The ecology and classification of wetland vegetation in the Maputaland Coastal Plain, South Africa
Pretorius, Lulu; Brown, Leslie R.; Bredenkamp, George J.; van Huyssteen, Cornie W.
Aims: The purpose of this paper is to identify and discuss the plant species composition of five different wetland types found on the Maputaland Coastal Plain (MCP), to determine whether the vegetation patterns can be related to the major substrate types, and to determine the relationship between environmental variables and plant communities in order to elucidate the delineation of wetland and wetland zones in this area. Location: The MCP in north-eastern KwaZulu-Natal (KZN) is known for its biodiversity, diverse ecosystems, high density of wetlands, and highest proportion of all South Africa's peatlands. Yet there is insufficient wetland vegetation research in the region. Additionally, the delineation of wetlands in this area is widely regarded as problematic due to complex wetland soils. It is believed that an understanding of the vegetation composition of wetland zones in different types of wetlands can aid the understanding of wetland types and wetland zone delineation on sandy coastal aquifers as is found in northern KZN. Methods: Twenty wetlands from five wetland types were surveyed. The vegetation of each wetland was sampled along a transect following the Braun-Blanquet approach. The software packages Turboveg for Windows 1.97, JUICE 7.0, TWINSPAN, and PC-ORD 5 were used to analyse the data. Both Detrended Correspondence Analysis (DCA) as well as Canonical Correspondence Analysis (CCA) were applied to the data. Results: The results indicated that the strongest correlation with wetland plant communities on the MCP is the substrate type and hydrological regime, with the wetland type as the finer classification factor. Specific plant communities are best associated with specific wetland types. Conclusions: Vegetation composition cannot be used to distinguish between each and every unique wetland zone, but it can be successfully used to differentiate between the different topographical positions on a slope, which can be correlated to the hydrological regime.