An ecological study of the plant communities and degraded areas of the Highveld National Park, North West Province, South Africa

Thesis (M.Sc. (Botany))--North-West University, Potchefstroom Campus, 2008.The objectives of the study were to identify, classify, describe and map the plant communities in the proposed Highveld National Park, including the degraded Spitskop areas. Vegetation sampling was done by means of the Braun-Blanquet method and a total of 108 stratified random relevés were sampled. A numerical classification technique (TWINSPAN) was used and the result was refined by Braun-Blanquet procedures. The final results of the classification procedure were presented in the form of phytosociological tables and twelve plant communities were described. For indirect ordination, a Detrended Correspondence Analysis (DCA) algorithm was applied to the data set to confirm the phytosociological association and to assess floristic relations between communities. For direct environmental gradient analysis the Canonical Correspondence Analysis (CCA) was applied to the data using the CANOCO software program. The plant communities were combined into six management units based on similarities regarding vegetation composition, habitat, topography and soil characteristics. Characterization of land degradation was done by grouping erosion into different classes and different degrees of severity. Degraded areas in need of rehabilitation and restoration were identified and described. Recommendations were made with regard to rehabilitation and monitoring of all degraded areas in the HNP.Master

An ecological study of the plant communities in the proposed Highveld National Park, in the peri-urban area of Potchefstroom, South Africa

http://dx.doi.org/10.4102/koedoe.v52i1.70

The spatial distribution of the woodland communities and their associated environmental drivers in the Golden Gate Highlands National Park, South Africa

The extreme variability in the topography, altitude and climatic conditions in the temperate Grassland Mountains of Southern Africa is associated with the complex mosaic of grassland communities with pockets of woodland patches. Understanding the relationships between plant communities and environmental parameters is essential in biodiversity conservation, especially for current and future climate change predictions. This article focused on the spatial distribution of woodland communities and their associated environmental drivers in the Golden Gate Highlands (GGHNP) National Park in South Africa. A generalized linear model (GLM) assuming a binomial distribution, was used to determine the optimal environmental variables influencing the spatial distribution of the woodland communities. The Coefficient of Variation (CV) was relatively higher for the topographic ruggedness index (68.78%), topographic roughness index (68.03), aspect (60.04%), coarse fragments (37.46%) and the topographic wetness index (31.33) whereas soil pH, bulk density, sandy and clay contents had relatively less variation (2.39%, 3.23%, 7.56% and 8.46% respectively). In determining the optimal number of environmental variables influencing the spatial distribution of woodland communities, roughness index, topographic wetness index, soil coarse fragments, soil organic carbon, soil cation exchange capacity and remote-sensing based vegetation condition index were significant (p < 0.05) and positively correlated with the woodland communities. Soil nitrogen, clay content, soil pH, fire and elevation were also significant but negatively correlated with the woodland communities. The area under the curve (AUC) of the receiver operating characteristics (ROC) was 0.81. This was indicative of a Parsimonious Model with explanatory predictive power for determination of optimal environmental variables in vegetation ecology. CONSERVATION IMPLICATIONS : The isolated woodland communities are sources of floristic diversity and important biogeographical links between larger forest areas in the wider Drakensberg region. They provide suitable habitats for a larger number of forest species and harbour some of the endemic tree species of South Africa. They also provide watershed protection and other important ecosystem services. Understanding the drivers influencing the spatial distribution and persistence of these woodland communities is therefore key to conservation planning in the area.http://www.koedoe.co.zaam2022Geography, Geoinformatics and Meteorolog

Classification and description of the vegetation in the Spitskop area in the proposed Highveld National Park, North West Province, South Africa

The objective of the proposed Highveld National Park (HNP) is to conserve a considerable area of the poorly conserved Rocky Highveld Grassland and Dry Sandy Highveld Grassveld of the western Grassland Biome in South Africa. The park has not yet been proclaimed, but is currently under the management of the North West Parks and Tourism Board. The main aim of this study was to classify and describe the vegetation in the Spitskop area in the HNP. The areas affected by soil degradation were on the midslopes, footslopes, valley bottomland and the floodplains around the Spitskop hill. The concentrated grazing around the Spitskop area was also influenced by the existing dam in the floodplains. Floristic and soil degradation data were collected and used to classify and describe the plant communities of the Spitskop area. Vegetation sampling was performed by means of the Braun-Blanquet method and a total of twenty plots were sampled. A numerical classification technique (TWINSPAN) was applied to the floristic data to derive a first approximation of the main plant communities. Further refinement was achieved by Braun-Blanquet procedures. The final results of the classification procedure were presented in the form of a phytosociological table, with three major communities and three subcommunities being described. Canonical correspondence analysis was used to determine the direct correlation between plant communities and soil degradation types. Soil compaction and sheet erosion were found to be the most significant variables determining plant community composition. Rill and gully erosion were shown to be of lesser significance in explaining the variation in plant communities. Conservation implications: Grasslands are amongst the most threatened biomes in South Africa, yet less than 1.3% are currently being conserved. The HNP has significant value for biodiversity conservation and the protection of this area will contribute to the preservation of the highly threatened Highveld vegetation types

Efficient Evaluation of Biodiversity Concerns in Protected Areas

Monitoring is a vital component of keeping protected areas in desired states. Lack of robust designs, however, impedes efficient monitoring. We ask two questions—how does effort at a specific site as well as number of sites in a plant community influence richness, abundance, and diversity indicators. Large mammal herbivory biodiversity influences are a key concern for managers of Mokala National Park. We anticipated that changes in biodiversity indicators (vegetation, ants, and birds) associate with herbivore intensity of use of landscapes. We identified flat deep sandy plains and undulating shallow rocky hills as focal landscapes. Our focus was on finding optimized effort at survey sites as well as the number of sites. Monitoring to evaluate change in diversity and abundance needs far less effort than evaluating change in richness. Furthermore, given the variance at the landscape level, monitoring of species abundance and diversity allows easier detection with less effort and at shorter intervals between surveys than that required for richness. Even though a mechanisms-based approach directs monitoring, conservationists need to evaluate feasibility. In our case, measurement of richness is unlikely to detect herbivore effects. In general though, we have illustrated that focused monitoring designs can robustly evaluate conservation objectives

From numbers to ecosystems and biodiversity: A mechanistic approach to monitoring

Diverse political, cultural and biological needs epitomise the contrasting demands impacting on the mandate of the South African National Parks (SANParks) to maintain biological diversity. Systems-based approaches and strategic adaptive management (learn by doing) enable SANParks to accommodate these demands. However, such a management strategy creates new information needs, which require an appropriate analytical approach. We use conceptual links between objectives, indicators, mechanisms and modulators to identify key concerns in the context of and related to management objectives. Although our suggested monitoring designs are based mostly on defined or predicted underlying mechanisms of a concern, SANParks requires inventory monitoring to evaluate its key mandate. We therefore propose a predictive inventory approach based on species assemblages related to habitat preferences. Inventories alone may not always adequately serve unpacking of mechanisms: in some cases population size needs to be estimated to meet the information needs of management strategies, but actual population sizes may indirectly affect how the species impact on other values. In addition, ecosystem objectives require multivariate assessments of key communities, which can be used in trend analysis. SANParks therefore needs to know how to detect and define trends efficiently, which, in turn, requires precision of measures of variables. Conservation implications: Current research needs with regard to monitoring should focus on defining designs to yield optimal precision whilst taking methodology, survey trade-offs and analytical approaches into account. Use of these directives and research will guide monitoring during evaluation of SANParks objectives at various scales