the influence of rainfall conditions on species composition changes, which could serve as a basis for determining the long term influence of rainfall increase (e.g. cloud stimulation) and rainfall decrease (e.g. long term droughts). Certain species were found to occur in all the rainfall zones while others were limited to either the high or the low rainfall area. The reaction of species on the rainfall gradient also differs in vegetation representing different degradation stadia. The predictions of the reactions of key species on rainfall decrease or increase are of special importance for the eventual determination of grazing capacity.