The distribution of the dwarf succulent genus Conophytum N.E.Br. (Aizoaceae) in southern Africa
Keywords:
Succulent Karoo, Conophytum, AizoaceaeAbstract
Background: The dwarf succulent genus Conophytum N.E.Br. is one of the most species rich in the Aizoceae. The genus is most closely associated with a region of high floral endemism and biodiversity, the Succulent Karoo biome in south-western Africa.
Objectives: To examine the distribution of Conophytum in south-western Namibia and in the Northern and Western Cape Provinces of South Africa.
Method: A database comprising 2798 locality records representing all known species and subspecies of the genus Conophytum has been constructed.
Results: The genus is primarily restricted to the arid winter-rainfall region of the Northern and Western Cape Provinces of South Africa and south-western Namibia, within the Greater Cape Floristic Region. Whilst taxa are found across all the main biomes in the region (the Succulent Karoo, Nama Karoo, Desert and Fynbos biomes), 94% of Conophytum taxa are found only in the Succulent Karoo biome and predominantly (88% of taxa) within South Africa. Endemism within specific bioregions is a feature of the genus and ~60% of taxa are endemic to the Succulent Karoo. Approximately 28% of all taxa could be considered point endemics. Whilst the genus has a relatively wide geographical range, we identify a pronounced centre of endemism in the southern Richtersveld.
Conclusion: The genus Conophytum can be used as a good botanical model for studying patterns of diversity and speciation in the Succulent Karoo biome, the effects of climate change on dwarf succulents, and for informing conservation planning efforts.
Downloads
References
Born, J., Linder, H.P. & Desmet, P., 2007, ‘The Greater Cape Floristic Region’, Journal of Biogeography 34, 147–162.
Bradshaw, P.L. & Cowling, R.M., 2014, ‘Landscapes, rock types, and climate of the Greater Cape Floristic Region’, in N. Allsopp, J.F. Colville & A.A. Verboom (eds.), Fynbos: Ecology, evolution, and conservation of a Megadiverse Region, pp. 26–47, Oxford University Press, Oxford.
Cowling, R.M. & Hilton-Taylor, C., 1994, ‘Phytogeography, flora and endemism’, in R.M. Cowling, D.M. Richardson & S.M. Pierce (eds.), Vegetation of Southern Africa, pp. 3–61, Cambridge University Press, Cambridge.
Cowling, R.M. & Hilton-Taylor, C., 1999, ‘Plant biogeography, endemism and diversity’, in W.R.J. Dean & S. Milton (eds.), The Karoo. Ecological patterns and processes, pp. 42–56, Cambridge University Press, Cambridge.
Cowling, R.M., Rundel, P.W., Desmet, P.G. & Esler, K.J., 1998, ‘Extraordinary high regional-scale plant diversity in southern African arid lands: Subcontinental and global comparisons’, Diversity and Distributions 4, 27–36.
Desmet, P. & Cowling, R., 1999a, ‘Biodiversity, habitat and range-size aspects of a flora from a winter-rainfall desert in north-western Namaqualand, South Africa’, Plant Ecology 142, 23–33.
Desmet, P. & Cowling, R., 1999b, ‘The climate of the karoo. A functional approach’, in W.R.J. Dean & S. Milton (eds.), The Karoo. Ecological patterns and processes, pp. 3–16, Cambridge University Press, Cambridge.
Desmet, P.G., Ellis, A.G. & Cowling, R.M., 1998, ‘Speciation in the Mesembryanthemacae’, Aloe 35, 38–43.
Driver, A., Desmet, P., Rouget, M., Cowling, R. & Maze, K., 2003, Succulent Karoo ecosystem plan: Biodiversity component, Cape Conservation Unit Technical Report, Cape Town.
Giess, W., 1971, ‘A preliminary vegetation map of South West Africa’, Dinteria 4, 5–14.
Hammer, S.A., 1993, The genus Conophytum: A conograph, Succulent Plant Publications, Pretoria.
Hammer, S.A., 2002, Dumpling and his wife: New views on the genus Conophytum, EAE Creative Colour Ltd, Norwich.
Hammer, S.A. & Young, A.J., in press, ‘Conophytum: Ruschioideae’, in HE.K. Hartman, (ed.), Illustrated handbook of succulent plants, Springer-Verlag, Heidelberg.
Hilton-Taylor, C., 1996, ‘Patterns and characteristics of the flora of the Succulent Karoo Biome in southern Africa’, in L.J.E. Van der Maesen, X.M. Van der Burgt & J.M. Van Medenbach de Rooy (eds.), The biodiversity of African plants, pp. 58–72, Kluwer Academic Publishers, Dordrecht.
Ihlenfeldt, H.-D., 1994, ‘Diversification in an arid world: The mesembrythanthemacea’, Annual Review of Ecology and Systematics 25, 521–546.
Jürgens, N., 1991, ‘A new approach to the Namib Region. I, Phytogeographic subdivision’, Vegetation 97, 21–38.
Jürgens, N., 1997, ‘Floristic biodiversity and history of African arid regions’, Biodiversity and Conservation 6, 495–514.
Jürgens, N., 2006, ‘Desert Biome’, in L. Mucina & M.C. Rutherford (eds.), The vegetation of South Africa, Lesotho and Swaziland, Strelitzia 19, pp. 301–323, South African National Biodiversity Institute, Pretoria.
Jürgens, A. & Witt, T., 2014, ‘Pollen-ovule ratios and flower visitors of day-flowering and night-flowering Conophytum (Aizoaceae) species in South Africa’, Journal of Arid Environments 109, 44–53.
Matimati, I., Musil, C.F., Raitt, L. & February, E., 2012, ‘Non rainfall moisture interception by dwarf succulents and their relative abundance in an inland arid South African ecosystem’, Ecohydrology 6, 818–825.
Mittermeier, R.A., Robles Gil, P., Hoffman, M., Pilgrim, J., Brooks, T., Goettsch Mittermeier, C. et al., 2004, Hotspots revisited: Earth’s biologically richest and most endangered terrestrial ecoregions, Conservation International & CEMEX. P. 392, Mexico City.
Mucina, L., Jürgens, N., Le Roux, A., Rutherford, M.C., Schmiedel, U., Esler, K. et al., 2006a, ‘Succulent Karoo Biome’, in L. Mucina & M.C. Rutherford (eds.), The vegetation of South Africa, Lesotho and Swaziland, Strelitzia 19, pp. 221–299, South African National Biodiversity Institute, Pretoria.
Mucina, L. & Rutherford, M.C. (eds.), 2006, The vegetation of South Africa, Lesotho and Swaziland, Strelitzia 19, South African National Biodiversity Institute, Pretoria.
Mucina, L., Rutherford, M.C., Palmer, A.R., Milton, S.J., Scott, L., Lloyd, W. et al., 2006b, ‘Nama-Karoo Biome’, in L. Mucina & M.C. Rutherford (eds.), The vegetation of South Africa, Lesotho and Swaziland, Strelitzia 19, pp. 221–299, South African National Biodiversity Institute, Pretoria.
Opel, M.R., 2002, ‘Chromosome numbers of Conophytum and related genera’, in S.A. Hammer (ed.), Dumpling and his wife: New views on the genus Conophytum, pp. 332–340, EAE Creative Colour Ltd, Norwich.
Rebelo, A.G., Boucher, C., Helme, N., Mucina, L. & Rutherford, M.C. 2006, ‘Fynbos Biome’, in L. Mucina & M.C. Rutherford (eds.), The vegetation of South Africa, Lesotho and Swaziland, Strelitzia 19, pp. 53–219, South African National Biodiversity Institute, Pretoria.
Snijman, D.A., 2013, ‘The Greater Cape Floristic Region: The Extra Cape Subregion’, in D.A. Snijman (ed.), Plants of the Greater Cape Floristic Region, The Extra Cape Flora, Strelitzia 30, Vol. 2, pp. 1–23, South African National Biodiversity Institute, Pretoria.
South African National Biodiversity Institute, 2009, Vegetation map of South Africa, Lesotho and Swaziland 2009, viewed 09 November 2015, from http://www.bgis. sanbi.org
South African National Biodiversity Institute, 2015, Red list of South African plants, viewed from http://redlist.sanbi.org. 14/12/2015.
Van Wyk, A.E. & Smith, G.F., 2001, Regions of floristic endemism in southern Africa: A review with emphasis on succulents, Umdaus Press, Pretoria.
Young, A.J., Guo, D., Desmet, P.G. & Midgley, G.F., 2016, ‘Biodiversity and climate change: Risks to dwarf succulents in Southern Africa’, Journal of Arid Environments 129, 16–24.
Young, A.J., Rodgerson, C., Opel, M.R. & Hammer, S.A., 2015, ‘Conophytum bachelorum and its relatives: The introduction of a new Conophytum from Namaqualand, C. confusum’, Bradleya 33, 39–47.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2016 Andrew Young, Phillip G. Desmet
This work is licensed under a Creative Commons Attribution 4.0 International License.
