Floristic diversity of the Soutpansberg, Limpopo Province, South Africa

Abstract

The observations, data and deductions described in this thesis were collected from the Soutpansberg and surrounding areas over a period of over 20 years. This thesis aims to explain the underlying mechanisms driving the processes in the Soutpansberg that have brought forth its immense floristic diversity. It is envisaged that this thesis could serve as a guide towards the implementation of management policies for this unique mountain range and assist in the proclamation of the Vhembe as a Biosphere Reserve. As an introduction the study area is described in terms of geology, geography, cli-mate, history and previous vegetation descriptions. The floristic diversity was analysed and it is concluded that the area is a hotspot for floristic diversity. The total number of plant species of the area was established at 2693 with 594 tree taxa, one of the highest in southern Africa. Families with the highest number of taxa are the Fabaceae, Poaceae and Asteraceae. The analysis confirmed the area as a Centre of Endemism. The Soutpansberg dis-plays a strong biological interchange with the Blouberg, Chimanimani, Limpopo Valley, Maputaland, Sekhukhune, Strydpoort, Waterberg and Wolkberg. To resolve the problems concerning the definition of their biological interchange, a new interpretation of the concept of near-endemic is proposed. To make sense of interaction between various centres of endemism with the Sout-pansberg centre sensu strictu, a new term namely paraendemic was defined, and the terms protoparaendemic and biparaedemic were introduced for near endemic taxa with a wider distribution between centres of endemism. This resulted in a new interpretation of the Soutpansberg endemic plants. The endemics and paraendemics of the Soutpansberg and the related regions were identified and these are discussed n detail. It was found that most endemic species are restricted to the mist belt and occur on nutrient poor soils derived from quartzite or sandstone. It is concluded that the endemic flora did not arise as a result of a single group diversifying. The immense floristic diversity is attributed to the contribution of several distinct flo-ristic elements acting upon the Soutpansberg. These includes an arid group, a sa-vanna group, a temperate group including forest and grassland elements and a tropical group, being discussed in detail. Copyright