Plant communities of the Soutpansberg Arid Northern Bushveld

Abstract

The Soutpansberg Arid Northern Bushveld is one of eight major vegetation types (MVT) described for the Soutpansberg-Blouberg region. The plant communities of this MVT are described in detail. Main ecological drivers of the vegetation structure and species composition of these communities are discussed and some conservation recommendations are made. Phytosociological data from a subset of 72 Braun-Blanquet sample plots collected in the Soutpansberg Arid Northern Bushveld were classified using Two-way Indicator Species Analysis (TWINSPAN) and ordinated using a Detrended Correspondence Analysis (DECORANA). The resulting classification was further refined with table-sorting procedures based on the Braun-Blanquet floristic-sociological approach to vegetation classification using the computer software MEGATAB and JUICE. Eight plant communities were identified and described as <em>Commiphora tenuipetiolata-Adansonia digitata</em> short open woodland, <em>Ledebouria ovatifolia-Commiphora mollis</em> short bushland, <em>Phyllanthus reticulatus-Acacia nigrescens</em> short bushland, <em>Tinnea rhodesiana-Combretum apiculatum</em> short bushland, <em>Dichrostachys cinerea</em> subsp. <em>africana-Spirostachys africana</em> low thickets, <em>Themeda triandra-Pterocarpus rotundifolius</em> short closed grassland on steep basaltic slopes, <em>Cyperus albostriatus-Syzygium cordatum</em> sandveld wetlands, and <em>Sesamothamnus lugardii-Catophractes alexandri</em> tall sparse shrubland. These plant communities are event-driven ecosystems, predominantly infl uenced by frequent droughts, exposure to desiccation and unpredictable rainfall events. The complex topography of the Soutpansberg further contributes to the aridity of these ecosystems. The classifi cation and ordination analyses show similar groupings in the vegetation of the Soutpansberg Arid Mountain Bushveld. This confi rms the usefulness of complimentary analysis, using both classifi cation and ordination methods on a single data set in order to examine patterns and to search for group structure.<p><strong>Conservation implications:</strong> The results from this study will alter existing regional vegetation maps profoundly. The described plant communities of these arid event-driven ecosystems should be used as benchmark examples of the region’s primary vegetation. Conservation and management planning should be based on these vegetation units.</p><p><strong>How to cite this article:</strong> Mostert, T.H.C., Bredenkamp, G.J. & Mostert, R.E., 2009, ‘Plant communities of the Soutspanberg Arid Northern Bushveld’, <em>Koedoe</em> 51(1), Art. #687, 11 pages. DOI: 10.4102/koedoe.v51i1.687</p&gt

A tropical grass resource for pasture improvement and landscape management: Themeda triandra Forssk

“…Soil composition is the other key abiotic factor that constrains the vegetative growth of T. triandra . This species grows in soils generally poor in nutrients that normally range from clay to loamy, but with some degree of tolerance it can also be found in alluvial silts and loose sandy soils (Mostert et al ., ; FAO, ). The upper soil profile associated with East African T. triandra dominance has a dry, very dark brown clay loam composition and pH 6·2 (Anderson and Talbot, ).…”