Biodiversity value of grassland ecological networks in afforested areas, KwaZulu-Natal, South Africa

[摘要] ENGLISH ABSTRACT: The current biodiversity crisis requires creative initiatives for mitigating furtherbiodiversity loss. The use of ecological networks (ENs) is such an initiative. The SouthAfrican forestry industry recognizes that there is loss of biodiversity at the smaller patchscale, while attempting to mitigate this loss at the landscape scale by implementing largescaleENs.The aim of this study was to determine how representative grassland biodiversity inENs are of similar habitat in a nature reserves (NR). The study was conducted in the northeastof the KwaZulu-Natal Province, adjacent iSimangaliso Wetland Park, which is a naturalWorld Heritage site. A systematic approach compared a wide range of taxa, namely plants,decomposition macrofungi, vertebrates (birds and large mammals) and faunal manifestations(e.g. molehills, dung and ant nests) between the EN and nature reserve, while controlling fordifferences in disturbance regime. Species richness was compared using Mann-Whitney Utests, while differences in species composition were determined using CorrespondenceAnalyses, Multi-Dimensional Scaling and Analyses of Similarity.Grassland ENs had significantly less plant species. In addition, there were differencesin plant and fungi species composition. Differences were probably caused by (1) degree ofisolation i.e. proximity to source habitat patches in the surrounding matrix, and (2) habitatquality. Habitat quality was determined by local disturbance regimes (e.g. grazing and fire)and plantation-induced drought for plants, and size and amount of coarse woody debris forfungi. In addition, significant differences in abundances of mole hills (NR>EN) and smallmammal burrows (EN>NR) might have had an effect on succession and regeneration of plantcommunities.There were differences in plant species composition between grassland EN and that atthe adjacent nature reserve. However, differences between EN and NR were small whencompared to differences between habitat types at the landscape spatial scale. It is concludedthat grassland ENs among forestry plantations contribute to biodiversity conservation in thecommercially-productive landscape. This approach to land use planning should be exploredfor other commercial land uses.

[发布机构] Stellenbosch University