Begonias and African rain forest refuges: general aspects and recent progress

  • M. S. M. Sosef

Abstract

In tropical Africa during the last glacial the climate was cooler and drier and the ram forest retreated. It remained present in several small forest refuge areas only. The species of two sections of Begonia are ideal to serve as bioindicators of the localities of former forest refuges. Their distribution patterns have been analyzed elsewhere but are discussed here in the light of new evidence and data. This is followed by a discussion on the validity of deducing localities of forest refuges by means of present day distributional data.

Key words

Begonia Biodiversity Biogeography Forest refuges Palaeoenvironments Rain forest 

Résumé

En Afrique tropicale, durant la dernière période glaciaire, le climat était plus froid et plus sec et la forêt ombrophile se retira. Elle ne subsista que dans plusieurs petites superficies de refuges forestiers. Les espèces de deux sections du genre Begonia représentent des bioindicateurs idéaux pour situer les endroits de ces anciens refuges forestiers. Leurs modes de distributions ont été analysés ailleurs mais il en est discuté ici à la lumière de nouvelles preuves et données. S’en suit une discussion concernant la valeur que l’on peut accorder à la déduction des emplacements de refuges forestiers à partir des données actuelles de la distribution.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aubréville, A., 1962. Savanisation tropical et glaciations quaternaires. Adansonia 2: 16–84.Google Scholar
  2. Bonnefille, R., J.C. Roeland & J. Guiot, 1990. Temperature and rainfall estimates for the past 40,000 years in equatorial Africa. Nature 346: 347–349.CrossRefGoogle Scholar
  3. Colyn, M., A. Gautier-Hion & W. Verheyen, 1991. A re-appraisal of palaeoenvironmental history in central Africa: evidence for a major fluvial refuge in the Zaire Basin. J. Biogeogr. 18: 403–407.CrossRefGoogle Scholar
  4. Diamond, A.W. & A.C. Hamilton, 1980. The distribution of forest passerine birds and Quaternary climatic change in tropical Africa. J. Zool., Lond. 191: 379–402.CrossRefGoogle Scholar
  5. Dupont, L., 1993. Vegetation zones in NW Africa during the Brunhes Chron reconstructed from marine palynological data. Quaternary Sci. Rev. 12: 189–202.CrossRefGoogle Scholar
  6. Elenga, H. & A. Vincens, 1990. Paléoenvironnements Quaternaires récents des Plateaux Batéké (Congo): étude palynologique des dépôts de la dépression du Bois de Bilanko. In: R. Lanfranchi & D. Schwartz (eds). Paysages Quaternaires de l’Afrique centrale Atlantique: 271–282. Didactiques, Travaux et Documents ORSTOM, Paris.Google Scholar
  7. Grubb, P., 1982. Refuges and dispersal in the speciation of African forest mammals In: G.T. Prance (ed.). Biological diversification in the tropics: 537–553. Columbia University Press, New York.Google Scholar
  8. Guillaumet, J.L., 1967. Recherches sur la végétation et la flore de la région du Bas-Cavally (Côte d’Ivoire). Mémoires ORSTOM no 20. ORSTOM, Paris.Google Scholar
  9. Hamilton, A.C., 1976. The significance of patterns of distribution shown by forest plants and animals in tropical Africa for the reconstruction of upper Pleistocene palaeoenvironments: a review. In: E.M. van Zinderen Bakker (ed.). Palaeoecology of Africa 9: 63–97. A.A. Balkema, Cape Town.Google Scholar
  10. Hamilton, A.C., 1982. Environmental history of east Africa. A study of the Quaternary. Academic Press, London.Google Scholar
  11. Hamilton, A.C., & D. Taylor, 1991. History of climate and forests in tropical Africa during the last 8 million years. In: N. Myers (ed.). Tropical forests and climate: 65–78. Kluwer Academic Publishers, Dordrecht. (= Climatic Change 19 ).Google Scholar
  12. Kingdon, J.S., 1980. The role of visual signals and face patterns in African forest monkeys (guenons) of the genus Cercopithecus. Trans. Zool. Soc., London 35: 425–475.CrossRefGoogle Scholar
  13. Livingstone, D.A., 1982. Quaternary geography of Africa and the refuge theory. In: G.T. Prance (ed.). Biological diversification in the tropics: 523–536. Columbia University Press, New York.Google Scholar
  14. Maley, J., 1987. Fragmentation de la forêt dense humide Africaine et extensions des biotopes montagnards au Quaternaire récent: nouvelles donnees polliniques et chronologiques. Implications paléoclimatiques et biogéographiques. In: J.A. Coetzee (ed.). Palaeoecology of Africa 18: 307–334. A.A. Balkema, Rotterdam.Google Scholar
  15. Maley, J., 1989. Late Quaternary climatic changes in the African rain forest: forest refugia and the major role of sea surface temperature variations. In: M. Leinen & M. Samthein (eds). Paleoclimatology and paleometeorology: Modern and past patterns of global atmospheric transport. NATO Adv. Sci. Inst. Series, C: Math. & Phys. Sci. 282: 585–616. Kluwer Academic Publishers, Dordrecht.Google Scholar
  16. Maley, J. & P. Brenac, 1987. Analyses polliniques préliminaires du Quaternaire récent de l’Ouest Cameroun: mise en évidence de refuges forestièrs et discussion des problèmes paléoclimatiques. In: G. Cambon, P. Richard & J.-P. Suc (eds). Palynology et milieux tropicaux. Mém. Tray. Ecole Prat. Htes Inst. Montpellier 17: 129–142.Google Scholar
  17. Maley, J., & H. Elenga, 1993. Le rôle des nuages dans l’évolution des paléoenvironnements montagnards de l’Afrique tropicale. Vielle Climatique Satellitaire 46: 51–63.Google Scholar
  18. Rietkerk, M., P. Ketner & J.J.F.E. de Wilde, 1995. Caesalpinioideae and the study of forest refuges in Gabon: Preliminary results. Bull. Mus. natl. Hist. nat., Paris, 4e sér., 17, section B, Adansonia, nos 1–2: 95–105.Google Scholar
  19. Sosef, M.S.M., 1992. New species of Begonia in Africa and their relevance to the study of glacial rain forest refuges. In: J.J.F.E. de Wilde (ed.). Studies in Begoniaceae III. Wageningen Agric. Univ. Papers 91–4: 117–151 (also Belmontia n.s. 24, no 148 ).Google Scholar
  20. Sosef, M.S.M., 1994a. Refuge begonias. Taxonomy, phylogeny and historical biogeography of Begonia sect. Loasibegonia and sect. Scutobegonia in relation to glacial rain forest refuges in Africa. Wageningen Agric. Univ. Papers 94–1: 1–306 (also Belmontia n.s. 26, no 151).Google Scholar
  21. Sosef, M.S.M., 1994b. Glacial rain forest refuges in relation to speciation in Begonia sect. Loasibegonia and sect. Scutobegonia. In: J.H. Seyani & A.C. Chikuni (eds). Proceedings of the XIIIth plenary meeting of AETFAT, Zomba, Malawi, 2–11 April 1991, vol. 2: 1297–1302. National Herbarium and Botanic Gardens of Malawi, Zomba.Google Scholar
  22. Van Rompaey, R.S.A.R., 1993. Forest gradients in West Africa. A spatial gradient analysis. PhD thesis, Wageningen Agricultural University. 142 p.Google Scholar
  23. White, F., 1983. The vegetation of Africa. Natural Resources Research No 20. UNESCO, Paris.Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • M. S. M. Sosef
    • 1
  1. 1.Department of Plant Taxonomy, Herbarium VadenseWageningen Agricultural UniversityWageningenThe Netherlands

Personalised recommendations