The subcontinent’s status as a floristic hot spot brings with it the responsibility of safeguarding our heritage, nowhere more so than in the Fynbos Biome: while South Africa as a whole has 2 577 plant species (13 per cent of its flora) considered to be in danger of extinction, no fewer than 1 736 of these are from the Fynbos Biome, with a total of 3 087 (36 per cent) of the fynbos flora considered to be of conservation concern. High levels of land transformation in the Cape lowlands, and the invasion of alien species on both lowlands and in the mountains, are the main causes of species loss.
Trips To Australia And Kirstenbosch National Botanical Garden Photo Gallery
Thus the high levels of species richness, endemism and the threat of extinction make the tiny Cape Floral Kingdom the ‘hottest hot spot’ of them all.
Endemism is the second criterion in hot-spot analysis. Endemics are species (or genera or families) that are found nowhere else on Earth. We have already seen how rich the Cape Floral Kingdom is in endemics, with no fewer than 68 per cent of its 9 381 species being endemic to its 90 760 square kilometres. Local, or narrow, endemics can be found on most mountains or unusual soil types -adding, at fine scale, to the complexity and vulnerability of the flora.
The measures of species richness and endemism of plants within the Cape Floral Kingdom are exceptional, by any standard. But richness and endemism are only two of the criteria used to assess and identify hot spots – threat is as important as the first two.
Since the mid-1970s, South African scientists have collaborated in ongoing projects aimed at measuring and monitoring the levels and kinds of activities and processes threatening the survival of our plant and animal species. Initiated by the then National Programme for Environmental Sciences, co-ordinated by the Council for Scientific and Industrial Research (CSIR), the programme produced an impressive series of Red Data blogs, which presented syntheses of knowledge on the status of rare plants, birds, mammals, fish, frogs, reptiles and butterflies. In 1996 Kirstenbosch Research Centre conservation scientist Craig Hilton-Taylor, working with a dozen colleagues around the region, listed 4 149 species assessed in South Africa, Botswana, Lesotho, Swaziland and Namibia. Of these, 1 435 were considered globally threatened with extinction at the time.
Hilton-Taylor’s database was later vastly expanded by a new Threatened Species Programme, again led by SANBI, but now from its Pretoria offices. From 2002 to 2008, the team compiled the world’s most comprehensive synthesis on a national flora ever undertaken – the full 20 456 species of fern and flowering plant of South Africa being assessed using the objectively rigorous ‘IUCN 2001’ criteria across seven categories of threat.
On 2 November 1774, Carl Thunberg and Francis Masson climbed the Bokkeveld escarpment, discovering the amazing Aloe dichotoma, or Kokerboom, at a site not far from the Hantam National Botanical Garden.