Vegetation degradation gradients and ecological index of key grass species in the south-eastern Kalahari South Africa

Abstract

An ecological assessment of the vegetation was conducted in the south-eastern part of the Kalahari. Detailed classification of the vegetation of Witsand Nature Reserve to determine small scale plant communities for a Nature Reserve management plan – 44 Braun-Blanquet plots revealed 7 detailed plant communities. One hundred and twenty six (126) sample plots, making up 45 sites, were used for the TWINSPAN classification, refined by Braun-Blanquet procedures, illustrated in a dendrogram, revealed 3 broad plant communities. A description of the communities is given and a vegetation map of the study area is provided. The step-point method was used and data collected at each sample plot in such a way that different degradation stages could be identified, an ordination technique (multivariate analytical procedures) was used to define the grazing gradient. Species abundance curves were statistically fitted to the grazing gradient and used to classify the species objectively into categories. Ecological index values were determined for each of the significant species within each community. Copyright