African Protected Area Conservation and Science http://www.koedoe.co.za KOEDOE Original Research Article #710 (page number not for citation purposes) A foristic analysis of the vegetation of Platberg 1 Authors: Robert F. Brand 1 Leslie R. Brown 1 Pieter J. du Preez 2 Affliations: 1 Applied Behavioural Ecology and Ecosystem Research Unit, Department of Environmental Sciences, University of South Africa, Florida campus, South Africa 2 Department of Plant Sciences, University of the Free State, South Africa Correspondence to: Leslie R. Brown email: lrbrown@unisa.ac.za Postal address: Department of Environmental Sciences, UNISA, Florida campus, Private Bag X6, Florida, 1710, South Africa Keywords: Drakensberg Alpine Centre; endemism; Platberg; Red Data species; species richness Dates: Received: 18 June 2009 Accepted: 11 Oct. 2009 Published: 29 Mar. 2010 How to cite this article: Brand, R.F., Brown, L.R., du Preez, P.J., 2010, ‘A foristic analysis of the vegetation of Platberg, eastern Free State, South Africa’, Koedoe 52(1), Art. #710, 11 pages, DOI: 10.4102/koedoe.v52i1.710 This article is available at: http://www.koedoe.co.za © 2010. The Authors. Licensee: OpenJournals Publishing. This work is licensed under the Creative Commons Attribution License. Vol. 52 No. 1 Page 1 of 11 ABSTRACT A checklist of vascular plants of Platberg was compiled to determine species richness, rarity and endemism. The foristic analysis is part of the Department of Economic, Tourism and Environmental Affairs Free State biodiversity assessment programme and conservation management plan for Platberg. The analysis identifed a total of 669 species belonging to 304 genera and 95 families, with 214 species belonging to the Monocotyledoneae and 438 species to the Dicotyledoneae. The largest family is Asteraceae with 126 species, followed by Poaceae with 73 species, Cyperaceae with 39 species, Fabaceae with 33 species, and Scrophulariaceae with 27 species. Various fynbos species were found, as well as 26 endemic/near-endemic species belonging to the Drakensberg Alpine Centre or Eastern Mountain Region. The results of this study revealed that Platberg shares inselberg foral richness and endemism that can be tracked via the Afromontane archipelago-like string of inselbergs and mountains, which stretch north through the Chimanimani Mountains, into Malawi, the Eastern Arc Mountains via Tanzania and north through Ethiopia, into Eurasia. Conservation implications: Platberg, as an inselberg, is a site of signifcant biological diversity, with high species richness, vegetation selection and ecosystem complexity. It shares foral richness and endemism via inselbergs and mountains throughout Africa. The high species richness, Red Data species and ecosystems make this area an important conservation site that should be legislated and protected. A floristic AnAlysis of the vegetAtion of PlAtberg, eAstern free stAte, south AfricA INTRODUCTION With the human population steadily on the rise, the natural environment is under greater pressure than ever before (Huntley 1991). Natural areas act as reservoirs for plant and animal populations (IUCN 1980). Platberg, overlooking the town of Harrismith in the Free State, is an inselberg that presents a refuge for indigenous plants and animals (Burke 2001; Gröger et al. 1996; Mutke et al. 2001; Porembski et al. 1997, 1998; Porembski & Brown 1995). Vegetation surveys provide information on the different plant communities and plant species present and form the basis of any management plan for a specifc area (Brown et al. 1996). Little is known about the different taxa of Platberg and hence a detailed foristic and ecological survey was undertaken to quantify threats to the native fora and to establish whether links exist with higher-altitude Afro-alpine fora occurring on the Drakensberg. No extensive vegetation surveys had been undertaken on Platberg prior to this study; only limited opportunistic foristic collections were done in the mid-1960s by Mrs. Jacobs (these vouchers were mounted and authenticated in 2006 and are now housed at the Geo Potts Herbarium, Botany Department, University of the Free State). Similarly, 50 relevés were sampled between 1975 and 1976 by Professor H.J.T. Venter, Department of Genetics and Plant Sciences, University of the Free State. Study area Location The town of Harrismith is located at the foot of Platberg (29º10’ S and 28º16’ E), along the N3 highway between Johannesburg and Durban (Figure 1). Platberg’s altitude ranges from 1 900 m to 2 394 m. The surface area covers approximately 3 000 ha. The slopes are steep with numerous vegetated gullies and boulder scree slopes below vertical cliffs that are 20 m to 45 m high. Waterfalls cascade down the southern cliffs after rain. A permanent stream arising from the Gibson Dam on the undulating plateau fows off the escarpment and cascades as a waterfall (Figure 2). From a distance, Platberg appears to have a distinct fat top. However, once on the summit the plateau is found to be undulating, with rolling grass-covered slopes. The vegetation of the plateau is dominated by grassland, with a few rocky ridges, sheet rock and rubble patches, as well as numerous seasonal wetlands and a permanent open playa (pan) on its far western side. Woody patches of the genera Leucosidea, Buddleja, Kiggelaria, Polygala, Heteromorpha and Rhus shrubs, as well as the indigenous Mountain bamboo Thamnocalamus tessellatus, grow along the base of the cliffs. The shrubland vegetation is concentrated on the cool side of Platberg, on sandstone of the Clarens Formation, in gullies, on scree slopes, mobile boulder beds, and on rocky ridges. Shrubs and trees also occur in a riparian habitat in the south-facing cleft, in which the only road ascends steeply to the summit.