Advertisement

Biodiversity & Conservation

, Volume 5, Issue 5, pp 575–589 | Cite as

Profiling a besieged flora: endemic and threatened plants of the Cape Peninsula, South Africa

  • H. Trinder-Smith
  • R. M. Cowling
  • H. P. Linder
Papers

Abstract

The Cape Peninsula (area: 471 km2), situated at the south-western extremity of the Cape Floristic Region, has exceptionally high plant species richness (2285 species and infraspecific taxa) and numbers of endemic (90; 88 species and two infraspecific) and threatened (141; 138 species and three infraspecific) taxa (termed species from here on). This biodiversity is threatened by urban development and the spread of invasive alien plants. Peninsula endemics are concentrated in a few, predominantly species-rich families and these correspond well with endemic-rich families in other areas of the Cape Floristic Region. A high level of similarity exists between families with threatened and families with endemic species. A frequency analysis of the biological traits of both endemic and threatened species shows that low growing, ant-dispersed shrubs are over-represented in both groups. Endemics are most likely to be non-sprouters, but threatened plants do not have a specific post-fire regeneration strategy. Threatened species have higher frequencies of geophytes, sprouters and wind-dispersed species compared to endemic species. Numbers of endemic and threatened species are not randomly distributed with regard to occurrence in vegetation types and patterns are similar for both groups. The habitat and biological profiles of both endemic and threatened species suggest that they are highly vulnerable to extinction as a result of increasing rates of alien plant infestation, urbanization and inappropriate fire regimes.

Keywords

Cape Peninsula fynbos endemism rarity taxonomic profile biological profile threats 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Adamson, R.S. and Salter, T.M. (eds) (1950) Flora of the Cape Peninsula. Cape Town: Juta.Google Scholar
  2. Arnold, T.H. and de Wet, B.C. (eds) (1993) Plants of Southern Africa: Names and distribution. Memoirs of the Botanical Survey of South Africa No. 62 pp. 825. Pretoria: National Botanical Institute.Google Scholar
  3. Baskin, J.M. and Baskin, C.C. (1988) Endemism in rock outcrop plant communities of unglaciated eastern United States: an evaluation of the roles of edaphic, genetic and light factors. J. Biogeogr. 15, 829–40.Google Scholar
  4. Bolus, H. and Wolley-Dod, A. (1903) A list of the flowering plants and ferns of the Cape Peninsula, with notes on some critical species. Trans. S. Afr. Phil. Soc. 14, 207–373.Google Scholar
  5. Bond, W.J. (1983) On alpha diversity and the richness of the Cape flora: a study in the southern Cape Fynbos. In Ecological Studies, Vol. 43: Mediterranean-Type Ecosystems (F.J. Kruger, D.T. Mitchell and J.U.M. Jarvis, eds) pp. 337–56. Berlin: Springer-Verlag.Google Scholar
  6. Bond, P. and Goldblatt, P. (1984) Plants of the Cape flora: a descriptive catalogue. J. S. Afr. Bot. Sup. vol 13, 1–455.Google Scholar
  7. Bond, W.J. and Slingsby, P. (1983) Seed dispersal by ants in shrublands of the Cape Province and its evolutionary implications. S. Afr. J. Sci. 79, 231–3.Google Scholar
  8. Bond, W.J., Le Roux, D. and Erntzen, R. (1990) Fire intensity and regeneration of myrmecochorous Proteaceae. S. Afr. J. Bot. 56, 326–30.Google Scholar
  9. Cody, M.L. (1986) Diversity, rarity and conservation in Mediterranean-climate regions. In Conservation Biology (M. Soulé, ed.) pp. 122–52. Sunderland, Massachusetts: Sinauer Press.Google Scholar
  10. Cowling, R.M. (1983) Phytochorology and vegetation history in the south-eastern Cape, South Africa. J. Biogeogr. 10, 393–419.Google Scholar
  11. Cowling, R.M. and Holmes, P. (1992) Endemism and speciation in the lowland flora from the Cape Floristic Region. Biol. J. Linn. Soc. 47, 367–83.Google Scholar
  12. Cowling, R.M., Holmes, P. and Rebelo, A.G. (1992) Plant diversity and endemism. In The Ecology of Fynbos: Nutrients, Fire and Diversity (R.M. Cowling, ed.) pp. 62–110. Cape Town: Oxford University Press.Google Scholar
  13. Cowling, R.M., Macdonald, I.A.W. and Simmons, M.T. (1996) The Cape Peninsula, South Africa: physiographical, biological and historical backround to an extraordinary hot-spot of biodiversity. Biodiv. Conserv 5, 527–50.Google Scholar
  14. Cowling, R.M. and Samways, M.J. (in press) Predicting global patterns of endemic plant species richness. Biodiv. Lett. Google Scholar
  15. Dahlgren, R.M.T. and Clifford, H.T. (1982) The Monocotyledons. A comparative study. London: Academic Press.Google Scholar
  16. Dent, M.C., Lynch, S.D. and Schulze, R.E. (1987) Mapping mean annual and other rainfall statistics over southern Africa. Water Res. Commission Rep. 109/1/89.Google Scholar
  17. Dobzhansky, T., (1950) Evolution in the tropics. Am. Sci. 38, 208–21.Google Scholar
  18. Gentry, A.H. (1986) Endemism in tropical versus temperate plant communities. In Conservation Biology (M. Soulé, ed.) pp. 153–81. Sunderland, Massachusetts: Sinauer Press.Google Scholar
  19. Goldblatt, P. (1978) An analysis of the flora of Southern Africa: its characteristics, relationships, and origins. Ann. Missouri Bot. Gard. 65, 369–436.Google Scholar
  20. Hall, A.H. and Ashton, E.R. (1983) Threatened Plants of the Cape Peninsula, pp. 26. Threatened Plants Research Group, University of Cape Town. Captrust.Google Scholar
  21. Hall, A.V. and Veldhuis, H.A. (1985) South African Red Data Book: Plants — Fynbos and Karoo Biomes, pp. 160. Pretoria: Council for Scientific and Industrial Research. Report No. 117.Google Scholar
  22. Hedberg, O. (1965) Afroalpine flora elements. Webbia 19, 519–29.Google Scholar
  23. Johnson, S.D. (1992) Plant-animal relationships. In The Ecology of Fynbos: Nutrients, Fire and Diversity (R.M. Cowling, ed.) pp. 175–205. Cape Town: Oxford University Press.Google Scholar
  24. Johnson, S.D. and Bond, W.J. (1992) Habitat dependent pollination success in a Cape orchid. Oecologia 91, 455–6.Google Scholar
  25. Kirkpatrick, J.B. (1983) An iterative method for establishing priorities for the selection of nature reserves: an example from Tasmania. Biol. Conserv. 25, 127–34.Google Scholar
  26. Kruckeberg, A.R. and Rabinowitz, D. (1985) Biological aspects of endemism in higher plants. Ann. Rev. Ecol. Syst. 16, 447–79.Google Scholar
  27. Lamont, B.B., Downes, S. and Fox, J.E.D., (1977) Importance value curves and diversity indices applied to a species-rich heathland in Western Australia. Nature 265, 438–41.Google Scholar
  28. Lewis, H. (1962) Catastrophic selection as a factor in speciation. Evolution 37, 79–85.Google Scholar
  29. Linder, H.P. (1985) Conspectus of the African species of Restionaceae. Bothalia 15, 387–503.Google Scholar
  30. Linder, H.P., Vlok, J.H., McDonald, D.J., Oliver, E.G.H., Boucher, C., van Wyk, B.-E. and Schutte, A. (1993) The high altitude flora and vegetation of the Cape Floristic Region, South Africa. Opera Botanica 121, 247–61.Google Scholar
  31. Lucas, S. and Synge, H. (1978) The IUCN Plant Red Data Book. Morges: IUCN.Google Scholar
  32. MacArthur, R.H. (1965) Patterns of species diversity. Biol. Rev. 40, 510–33.Google Scholar
  33. McDonald, D.J. and Cowling, R.M. (1995) Towards a profile of an endemic mountain fynbos flora: implications for conservation. Biol. Conserv. 72, 1–12.Google Scholar
  34. McDonald, D.J., Juritz, J.M., Cowling, R.M. and Knottenbelt, W.J. (in press) Modelling the biological aspects of local endemism in South African Fynbos. Plant Syst. Evol. Google Scholar
  35. Mace, G. and Stuart, S. (1994) Draft IUCN Red List Categories, Version 2.2 Species No. 21-22, pp. 13–24. Newsletter of the Species Survival Commission. IUCN: The World Conservation Union.Google Scholar
  36. Maddox, J.C. and Carlquist, S. (1985) Wind dispersal in Californian desert plants: Experimental studies and conceptual considerations. Aliso 11, 77–96.Google Scholar
  37. Major, J. (1988) Endemism: a botanical perspective. In Analytical Biogeography: an Integrated Approach to the Study of Animal and Plant Distributions (A.A. Myers and P.S. Giller, eds) pp. 117–46. New York: Chapman and Hall.Google Scholar
  38. Moll, E.J. and Trinder-Smith, T.H. (1992) Invasion and control of alien woody plants on the Cape Peninsula Mountains, South Africa — 30 years on. Biol. Conserv. 60, 135–43.Google Scholar
  39. Myers, N. (1988) Threatened biotas: ‘Hotspots’ in tropical forests. Environmentalist 8, 1–20.Google Scholar
  40. Myers, N. (1990) The biodiversity challenge: expanded hot-spot analysis. Environmentalist 10, 243–55.Google Scholar
  41. Oliver, E.G.H., Linder, H.P. and Rourke, J.P. (1983) Geographical distribution of present-day Cape taxa and their phytogeographical significance. Bothalia 14 (3 & 4), 427–40.Google Scholar
  42. Papanicolaou, K., Babalonas, D. and Kokkini, S. (1983) Distribution patterns of some Greek mountain endemic plants in relation to geological substrate. Flora 174, 405–37.Google Scholar
  43. Pianka, E.R. (1966) Latitudinal gradients in species diversity: a review of concepts. Am. Nat. 100, 33–46.Google Scholar
  44. Rabinowitz, D., Cairns, S. and Dillon, T. (1986) Seven forms of rarity and their frequency in the flora of the British Isles. In Conservation Biology (M. Soulé, ed.) pp. 182–204. Sunderland. Massachusetts: Sinauer Publishers.Google Scholar
  45. Raven, P.H. (1964) Catastrophic selection and edaphic endemism. Evolution 18, 336–8.Google Scholar
  46. Raven, P.H. and Axelrod, D.I. (1978) Origin and relationships of the California flora. Univ. Calif. Pub. Bot. 72, 1–134.Google Scholar
  47. Rebelo, A.G. (1994) Iterative selection procedures: centres of endemism and optimal placement of reserves. In Botanical Diversity in Southern Africa (B.J. Huntley ed.) pp. 231–57. Pretoria: National Botanical Institute.Google Scholar
  48. Renner, S.S. (1990) Reproduction and evolution in some genera of neotropical Melastomataceae. Mem. N.Y. Bot. Gard. 55, 143–52.Google Scholar
  49. Rhode, K. (1992) Latitudinal gradients in species diversity: the search for the primary cause. Oikos 65, 514–27.Google Scholar
  50. Richardson, D.M. and van Wilgen, B.W. (1986) Effects of thirty-five years of afforestation with Pinus radiata on the composition of Mesic Mountain Fynbos near Stellenbosch. S. Afr. J. Bot. 52, 309–15.Google Scholar
  51. Richardson, D.M., Macdonald, I.A.W. and Forsyth, G.G. (1989) Reductions in plant species richness under stands of alien trees and shrubs in the Fynbos Biome. S. Afr. For. J. 149, 1–8.Google Scholar
  52. Richardson, D.M., van Wilgen, B.W., Higgins, S.I., Trinder-Smith, T.H., Cowling, R.M. and McKelly, D.H. (1996) Current and future threats to plant biodiversity in the Cape Peninsula, South Africa. Biodiv. Conserv. 5, 607–47.Google Scholar
  53. Simmons, M.T. and Cowling, R.M. (1996) Why is the Peninsula so rich in plant species? An analysis of the independent diversity components. Biodiv. Conserv. 5, 551–573.Google Scholar
  54. Stebbins, G.L. and Major, J. (1965) Endemism and speciation in the California flora. Ecol. Monogr. 35, 1–35.Google Scholar
  55. Stevens, G.C. (1989) The latitudinal gradient in geographical range: how so many species coexist in the tropics. Am. Nat. 133, 240–56.Google Scholar
  56. Stevens, G.C. (1992) The elevational gradient in altitudinal range: an extention of Rapoport's latitudinal rule to altitude. Am. Nat. 140, 893–911.Google Scholar
  57. Taylor, H.C. (1978) Capensis. In Biogeography and Ecology of Southern Africa (M.J.A. Werger, ed.) pp. 171–229. The Hague: Dr W. Junk.Google Scholar
  58. Terborgh, J. (1974) Preservation of natural diversity: the problem of extinction prone species. BioScience 24, 715–22.Google Scholar
  59. Terborgh, J. and Winter, B. (1983) A method of siting parks and reserves with special reference to Columbia and Ecuador. Biol. Conserv. 27, 45–58.Google Scholar
  60. Trinder-Smith, T.H., Lombard, A.T. and Picker, M. (1996) Reserve scenarios for the Cape Peninsula: high, middle and low road options for conserving the remaining biodiversity. Biodiv. Conserv. 5, 649–69.Google Scholar
  61. Usher, M.B. (1987) Effects of fragmentation on communities and populations: a review with applications to wildlife conservation. In Nature Conservation: the Role of Remnants of Native Vegetation (D.A. Saunders, G.W. Arnold, A.A. Burbidge and A.J.M. Hopkins, eds) pp. 103–21. Surrey Beatty and Sons Pty Ltd. in association with CSIRO and CALM.Google Scholar
  62. van Wilgen, B.W., Bond, W.J. and Richardson, D.M. (1992) Ecosystem management. In The Ecology of Fynbos: Nutrients, Fire and Diversity (R.M. Cowling, ed.) pp. 345–71. Cape Town: Oxford University Press.Google Scholar

Copyright information

© Chapman & Hall 1996

Authors and Affiliations

  • H. Trinder-Smith
    • 1
  • R. M. Cowling
    • 2
  • H. P. Linder
    • 1
  1. 1.Bolus Herbarium, Department of BotanyUniversity of Cape TownRondeboschRepublic of South-Africa
  2. 2.Institute for Plant Conservation, Department of BotanyUniversity of Cape TownRondeboschRepublic of South Africa

Personalised recommendations