Vegetation ecology of the Soutpansberg and Blouberg area in the Limpopo Province

The fast growing local human population, especially through immigration from countries north of South Africa, is placing the Soutpansberg and Blouberg areas under increasing pressure. The insatiable demand for more arable land within these agriculturally marginal and semi-arid areas is leading to severe degradation of the remaining natural resources. The Soutpansberg–Blouberg region has been recognized as a Centre of Endemism and is regarded as a region of exceptionally high biological diversity. The Soutpansberg Conservancy and the Blouberg Nature Reserve reveal extremely rich diversities of plant communities relative to the sizes of these conservation areas. The Major Vegetation Types and plant communities of the Soutpansberg Centre of Endemism are described in detail with special reference to the Soutpansberg Conservancy and the Blouberg Nature Reserve. Phytosociological data from 466 sample plots were ordinated using a Detrended Correspondence Analysis (DECORANA) and classified using Two–way Indicator Species Analysis(TWINSPAN). The resulting classification was further refined with table–sorting procedures based on the Braun–Blanquet floristic–sociological approach of vegetation classification using MEGATAB. Eight Major Vegetation Types were identified and described as Eragrostis lehmanniana var. lehmanniana–Sclerocarya birrea subsp. caffra BNR Northern Plains Bushveld, Euclea divinorum–Acacia tortilis BNR Southern Plains Bushveld, Englerophytum magalismontanum–Combretum molle BNR Mountain Bushveld, Adansonia digitata–Acacia nigrescens Soutpansberg Arid Northern Bushveld, Catha edulis–Flueggia virosa Soutpansberg Moist Mountain Thickets, Diplorhynchus condylocarpon–Burkea africana Soutpansberg Leached Sandveld, Rhus rigida var. rigida–Rhus magalismontanum subsp. coddii Soutpansberg Mistbelt Vegetation and Xymalos monospora–Rhus chirendensis Soutpansberg Forest Vegetation. Plant communities of each of the Major Vegetation Types are described. The primary ecological drivers of the event-driven and the classic climax vegetation types are discussed and management recommendations are made for effective conservation of these last remaining pockets of wilderness. The available data supports the recognition of the region as an important Centre of Plant Endemism and Biological Diversity requiring conservation attention. CopyrightThesis (PhD)--University of Pretoria, 2010.Plant Scienceunrestricte

Plant communities of the Soutpansberg Arid Northern Bushveld

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 classifi ed using Two-way Indicator Species Analysis (TWINSPAN) and ordinated using a Detrended Correspondence Analysis (DECORANA). The resulting classifi cation was further refi ned with table-sorting procedures based on the Braun-Blanquet fl oristic-sociological approach to vegetation classifi cation using the computer software MEGATAB and JUICE. Eight plant communities were identifi ed and described as Commiphora tenuipetiolata-Adansonia digitata short open woodland, Ledebouria ovatifolia-Commiphora mollis short bushland, Phyllanthus reticulatus- Acacia nigrescens short bushland, Tinnea rhodesiana-Combretum apiculatum short bushland, Dichrostachys cinerea subsp. africana-Spirostachys africana low thickets, Themeda triandra-Pterocarpus rotundifolius short closed grassland on steep basaltic slopes, Cyperus albostriatus-Syzygium cordatum sandveld wetlands, and Sesamothamnus lugardii-Catophractes alexandri 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. CONSERVATION IMPLICATIONS: 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.The National Research Foundationhttp://www.koedoe.co.zaam201

Guidelines for phytosociological classifications and descriptions of vegetation in southern Africa

Changes in the environment are first observed in changes in the vegetation. Vegetation survey, classification and mapping form the basis on which informed and scientifically defendable decisions on the environment can be taken. The classification and mapping of vegetation is one of the most widely used tools for interpreting complex ecosystems. By identifying different plant communities we are essentially identifying different ecosystems at a particular hierarchical level. Phytosociologists in Europe have been involved in such studies following, in particular, the Braun-Blanquet approach since the early 1900s. In South Africa, such studies were undertaken on a limited basis from the early 1970s and have since then steadily increased. The surveying of the enormous diversity of South African vegetation is one of the objectives of phytosociological studies. The demand for such data has steadily increased over the past few years to guide conservation policies, biodiversity studies and ecosystem management. In South Africa, numerous publications on the vegetation of conservation and other areas in the different biomes have been produced over the last few decades. However, vegetation scientists in South Africa experience unique problems. The purpose of this article is therefore to provide an overview of the history and the specific focus of phytosociological studies in South Africa and to recommend minimum requirements and methods to be followed when conducting such studies. It is believed that the incorporation of these requirements will result in scientifically justifiable research of high quality by phytosociologists in South Africa. CONSERVATIOM IMPLICATIONS: Effective conservation cannot be obtained without a thorough knowledge of the ecosystems present in an area. Consistent vegetation classifications and descriptions form the basis of conservation and monitoring exercises to maintain biodiversity. The incorporation of these guidelines and requirements will facilitate quality phytosociological research in South Africa.http://www.koedoe.co.zaam201