School of Animal, Plant and Environmental Sciences
Permanent URI for this communityhttps://wiredspace.wits.ac.za/handle/10539/20141
For queries regarding content of Faculty of Science please contact Salome Potgieter by email : salome.potgieter@wits.ac.za or Tel : 011 717 1961
Browse
2 results
Search Results
Item Land-cover change in the Kruger to Canyons Biosphere Reserve 1993-2006): A first step towards creating a conservation plan for the subregion.(Academy of Science of South Africa (ASSAf), 2010-07) Coetzer, K.L.; Erasmus, B.F.N.; Witkowski, E.T.F.; Bachoo, A.K.This paper is a first step towards a conservation plan for the Kruger to Canyons Biosphere Reserve K2C) on the South African Central Lowveld, quantifying the historical land-cover trends 1993-2006). During the analysis period, 36% of the biosphere reserve BR) underwent land-cover change. Settlement areas increased by 39.7%, mainly in rural areas, becoming denser, particularly along roadways. Human-Impacted Vegetation increased by 6.8% and Intact Vegetation declined by 7.3%, predominantly around settlement areas, which is testament to the interdependency between rural communities and the local environment. However, settlement expansion exceeded the rate of rangeland growth; in the long term, this may raise questions for sustainable resource extraction. Similarly, the block losses of intact vegetation are of concern; issues of fragmentation arise, with knock-on effects for ecosystem functioning. In the economic sector, agriculture increased by 51.9%, while forestry and mining declined by 7.1% and 6.3%, respectively. The future of these three sectors may also have significant repercussions for land-cover change in the BR. The identification of historical drivers, along with the chance that existing trends may continue, will have important implications for biodiversity protection in this landscape. Applied within a conservation-planning framework, these land-cover data, together with economic and biodiversity data, will help reconcile the spatial requirements of socio-economic development with those of conservation.Item Systematic land-cover change in KwaZulu-Natal, South Africa: Implications for biodiversity.(Academy of Science of South Africa (ASSAf), 2015-09) Jewitt, D.; Goodman, P.S.; Erasmus, B.F.N.; O'Connor, T.G.; Witkowski, E.T.F.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 formed a significant part of landscape change, including a return from anthropogenic categories to secondary vegetation, which we suggest should be tracked in analyses. Longer-term rates of habitat loss were determined using additional land-cover maps (1994, 2000). An average of 1.2% of the natural landscape has been transformed per annum since 1994. Apart from the direct loss of natural habitat, the anthropogenically transformed land covers all pose additional negative impacts for biodiversity remaining in these or surrounding areas. A target of no more than 50% of habitat loss should be adopted to adequately conserve biodiversity in the province. Our analysis provides the first provincial assessment of the rate of loss of natural habitat and may be used to fulfil incomplete criteria used in the identification of Threatened Terrestrial Ecosystems, and to report on the Convention on Biological Diversity targets on rates of natural habitat loss.