A multi-taxa functional diversity assessment of the effects of eco-estate development in the mixed land-use mosaic of the KwaZulu-Natal North Coast, South Africa

Global biodiversity is currently under threat from human population expansion and the required land transformation for shelter and resources. Land transformation, in the form of agriculture or urbanisation is believed to reduce habitats and their resources, increase fragmentation of natural habitats, and increase the likelihood of successful invasion by exotic species. These all affect existing biodiversity, its structure, and the ecosystem services which it provides. In recent years, development from natural and agricultural (mainly sugarcane) land into eco-estates (housing developments with the intention of conserving the environment) has become increasingly popular along the north coast of KwaZulu-Natal (KZN), South Africa. However, research on their impacts on the local environment is limited. We predicted that these eco-estates are, by their design, improving the functional diversity of amphibians, birds, and mammals, and ultimately ecosystem functioning. A multi-taxa assessment of the three components of functional diversity (functional richness, functional evenness, and functional divergence) suggested that eco-estate development was improving certain components for each of the taxa assessed. However, the management and development of these eco-estates was the key determinant. Eco-estates with increased interconnected indigenous forest and thicket/dense bush, with reduced housing and road density, exhibited improved functional diversity in comparison with those more densely inhabited containing isolated natural land-cover patches. We believe that these eco-estates could provide an effective mitigation method of population expansion whilst maintaining ecosystem health, but only under the recommended development and management plans.