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The African rain forest – main characteristics of changes in vegetation and climate from the Upper Cretaceous to the Quaternary

Published online by Cambridge University Press:  05 December 2011

Jean Maley
Affiliation:
Paléoenvironnement et Palynologie (CNRS/ISEM & ORSTOM), Université de Montpellier-2, Montpellier 34095, France
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Synopsis

This chapter sets out to give a historical overview of the African rain forest from its origins, towards the end of the Cretaceous period. The areas around the Gulf of Guinea, in particular from Ivory Coast to Nigeria and especially Cameroon, Gabon and Congo, appear to have been already occupied at this time by wet tropical forest formations mainly composed of Angiosperms which were then becoming established. In the course of the Tertiary period the combined effect of the equator being situated further north than now and the development of the Antarctic ice cap favoured the development of wet tropical conditions over a large part of North Africa which in turn led to the extension of tropical forest to various sites on the shores of the Tethys Sea. There were probably at this time common taxa and similar vegetation patterns stretching from the Gulf of Guinea to the Tethys Sea.

Towards the end of the Tertiary, the equator reached its present position and the northern hemisphere ice caps appeared, and these phenomena resulted in the disappearance of the forest formations spread across the north of Africa, and the concentration of these formations near the equatorial zone around the Gulf of Guinea and in the Congo–Zaïre basin. From 800 000 years ago onwards the marked glacial variations at middle and high latitudes in both hemispheres, with a periodicity of about 100 000 years determined by the orbital variations of the earth around the sun, lowered temperatures in equatorial areas and brought arid climates at times of maximum glacial extension. The most arid periods resulted in the fragmentation of the forest cover, and the forest biotopes and their biodiversity were preserved in a series of refugia. The lowering of temperatures also resulted in the extension of montane flora to low altitudes, with migration of montane flora and fauna between main mountain ranges. These compounded phenomena of isolation and migration, probably involving genie exchange, must have resulted in numerous speciation phenomena. Subsequently, such montane flora or fauna became isolated on mountain areas during periods of maximum warming, in the last instance in the course of the Holocene, when a vast forest cover became re-established from Guinea westwards, and to the East as far as the Lake Victoria area. The phases of maximum fragmentation, which appear to have been connected with only the coldest periods – in the last instance during the second part of isotopic stages 6 (from c. 160 to 130 000 years) and 2 (from c. 24 to 12000 years BP) – relate to less than 10% of the last 800 000 years, and the phases of maximum forest extension would likewise appear to be less than 10% of the period. The remaining 80–90% of the time relates to ‘intermediate situations’ which varied from period to period, and these intermediate extension situations seem to have been the norm over the larger part of the Quaternary, rather than the present situation which is closer to a situation of maximum extension.

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Research Article
Copyright
Copyright © Royal Society of Edinburgh 1996

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References

Absy, M. L., Cleef, A. L., Fournier, M., Martin, L., Servant, M., Sifeddine, A., Da Silva, M. F., Soubies, F., Suguio, K., Turcq, B. & Van der Hammen, Th. 1991. Mise en évidence de quatre phases d'ouverture de la forêt dense dans le sud-est de l'Amazonie au cours des 60.000 dernières années. Comptes Rendus de l'Académie des Sciences, Paris II, 312, 673–8.Google Scholar
Achoundong, G. 1985. Etude écologique et floristique de la végétation des collines de Yaoundé au-dessus de 1000 m. Thèse Ecologie Végétale, Université de Yaoundé, 301 p.Google Scholar
Amiet, J. L. 1987. Aires disjointes et taxons vicariants chez les Anoures du Cameroun: implications paléoclimatiques. Alytes, Paris 6, 99115.Google Scholar
Aspliden, C. I. & Adefolalu, D. 1976. The mean troposphere of West Africa. Journal of Applied Meteorology 15, 705–16.2.0.CO;2>CrossRefGoogle Scholar
Aubréville, A. 1949. Contribution à la paléohistoire des forêts de l'Afrique tropicale. Société Edition Géographique. Maritime et Coloniale, Paris, 99 pp.Google Scholar
Aubréville, A. 1955. La disjonction africaine dans la flore forestière tropicale. Comptes rendus Réunions de la Socièté de Biogéographie, Paris 278, 42–9.Google Scholar
Aubréville, A. 1962. Savanisation tropicale et glaciations quaternaires. Adansonia 2, 1684.Google Scholar
Aubréville, A. 1964. Vues d'ensemble sur la géographie et l'écologie des Conifères et Taxacées – à propos de l'ouvrage de Rudolf Florin. Adansonia 4, 818.Google Scholar
Aubréville, A. 1968. Les Césalpinioidées de la flore Camerouno–Congolaise. Considérations taxinomiques, chorologiques, écologiques, historiques et évolutives. Adansonia 8, 147–75.Google Scholar
Aubréville, A. 1973a. Déclin des genres de Conifères tropicaux dans le temps et l'espace. Adansonia 13, 535.Google Scholar
Aubréville, A. 1973b. Distribution des Conifères dans la Pangée, essais. Adansonia 13, 125–33.Google Scholar
Aubréville, A. 1975. Essais sur l'origine et l'histoire des flores tropicales africaines. Application de la théorie des origines polytopiques des Angiospermes tropicales. Adansonia 15, 3156.Google Scholar
Awad, M. Z. & Breir, F. A. 1993. Oligo-Miocene to Quaternary palaeoenvironment in Gezira area, central Sudan. In Thorweihe, U. & Schandelmeier, H. (Eds) Geoscientific research in northeast Africa, pp. 465–70. Rotterdam: A.A. Balkema.Google Scholar
Awad, M. Z. 1994. Stratigraphic, palynological and paleoecological studies in the east-central Sudan (Khartum & Kosti basins), late Jurassic to Mid-Tertiary. Berliner Geowissenschaftliche Abhandlungen, A, 161.Google Scholar
Axelrod, D. I. & Raven, P. H. 1978. Late cretaceous and Tertiary vegetation history of Africa. In Werger, M. J. A. & Van Bruggen, A. C. (Eds) Biogeography and ecology of Southern Africa, pp. 77130. The Hague: W. Junk Publ.CrossRefGoogle Scholar
Bahuchet, S. 1993. History of the inhabitants of the central African rain forest: perspectives from comparative linguistics. In Hladik, C. et al. (Eds) L'alimentation en forêt tropicale: interactions bioculturelles et applications au developpement, pp. 3754. Paris: Parthenon/UNESCO, Publ.Google Scholar
Barker, P. F., Kennett, J. P. et al. (les 25 participants du ODP Leg 113) 1988. Résultats préliminaires de la campagne 113 du Joides-Resolution (Ocean Drilling Program) en mer de Weddell: histoire de la glaciation Antarctique. Comptes Rendus de l'Académie des Sciences, Paris, II 306, 73–8.Google Scholar
Barron, J., Larsen, B., Baldauf, J. G. et al. 1988. Early glaciation of Antarctica. Nature 333, 303–4.Google Scholar
Bengo, M. D. & Maley, J. 1991. Analyses des flux polliniques sur la marge sud du Golfe de Guinée depuis 135 000 ans. Comptes Rendus de l'Académie des sciences, Paris, II 313, 843–9.Google Scholar
Blanc, P. 1989. Biologie des plantes de sous-bois tropicaux. These Science Université de Paris VI.Google Scholar
Blanc, P. 1995. Disjonctions et singularités dans les flores hygrophiles de sous-bois en Afrique. Colloque International de Phytogéographie Tropicale. Paris: Mémoire ORSTOM.Google Scholar
Boltenhagen, E., Dejax, J. & Salard-Cheboldaeff, M. 1985. Evolution de la végétation tropicale africaine du Crétacé à l'Actuel d'après les données de la palynologie. Comité des Travaux Scientifiques et Historiques, Section Science, Paris 8, 165–94.Google Scholar
Bond, W. J. 1989. The tortoise and the hare: ecology of Angiosperm dominance and Gymnosperm persistence. Biological Journal of the Linnean Society 36, 227–49.CrossRefGoogle Scholar
Bonifay, D. & Giresse, P. 1992. Middle to late Quaternary sediment flux and post-depositional processes between the continental slope off Gabon and the mid-Guinean margin. Marine Geology 106, 107–29.CrossRefGoogle Scholar
Bonnefille, R. 1980. Vegetation history of savanna in East Africa during the Plio-Pleistocene. IV int. Palynolological Conference, Lucknow, India 3, 7589.Google Scholar
Bonnefille, R. 1983. Evidence for a cooler and drier climate in the Ethiopian uplands towards 2.5 Myr ago. Nature 303, 487–91.CrossRefGoogle Scholar
Bonnefille, R. 1984. Cenozoic vegetation and environments of early hominids in East Africa. In Whyte, R. O. (Ed.) The evolution of the East Asian environment – Palaeobotany, Palaeozoology and Palaeoanthropology, 3, pp. 579612. Hong Kong: Centre of Asian Studies Publication, University of Hong Kong.Google Scholar
Bonnefille, R. & Riollet, G. 1988. The Kashiru pollen sequence (Burundi): palaeoclimatic implications for the last 40,000 yr BP in tropical Africa. Quaternary Research 30, 1935.CrossRefGoogle Scholar
Bonnefille, R. & Vincens, A. 1977. Représentation pollinique d'environnement arides à l'est du lac Turkana (Kenya). Bulletin Association Française de l'Etude du Quaternaire 50 (supplm.), 235–47.Google Scholar
Boudouresque, L., Dubois, D., Lang, J. & Trichet, J. 1982. Contribution à la stratigraphie et à la paléogéographie de la bordure occidentale du bassin des Iullemmeden au Crétacé supérieur et au Cénozoïque (Niger et Mali, Afrique de l'Ouest). Bulletin de la Société Géologique de France 24, 685–95.CrossRefGoogle Scholar
Boureau, E., Cheboldaeff-Salard, M., Koeniguer, J. C. & Louvet, P. 1983. Evolution des flores et de la végétation tertiaires en Afrique au nord de l'èquateur. Bothalia 14, 355–67.CrossRefGoogle Scholar
Brenac, P. 1988. Evolution de la végétation et du climat dans l'Ouest Cameroun entre 25.000 et 11.000 ans BP. Actes Xème Symposium Ass.Palynologues Langue Française. Travaux de la Section des Sciences & Techiques de l'Institut Français de Pondichéry 25, 91103.Google Scholar
Brenan, J. P. M. 1978. Some aspects of the phytogeography of tropical Africa. Annals of Missouri Botanical Garden 65, 437–78.CrossRefGoogle Scholar
Breteler, F. J. 1990. Gabon's evergreen forest: the present status and its future. Mitteilungen Institut Allgemeine Botanik Hamburg 23a, 219–24.Google Scholar
Broecker, W. S. & Denton, G. H. 1989. The role of ocean-atmosphere reorganization in glacial cycles. Geochimica et Cosmochimica Acta 53, 2465–501.CrossRefGoogle Scholar
Bruijnzeel, L. A. & Proctor, J. 1993. Hydrology and biochemistry of tropical montane cloud forests: what do we really know? In Hamilton, L. S., Juvik, J. O. & Scatena, F. N. (Eds) Tropical montane cloud forests, pp. 2546, Hawaï: East-West Center.Google Scholar
Burke, K. 1976. Neogene and Quaternary tectonics of Nigeria. In Kogbe, C. A. (Ed.) Geology of Nigeria, pp. 363–9. Lagos: Elizabethan Publ.Google Scholar
Cahen, L. 1954. Le Cénozoïque. In: La Géologie du Congo Belge, pp. 323–32. Liège: Vaillant-Carmanne Publ.Google Scholar
Calleja, M., Rossignol-Strick, M. & Duzer, D. 1993. Atmospheric pollen content off West Africa. Review of Palaeobotany & Palynology 79, 335–68.CrossRefGoogle Scholar
Carlquist, S. 1975. Ecological strategies of xylem evolution. Berkeley, CA: Univ. California Press.CrossRefGoogle Scholar
Carcasson, R. H. 1964. A preliminary survey of the zoogeography of African butterflies. East African Wild Life Journal 2, 122–57.CrossRefGoogle Scholar
Cavalli-Sforza, L. L., Menozzi, P. & Piazza, A. 1993. Demic expansions and human evolution. Science 259, 639–46.CrossRefGoogle ScholarPubMed
Cerling, T. E. 1992. Development of grasslands and savannas in East Africa during the Neogene. Palaeogeography, Palaeoclimatology, Palaeoecology, Global & Planetary Change 97, 241–7.CrossRefGoogle Scholar
Cerling, T. E., Wang, Y. & Quade, J. 1993. Expansion of C4 ecosystems as an indicator of global ecological change in the late Miocene. Nature 361, 344–5.CrossRefGoogle Scholar
Cheek, M. & Cable, S. 1994. Mapping plant biodiversity on Mount Cameroon. 14th Congress Association Etude Taxonomie et Flore Afrique Tropicale, Univ. Wageningen, Abstract & Poster, p. 33 & 138.Google Scholar
Citeau, J., Carn, M., Fongang, S. & Sagna, P. 1994. Relationships between western Africa ITCZ and St. Helena Anticyclone suggested by a watch of Meteosat-WV Channel. Proceedings International Conference on Monsoon Variability & Prediction. World Meteorological Organisation. TD 619, 1, 9398.Google Scholar
Coetzee, J. A. 1978. Climatic and biological changes in south-western Africa during the Late Cainozoic. Palaeoecology of Africa 10, 1329.Google Scholar
Coetzee, J. A. & Muller, J. 1984. The phytogeographic significance of some extinct Gondwana pollen types from the Tertiary of the southwestern Cape (South Africa). Annals of Missouri Botanical Garden 71, 1088–99.CrossRefGoogle Scholar
Colyn, M. M. 1987. Les Primates des forêts ombrophiles de la cuvette du Zaïre: interprétations zoogéographiques des modèles de distribution. Revue de Zoologie africaine, Tervuren 101, 183–96.Google Scholar
Colyn, M. M. 1991. L'importance zoogéographique du bassin du fleuve Zaïre pour la spéciation: le cas des Primates Simiens. Annales Musée Royal de l'Afrique Centrale, Section Zoologie, Tervuren 264, 250 pp.Google Scholar
Colyn, M. M., Gautier-Hion, A. & Verheyen, W. 1991. A re-appraisal of palaeoenvironmental history in Central Africa: evidence for a major fluvial refuge in the Zaire basin. Journal of Biogeography 18, 403–7.CrossRefGoogle Scholar
Crowe, T. M. & Crowe, A. A. 1982. Patterns of distribution, diversity and endemism in Afrotropical birds. Journal of Zoology, London 198, 417–42.CrossRefGoogle Scholar
De Beaulieu, J. L., Pons, A. & Reille, M. 1988. Histoire de la flore et de la végétation du Massif Central (France) depuis la fin de la dernière glaciation. Cahier de Micropaléontologie, Paris, 3, 536.Google Scholar
Denys, C., Chorowicz, J. & Jaeger, J. J. 1985. Tectonogenèse et évolution des faunes de rongeurs et autres mammifères du rift est-africain au Mio-Pliocène. Mise en évidence de corrélations. Bulletin de la Société Géologique de France (8)I, 381–89.CrossRefGoogle Scholar
De Ploey, J., Lepersonne, J. & Stoops, G. 1968. Sédimentologie et origine des sables de la série des Sables Ocres et de la Série des ‘Grès Polymorphes” (Système du Kalahari) au Congo Occidental. Musée Royal de l'Afrique Centrale, Tervuren, Annales in 8°, Sciences Géologiques 61, 72 pp.Google Scholar
Robin, De, 1988. The Antarctic ice sheet, its history and response to sea level and climatic changes over the past 100 million years. Palaeogeography, Palaeoclimatology, Palaeoecology 67, 3150.CrossRefGoogle Scholar
Doyle, J. A. 1978. Fossil evidence on the evolutionary origin of tropical trees and forests. In Tomlinson, P. B. & Zimmermann, M. H. (Eds) Tropical trees as living systems, pp. 330. Cambridge University Press.Google Scholar
Doyle, J. A., Biens, P., Doerenkamp, A. & Jardiné, S. 1977. Angiosperm pollen from the pre-Albian lower Cretaceous of equatorial Africa. Bulletin du Centre de Recherche, Exploration et Production d'Elf-Aquitaine 1, 451–73.Google Scholar
Doyle, J. A., Jardiné, S. & Doerenkamp, A. 1982. Afropollis, a new genus of early Angiosperm pollen, with notes on the cretaceous palynostratigraphy and paleoenvironments of northern Gondwana. Bulletin du Centre de Recherche, Exploration et Production d'Elf-Aquitaine 6, 39117.Google Scholar
Doyle, J. A., Hotton, C. L. & Ward, J. V. 1990a. Early Cretaceous tetrads, zonasulculate pollen, and Winteraceae. I. Taxonomy, morphology and ultrastructure. American Journal of Botany 77, 1544–57.CrossRefGoogle Scholar
Doyle, J. A., Hotton, C. L. & Ward, J. V. 1990b. Early Cretaceous tetrads, zonasulculate pollen, and Winteraceae. II. Cladistic analysis and implications. American Journal of Botany 77, 1558–68.CrossRefGoogle Scholar
Doyle, J. A. & Hotton, C. L. 1991. Diversification of early angiosperm pollen in a cladistic context. In Blackmore, S. & Barnes, S. H. (Eds) Pollen and spores. Patterns of diversification. The Systematics Assoc. 44, pp. 169–95, Oxford: Clarendon Press.CrossRefGoogle Scholar
Doyle, J. A. & Donoghue, M. J. 1993. Phylogenies and angiosperm diversification. Paleobiology 19, 141–67.CrossRefGoogle Scholar
Dupéron-Laudouneix, M. & Dupéron, J. 1995. Inventory of Mesozoic and Cenozoic woods from equatorial and north equatorial Africa. Review of Palaeobotany & Palynology 84, 439–80.CrossRefGoogle Scholar
Dupéron-Laudouneix, M. & Pons, D. 1985. Nouvelle étude de Mesembrioxylon libanoticum Edwards (Conifère du Mésozoïque supérieur); intérêts paléogéographique, biostratigraphique et paléoclimatique. Giornale Botanico Italiano 119, 151166.CrossRefGoogle Scholar
Dupont, L. M. & Agwu, C. O. C. 1991. Environmental control of pollen grain distribution patterns in the Gulf of Guinea and offshore NW-Africa. Geologische Rundschau 80, 567–89.CrossRefGoogle Scholar
Dupont, L. M. & Agwu, C. O. C. 1992. Latitudinal shifts of forest and savanna in NW Africa during the Brunhes chron: further marine palynological results from site M 16415 (9°N–19°W). Vegetation History and Archaeobotany 1, 163–75.CrossRefGoogle Scholar
Eisentraut, M. 1963. Die Wirbeltiere des Kamerungebirges. Hamburg: Parey.Google Scholar
Eisentraut, M. 1970. Eiszeitklima und heutige Tierverbreitung im tropischen Westafrika. Umschau Wissenschaft und Technik 3, 7075.Google Scholar
Elenga, H. 1992. Végétation et climat du Congo depuis 24.000 ans BP. Analyse palynologique de séquences sédimentaires du pays Batéké et du littoral. Thèse Science, Univ. Aix-Marseille.Google Scholar
Elenga, H., Vincens, A. & Schwartz, D. 1991. Présence d'éléments forestiers montagnards sur les Plateaux Batéké (Congo) au Pléistocène supérieur: nouvelles données palynologiques. Palaeoecology of Africa, 22, 239–52.Google Scholar
El Sabrouty, N. 1984. Palynological studies on some Tertiary sedimentary rocks from the NW desert of Egypt. Thesis Geology, Univ. Sohag Assiut.Google Scholar
Endler, J. A. 1982. Pleistocene forest refuges: fact or fancy. In Prance, G. T. (Ed.) Biological diversification in the tropics, pp. 641–57. New York: Columbia University Press.Google Scholar
Fedorov, A. A. 1966. The structure of the tropical rain forest and speciation in the humid tropics. Journal of Ecology 54, 111.CrossRefGoogle Scholar
Flohn, H. 1971. Tropical circulation pattern. Bonner Meteorologische Abhandlungen 15, 55 p.Google Scholar
Flohn, H. 1978. Comparison of Antarctic and Arctic climate and its relevance to climatic evolution. In Van Zinderen Bakker, E. M. (Ed.) Antarctic glacial history and world palaeoenvironments, pp. 313. Rotterdam: Balkema Publ.Google Scholar
Flohn, H. 1982. Oceanic upwelling as a key for abrupt climatic change. Journal of Meteorology of Japan 60, 268–73.Google Scholar
Flohn, H. 1984. Climate evolution in the Southern Hemisphere and the equatorial region during the Late Cenozoic. In Vogel, J. C. (Ed.) Late Cainozoic palaeoclimates of the Southern Hemisphere, pp. 520. Amsterdam: A.A. Balkema Publ.Google Scholar
Flohn, H. 1987. The role of large-scale ice sheets in climatic history. In: The physical basis of ice sheet modelling. International Association of Hydrological Sciences, Publ. 170, 231–41.Google Scholar
Fontaine, B. 1991. Variations pluviométriques et connexions climatiques: l'exemple des aires de mousson indienne et ouest-africaine. Sécheresse 2, 259–64.Google Scholar
Frédoux, A. & Tastet, J. P. 1993. Analyse pollinique d'une carotte marine au large de la Côte d'lvoire. Variations de la végétation et du climat depuis 225 000 ans. Palynosciences 2, 173–88.Google Scholar
Gentry, A. H. 1989. Speciation in tropical forests. In Holm-Nielsen, L. B., Nielsen, I. C. & Balslev, H. (Eds) Tropical forests. Botanical dynamics, speciation and diversity, pp. 113–34. London: Academic Press.Google Scholar
Germeraad, J. H., Hopping, C. A. & Muller, J. 1968. Palynology of Tertiary sediments from tropical areas. Review of Palaeobotany & Palynology 6, 189348.CrossRefGoogle Scholar
Gioda, A., Acosta Baladon, A. N., Fontanel, P., Hernandez Martin, Z. & Santos, A. 1992. L'arbre fontaine. La Recherche 249, 1400–08.Google Scholar
Giresse, P., Bongo-Passi, G., Delibrias, G. & Duplessy, J. C. 1982. La lithostratigraphie des sédiments hémipélagiques du delta du fleuve Congo et ses indications sur les paléoclimats de la fin du Quaternaire. Bulletin de la Sociétè Géologique de France 24, 803–15.CrossRefGoogle Scholar
Giresse, P., Maley, J. & Kelts, K. 1991. Sedimentation and palaeoenvironment in crater lake Barombi Mbo, Cameroon, during the last 25,000 years. Sedimentary Geology 71, 151–75.CrossRefGoogle Scholar
Giresse, P., Maley, J. & Brenac, P. 1994. Late Quaternary palaeoenvironments in the lake Barombi Mbo (Cameroon) deduced from pollen and carbon isotopes of organic matter. Palaeogeography, Palaeoclimatology, Palaeoecology 107, 6578.CrossRefGoogle Scholar
Gros, J. P. 1990. Etudes xylotomiques et systématiques de bois fossiles cénozoïques de la basse vallée de l'Omo, Ethiopie. Leurs apports à la connaissance des Bignoniaceae, Irvingiaceae, Mimosaceae, Rubiaceae fossiles et à la reconstitution des flores et végétations ligneuses passées. Thèse Science, Univ. Claude Bernard, Lyon I, 2 t, 560 p.Google Scholar
Grubb, P. 1982. Refuges and dispersal in the speciation of African mammals. In Prance, G. T. (Ed.) Biological diversification in the tropics, pp. 537–53. New York: Columbia University Press.Google Scholar
Guillaumet, J. L. 1967. Recherches sur la végétation et la flore de la région du Bas-Cavally (Côte d'lvoire). Mémoire ORSTOM 20, 247 p.Google Scholar
Guinet, P., El Sabrouty, N., Soliman, H. A. & Omran, A. M. 1987. Etude des caractères du pollen des Légumineuses - Mimosoideae des sédiments Tertiaires du nord-ouest de l'Egypte. Mémoire des Travaux de l'Ecole Pratique des Hautes Etudes, Institut de Montpellier 17, 159–71.Google Scholar
Guinet, P. & Salard-Cheboldaeff, M. 1975. Grains de pollen du Tertiaire du Cameroun pouvant être rapportés aux Mimosacées. Boissiera, Genève 24, 2128.Google Scholar
Guiraud, R. & Maurin, J. C. 1991. Le rifting en Afrique au Crétacé inférieur: synthèse structurale, mise en évidence de deux étapes dans la genèse des bassins, relations avec les ouvertures océaniques péri-africaines. Bulletin de la Sociétè Géologique de France 162, 811–23.CrossRefGoogle Scholar
Haffer, J. 1982. General aspects of the Refuge theory. In Prance, G. T. (Ed.) Biological diversification in the tropics, pp. 641–57. New York: Columbia Univ. Press.Google Scholar
Haffer, J. 1993. Time's cycle and time's arrow in the history of Amazonia. Biogeographica 69, 1545.Google Scholar
Hall, J. B. 1984. Juniperus excelsa in Africa: a biogeographical study of an Afromontane tree. Journal of Biogeography 11, 4761.CrossRefGoogle Scholar
Hall, J. B. 1973. Vegetational zones on the southern slopes of Mount Cameroon. Vegetation 27, 4969.CrossRefGoogle Scholar
Hall, J. B. & Swaine, M. D. 1981. Distribution and ecology of vascular plants in a tropical rain forest: Forest vegetation in Ghana. The Hague: W. Junk.CrossRefGoogle Scholar
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. Palaeoecology of Africa 9, 6397.Google Scholar
Hamilton, A. C. 1982. Environmental history of East Africa. A study of the Quaternary. London: Academic Press.Google Scholar
Hamilton, A. C. 1991. History of climate and forests in tropical Africa during the last 8 million years. Climatic Change 19, 6578.CrossRefGoogle Scholar
Haq, B. U., Hardenbol, J. & Vail, R. P. 1987. Chronology of fluctuating sea levels since the Triassic. Science 235, 1156–67.CrossRefGoogle ScholarPubMed
Harris, J. 1993. Ecosystem structure and growth of the African savanna. Global & Planetary Change 8, 231–48.CrossRefGoogle Scholar
Herngreen, G. F. W. & Chlonova, A. F. 1981. Cretaceous microfloral provinces. Pollen & Spores 23, 441555.Google Scholar
Hooghiemstra, H. & Agwu, C. O. 1988. Changes in the vegetation and trade winds in equatorial northwest Africa 140,000–70,000 yr B.P. as deduced from two marine pollen records. Palaeogeography, Palaeoclimatology, Palaeoecology 66, 173213.CrossRefGoogle Scholar
Hooghiemstra, H. & Agwu, C. O. 1986. Distribution of palynomorphs in marine sediments: a record for seasonal wind patterns over NW Africa and adjacent Atlantic. Geologische Rundschau 75, 8195.CrossRefGoogle Scholar
Horrell, M. A. 1991. Phytogeography and paleoclimatic interpretation of the Maestrichtian. Palaeogeography, Palaeoclimatology, Palaeoecology 86, 87138.CrossRefGoogle Scholar
Jansen, J. H. F., Van Weering, T. C., Gieles, R. & Van Iperen, J. 1984. Middle and late Quaternary oceanography and climatology of the Zaire–Congo fan and the adjacent eastern Angola basin. Netherlands Journal of Sea Research 17, 201–48.CrossRefGoogle Scholar
Jansen, J. H. F., Kuijpers, A. & Troelstra, S. R. 1986. A mid-Brunhes climatic event: long-term changes in global atmosphere and ocean circulation. Science 232, 619–22.CrossRefGoogle ScholarPubMed
Kahn, F. 1993. Richesse générique et spécifique des Palmiers en Amazonie: phytogéographie, diversité et spéciation. Colloque International de Phytogéographie Tropicale, Paris, Résumé 1 p.Google Scholar
Kasas, M. 1956. The mist oasis of Erkwit, Sudan. Journal of Ecology 44, 180–94.CrossRefGoogle Scholar
Kedves, M. 1971. Présence de types sporomorphes importants dans les sédiments préquaternaires égyptiens. Acta Botanica. Academiae Scientianum Hungaricae 17, 371–78.Google Scholar
Kendall, R. L. 1969. An ecological history of the lake Victoria basin. Ecological Monographs 39, 121–76.CrossRefGoogle Scholar
Kennett, J. P. 1977. Cenozoic evolution of Antarctic glaciation, the circum-Antarctic ocean and their impact on global paleoceanography. Journal of Geophysical Research 82, 3843–60.CrossRefGoogle Scholar
Kerfoot, O. 1968. Mist precipitation on vegetation. Forestry Abstracts 29, 820.Google Scholar
Knaap, W. A. 1971. A montane pollen species from the upper Tertiary of the Niger delta. Journal of Mining & Geology, Lagos 6, 2329.Google Scholar
Kraus, , 1977. The seasonal excursion of the Intertropical Convergence Zone. Monthly Weather Review 105, 1052–5.2.0.CO;2>CrossRefGoogle Scholar
Lachaise, D., Cariou, M. L., David, J. R., Lemeunier, F., Tsacas, L. & Ashburner, M. 1988. Historical biogeography of the Drosophila melanogaster species subgroup. In Hecht, M. K., Wallace, B. & Prance, G. T. (Eds) Evolutionary biology 22, pp. 159225. New York: Plenum.CrossRefGoogle Scholar
Lamb, H. H. 1972. Climate: present, past and future. I, Fundamentals and climate now. London: Methuen.Google Scholar
Lamb, H. F., Eicher, U. & Switsur, V. R. 1989. An 18,000-year record of vegetation, lake-level and climatic change from Tigalmamine, Middle Atlas, Morocco. Journal of Biogeography 16, 6574.CrossRefGoogle Scholar
Lanfranchi, R. & Schwartz, D. 1991. Les remaniements de sols pendant le Quaternaire supérieur au Congo. Evolution des paysages dans la région de la Sangha. Cahiers ORSTOM, série Pédologie 26, 1124.Google Scholar
Le Fournier, J. 1980. Dépôts de préouverture de l'Atlantique Sud. Comparaison avec la sédimentation actuelle dans la branche occidentale des Rifts Est-Africains. Recherches Géologiques en Afrique, CNRS 5, 127–30.Google Scholar
Maréchal, Le, 1966. Contribution à l'étude des Plateaux Batékés. Géologie, Géomorphologie, Hydrogéologie. Rapport ORSTOM, Brazzaville, MC 137, 43 p.Google Scholar
Thomas, Le, 1981. Ultrastructural characters of the pollen grains of African Annonaceae and their significance for the phylogeny of primitive Angiosperms (second part). Pollen & Spores 23, 536.Google Scholar
Léonard, J. 1965. Contribution à la subdivision phytogéographique de la région guinéo-congolaise d'après la répartition géographique d'Euphorbiacées d'Afrique tropicale. Webbia 19, 627–49.Google Scholar
Lepersonne, J. 1961. Quelques problèmes de l'histoire géologique de l'Afrique au sud du Sahara, depuis la fin du Carbonifere. Annales de la Socièté Géologique de Belgique 84, 21–85 (cf. pp. 6263).Google Scholar
Leroux, M. 1993. The mobile polar high: a new concept explaining present mechanisms of meridional air-mass and energy exchanges and global propagation of palaeoclimatic changes. Global & Planetary Change 7, 6993.CrossRefGoogle Scholar
Letouzey, R. 1968. Etude phytogéographique du Cameroun. Encyclopédic Biologique 49, 508 p.Google Scholar
Letouzey, R. 1978. Notes phytogéographiques sur les Palmiers du Cameroun. Adansonia 18, 293325.Google Scholar
Letouzey, R. 1985. Notice de la carte phytogéographique du Cameroun au 1/500.000. Institut de la Carte Internationale de Végétation, Toulouse & Institut de Recherche Agronomique, Yaoundé.Google Scholar
Lézine, A. M. 1989. Late Quaternary vegetation and climate of the Sahel. Quaternary Research 32, 317–34.CrossRefGoogle Scholar
Lidgard, S. & Crane, P. R. 1990. Angiosperm diversification and Cretaceous floristic trends: a comparison of palynofloras and leaf macrofloras. Paleobiology 16, 7793.CrossRefGoogle Scholar
Louvet, P. 1970. Sonneratioxylon aubrevillei, n.sp. Comptes Rendus de l'Academie des Sciences, Paris D 270, 2268–71.Google Scholar
Louvet, P. 1973. Sur les affinités des Sores tropicales ligneuses africaines tertiaire et actuelle. Bulletin de la Socièté Botanique de France 120, 385–96.CrossRefGoogle Scholar
Louvet, P. & Magnier, P. 1971. Confirmation de la dérive du continent africain au Tertiaire par la paleobotanique. 96è Congrès National des Sociètés Savantes, Section. 5, 177189.Google Scholar
McIntyre, A., Ruddiman, W. F., Karlin, K. & Mix, A. C. 1989. Surface water response of the equatorial Atlantic ocean to orbital forcing. Paleoceanography 4, 1955.CrossRefGoogle Scholar
Mahé, G. & Citeau, J. 1993. Relations Ocean–Atmosphère–Continent dans l'espace Africain de la mousson Atlantique. Schéma général et cas particulier de 1984. Veille Climatique Satellitaire, Lannion 44, 3454.Google Scholar
Maley, J. 1980. Les changements climatiques de la fin du Tertiaire en Afrique: leur conséquence sur l'apparition du Sahara et de sa végétation. In Williams, M. A. J. & Faure, H. (Eds) The Sahara and the Nile, pp. 6386. Rotterdam: A.A. Balkema.Google Scholar
Maley, J. 1981. Etudes palynologiques dans le bassin du Tchad et paléoclimatologie de l'Afrique nordtropicale de 30000 ans à l'époque actuelle. Travaux & Documents de l'ORSTOM 129, 586 p.Google Scholar
Maley, J. 1982. Dust, clouds, rain types and climatic variations in tropical North Africa. Quaternary Research 18, 116.CrossRefGoogle Scholar
Maley, J. 1987. Fragmentation de la forêt dense humide africaine et extension des biotopes montagnards au Quaternaire récent: nouvelles données polliniques et chronologiques. Implications paléoclimatiques et biogéographiques. Palaeoecology of Africa 18, 307–34.Google Scholar
Maley, J. 1989. Late Quaternary climatic changes in the African rain forest: the question of forest refuges and the major role of sea surface temperature variations. In Leinen, M. & Sarnthein, M. (Eds) Paleoclimatology and paleometeorology: modern and past patterns of global atmospheric transport, NATO Adv. Sc. Inst., Ser. C., Math. & Phys. Sci. 282, pp. 585616. Dordrecht: Kluwer Acad. Publ.CrossRefGoogle Scholar
Maley, J. 1990. Synthèse sur le domaine forestier africain au Quaternaire récent. In Lanfranchi, R. & Schwartz, D. (Eds) Paysages Quaternaires de l'Afrique centrale Atlantique, pp. 383–9. Paris: Didactiques, ORSTOM.Google Scholar
Maley, J. 1991. The African rain forest vegetation and palaeoenvironments during late Quaternary. Climatic Change 19, 7998.CrossRefGoogle Scholar
Maley, J. 1992. Mise en évidence d'une péjoration climatique entre ca. 2500 et 2000 ans BP en Afrique tropicale humide. Bulletin de la Socièté Géologique de France 163, 363–5.Google Scholar
Maley, J. 1995. Holocene changes in the African rain forest: paleomonsoon and sea surface temperature variations. Terra Nostra, XIVth International Quaternary Congress, Berlin, Abstract, p. 176.Google Scholar
Maley, J. & Brenac, P. 1987. Analyses polliniques préliminaries du Quaternaire récent de l'Ouest Cameroun: mise en évidence de refuges forestiers et discussion des problèmes paléoclimatiques. Mémoire des Travaux de l'Ecole Pratique des Hautes Etudes, Institut de Montpellier 17, 129–42.Google Scholar
Maley, J., Caballé, G. & Sita, P. 1990. Etude d'un peuplement résiduel à basse altitude de Podocarpus latifolius sur le flanc Congolais du Massif du Chaillu. Implications paleoclimatiques et biogéographiques. Etude de la pluie pollinique actuelle. In Lanfranchi, R. & Schwartz, D. (Eds) Paysages Quaternaires de l'Afrique centrale Atlantique, pp. 336–52. Paris: Didactiques, ORSTOM.Google Scholar
Maley, J. & Elenga, H. 1993. Le rôle des nuages dans l'évolution des paléoenvironnements montagnards de l'Afrique tropicale. Veille Climatique Satellitaire, Lannion 46, 5163.Google Scholar
Maley, J. & Livingstone, D. A. 1983. Extension d'un élément montagnard dans le sud du Ghana (Afrique de l'Ouest) au Pléistocène supérieur et à l'Holocène inférieur: premières données polliniques. Comptes Rendus de l'Académie des Sciences, Paris 2, 296, 1287–92.Google Scholar
Mariotti, A. 1991. Le carbone 13 en abondance naturelle, traceur de la dynamique de la matière organique des sols et de l'évolution des paléoenvironnements continentaux. Cahiers ORSTOM, Pédologie 26, 299313.Google Scholar
Martin, L., Fournier, M., Mourguiart, P., Sifeddine, A., Turcq, B., Absy, M. L. & Flexor, J. M. 1993. Southern Oscillation signal in South American palaeoclimatic data of the last 7000 years. Quaternary Research 39, 338–46.CrossRefGoogle Scholar
Martinson, D. G., Pisias, N. G., Hays, J. D., Imbrie, J., Moore, T. C. & Shackleton, N. J. 1987. Age dating and the orbital theory of the Ice Ages: development of a high-resolution 0 to 300,000-year chronostratigraphy. Quaternary Research 27, 129.CrossRefGoogle Scholar
Mayr, E. & O'Hara, R. J. 1986. The biogeographic evidence supporting the Pleistocene forest refuge hypothesis. Evolution 40, 5567.CrossRefGoogle ScholarPubMed
Melguen, M. 1978. Facies evolution, carbonate dissolution cycles in sediments from the eastern south Atlantic (DSDP Leg 40) since the early Cretaceous. Initial Report of Deep Sea Drilling Project 40, 9811024.Google Scholar
Mercer, J. H. 1983. Cenozoic glaciation in the Southern Hemisphere. Annual Review of Earth and Planetary Sciences 11, 99132.CrossRefGoogle Scholar
Midgley, J. J. & Bond, W. J. 1989. Evidence from southern african Coniferales for the historical decline of the Gymnosperms. South African Journal of Science 85, 81–4.Google Scholar
Miller, K. G., Wright, J. D. & Fairbanks, R. G. 1991. Unlocking the Ice House: Oligocene-Miocene oxygen isotopes, eustasy and margin erosion. Journal of Geophysical Research 96, 6829–48.CrossRefGoogle Scholar
Mix, A. C., Ruddiman, W. F. & McIntyre, A. 1986. Late Quaternary paleoceanography of the tropical Atlantic. 2: The seasonal cycle of sea surface temperatures, 0–20,000 years B.P. Paleoceanography 1, 339–53.CrossRefGoogle Scholar
Moll, E. J. 1972. The current status of the mistbelt mixed Podocarpus forests in Natal. Bothalia, Pretoria 10, 595–8.CrossRefGoogle Scholar
Moore, H. E. Jr. 1973. Palms in the tropical forest ecosystems of Africa and South America. In Meggers, B. J., Ayensu, E. S. & Duckworth, W. D. (Eds) Tropical forest ecosystems in Africa and South America: a comparative review, pp. 6388. Washington: Smithsonian Inst. Press.Google Scholar
Moreau, R. E. 1963. The distribution of tropical African birds as an indicator of past climatic changes. In Howell, F. C. & Bourlière, F. (Eds) African ecology and human evolution, pp. 2842. Chicago: Aldine Press.Google Scholar
Moreau, R. E. 1966. The bird faunas of Africa and its islands. New York: Academic Press.Google Scholar
Moreau, R. E. 1969. Climatic changes and the distribution of forest vertebrates in West Africa. Journal of Zoology, London 158, 3961.CrossRefGoogle Scholar
Morley, R. J. & Richards, K. 1993. Gramineae cuticle: a key indicator of Late Cenozoic climatic change in the Niger delta. Review of Palaeobotany and Palynology 77, 119–27.CrossRefGoogle Scholar
Muller, J. 1959. Palynology of recent Orinoco delta and shelf sediments. Micropaleontology 5, 132.CrossRefGoogle Scholar
Muller, J. 1984. Significance of fossil pollen for Angiosperm history. Annals of the Missouri Botanical Garden 71, 419–43.CrossRefGoogle Scholar
Ndjelé, M. 1988. Principales distributions obtenues par l'analyse factorielle des éléments phytogéographiques présumés endémiques dans la flore du Zaïre. Monograph of Systematic Botany of the Missouri Botanical Garden 25, 631–8.Google Scholar
Parrish, J. T., Ziegler, A. M. & Scotese, C. R. 1982. Rainfall patterns and the distribution of coals and evaporites in the Mesozoic and Cenozoic. Palaeogeography, Palaeoclimatology, Palaeoecology 40, 67101.CrossRefGoogle Scholar
Perrott, R. A. 1982. A high altitude pollen diagram from Mount Kenya: its implications for the history of glaciation. Palaeoecology of Africa 14, 7783.Google Scholar
Poumot, C. 1989. Palynological evidence for eustatic events in the tropical Neogene. Bulletin du Centre de Recherche, Exploration et Production d'Elf-Aquitaine 13, 437–53.Google Scholar
Poumot, C. & Suc, J. P. 1984. Flore pollinique de la fin du Néogène en Méditerranée sud-orientale. Paléobiologie Continentale 14, 397401.Google Scholar
Prell, W. L., Gardner, J. V., Be, A. W. H. & Hays, J. D. 1976. Equatorial Atlantic and Caribbean foraminiferal assemblages, temperatures and circulation: interglacial and glacial comparisons. Geological Society of America Memoir 145, 247–66.CrossRefGoogle Scholar
Richards, P. W. 1963. Ecological notes on West African vegetation. II. Lowland forest of the southern Bakundu Forest Reserve. Journal of Ecology 51, 123–49.CrossRefGoogle Scholar
Richards, P. W. 1969. Speciation in the tropical rain forest and the concept of the niche. Biological Journal of the Linnean Society 1, 149–53.CrossRefGoogle Scholar
Richards, P. W. 1973. Africa, the “Odd man out”. In Meggers, B. J., Ayensu, E. S. & Duckworth, W. D. (Eds) Tropical forest ecosystems in Africa and South America: a comparative review, pp. 21–6. Washington: Smithsonian Institute Press.Google Scholar
Rietkerk, M., Ketner, P. & De Wilde, J. J. F. E. 1995. Caesalpinioideae and the study of forest refuges in Gabon: preliminary results. Bulletin du Museum National d'Histoire Naturelle, Paris, Adansonia 17, 95105.Google Scholar
Robert, C. 1980. Climats et courants cénozoïques dans l'Atlantique Sud d'apres l'étude des minéraux argileux (legs 3, 39 et 40). Oceanologica Acta 3, 369–76.Google Scholar
Robert, C. & Chamley, H. 1987. Cenozoic evolution of continental humidity and paleoenvironment, deduced from the kaolinite content of oceanic sediments. Palaeogeography, Palaeoclimatology, Palaeoecology 60, 171–87.CrossRefGoogle Scholar
Robbins, C. B. 1978. The Dahomey Gap. A reevaluation of its significance as a faunal barrier to West African high forest mammals. Bulletin of the Carnegie Museum of Natural History 6, 168–74.Google Scholar
Robbrecht, E. 1994. Geography of African Rubiaceae with reference to glacial rain forest refuges. 14th Congress Association pour l'Etude Taxonomique de la Flore de l'Afrique Tropicale, Univ. Wageningen, Abstract, p. 104.Google Scholar
Ruddiman, W. F., Sarnthein, M. & Leg 108 shipboard scientific party. 1986. Palaeoclimatic linkage between high and low latitudes. Nature 322, 211–12.Google Scholar
Ruddiman, W. F., Sarnthein, M., Backman, J., Baldauf, J. G., Curry, W., Dupont, L. M., Janececk, T., Pokras, E. M., Raymo, M. E., Stabell, B., Stein, R. & Tiedemann, R. 1989. Late Miocene to Pleistocene evolution of climate in Africa and the low-latitude Atlantic: overview of Leg 108 results. Proceedings of the Ocean Drilling Program, Scientific Results 108, 463–84.Google Scholar
Runge, J. & Runge, F. (à paraître). Late Quaternary palaeoenvironmental conditions in eastern Zaire (Kivu) deduced from remote sensing, morphopedological and sedimentological studies (phytoliths, pollen, C-14 data). Actes 2ème Symposium de Palynologie Africaine, Tervuren, 19 p.Google Scholar
Salard-Cheboldaeff, M. 1977. Paléopalynologie du bassin sédimentaire littoral du Cameroun dans ses rapports avec la stratigraphie et la paléoécologie. Thèse Science, Univ. Paris VI, 262 pp.Google Scholar
Salard-Cheboldaeff, M. 1981. Palynologie Maestrichtienne et Tertiaire du Cameroun. Résultats botaniques. Review of Palaeobotany and Palynology 32, 401–39.CrossRefGoogle Scholar
Salard-Cheboldaeff, M. & Dejax, J. 1991. Evidence of Cretaceous to recent West African intertropical vegetation from continental sediment spore-pollen analysis. Journal of African Earth Sciences 12, 353–61.CrossRefGoogle Scholar
Salard-Cheboldaeff, M. & Boltenhagen, E. 1992. La palynologie des évaporites d'Afrique équatoriale et ses rapports avec le paléoenvironnement. Journal of African Earth Sciences 14, 191–5.CrossRefGoogle Scholar
Salard-Cheboldaeff, M., Mouton, J. & Brunet, M. 1992. Paléoflore tertiaire du bassin d'Anloua, Plateau de l'Adamaoua, Cameroun. Revista Espanola de Micropaleontologia 24, 131–62.Google Scholar
Schnell, R. 1977. Introduction à la phytogéographie des pays tropicaux.4: La flore et la végétation de l'Afrique tropicale. Paris: Publ. Gauthier-Villars.Google Scholar
Schwartz, D. 1992. Assèchement climatique vers 3000 B.P. et expansion Bantu en Afrique centrale atlantique: quelques réflexions. Bulletin de la Société Géologique de France 163, 353–61.Google Scholar
Schwartz, D., Guillet, B. & Dechamps, R. 1990. Etude de deux flores forestières mi-Holocène (6000–3000 BP) et subactuelle (500 BP) conservées in situ sur le littoral Pontenegrin (Congo). In Lanfranchi, R. & Schwartz, D. (Eds) Paysages Quaternaires de l'Afrique centrale Atlantique pp. 283–97. Paris: Didactiques, ORSTOM.Google Scholar
Servant, M., Maley, J., Turcq, B., Absy, M. L., Brenac, P., Fournier, M. & Ledru, M. P. 1993. Tropical forest changes during the late Quaternary in African and South American lowlands. Global & Planetary Change 7, 2540.CrossRefGoogle Scholar
Servant-Vildary, S. 1973. Le Plio-Quaternaire ancien du Tchad: évolution des associations de diatomées, stratigraphie, paléoécologie. Cahiers ORSTOM, série Géologie 5, 169216.Google Scholar
Siesser, W. M. 1978. Aridification of the Namib desert: evidence from oceanic cores. In Vogel, J. C. (Ed.) Late Cainozoic palaeoclimates of the Southern Hemisphere, pp. 105–13. Amsterdam: A.A. Balkema Publ.Google Scholar
Sosef, M. S. M. 1991. New species of Begonia in Africa and their relevance to the study of glacial rain forest refuges. Wageningen Agricultural University Papers 91, 120–51.Google Scholar
Sosef, M. S. M. 1994. Refuge Begonias: taxonomy, phylogeny and historical biogeography of Begonia sect. Loasibegonia and sect. Scutobegonia in relation to glacial rain forest refuges in Africa. (Thesis University Wageningen & Wageningen Agricultural University Papers) Studies in Begoniaceae 5. 306 pp.Google Scholar
Sowunmi, M. A. 1981. Late Quaternary environmental changes in Nigeria. Pollen & Spores 23, 125–48.Google Scholar
Sowunmi, M. A. 1991. Late Quaternary environments in equatorial Africa: palynological evidence (Lake Mobutu Sese Seko). In Ballouche, A. & Maley, J. (Eds) Proceedings First Symposium on African Palynology. Palaeoecology of Africa 22, 213–38.Google Scholar
Start, G. G. & Prell, W. L. 1984. Evidence for two Pleistocene climatic modes: data from DSDP site 502. In Berger, A. L. & Nicolis, C. (Eds) New perspectives in climate modelling. Developments in Atmospheric Science 16, 322.Google Scholar
Swaine, M. D. & Hall, J. B. 1986. Forest structure and dynamics. In Lawson, G. W. (Ed.) Plant ecology in West Africa, pp. 4793. Chichester: J. Wiley.Google Scholar
Talbot, M. R., Livingstone, D. A., Palmer, P. G., Maley, J., Melack, J. M., Delibrias, G. & Gulliksen, S. 1984. Preliminary results from sediment cores from Lake Bosumtwi, Ghana. Palaeoecology of Africa 16, 173–92.Google Scholar
Tardy, Y., Kolbisek, B. & Paquet, H. 1991. Mineralogical composition and geographical distribution of African and Brazilian periatlantic laterites. The influence of continental drift and tropical paleoclimates during the past 150 million years and implications for India and Australia. Journal of the African Earth Sciences 12, 283–95.CrossRefGoogle Scholar
Thiébaut, B. 1982. Existe-t-il une hîtraie Méditerranéenne distincte des autres forîts de hître en Europe occidentale? Vegetatio 50, 2342.CrossRefGoogle Scholar
Thomas, D. W. 1986. Vegetation in the montane forests of Cameroon. In Stuart, S. N. (Ed.) Conservation of Cameroon montane forests pp. 20–7. Cambridge, UK: International Council Bird Preservation.Google Scholar
Thomas, M. F. & Thorp, M. B. 1995. Geomorphic response to rapid climatic and hydrologic change during the late Pleistocene and early Holocene in the humid and sub-humid tropics. Quaternary Science Reviews 14, 193207.CrossRefGoogle Scholar
Tomlinson, P. B., Braggins, J. E. & Rattenbury, J. A. 1991. Pollination drop in relation to cone morphology in Podocarpaceae: a novel reproductive mechanism. American Journal of Botany 78, 1289–303.CrossRefGoogle Scholar
Trochain, J. 1939. La flore et la végétation des Niayes (Sénégal). Compte Rendu Sommaire des Séances de la Socièté de Biogéographie Paris 132–133, 1018.Google Scholar
Troll, C. 1956. Das Wasser als pflanzengeographischer Faktor. In Ruhland, W. (Ed.) Handbuch der Pflanzenphysiologie, pp. 750–86. Berlin: Springer-Verlag.Google Scholar
Troll, C. 1960. The relationship between the climates, ecology and plant geography of the southern cold temperate zone and the tropical high mountains. Proceedings of the Royal Society, B 152, 529–32.Google Scholar
Tyson, P. D. 1969. Atmospheric circulation and precipitation over South Africa. Occasional Paper, Department of Geography & Environmental Studies, Univ. Witwatersrand 2.Google Scholar
Upchurch, G. R. & Wolfe, J. A. 1987. Mid-Cretaceous to Early Tertiary vegetation and climate: evidence from fossil leaves and woods. In Friis, E. M., Chaloner, W. G. & Crane, P. R. (Eds) The origins of Angiosperms and their biological consequences, pp. 75105. Cambridge, UK: Cambridge University Press.Google Scholar
Van Neer, W. 1990. Les faunes de vertébrés quaternaires en Afrique centrale. In Lanfranchi, R. & Schwartz, D. (Eds) Paysages Quaternaires de l'Afrique centrale Atlantique, pp. 195220. Paris: Didactiques, ORSTOM.Google Scholar
Van Rompaey, R. S. A. R. 1993. Forest gradients in West Africa: a spatial gradient analysis. Doctoral thesis, Wageningen Agricultural Univ., 142 pp.Google Scholar
Van Rompaey, R. S. A. R. 1994. Locating rain forest refugia in Liberia and western Côte d'Ivoire using biogeographic evidence from mainly endemic Caesalpiniaceae species: coastal versus submontane position. 14th Congress Association Etude Taxonomie et Flore Afrique Tropicale, Univ. Wageningen, Poster & Abstract, p. 108 (and manuscript to be published in the Congress Proceedings).Google Scholar
Van Zinderen Bakker, E. M. 1973. Ecological investigations of forest communities in the eastern Orange Free State and the adjacent Natal Drakensberg. Vegetatio 28, 299334.CrossRefGoogle Scholar
Van Zinderen Bakker, E. M. & Mercer, J. H. 1986. Major late Cainozoic climatic events and Palaeoenvironmental changes in Africa viewed in a world wide context. Palaeogeography, Palaeoclimatology, Palaeoecology 56, 217–35.CrossRefGoogle Scholar
Vogt, J. 1966. Le complexe de la stone-line. Mise au point. Bulletin du Bureau de Recherches Géologiques et Minières, Paris 4, 351.Google Scholar
Walker, J. W., Brenner, G. J. & Walker, A. G. 1983. Winteraceous pollen in the Lower Cretaceous of Israel: early evidence of a Magnolialean angiosperm family. Science 220, 1273–5.CrossRefGoogle ScholarPubMed
White, F. 1979. The Guineo–Congolian Region and its relationships to other phytocoria. Bulletin du Jardin Botanique National de Belgique 49, 1155.CrossRefGoogle Scholar
White, F. 1981. The history of the Afromontane archipelago and the scientific need for its conservation. African Journal of Ecology 19, 3354.CrossRefGoogle Scholar
White, F. 1983. The vegetation of Africa. UNESCO/AETFAT/UNSO, Maps & Memoir, 356 p.Google Scholar
Wright, E. P. 1978. Geological studies in the northern Kalahari. Geographical Journal 144, 235–49.CrossRefGoogle Scholar
Zachos, J. C., Breza, J. R. & Wise, S. W. 1992. Early Oligocene ice-sheet expansion on Antarctica: stable isotope and sedimentological evidence from Kerguelen Plateau, southern Indian Ocean. Geology 20, 569–73.2.3.CO;2>CrossRefGoogle Scholar
Zeven, A. C. 1964. On the origin of the oil palm (Elaeis guineensis Jacq.). Grana Palynologica 5, 121–23.CrossRefGoogle Scholar