Phytosociology of northwestern KwaZulu-Natal

Abstract

In depth studies of the vegetation of large parts of southern Africa, including detailed maps and descriptions of vegetation units are mainly limited to small areas. Meanwhile, various agricultural practises have led to destruction or deterioration of the quality of natural grassland ecosystems. The agricultural sector in developed and rapidly developing areas of southern Africa is confronted with problems like veld deterioration and the loss of natural areas that effectively contribute to the depopulation of rural areas. The necessity to identify, classify and describe the vegetation types and communities within the Grassland Biome was stressed by Mentis and Huntley (1982). The aim of the Grassland Biome Project is to integrate knowledge. comprehension and expertise, which will enable scientists to forecast the results of the available options of grassland management programmes. The phytosociological classification of northwestern KwaZulu-Natal forms part of this project. Known previous vegetation studies of this area were conducted on a large scale and a considerable time ago, which underlines the necessity for a more comprehensive and phytosociologically refined investigation of this area. The study area lies in the northern part of KwaZulu-Natal and comprises the Drakensberg mountains and slopes in the west and undulating plains and bushveld valleys in the east and south. Relevés were compiled in 526 stratified random sample plots over an area of 9300 km2, comprising the northwestern part of KwaZulu-Natal. The vegetation was classified by means of TWINSP AN and Braun-Blanquet procedures. A phytosociological investigation of this vegetation revealed great variation in floristic composition. Further refinement of the data disclosed five major vegetation types containing nine plant communities. The topography and geology of the study area contributes greatly to the diversity of the vegetation, but poor agricultural practises have caused deterioration of the vegetation.