干旱区生态环境知识资源中心

The size class distributions of the seven most abundant woody species in an area of the Transvaal Lowveld were determined for two contrasting management systems, i.e. communal land and a protected area. Most of the size class profiles indicated that the populations were not stable, experiencing fluctuating recruitment and/or mortality rates. This is probably the norm in semi-arid environments characterized by large fluctuations in the timing and intensity of controlling variables. Communal management reduced absolute densities and altered the size class profile of all but one of the species considered. This was usually manifested as a reduction in the proportion of larger individuals.