Exploring the significance of land-cover change in South Africa (original) (raw)
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Mapping Land-Use/Land-Cover Change in a Critical Biodiversity Area of South Africa
International Journal of Environmental Research and Public Health
Land-use/land-cover (LULC) changes have implications for the long-term outlook of environmental processes, especially in the face of factors such as climate change. These changes can have serious consequences for humans. In this study, remote sensing and geographic information system methods were used to investigate LULC changes in a critical biodiversity area (CBA) in the northern sections of Limpopo Province in South Africa from 1990 to 2018 using data obtained from the South African National Land Cover project. In 1990, the dominant land cover comprised thickets and dense bush, followed by woodland and built-up areas, covering proportions of 40, 24 and 18% of the total land-cover area, respectively. Bare and forest areas were the least dominant classes during this time. In 2018, the dominant land cover was woodland, followed by built-up areas, comprising 71 and 20% of the total area, respectively. Subsistence agriculture is a land-cover class with a relatively higher area compare...
Systematic land-cover change in KwaZulu-Natal, South Africa: Implications for biodiversity
South African Journal of Science, 2015
Land-cover change and habitat loss are widely recognised as the major drivers of biodiversity loss in the world. Land-cover maps derived from satellite imagery provide useful tools for monitoring land-use and land-cover change. KwaZulu-Natal, a populous yet biodiversity-rich province in South Africa, is one of the first provinces to produce a set of three directly comparable land-cover maps (2005, 2008 and 2011). These maps were used to investigate systematic land-cover changes occurring in the province with a focus on biodiversity conservation. The Intensity Analysis framework was used for the analysis as this quantitative hierarchical method addresses shortcomings of other established land-cover change analyses. In only 6 years (2005-2011), a massive 7.6% of the natural habitat of the province was lost to anthropogenic transformation of the landscape. The major drivers of habitat loss were agriculture, timber plantations, the built environment, dams and mines. Categorical swapping...
South African Journal of Science
Rural landscapes in South Africa experience high conversion rates due to intense land use; however, the changes are site specific and depend on the socio-economic and political history of the area. Land cover change (LCC) was assessed in response to socio-economic and political factors in uThukela Municipal District, KwaZulu-Natal, using Landsat imagery from 1984 to 2014, while making comparisons to other studies in South Africa. Socio-economic/political data were used to gain insights into the observed LCC patterns. Land cover was classified using a random forest classifier, and accuracies ranging from 87% to 92% were achieved. Systematic and intensity analysis methods were used to describe patterns, rates, and transitions of LCC in Imbabazane (ILM) and Okhahlamba (OLM) local municipalities. The results showed a reduced rate of change intensity from 3.4% to 0.9% in ILM and from 3.1% to 1.1% in OLM between 1984 and 2014. Grassland was persistent, covering over 70% in both local muni...
Heliyon, 2018
Future land cover changes may result in adjustments to biophysical drivers impacting on net ecosystem carbon exchange (NEE), catchment water use through evapotranspiration (ET), and the surface energy balance through a change in albedo. The Land Change Modeller (Idrisi Terrset 18.08) and land cover for 2000 and 2014 are used to create a future scenario of land cover for two catchment with different land management systems in the Eastern Cape Province for the year 2030. In the S50E catchment, a dualistic farming system, the trend shows that grasslands represented 57% of the total catchment area in 2014 decreasing to 52% by 2030 with losses likely to favour a gain in woody plants and cultivated land. In T35B, a commercial system, persistence of grasslands is modelled with approximately 80% coverage in both years, representing a more stable system. Finally, for S50E, NEE and ET will increase under this land cover change scenario leading to increased carbon sequestration but less water availability and corresponding surface temperature increases. This implies that rehabilitation and
The Race for Space: Tracking Land-Cover Transformation in a Socio-ecological Landscape, South Africa
Environmental Management, 2013
Biosphere Reserves attempt to align existing biodiversity conservation with sustainable resource use, specifically for improving socioeconomic circumstances of resident communities. Typically, the Biosphere Reserve model is applied to an established landscape mosaic of existing land uses; these are often socio-ecological systems where strict environmental protection and community livelihoods are in conflict, and environmental degradation frequently accompanies ''use''. This raises challenges for successful implementation of the model, as the reality of the existing land-use mosaic undermines the theoretical aspirations of the Biosphere concept. This study focuses on the Kruger to Canyons Biosphere Reserve (K2C), South Africa; a socio-ecological landscape where formal conservation is juxtaposed against extensive impoverished rural communities. We focus on land-cover changes of the existing land-use mosaic (1993-2006), specifically selected land-cover classes identified as important for biodiversity conservation and local-level resource utilization. We discuss the implications of transformation for conservation, sustainable resource-use, and K2C's functioning as a ''Biosphere Reserve''. Spatially, changes radiated outward from the settlement expanse, with little regard for the theoretical land-use zonation of the Biosphere Reserve. Settlement growth tracked transport routes, transforming cohesive areas of communal-use rangelands. Given the interdependencies between the settlement population and local environmental resources, the Impacted Vegetation class expanded accordingly, fragmenting the Intact Vegetation class, and merging rangelands. This has serious implications for sustainability of communal harvesting areas, and further transformation of intact habitat. The distribution and magnitude of Intact Vegetation losses raise concerns around connectivity and edge effects, with longterm consequences for ecological integrity of remnant habitat, and K2C's existing network of protected areas.
Journal of Vegetation Science, 2015
Questions: How has the vegetation of the major biomes (Grassland, Nama-karoo, Albany Thicket, Azonal) of southeastern South Africa changed over the course of the 20th century? How do changes in climate and land-use drivers relate to long-term changes in vegetation? What are the implications of these findings for land degradation hypotheses and future climate change projections for the region? Location: The biogeographically complex semi-arid, Karoo Midlands region of the southeastern part of South Africa. Methods: We re-photographed 65 historical landscape photographs, the majority of which dated from 1950 to 1970, to measure long-term changes in the cover of grasses, dwarf shrubs, tall shrubs and alien plants. The cover of each growth form as well as total vegetation cover was estimated from matched photograph pairs with the aid of detailed cover estimates recorded in the field. The change in cover was relativized between sites by dividing the difference in cover between the two time steps by the number of years between photographs, expressed as the percentage change in cover per decade. Significant changes in mean annual rainfall and the standardized precipitation index (SPI) from 27 climate stations were assessed using a Mann-Kendall test for trend. This non-parametric test was also used to assess the significance of long-term trends in the number of cattle, sheep and goats in each of the biomes over the period 1911-1996. Results: Grass cover and total vegetation cover had increased by between 1.0% to 4.5% per decade and 2.0% to 4.5% per decade, respectively, in all biomes investigated. In contrast, the cover of dwarf shrubs had decreased significantly by between 0.25% and 3.0% per decade, although not significantly so in the Nama-karoo biome. The change in tall shrub cover varied between different biomes but had generally increased in the study area. Alien plants were absent in the historical photographs and had increased significantly but only in Azonal habitats, where increases of 1.5% per decade were recorded. For the majority of climate stations no significant trend in mean annual rainfall and SPI values was recorded, while stocking rate had declined significantly in all biomes by between 36% and 48% from 1911 to 1996. Conclusions: The findings support the hypothesis that vegetation cover and condition has improved in the semi-arid regions of South Africa. These findings are discussed in light of future projections for the region.
African Journal of Range & Forage Science, 2019
Although wildlife production is widely considered beneficial for semi-arid environments, few studies have reported on the long-term environmental effects of converting from livestock production to game ranching. Asante Sana Game Reserve in South Africa was stocked with domestic livestock for centuries. However, after 1996 game ranching was adopted in the reserve. We investigated the long-term (1987-2017) spatial and temporal change in vegetation productivity and type on the reserve using Landsat multispectral data and soil adjusted vegetation index (SAVI), and explored the relationship between changes in vegetation productivity and the potential drivers. The results show that while Thicket has decreased overall, it has expanded into parts of Grassland and Shrubland, and Bare-ground has expanded into parts of Shrubland and Thicket. Overall vegetation productivity increased over time, with the greatest increases in Thicket and Grazing lawn and the lowest in Shrubland and Bare-ground. Changes in rainfall, fire and stocking rates were all significant predictors of the observed changes in vegetation productivity, but rainfall had the strongest effect. This research highlights some of the complex responses that arise in semi-arid vegetation when domestic livestock production is replaced by game ranching, and points towards key issues that can be addressed by management.
Environmental Conservation, 2016
SUMMARYAs multi-use conservation landscapes, biosphere reserves (BRs) exemplify the landscape mosaic approach to environmental decision-making. In this study, time-series remotely-sensed data (1993–2006–2012) were used to monitor vegetation transformation in the Kruger to Canyons Biosphere Reserve (K2C) of South Africa, updating previous land-cover research. We identified changes in spatial extent, rate and intensity of land-cover change and extrapolated observed trends to 2018. The increased rate of change in the recent observation period (2.3 vs. 5.7%) was driven by more intensive gains in impacted vegetation and settlement since 2006 (>210 km2and >120 km2), with resultant transformation of intact habitat undermining regional connectivity. By 2012, intact vegetation had suffered losses of 6.3% (>350 km2) since 2006 and >14% (>750 km2) since 1993. A further 9.5% loss of intact habitat may represent a critical threshold, establishing K2C above the 50% threshold of lan...
Environmental Monitoring and Assessment
In semi-arid regions, interactions between biophysical and socio-economic variables are complex. Such interactions and their respective variables significantly alter land use and land cover, degrade landscape’s structure, and impede the efficacy of the adopted land management interventions. This scenario is particularly prevalent in communal land tenure system or areas managed by a hybrid of traditional and state led institutions. Hence, this study sought to investigate the impacts of land use and land cover changes (LULCCs) on land degradation (LD) under communal rural districts, and the key drivers of habitat fragmentation in the Greater Sekhukhune District Municipality (GSDM), South Africa. The study used the wet and dry season multi-temporal remotely sensed image data, key-informant interviews, and workshop with tribal council to determine the major drivers of LULCC and LD. Results revealed that mines and quarries, subsistence and commercial cultivation, and thicket/dense bush L...