The wetland flora of South Africa: Occurrence patterns, frequency and dominance across a diverse landscape

Abstract

A survey of vascular plant species occurring in various wetland habitats in South Africa has been generated by supplementing the species list from a vegetation survey with a herbarium checklist and this list of wetland species is compared with the overall flora of South Africa. About 18.8% of all the South African species occur in wetlands and about 4.5% of all species are obligate wetland species, in the sense that they will not be found outside of the wetland environment. These fractions are compared with the fractions calculated per family and this indicates which families are over- or underrepresented in the South Africa wetland flora. Most of the families that are well represented in wetlands are in the monocots and particularly in the Poales, but wetlands in the Fynbos Biome are much more phylogenetically diverse. There are four main wetland assemblages that can be defined by their family composition and that are characteristic of specific wetland environments. These can generally be described as the environments that are permanently submerged, the environments that are permanently to intermittently inundated, the environments of inland saline pans and environments on extremely nutrient-poor substrates consisting of coastal sands, quartzites or peat.