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Biodiversity is the foundation of life-support systems on earth and underpins the delivery of ecosystem services (ES) important for human well-being. The loss of biodiversity worldwide, however, remains one of the most daunting challenges. Among the major causes of biodiversity loss is habitat loss due to transformation of land to agricultural, mining and urban areas. We applied the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) biodiversity modelling tool to assess the condition of habitats to support the delivery of ES in a biosphere reserve (BR) in South Africa. Results indicated that 72% of the surveyed habitats were of high quality to provide the necessary services. However, some of the habitats were found to be affected by threats as follows: low (0–20%) to moderate (20–32%) habitat loss was recorded in habitats adjacent to mining and plantation areas, and high (32–56%) to severe (56–95%) habitat loss was recorded in habitats in close proximity to urban and cultivated areas. At least 56% of the vegetation types found in the study area were threatened by transformation to agriculture, mining and urban areas. We strongly recommend that existing biodiversity policies and legislation should be enforced to avoid habitat loss and degradation. [ABSTRACT FROM AUTHOR]

Using an analysis of aerial photographs from 1942, 1985 and 2004 we assessed the impact of changing land tenure and land-use regimes on the cover of thicket vegetation on the Grahamstown commonage. Land-use impacts were examined by comparing plant species composition within three vegetation types between sites incorporated into commonage for different lengths of time and sites outside the commonage. Results showed that thicket cover increased by 87% between 1942 and 1985 but declined by 11% between 1985 and 2004. The increase in thicket cover was highest on land where goat browsing and wood harvesting was excluded. There was a decline in thicket cover when uncontrolled goat browsing and wood harvesting were introduced. An analysis of plant species composition suggests an increase in the impact of livestock in areas closest to the urban area and with time since inclusion into commonage. Such areas exhibited greater cover of Increaser II grasses and dwarf shrubs in the herbaceous layer and lower cover of succulents within subtropical thicket. We interpret the decline in thicket cover and shift to a less palatable and less productive vegetation as resulting from the open-access land use system that has prevailed on the commonage since 1994. [ABSTRACT FROM AUTHOR]

We examined the effect of changes in land use and land tenure on bush encroachment and vegetation condition. An analysis of aerial photographs from three time steps (1949, 1985 and 2004) was used to document changes in woody plant density in different vegetation types on commonage and an adjacent commercial farm in Fort Beaufort, South Africa. Rangeland condition was assessed in different vegetation units of the area and woody plant density was related to distance from urban settlement. Results showed that there has been an increase in woody plant cover in both commonage and commercial farming areas, particularly between 1949 and 1985. However, since 1985, increased rates of urbanisation have stabilised, and in some areas reduced, woody plant thickening, especially at locations closest to urban settlements. Bush encroachment is being controlled to some extent by fuelwood harvesting and goat browsing, resulting in a reduction in height of favoured woody species such asAcacia karroo(Vachellia karroo). There has been a shift to less palatable browse species on the commonage areas and the condition of the grass sward is poor. Change in woody plant cover is significantly influenced by changing patterns of land use and land tenure over time which, in turn, affect rangeland condition. [ABSTRACT FROM AUTHOR]

Environmental systems are in constant flux, with feedbacks and non-linearities catalysed by natural trends and shocks as well as human actions. This poses challenges for sustainable management to promote human well-being. It requires environmental understanding and application that can accommodate such fluxes and pressures, as well as knowledge production systems and institutions that produce graduates with appropriate skills. In this article we consider these challenges in the South African context. Firstly, we summarise six significant environmental realisations from the last decade of environmental science internationally and question what they mean for the teaching of environmental science and research into environmental systems in South Africa in the near future. We then consider these lessons within the context of a horizon scan of near-term pressing environmental issues in South Africa. These include water-use efficiency, poverty, food security, inequities in land and resource access, urbanisation, agrochemicals and water quality, promoting human well-being and economic adaptability in the face of climate change, and imbuing stronger environmental elements and stewardship into the integrated development planning processes and outcomes. Lastly, we consider the knowledge areas and skills that environmental graduates will require to be able to confront these problems in South Africa and simultaneously contribute to international debates and understandings around the complexity of environmental systems and how to manage them. [ABSTRACT FROM AUTHOR]

The negative impacts of invasive alien species on the environment are well documented. However, despite the predominantly negative perceptions associated with invasive species, it is evident that a number of these plants have been part of the landscape for generations and have numerous commercial and non-market uses. Consequently, there is a need for research that considers the impact of invasive species on the livelihoods and well-being of local communities. The authors investigated the contribution that the trade in prickly pear (Opuntia ficus-indica), an invasive alien species, makes to the household income streams of poor trading households. The research highlights the apparent conflict of interests and trade-offs that exists between local traders, for whom the sale of the prickly pear provides a livelihood source, and the South African Government, who are actively seeking to remove the plant from the landscape. [ABSTRACT FROM AUTHOR]