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What do we mean by vegetation? At its simplest, vegetation can be described as the group of plants forming the plant cover of a geographic area. As humans, we tend to classify things, and so vegetation has been classified too. Floral KingdomsAt a global scale the vegetation of the world is sometimes described in terms of six Floristic Regions, often called the Floral Kingdoms of the world. The distinction between regions is based on distinctive suites of flowering plants, taking into account those (particularly families) that are exclusive (endemic) to the region. Of particular note to South Africans is that the Cape forms one of these distinct kingdoms; the Cape Floral Kingdom, covering 0.08% of the world's land surface, but containing about 3% of the world's plants. This is a precious resource to be proud of and to conserve for future generations. For more information about the Cape Floral Kingdom, see Fynbos Biome. BiomesGroupings called Biomes have been described based on dominant forms of plant life and prevailing climatic factors. Biomes have plants and/or animals living together with some degree of permanence, and one can observe large-size patterns in global plant cover. Biomes broadly correspond with climatic regions as moisture and temperature strongly influence plant establishment and survival, although other environmental controls are sometimes important. Each biome has a characteristic set of plant and animal species as well as a characteristic overall physiognomy. Physiognomy is used to interpret a person's character from facial features, so one can recognize a biome by its general appearance given by the shapes of the plants, and the landscape. The general plant characteristics give a distinctive appearance or visual signature that enables one to recognize the biome. For example, grasslands have mostly grass, deserts have much bare ground for most of the year but lots of annual plants following rain, forests have mostly tall trees with plants growing beneath the canopy at ground layer and at other levels. Mucina and Rutherford (2006) map nine biomes in South Africa:
and two on the subantarctic Prince Edward Islands:
Rutherford and Westfall (1994) map six biomes in South Africa :
Map of Biomes (.jpg) Map of Biomes according to Mucina and Rutherford (2006) Vegetation map The vegetation of South Africa has recently been mapped and described by groups of local experts. The book 'The Vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19' was published in 2006. There are 435 vegetation types described in South Africa, Lesotho and Swaziland, with 5 units mapped for the Prince Edward Islands. There are descriptions for each vegetation type in each Biome. The descriptions include paragraphs that give details about how each vegetation type relates to previously published vegetation maps, distribution of the mapped vegetation, vegetation and landscape features, geology and soils, climate, lists of biogeographically important and endemic taxa, conservation, and remarks. A vegetation type is not as easy to recognize as a biome. The biome can be seen as the broad landscape and looks at dominant life forms and not at species. The vegetation type is defined in terms of dominant, common as well as rare species, as well as association with landscape features such as soil or geology, topography and climate. Veld types For many years the Veld Types described by John Acocks were the used and accepted vegetation units. Acocks travelled very widely throughout South Africa during a 40-year period and sampled some 3300 sites. He was meticulous in recording plant species at the various sites and he described vegetation patterns at a scale that is much smaller than the biome. He described 70 Veld Types in South Africa, Lesotho and Swaziland. One can refer to Acocks' book Veld Types of South Africa for the descriptions, together with photographs, species compositions, and some other characteristics of each veld type. Map
of Acocks' Veld Types (.jpg) Other vegetation maps There was a map produced in 1935 by Pole Evans that describes 12 vegetation types for South Africa. This was followed in 1938 by Adamson who published a map with 14 vegetation types. GIS
files Next time you travel, take time to look around to see if you can recognise characteristic patterns and shapes to the vegetation about you. Alien Plants The natural vegetation of South Africa is being invaded by alien plants (plants from elsewhere in the world). These are the Declared Weeds & Invader Plants as listed in 2001. Red data lists, protected plants and permits Further Reading on Vegetation
Further information on vegetation can be found on the SANBI website:
Adapted from an article by Les Powrie September 2000
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© S A National Biodiversity Institute |
