Skip to main content
Log in

Reserve selection in the Succulent Karoo, South Africa: coping with high compositional turnover

  • Published:
Plant Ecology Aims and scope Submit manuscript

Abstract

The Succulent Karoo biome is home to the world's richest succulent flora. It has approximately 1954 endemic plant species, and is the only semi-arid region to qualify as a hotspot of global significance. Despite its importance, only 2% of the biome is currently protected. Based on its flora, the biome can be divided into 12 bioregions, reflecting its high compositional turnover in relation to environmental and geographical gradients. Only three of these bioregions (the Gariep Centre, the Namaqualand Rocky Hills and the Tanqua Karoo) contain National Parks, and three contain large (over 10 000 ha) provincial reserves (the Gariep Centre, the Namaqualand Rocky Hills and the Little Karoo). The current reserve system does little to conserve biodiversity, with only one reserve significantly conserving Red Data Book (RDB) plant diversity. Using a RDB plant species database of 3874 records at a quarter degree scale (QDS = 15′×15′), we used hotspot analyses and iterative reserve selection algorithms to identify possible locations for future reserves. The hotspot analysis and iterative analyses yielded similar results for the top 11 QDS, mainly due to very high local endemism. Also because of the local endemism and the high species turnover within the biome, the real-world iterative algorithm (starting with the seven already reserved QDS) selected a very large total number of QDS (59% of the total in the biome) to conserve all RDB species. As a possible alternative to conservation planning based on QDS, we also assessed priorities at the scale of bioregions, but showed that representation at this geographic level misses important areas defined at a finer scale. We suggest that if the objective is to maximise the retention of RDB species in the landscape (to pre-empt extinction by scheduling the allocation of limited conservation resources), at least the top 5% of QDS (n=11) selected by the iterative procedure, and identified as the core conservation sequence by analysis of endemicity and threat, should be given priority for reservation. Less extensive and, in some cases, less formal conservation action can be applied to QDS later in the sequence, based on species-specific monitoring and action plans. Of the 11 core areas, four fall in a node centred on the Vanrhynsdorp Centre, two fall in a node centred on the Kamiesberg, and the remaining five are isolated. With existing reserves, the core areas capture 50% of the RDB flora in 8% of the biome.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Bedward, M., Pressey, R. L. & Keith, D. A. 1992. A new approach for selecting fully representative reserve networks: addressing efficiency, reserve design and land suitability with an iterative analysis. Biol. Conserv. 62: 115-125.

    Google Scholar 

  • Beissinger, S. R., Steadman, E. C., Wohlengenant, T., Blate, G. & Zack, S. 1996. Null models for assessing ecosystem conservation priorities: threatened birds as titers of threatened ecosystems in South America. Conserv. Biol. 10: 1343-1352.

    Google Scholar 

  • Bittrich, V. & Hartmann, H. 1988. The Aizoaceae-a new approach. Bot. J. Linn. Soc. 97: 239-254.

    Google Scholar 

  • Branch, W. R., Benn, G. A. & Lombard, A. T. 1995. The tortoises (Testudinidae) and terrapins (Pelomedusidae) of southern Africa: their diversity, distribution and conservation. S. Afr. J. Zool. 30: 91-102.

    Google Scholar 

  • Brooks, T. M., Pimm, S. L. & Collar, N. J. 1997. Deforestation predicts the number of threatened birds in insular southest Asia. Conserv. Biol. 11: 382-394.

    Google Scholar 

  • Cowling, R. M., Esler, K. J. & Rundel, P. W. 1999. Namaqualand, South Africa-an overview of a unique winter-rainfall desert ecosystem. Plant Ecol. 142: 3-21 (this issue).

    Google Scholar 

  • Cowling, R. M. & Hilton-Taylor, C. 1994. Patterns of plant diversity and endemism in southern Africa: an overview. Pp. 31-52. In: Huntley, B. J. (ed.), Botanical diversity in southern Africa. Strelitzia 1. National Botanical Institute, Pretoria.

    Google Scholar 

  • Cowling, R. M. & Hilton-Taylor, C. In press. Plant biogeography, endemism and diversity. In: Dean, W. R. J. & Milton, S. J. (eds), The Karoo: ecological patterns and processes. Cambridge University Press, Cambridge.

  • Cowling, R. M., Gibbs Russell, G. E., Hoffman, M. T. & Hilton-Taylor, C. 1989. Patterns of plant species diversity in southern Africa. Pp. 19-50. In: Huntley, B. J. (ed.), Biotic diversity in southern Africa: concepts and conservation. Oxford University Press, Cape Town.

    Google Scholar 

  • Cowling, R. M., Pressey, R. L., Lombard, A. T., Desmet, P. G. & Ellis, A. G. In press. From representation to persistence: requirements for a sustainable reserve system in the species-rich mediterranean-climate deserts of southern Africa. Diversity and Distributions.

  • Cowling, R. M., Rundel, P. W., Desmet. P. G. & Esler. K. J. 1998b. Extraordinarily high regional-scale plant diversity in southern African arid lands: subcontinental and global comparisons. Diversity and Distributions 4: 27-36.

    Google Scholar 

  • Dean, W. R. J. 1995. Where birds are rare and fill the air: the protection of the endemic and the nomadic avifaunas of the Karoo. Ph.D. Thesis. Percy FitzPatrick Institute of African Ornithology, University of Cape Town, South Africa.

    Google Scholar 

  • Desmet, P. G. & Cowling, R. M. 1996. An assessment of the farms Kookfontein (466) and Steenbokkraal (part of Doornfontein 464) for inclusion in the Skilpad Wildflower Reserve. Institute for Plant Conservation, University of Cape Town.

  • Desmet, P. G. & Cowling, R. M. 1999. Biodiversity, habitat and range-size aspects of a flora from the winter-rainfall desert in arid north-western Namaqualand, South Africa. Plant Ecol. 142: 23-33 (this issue).

    Google Scholar 

  • Drinkrow, D. R. & Cherry, M. I. 1995. Anuran distribution, diversity and conservation in South Africa, Lesotho and Swaziland. S. Afr. J. Zool. 30: 82-90.

    Google Scholar 

  • Gelderblom, C. M. & Bronner, G. N. 1995. Patterns of distribution and current protection status of the endemic mammals in South Africa. S. Afr. J. Zool. 30: 127-135.

    Google Scholar 

  • Gelderblom, C. M., Bronner, G. N., Lombard, A. T. & Taylor, P. J. 1995. Patterns of distribution and current protection status of the Carnivora, Chiroptera and Insectivora in South Africa. S. Afr. J. Zool. 30: 103-114.

    Google Scholar 

  • Harrison, J. A., Allan, D. G., Underhill, L. G., Herremans, M., Tree, A. J., Parker, V. & Brown, C. J. (eds). 1997. The Atlas of southern African Birds. Birdlife South Africa, Johannesburg.

    Google Scholar 

  • Hilton-Taylor, C. 1994. Karoo-Namib Region: Western Cape Domain (Succulent Karoo). Pp. 204-217. In: Davis, S. D., Heywood, V. H. & Hamilton, A. C. (eds), Centres of plant diversity: a guide and strategy for their conservation. IUCN Publications Unit, Cambridge.

    Google Scholar 

  • Hilton-Taylor, C. 1996a. Patterns and characteristics of the flora of the Succulent Karoo biome, southern Africa. Pp. 58-72. In: van der Maesen, L. J. G., van der Burgt, X. M. & van Medenbach de Rooy, J. M. (eds), The Biodiversity of African plants. Kluwer Academic Publishers, Dordrecht, The Netherlands.

    Google Scholar 

  • Hilton-Taylor, C. 1996b. Red Data list of southern African plants. Strelitzia 4. National Botanical Institute, Pretoria.

  • Hilton-Taylor, C. & Le Roux, A. 1989. Conservation status of the fynbos and karoo biomes. Pp. 202-223. In: Huntley, B. J. (ed.), Biotic diversity in southern Africa: concepts and conservation. Oxford University Press, Cape Town.

    Google Scholar 

  • Hoffman, M. T. 1996. Succulent Karoo biome. In: Low, A. B. & Rebelo, A. G. (eds), Vegetation of South Africa, Lesotho and Swaziland. Department of Water Affairs and Forestry, Pretoria.

    Google Scholar 

  • Jürgens, N. 1991. A new approach to the Namib Region. 1: Phytogeographic subdivision. Vegetatio 97: 21-38.

    Google Scholar 

  • Jürgens, N., Gotzmann, I. H. & Cowling, R. M. 1999. Remarkable medium-term dynamics of leaf succulent Mesembryanthema (Aizoaceae) in the winter-rainfall desert of northwestern Namaqualand, South Africa. Plant Ecol. 142: 87-96 (this issue).

    Google Scholar 

  • Kershaw, M., Mace, G. M. & Williams, P. H. 1995. Threatened status, rarity, and diversity as alternative selection measures for protected areas: a test using Afrotropical antelopes. Conserv. Biol. 9: 324-334.

    Google Scholar 

  • Kirkpatrick, J. B. 1983. An iterative method for establishing priorities for the selection of nature reserves: an example from Tasmania. Biol. Conserv. 25: 127-134.

    Google Scholar 

  • Lombard, A. T. 1995. The problems with multi-species conservation: do hotspots, ideal reserves and existing reserves coincide? S. Afr. J. Zool. 30: 145-163.

    Google Scholar 

  • Lombard, A. T., Nicholls, A. O. & August, P. V. 1995. Where should nature reserves be located in South Africa? A snake's perspective. Conserv. Biol. 9: 363-372.

    Google Scholar 

  • Maggs, G. L., Craven, P. & Kolberg, H. H. 1998. Plant species richness, endemism and genetic resources in Namibia. Biodiv. Conserv. 7: 435-446.

    Google Scholar 

  • Margules, C. R., Nicholls, A. O. & Pressey, R. L. 1988. Selecting networks of reserves to maximise biological diversity. Biol. Conserv. 43: 63-76.

    Google Scholar 

  • McNeely, J. A. (ed) 1993. Parks for life. Report of the IVth World Congress of Parks and Protected Areas. IUCN, Gland, Switzerland.

    Google Scholar 

  • Milton, S. J., Yeaton, R. I., Dean, W. R. J. & Vlok, H. J. 1997. Succulent Karoo. Pp. 131-166. In: Cowling, R. M., Richardson, D. M. & Pierce, S. M. (eds), Vegetation of southern Africa. Cambridge University Press, Cambridge.

    Google Scholar 

  • Mittermeier, R. A., Myers, N., Thomsen, J. B., da Fonseca, G. A. B. & Olivieri, S. 1998. Biodiversity hotspots and major tropical wilderness areas: approaches to setting conservation priorities. Conserv. Biol. 12: 516-520.

    Google Scholar 

  • Mugo, D. N., Lombard, A. T., Bronner, G. N., Gelderblom, C. M. & Benn, G. A. 1995. Distribution and protection of endemic or threatened rodents, lagomorphs and macrosceledids in South Africa. S. Afr. J. Zool. 30: 115-126.

    Google Scholar 

  • Nicholls, A. O. & Margules, C. R. 1993. An upgraded reserve selection algorithm. Biol. Conserv. 64: 165-169.

    Google Scholar 

  • Olson, D. M. & Dinerstein, E. 1998. The global 200: a representation approach to conserving the earth's most biologically valuable ecoregions. Conserv. Biol. 12: 502-515.

    Google Scholar 

  • Passmore, N. I. & Carruthers, V. C. 1995. South African frogs a complete guide. Southern Book Publishers.

  • Prendergast, J. R., Quinn, R. M., Lawton, J. H., Eversham, B. C. & Gibbons, D. W. 1993. Rare species, the coincidence of diversity hotspots and conservation strategies. Nature 365: 335-337.

    Google Scholar 

  • Pressey, R. L. 1997. Priority conservation areas: towards an operational definition for regional assessments. Pp. 337-357. In: Pigram, J. J. & Sundell, R. C. (eds.), National parks and protected areas: Selection, delimitation and management. Centre for Water Policy Research, University of New England, Armidale, Australia.

    Google Scholar 

  • Pressey, R. L., Ferrier, S., Hager, T. C., Woods, C. A., Tulley, S. L. & Weinman, K. M. 1996a. How well protected are the forests of north-eastern New South Wales?-Analyses of forest environments in relation to formal protection measures, land tenure, and vulnerability to clearing. Forest Ecol. Manag. 85: 311-333.

    Google Scholar 

  • Pressey, R. L., Possingham, H. P. and Margules, C. R. 1996b. Optimality in reserve selection algorithms: when does it matter and how much? Biol. Conserv. 76: 259-267.

    Google Scholar 

  • Pressey, R. L. & Nicholls, A. O. 1989. Efficiency in conservation evaluation: scoring versus iterative approaches. Biol. Conserv. 50: 199-218.

    Google Scholar 

  • Pressey, R. L., Possingham, H. P. & Day, J. R. 1997. Effectiveness of alternative heuristic algorithms for identifying indicative minimum requirements for conservation reserves. Biol. Conserv. 80: 207-219.

    Google Scholar 

  • Pressey, R. L. & Taffs, K. H. (submitted) Priority conservation areas: a definition for the real world applied to Western New South Wales. Biol. Conserv.

  • Pressey, R. L., Humphries, C. J., Margules, C. R., Vane-Wright, R. I. & Williams, P. H. 1993. Beyond opportunism: key principles for systematic reserve selection. TREE 8: 124-128.

    Google Scholar 

  • Rebelo, A. G. 1994. Iterative selection procedures: centres of endemism and optimal placement of reserves. Pp. 231-257. In: Huntley, B. J. (ed.), Botanical diversity in southern Africa. Strelitzia 1. National Botanical Institute, Pretoria.

    Google Scholar 

  • Rebelo, A. G. 1997. Conservation. Pp. 571-590. In: Cowling, R. M., Richardson, D. M. & Pierce, S. M. (eds), Vegetation of southern Africa. Cambridge University Press, Cambridge.

    Google Scholar 

  • Rebelo, A. G. & Siegfried, W. R. 1992. Where should nature reserves be located in the Cape Floristic Region, South Africa? Models for the spatial configuration of a reserve network aimed at maximizing the protection of floral diversity. Conserv. Biol. 6: 243-252.

    Google Scholar 

  • Rutherford, M. C. & Westfall, R. H. 1986. Biomes of southern Africa-an objective categorization. Mem. Bot. Surv. S. Afr. 54: 1-98.

    Google Scholar 

  • Skelton, P. H., Cambray, J. A., Lombard, A. T. & Benn, G. A. 1995. Patterns of distribution and conservation status of freshwater fishes in South Africa. S. Afr. J. Zool. 30: 71-81.

    Google Scholar 

  • Thackway, R. & Cresswell, I. D. 1997. A bioregional framework for planning the national system of protected areas in Australia. Nat. Areas J. 17: 241-247.

    Google Scholar 

  • Underhill, L. G. 1994. Optimal and suboptimal reserve selection algorithms. Biol. Conserv. 70: 85-87.

    Google Scholar 

  • Van Jaarsveld, E. 1987. The succulent riches of South Africa and Namibia. Aloe 24: 45-92.

    Google Scholar 

  • Vernon, C. J. In press. Biogeography, endemism and diversity of animals in the Karoo. In: Dean, W. R. J.&Milton, S. J. (eds), The Karoo: ecological patterns and processes. Cambridge University Press, Cambridge.

  • Williams, P., Gibbons, D., Margules, C., Rebelo, A., Humphries, C. & Pressey, R. 1996. A comparison of richness hotspots, rarity hotspots, and complementary areas for conserving diversity of British birds. Conserv. Biol. 10: 155-174.

    Google Scholar 

  • Williamson, G. 1997. Preliminary account of the floristic zones of the Sperrgebiet (Protected Diamond Area) in southwest Namibia. Dinteria 25: 1-68.

    Google Scholar 

  • Willis, C. K., Lombard, A. T., Cowling, R. M., Heydenrych, B. J. & Burgers, C. J. 1996. Reserve systems for limestone endemic flora of the Cape lowland fynbos: iterative versus linear programming. Biol. Conserv. 77: 53-62.

    Google Scholar 

Download references

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lombard, A., Hilton-Taylor, C., Rebelo, A. et al. Reserve selection in the Succulent Karoo, South Africa: coping with high compositional turnover. Plant Ecology 142, 35–55 (1999). https://doi.org/10.1023/A:1009866126729

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1009866126729

Navigation