Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-28T17:34:42.010Z Has data issue: false hasContentIssue false
  • English
  • Français

Lowland rainforest response to hydrological changes during the last 1500 years in Gabon, Western Equatorial Africa

Published online by Cambridge University Press:  20 January 2017

Alfred Ngomanda ,
Dominique Jolly ,
Ilhem Bentaleb ,
Alex Chepstow-Lusty ,
M'voubou Makaya ,
Jean Maley ,
Michel Fontugne ,
Richard Oslisly  and
Nicaise Rabenkogo
Alfred Ngomanda*
Affiliation:
Institut des Sciences de l'Evolution de Montpellier, UMR 5554, Université de Montpellier II Place Eugène Bataillon, cc 61, 34095 Montpellier Cedex 5, France
Dominique Jolly
Affiliation:
Institut des Sciences de l'Evolution de Montpellier, UMR 5554, Université de Montpellier II Place Eugène Bataillon, cc 61, 34095 Montpellier Cedex 5, France
Ilhem Bentaleb
Affiliation:
Institut des Sciences de l'Evolution de Montpellier, UMR 5554, Université de Montpellier II Place Eugène Bataillon, cc 61, 34095 Montpellier Cedex 5, France
Alex Chepstow-Lusty
Affiliation:
Institut des Sciences de l'Evolution de Montpellier, UMR 5554, Université de Montpellier II Place Eugène Bataillon, cc 61, 34095 Montpellier Cedex 5, France Centre de Bio-Archéologie et d'Ecologie (UMR 5059-CNRS/UM2/EPHE), Institut de Botanique, 163 rue Broussonnet, F-34090, Montpellier, France
M'voubou Makaya
Affiliation:
Laboratoire d'Etude de Géo-Environnements Marins, Université de Perpignan 52, Avenue Paul Alduy, 66000 Perpignan, France
Jean Maley
Affiliation:
Institut des Sciences de l'Evolution de Montpellier, UMR 5554, Université de Montpellier II Place Eugène Bataillon, cc 61, 34095 Montpellier Cedex 5, France
Michel Fontugne
Affiliation:
Laboratoire des Sciences du Climat et de l'Environnement, UMR CEA/CNRS 1572, Domaine du CNRS, 91198 Gif sur Yvette cedex, France
Richard Oslisly
Affiliation:
Wildlife Conservation Society, BP 7847 Libreville, Gabon and IRD, 5 rue du Carbone, 45072 Orléans cedex 2, France
Nicaise Rabenkogo
Affiliation:
IRSH/GREH, Centre National de Recherche Scientifique et Technique (CENAREST), BP 846 Libreville, Gabon
*
*Corresponding author. E-mail addresses:Alfred@isem.univ-montp2.fr, Ngomanda@yahoo.fr (A. Ngomanda).
Get access Rights & Permissions [Opens in a new window]

Abstract

Pollen and δ13CTOM data obtained from two contrasting lake sequences (Lakes Kamalété and Nguène), located 200 km apart in the lowland rainforest of Gabon, provide complementary local and regional 1500-yr records of high resolution (15–30 yr) vegetation change. A combination of aquatic, semi-aquatic and terrestrial pollen showed in both records that the tropical rainforest increased during periods of high rainfall and decreased during drought intervals. The strong fluctuations of water balance at decadal scale during the “Medieval Warm Period” (∼ 1100–800 cal yr BP) coincided with a noticeable increase in shade-intolerant taxa, indicating recurring rainforest canopy disturbance. The δ13CTOM signal showed high-amplitude variations in both records, which positively correlates with the rainforest dynamics and local vegetation changes. The similar trends in both the pollen and the δ13CTOM signals between these sites demonstrate the regional broadly synchronous timing of shifting hydrological conditions. The largely positive co-variation between strong fluctuations of hydrological conditions and changes in rainforest structure and composition indicate that regional climatic change is probably the driving force for major rainforest dynamics in Gabon. Any significant anthropogenic impact on vegetation has not been clearly identified, and this issue still needs to be resolved independently by obtaining detailed archeological records across the interval 1400–800 BP, which currently seem to be extremely rare or not easily available.

Keywords

PollenCarbon isotopesLake-level changesRainforest responseCanopy disturbanceGabonLate Holocene
Type
Research Article
Information
Quaternary Research , Volume 67 , Issue 3 , May 2007 , pp. 411 - 425
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Assoko Ndong, A. Synthèse des données archaeologiques récentes sur le peuplement à l'Holocène récent de la réserve de faune de la Lopé, Gabon. L'Anthropologie 106, (2002). 135–158.Google Scholar
Aucour, A.-M., Hilaire-Marcel, C., and Bonnefille, R. Late Quaternary biomass changes from 13C measurements in a highland peat bog from Equatorial Africa (Burundi). Quaternary Research 41, (1994). 225–233.CrossRefGoogle Scholar
Aucour, A.-M., Bonnefille, R., and Hilaire-Marcel, C. Source and accumulation rates of organic carbon in an equatorial peat bog (Burundi, East Africa) during the Holocene: carbon isotope constraints. Palaeogeography, Palaeoclimatology, Palaeoecology 150, (1999). 179–189.Google Scholar
Baker, J.C., Kassan, J., and Hamilton, P.J. Early diagenetic siderite as an indication of depositional environment in the Triassic Rewan Group, southern Bowen, eastern Australia. Sedimentology 43, (1995). 77–88.CrossRefGoogle Scholar
Bonnefille, R., and Riollet, G. Pollens des savanes d'Afrique orientale. (1980). C.N.R.S., Paris.Google Scholar
Bradley, R. 1000 years of climate change. Science 288, (2000). 1353 CrossRefGoogle Scholar
Bradshaw, R.H.W., Webb, T. III Relationships between contemporary pollen and vegetation data from Wisconsin and Michigan, USA. Ecology 66, (1985). 721–737.Google Scholar
Broecker, W.S. Was the Medieval Warm Period Global?. Science 291, (2001). 1497–1499.Google Scholar
Clist, B. Gabon: 100 000 ans d'Histoire. (1995). Centre Culturel Français Saint-Exupery (Gabon), Libreville.Google Scholar
Clist, B., (2005). "Des premiers villages aux premiers européens autour de l'Estuaire du Gabon: quatre millénaires d'interactions entre l'Homme et son milieu.". Unpublished PhD thesis, Université Libre de Bruxelles, .Google Scholar
Delègue, A.M., Fuhr, M., Schwartz, D., Mariotti, A., and Nasi, R. Recent origin of large part of the forest cover in the Gabon coastal area based on stable carbon isotope data. Oecologia 129, (2001). 106–113.Google Scholar
Denny, P. The Ecology and Management of African Wetland Vegetation. (1985). Dr. W. Junk Publishers, Dordrecht. 344 Google Scholar
Elenga, H., Schwartz, D., and Vincens, A. Changements climatiques et action anthropique sur le littoral congolais au cours de l'Holocène. Bulletin de la Société Géologique de France 163, (1992). 239–252.Google Scholar
Elenga, H., Schwartz, D., and Vincens, A. Pollen evidence of Late Quaternary vegetation and inferred climate changes in Congo. Palaeogeography, Palaeoclimatology, Palaeoecology 109, (1994). 345–356.CrossRefGoogle Scholar
Elenga, H., Schwartz, D., Vincens, A., Bertaux, J., de Namur, C., Martin, L., Wirrmann, D., and Servant, M. Diagramme pollinique holocène du Lac Kitina (Congo): mise en évidence de changements paléobotaniques et paléoclimatiques dans le massif forestier du Mayombe. Compte-Rendu de l'Académie des Sciences, Paris, série 2a 323, (1996). 345–356.Google Scholar
Elenga, H., Maley, J., Vincens, A., and Farrera, I. Palaeoenvironments, Palaeoclimates and Landscape development in Central Equatorial Africa. A review of major terrestrial keys sites covering the last 25 kyrs. Battarbee, R.W., Gasse, F., and Stickley, C.E. Past Climate Variability Through Europe and Africa. (2004). Springer, 181–198.Google Scholar
Evrard, C. Recherches écologiques sur les peuplements forestiers des sols hydromorphes de la Cuvette centrale congolaise. (1968). Publ. I.N.E.A.C., Bruxelles.Google Scholar
Faegri, K., and Iversen, J. Text Book of Modern Pollen Analysis. (1989). John Wiley and Sons Ltd., Chichester.Google Scholar
Foley, J.A., Prentice, C.I., Ramankutty, N., Levis, S., Pollard, D., Sitch, S., and Haxeltine, A. An integrated biosphere model of land surface processes, terrestrial carbon balance, and vegetation dynamics. Global Biogeochemical Cycles 10, (1996). 603–628.Google Scholar
Giresse, P., Maley, J., and Brenac, P. Late Quaternary palaeonvironments in Lake Barombi Mbo (West Cameroon) deduced from pollen and carbon isotopes of organic matter. Palaeogeography, Palaeoclimatology, Palaeoecology 107, (1994). 65–78.Google Scholar
Giresse, P., Maley, J., and Kossoni, A. Sedimentary environmental changes and millennial climatic variability in a tropical shallow lake (Lake Ossa, Cameroon) during the Holocene. Palaeogeography, Palaeoclimatology, Palaeoecology 218, (2005). 257–285.Google Scholar
Haxeltine, A., and Prentice, I.C. BIOME3: an equilibrium terrestrial biosphere model based on ecophysiological constraints, resource availability, and competition among plant functional types. Global Biogeochemical Cycles 10, (1996). 693–709.Google Scholar
Jackson, S.T. Pollen source area and representation in small lakes of northern United States. Review of Palaeobotany and Palynology 63, (1990). 53–76.Google Scholar
Jolly, D., (1993). “Evolution et Dynamique des Ecosystèmes du Burundi. Pollen et Statistique.”. Unpublished PhD thesis, Aix-Marseille II, .Google Scholar
Jolly, D., Prentice, I.C., Bonnefille, R., Ballouche, A., Bengo, M., Brenac, P., Buchet, G., Burney, D., Cazet, J.-P., Cheddadi, R., Edorh, T., Elenga, H., Elmoutaki, S., Guiot, J., Laarif, F., Lamb, H., Lezine, A.-M., Maley, J., Mbendza, M., Peryron, O., Reille, M., Reynaud-Farrera, I., Riollet, G., Ritchie, J.C., Roche, E., Scott, L., Ssemmanda, I., Straka, H., Umer, M., Van Campo, E., Vilimumbalo, S., Vincens, A., and Waller, M. Biome reconstruction from pollen and plant macrofossil data for Africa and Arabian peninsula at 0 and 6000 years. Journal of Biogeography 25, (1998). 1007–1027.Google Scholar
Kelts, K., and Talbot, M. Lacustrine carbonates as geochimical archives of environmental change and biotic/abiotic interactions. Tilze, M.M., and Serruya, C. Ecological Structure and Function in Large Lakes. (1990). Science Tech. Publ., Madison, WI, USA. 290–317.Google Scholar
Lamb, H., Darbyshire, I., and Verschuren, D. Vegetation response to rainfall variation and human impact in central Kenya during the past 1100 years. The Holocene 13, (2003). 285–292.Google Scholar
Lebrun, J., and Gilbert, G. Une classification écologique des forêts du Congo. (1954). Publ. I.N.E.A.C., Bruxelles.Google Scholar
Leroux, M. Le climat de l'Afrique tropicale. (1983). Champion, Paris.Google Scholar
Makaya, M., (2005). “Les paléoenvironnments sédimentaires fini-holocènes de trois lacs du Gabon (Kamalété, Nguène et Maridor). Etude sédimentologique et biogéochimique. . Unpublished PhD thesis, Université de Perpignan, .Google Scholar
Maley, J. Middle Holocene changes in tropical Africa and other continents: paleomonsoon and sea surface temperature variations. Dalfes, H.N., Kukla, G., and Weiss, H. Third Millennium BC Climate Change and Old World Collapse. NATO ASI Series (1997). Springer-Verlag, Berlin Heidleberg. 611–640.Google Scholar
Maley, J. L'expansion du Palmier à Huile (Elaeis guineensis) en Afrique centrale au cours des trois derniers millénaires: nouvelles données et interprétations. Bahuchet, S. L'Homme et la Forêt Tropicale. (1999). Travaux de la Société d'Ecologie Humaine, Marseille. 237–254.Google Scholar
Maley, J., and Brenac, P. Vegetation dynamics, paleoenvironments and climatic changes in the forests of western Cameroon during the last 28,000 years B.P.. Review of Palaeobotany and Palynology 99, (1998). 157–187.Google Scholar
Maley, J., and Chepstow-Lusty, A. Elaeis guineensis Jacq. (oil palm) fluctuations in central Africa during the late Holocene: climate or human driving forces for this pioneering species?. Vegetation history and Archaeobotany 10, (2001). 117–120.Google Scholar
Ngomanda, A., Chepstow-Lusty, A., Makaya, M., Schevin, P., Maley, J., Fontugne, M., Oslisly, R., Rabenkogo, N., and Jolly, D. Vegetation Changes during the past 1300 years in Western Equatorial Africa: a high-resolution pollen record from Lake Kamalété, Lopé Reserve, Central Gabon. The Holocene 15, (2005). 1021–1031.Google Scholar
Nguetsop, V.-F., Servant, M., and Servant-Vildary, S. Palaeolimnology and palaeoclimatology of Western Cameroon during the last 5000 years, from a diatom study of Lake Ossa. Comptes Rendus de l'Academie des Sciences – Series IIA – Earth and Planetary Science 327, (1998). 39–45.Google Scholar
Nguetsop, V.F., Servant-Vildary, S., and Servant, M. Late Holocene climatic changes in west Africa, a high resolution diatom record from equatorial Cameroon. Quaternary Science Reviews 23, (2004). 591–609.Google Scholar
Nicolas, P., (1977). “Contribution à l'Etude Phytogéographique de la Forêt du Gabon.”. Unpublished PhD thesis, Université de Paris 1, .Google Scholar
Osborne, P.L. Tropical Ecosystems and Ecological Concepts. (2000). Cambridge Univ. Press, Cambridge.Google Scholar
Oslisly, R. The middle Ogooué valley, Gabon: cultural changes and palaeoclimatic implications of the last four millennia. Azania XXIX-XX, (1995). 324–331.Google Scholar
Oslisly, R. Hommes et milieux à l'Holocène dans la moyenne vallée de l'Ogooué (Gabon). Bulletin de la Société Géologique de France 95, 1 (1998). 93–105.Google Scholar
Oslisly, R. The History of Human Settlement in the Middle Ogooué Valley (Gabon). Weber, W., White, L.J.T., Vedder, A., and Naughton-Treves, L. African Rain Forest Ecology and Conservation. (2001). Yale Univ. Press, New Haven. 101–118.Google Scholar
Peyron, O., Guiot, J., Cheddadi, R., Tarasov, P., Reille, M., de Beaulieu, J.-L., Bottema, S., and Andrieu, V. Climatic reconstruction in Europe for 18,000 yr B.P. from pollen data. Quaternary Research 49, (1998). 183–196.Google Scholar
Peyron, O., Jolly, D., Bonnefille, R., Vincens, A., and Guiot, J. Climate of East Africa 6000 14C yr B.P. as inferred from pollen data. Quaternary Research 54, (2000). 90–101.Google Scholar
Prentice, I.C., Guiot, J., Huntley, B., Jolly, D., and Cheddadi, R. Reconstructing biomes from paleoecological data: a general method and its application to European pollen data at 0 and 6 ka. Climate Dynamics 12, (1996). 185–194.Google Scholar
Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Bertrand, C.J.H., Blackwell, P.G., Buck, C.E., Burr, G.S., Cutler, K.B., Damon, P.E., Edwards, R.L., Fairbanks, R.G., Friedrich, M., Guilderson, T.P., Hogg, A.G., Hughen, K.A., Kromer, B., McCormac, G., Manning, S., Ramsey, C.B., Reimer, R.W., Remmele, S., Southon, J.R., Stuiver, M., Talamo, S., Taylor, F.W., van der Plicht, J., and Weyhenmeyer, C.E. INTCAL04 Terrestrial Radiocarbon age calibration, 0–26 cal Kyr B.P.. Radiocarbon 46, (2005). 1029–1058.Google Scholar
Reynaud-Farrera, I., Maley, J., and Wirrmann, D. Végétation et climat dans les forêts du Sud-Ouest Cameroun depuis 4770 ans B.P: analyse pollinique des sédiments du Lac Ossa. Compte-Rendu de l'Académie des Sciences, Paris, série 2a 322, (1996). 749–755.Google Scholar
Saint-Vil, J. Les climats du Gabon. Annales de l'Université Nationale du Gabon 1, (1977). 101–125.Google Scholar
Schnell, R. Introduction à la phytogéographie des pays tropicaux. La flore et la végétation de l'Afrique tropicale. (1976). Gauthier-Villars, Paris.Google Scholar
Schwartz, D. Intérêt de la mesure du d13C des sols en milieu naturel équatorial pour la connaissance des aspects pédologiques et écologiques des relations savane-forêt: example du Congo. Cahiers de l'Orstom, série Pédologique XXVI, 4 (1991). 327–341.Google Scholar
Sosef, M.S., (1994). Refuge Begonias; taxonomy, phylogeny and historical biogeography of Begonia sect. Loasibegonia and sect. Scutobegonia in relation to glacial rain forest refuges in Africa, p. 306, Wageningen Agric. Univ, . Papers.Google Scholar
Sowunmi, M.A. The significance of the oil palm (Elaeis guineensis Jacq.) in the late Holocene environments of west and west central Africa: a further consideration. Vegetation History and Archaeobotany 8, (1999). 199–210.Google Scholar
Sugita, S. A model of pollen source area for an entire lake surface. Quaternary Research 39, (1993). 239–244.Google Scholar
Sugita, S. Pollen representation of vegetation in Quaternary sediments: theory and method in patchy vegetation. Journal of Ecology 82, (1994). 881–897.Google Scholar
Thompson, K. Emergent plants of permanent and seasonally-flooded wetlands. Denny, P. The Ecology and Management of African Wetland Vegetation. (1985). Dr. W. Junk Publishers, Dordrecht. 43–107.Google Scholar
Vincens, A., Schwartz, D., Bertaux, J., Elenga, H., and de Namur, C. Late Holocene climatic changes in Western Equatorial Africa inferred from pollen from Lake Sinnda, Southern Congo. Quaternary Research 50, (1998). 34–45.Google Scholar
Vincens, A., Schwartz, D., Elenga, H., Reynaud-Farrera, I., Alexandre, A., Bertaux, J., Mariotti, A., Martin, L., Meunier, J.-D., Nguetsop, F., Servant, M., Servant-Vildary, S., and Wirrmann, D. Forest response to climate changes in Atlantic Equatorial Africa during the last 4000 years BP and inheritance on the modern landscapes. Journal of Biogeography 26, (1999). 879–885.Google Scholar
White, L.J.T. Forest-Savanna dynamics and the origins of Marantaceae forest in central Gabon. Weber, W., White, L.J.T., Vedder, A., and Naughton-Treves, L. African Rain Forest Ecology and Conservation. (2001). Yale University Press, New Haven. 165–182.Google Scholar
White, L.J.T., and Abernethy, K. A Guide to the Vegetation of the Lopé Reserve Gabon. (1997). ECOFAC GABON, Libreville.Google Scholar
Wirrmann, D., Bertaux, J., and Kossoni, A. Late Holocene paleoclimatic changes in Western Central Africa inferred from mineral abundance in dated sediments from Lake Ossa (Southwest Cameroon). Quaternary Research 56, (2001). 275–287.Google Scholar
Ybert, J.-P. Atlas de pollens de Côte d'Ivoire. (1979). ORSTOM, Paris.Google Scholar