Vegetation types
The following descriptions reflect the latest national vegetation information available 1 and the vegetation units described below (in alphabetical order) form the basis for the latest terrestrial conservation planning done in the City. Vegetation types are landscape-scale units of biodiversity that comprise a range of different plant communities and habitats. For example, calcrete outcrops and wetlands occur within particular vegetation types and contribute to overall biodiversity in those vegetation types. In addition, where two different vegetation types meet, there may be an abrupt vegetation boundary, reflecting a sudden change in underlying geology and soils, or else a wide transition zone – often called an ecotone – where physical changes are more gradual and attributes of both vegetation types are mixed.
It is important to note that all fynbos and renosterveld vegetation types are fire-prone and require periodic fires to regenerate their full species complement and prevent plant extinctions. Fire-return intervals are generally prescribed at between 8-30 years for fynbos and 4-10 years for renosterveld, with factors such as rainfall and soil-type playing a role in growth rates and required burning schedules. In the Cape Town area the natural fire season (and the optimal season for biodiversity conservation) is summer (January to March). By contrast, fire is not essential (but may occur occasionally) in strandveld and forest vegetation type.
Based on: Rebelo et al. Fynbos Biome (2006). In: Mucina L & Rutherford M L (editors). The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19, SANBI, Pretoria; Driver A (in prep) Threatened ecosystems for listing under NEM:BA 2008, South African Biodiversity Institute, Pretoria.