Automatic classification of the highveld grassland of Lichtenburg, south-western Transvaal*

摘要

A qualitative, semi-detailed plant ecological study o f the area between 25° 54' and 26° 22' E and 26° 00' and 26° 20' S, situated around the town o f Lichtenburg in the south-western Transvaal, Sou.h Africa, is reported. Mean annual temperature o f the study area is 17 °C and annual rainfall is about 600 mm. A basic difference is recognised between the Bankenveld Land System and the CT Grassland Land System. The former is underlain by dolomite with lithosolic soils, Bankenveld vegetation and cattle ranching as the chief iar.d-use, whereas the latter is underlain by granite, Ventersdorp lavas, Dwyka tillite and surface limestone with Snorrocks, Mangano and Lichtenburg series soils, Cymbopogon-Themeda Veld vegetation and extensive cultivation of maize as the chief land-use. One hundred and ten 16 m2 quadrats were placed within each Land System by means of a stratified-random strategy. Of the 247 species encountered, nearly 100 occurred in less than six quadrats. Themeda triandra, Aristida congesta, Elionurus argenteus, Anthospermum rigidum and Justicia anagaloides were common throughout. Two association analyses were carried out and 15 final groups were interpreted out of a total of 21? groups.