Temperate grassy wetlands of South Africa: Description, classification and explanatory environmental factors

• Published in: South African journal of botany 2017-11, Vol.113, p.68-76
• Main Authors: Sieben, E.J.J., Collins, N.B., Kotze, D.C., Mofutsanyana, S.S., Janks, M.
• Format: Article
• Language: English
• ISSN: 0254-6299; 1727-9321
• DOI: 10.1016/j.sajb.2017.07.009

The common wetland vegetation types categorized as temperate grassy wetlands have tall or medium tall graminoids that are found in the Highveld and other grassland areas in South Africa, but can extend into other biomes. The data on temperate grassy wetlands were extracted from a nationwide wetland vegetation database, consisting partly of historical vegetation data and partly newly collected data. A classification of these vegetation types took place using cluster analysis. Some of the vegetation data contained detailed soil parameters, which were used in canonical ordination to illustrate which environmental variables have the most impact on these vegetation types. Temperate grassy wetlands consist of twenty-five communities, which have been summarized in this paper into thirteen community groups. These wetlands occur over a wide altitudinal range as many of the species occurring in them have broad ecological amplitudes and are competitive even outside of their optimum range. The environmental variables that were the most important in explaining both the variation in the dataset and the vegetation types were wetness and altitude. •A database of wetland vegetation plots for South Africa has been constructed on the basis of existing and newly collected data.•Temperate grassy wetlands, represented by 1412 plots, have been pulled out of the national database.•Cluster analysis led to 25 communities which have been summarized into 13 community groups.•Canonical ordination reveals that the most important environmental factors are altitude and wetness.•The total variation explained is 12.2% which is quite low compared to other wetland types.