Equivalence of grasslands in an ecological network and a World Heritage Site
Ecological networks (ENs) of indigenous vegetation among commercial forestry plantations have been implemented to offset the negative effects of the alien plantation trees on local biodiversity. However, it is not known whether these ENs are equivalent to protected areas (PAs) in terms of their grassland biodiversity. To address this knowledge gap, we investigated how well grassland plant species richness and composition in an EN corresponds to similar habitats in an adjacent PA. This took place in grasslands on the east coast of South Africa, and was done at four paired sites using ten replicates at each of the eight sites. Pairwise comparisons (EN vs. PA) of plant species composition yielded statistically smaller differences than comparisons between different pairs of sites within either the EN or PA, illustrating considerable turnover of species whether or not they were in an EN or PA. Overall, there were fewer plant species in the EN for three of the four pairs of sites. Nevertheless, plant species composition was similar in each pair of sites. The grassland EN was also characterized by greater maximum vegetation height and less green vegetation cover. When differences between the EN and a PA were viewed against the natural variation of abiotic and biotic conditions across the landscape, they were small. We conclude that ENs of natural habitat contribute substantially to biodiversity conservation in transformed, commercially-productive landscapes, are almost as good as PAs for maintaining grassland plant diversity.
KeywordsBiodiversity conservation Afforested landscape matrix Grasses Habitat fragmentation World Heritage Site Plant diversity
We thank L Ezzy for field assistance, and C Burchmore, G Kruger, M Kruger and L Shaw for providing maps, accommodation at study sites, technical assistance and local knowledge. We also thank Ezemvelo KZN Wildlife, iSimangaliso Wetland Park Authority, Mondi South Africa and SiyaQhubeka Plantations for allowing sampling on their respective properties. The Mondi Ecological Network Programme (MENP) and the National Research Foundation (NRF) of South Africa funded the research.
- Clarke KR, Warwick RM (2001) Change in marine communities: an approach to statistical analysis and interpretation. PRIMER-E, PlymouthGoogle Scholar
- Grubb P (1981) Equus burchelli. Amer Soc Mammal 157:1–9Google Scholar
- Jaksic FM (1986) Predation upon small mammals in shrublands and grasslands of southern South America: ecological correlates and presumable consequences. Rev Chil Hist Nat 59:209–221Google Scholar
- Keeley JE (1998) Postfire ecosystem recovery and management: the October 1993 large fire episode in California. In: Moreno JM (ed) Large forest fires. Backhuys, Leiden, pp 69–90Google Scholar
- Mucina L, Rutherford MC, Powrie LW (2005) Vegetation map of South Africa, Lesotho and Swaziland, 1:1000000 scale sheet maps. South African National Biodiversity Institute (SANBI), PretoriaGoogle Scholar
- Neke KS, du Plessis MA (2004) The threat of transformation: quantifying the vulnerability of grasslands in South Africa. Conserv Biol 18:466–477Google Scholar
- SGS Qualifor (2007) Forest management certification report: Forest Management Certificate for SiyaQhubeka Forests, document no. AD 36-A-05. Unpublished Report. SGS South Africa (Qualifor Programme) Systems and Services Certificate Division, Richards BayGoogle Scholar
- United Nations Environment Programme and World Conservation Monitoring Centre (2011) World Heritage Sites: protected areas and world heritage. iSimangaliso Wetland Park, KwaZulu-Natal, South Africa. http://www.unep-wcmc.org/medialibrary/2011/06/29/0efed969/iSimangaliso.pdf. Accessed 19 Oct 2012
- van Wilgen BW, Govender N, MacFadyen S (2008) An assessment of the implementation and outcomes of recent changes to fire management in the Kruger National Park. Koedoe 50:22–31Google Scholar