New data on the recent history of the littoral forests of southern Cameroon: an insight into the role of historical human disturbances on the current forest composition
Charcoal; Forest composition; Human disturbances; Long-lived light-demanding tree species; Oil-palm endocarps; Potsherds; Slash-and-burn cultivation; Southern Cameroon
Résumé :
[en] Background and aims – Prior to European colonisation of Central Africa, human populations were dispersed through the forests, where they practiced slash-and-burn cultivation. From the 19th century they were progressively concentrated in villages along roads, leaving large areas of forest derelict. In south-western Cameroon, and elsewhere in Central Africa, forest canopy is dominated by long-lived lightdemanding tree species, suggesting a possible role of human disturbance. The aim of this study was to bring new insights into the possible effect of historical human disturbances in terms of timing and spatial extent on the current forest composition.
Location – Wet evergreen littoral forest in south-western Cameroon.
Methods and key results – A combined vegetation sampling and archaeobotanical survey were conducted. Potsherds, oil-palm endocarps, and charcoal were found throughout the study area, suggesting generalised human occupation and anthropogenic fire. Human occupancy occurred in two periods: between 2200 and 1500 BP, and, more recently, beginning three centuries ago. High frequency of fire and the presence of Elaeis guineensis both dated recently (between 260 and 145 BP) suggest slash-and-burn shifting cultivation practices. These human-induced disturbances may coincide with the age of the current emergent lightdemanding species, the age of which can be estimated around 200 years, or with the phases of drying climate recorded in the Central African forest in the early 18th century.
Conclusions – These results support the idea that historical human disturbances are one of the major factors that shaped the current forest composition in Central Africa.
Dedry, Laurent ; Université de Liège - ULiège > Forêts, Nature et Paysage > Gestion des ressources forestières et des milieux naturels
Daïnou, Kasso ; Université de Liège - ULiège > Forêts, Nature et Paysage > Laboratoire de Foresterie des régions trop. et subtropicales
Hardy, Olivier J.
Doucet, Jean-Louis ; Université de Liège - ULiège > Forêts, Nature et Paysage > Laboratoire de Foresterie des régions trop. et subtropicales
Langue du document :
Anglais
Titre :
New data on the recent history of the littoral forests of southern Cameroon: an insight into the role of historical human disturbances on the current forest composition
Date de publication/diffusion :
2015
Titre du périodique :
Plant Ecology and Evolution
ISSN :
2032-3913
eISSN :
2032-3921
Maison d'édition :
Royal Botanical Society of Belgium, Bruxelles, Belgique
Afripop (2013) Afripop Project [online]. Available from http://www.worldpop.org.uk/data/summary/?contselect=Africaandcountselect=Cameroonandtypeselect=Population [accessed 1 Oct. 2013].
Alexandre P. (1965) Proto-histoire du groupe beti-bulu-fang: essai de synthèse provisoire. Cahiers d’Etudes Africaines 5: 503–560.
Barton H., Denham T., Neumann K., Arroyo-Kalin M. (2012) Long-term perspectives on human occupation of tropical rainforests: An introductory overview. Quaternary International 249: 1–3. http://dx.doi.org/10.1016/j.quaint.2011.07.044
Bayon G., Dennielou B., Etoubleau J., Ponzevera E., Toucanne S., Bermell S. (2012a) Intensifying weathering and land use in Iron Age Central Africa. Science 335: 1219–1222. http://dx.doi.org/10.1126/science.1215400
Bayon G., Dennielou B., Etoubleau J., Ponzevera E., Toucanne S., Bermell S. (2012b) Response to comments on “Intensifying weathering and land use in Iron Age Central Africa”. Science 337: 1040e. http://dx.doi.org/10.1126/science.1222458
Biwolé A.B., Bourland N., Daïnou K., Doucet J.-L. (2012) Définition du profil écologique de l’azobé, Lophira alata, une espèce ligneuse africaine de grande importance: synthèse bibliographique et perspectives pour des recherches futures. Biotechnologie Agronomie Société Environnement. 16: 217–228.
Brncic T.M. (2003) Ecology and patch dynamics of Megaphrynium macrostachyum (Marantaceae) in the rain forest of Central African Republic. PhD Thesis, Oxford Forestery Institute and Linacre College, Oxford, UK.
Brncic T.M., Willis K.J., Harris D.J., Washington R. (2007) Culture or climate? The relative influences of past processes on the composition of the lowland Congo rainforest. Philosophical Transactions of the Royal Society Biological sciences 362: 229–242. http://dx.doi.org/10.1098/rstb.2006.1982
Bronk Ramsey C. (2013) OxCal 4.2 Manual [online]. Available from https://c14.arch.ox.ac.uk/oxcal/OxCal.html [accessed 1 Oct. 2013].
Carrière S. (1999) Les orphelins de la forêt. Influence de l’agriculture itinérante sur brûlis des Ntumu et des pratiques agricoles associées sur la dynamique forestière du sud Cameroun. PhD Thesis, Université de Montpellier II, Montpellier, France.
Clist B. (1990) Des derniers chasseurs aux premiers métallurgistes: sédentarisation et débuts de la métallurgie du fer (Cameroun, Gabon, Guinée équatoriale). In: Lanfranchi R., Schwartz D. (eds) Paysages quaternaires de l’Afrique centrale Atlantique: 458–478. Paris, ORSTOM.
Clist B. (1996) Traces de très anciennes occupations humaines de la forêt tropicale au Gabon. In: Biesbrouck K., Elders S., Rossel G. (eds) Central African hunter-gatherers in a multidisciplinary perspective: challenging elusiveness. Proceedings of the colloquium on hunter-gatherers of Equatorial Africa, held at Leiden, The Netherlands, October 7–9, 1996: 75–87. Leiden, CNWS.
Clist B. (1997) Le site d’Okala, Province de I’Estuaire, Gabon, et son importance pour la compréhension du passage à la sédentarisation en Afrique centrale. Comptes Rendus de l’Académie des Sciences, sér. IIa, Sciences de la Terre et des Planètes 325: 151–156. http://dx.doi.org/10.1016/S1251-8050(97)83977-8
Cochrane M.A. (2009) Tropical fire ecology. Climate change, land use, and ecosystem dynamics. Chichester, Spinger-Praxis. http://dx.doi.org/10.1007/978-3-540-77381-8
Diaw M.C. (1997) Si, Nda bot and Ayong. Shifting cultivation, land uses and property rights in Southern Cameroon. Rural Development Forestry Network.
Elenga H., Schwartz D., Vincens A., Bertaux J., de Namur C., Martin L., Wirrmann D., Servant M. (1996) Diagramme pollinique holocène du lac Kitina (Congo): mise en évidence de changements paléobotaniques et paléoclimatiques dans le massif forestier du Mayombe. Comptes Rendus de l’Académie des Sciences, sér. IIa, Sciences de la Terre et des Planètes 323: 403–410.
Essomba J.-M. (1998) L’archéologie de l’âge du fer au Cameroun méridional. In: Delneuf M., Essomba J.-M., Froment A. (eds) Paléo-anthropologie en Afrique centrale. Un bilan de l’archéologie au Cameroun: 233–247. Paris, L’Harmattan.
Fayolle A., Engelbrecht B., Freycon V., Mortier F., Swaine M., Réjou-Méchain M., Doucet J.-L., Fauvet N., Cornu G., Gourlet- Fleury S. (2012) Geological substrates shape tree species and trait distributions in African moist forests. PloS ONE 7: e42381. http://dx.doi.org/10.1371/journal.pone.0042381
Franqueville A. (1973) Atlas régional Sud-Ouest I. Echelles 1/500000 et 1/1 000000. République Unie du Cameroun. Paris, ORSTOM.
Gillet J.-F., Doucet J.-L. (2013) The abundance of Charcoal fragments emphasizes the assumption of huge Paleofires in the Mixed moist semi-evergreen rainforest of the Northern Republic of Congo. In: Damblon F. (ed.) Proceedings of the Fourth International Meeting of Anthracology: 113–120. Oxford, Archaeopress.
Hart T.B., Hart J.A., Dechamps R., Fournier M., Ataholo M. (1996) Changes in forest over the last 4000 composition years in the Ituri basin, Zaire. In: van der Maesen L.G.J., van der Burgt X.M., van Medenbach de Rooy J.M. (eds) The Biodiversity of African Plants: Proceedings XIVth AETFAT Congress 22–27 August 1994, Wageningen, The Netherlands: 545–563. Dordrecht, Springer Netherlands. http://dx.doi.org/10.1007/978-94-009-0285-5_70
Hawthorne W.D. (1995) Ecological profiles of Ghanaian forest trees. Oxford, Oxford Forestry Institute.
Jones E.W. (1956) Ecological studies on the rain forest of Southern Nigeria: IV (continued). The plateau forest of the Okomu Forest Reserve. Journal of Ecology 44: 83–117.
Kahlheber S., Bostoen K., Neumann K. (2009) Early plant cultivation in the Central African rain forest: first millennium BC pearl millet from South Cameroon. Journal of African Archaeology 7: 253–272. http://dx.doi.org/10.3213/1612-1651-10142
Lanfranchi R., Ndanga J., Zana H. (1997) Nouvelles datations 14C de la métallurgie du fer dans la forêt dense centrafricaine. Yale FandES Bulletin 102: 46–55.
Lavachery P., MacEachern S., Tchago Bouimon, Gouem Gouem B., Kinyock P., Mbairo J., Nkonkonda O. (2005) Komé to Ebomé: Archeological Research for the Chad Export Project, 1999–2003. Journal of African Archaeology 3: 175–193. http://dx.doi.org/10.3213/1612-1651-10049
Letouzey R. (1985) Notice de la carte phytogéographique du Cameroun au 1/500 000. Toulouse, Institut de la cartographie internationale de la végétation.
Maley J. (1999) L’expansion du palmier à huile (Elais guineensis) en Afrique centrale au cours des trois derniers millénaires: nouvelles données et interprétations. In: Bahuchet S., Bley D., Pagezy H., Vernazza-Licht N. (eds) L’homme et la forêt tropicale: 237–254. Marseille, Travaux sociétés d’Ecologie humaine.
Maley J. (2002) A catastrophic destruction of African forests about 2,500 years ago still exerts a major influence on present vegetation formations. IDS Bulletin 33: 13–30. http://dx.doi.org/10.1111/j.1759-5436.2002.tb00003.x
Maley J., Brenac P. (1998) Vegetation dynamics, palaeoenvironments and climatic changes in the forests of western Cameroon during the last 28,000 years B.P. Review of Palaeobotany and Palynology 99: 157–187. http://dx.doi.org/10.1016/S0034-6667(97)00047-X
Maley J., Vernet R. (2013) Peuples et évolution climatique en Afrique nord-tropicale, de la fin du Néolithique à l’aube de l’époque moderne. Afriques, débats, méthodes et terrains d’histoire 4. http://afriques.revues.org/1209
Maley J., Giresse P., Doumenge C., Favier C. (2012) Comment on “Intensifying weathering and land use in Iron Age Central Africa”. Science 337: 1040–1040. http://dx.doi.org/10.1126/science.1221820
Mbida C.M. (1998) Premières communautés villageoises au sud du Cameroun: Synthèse et données nouvelles. In: Delneuf M., Essomba J.-M., Froment A. (eds) Paléo-anthropologie en Afrique centrale. Un billan de l’archéologie au Cameroun. Paris, L’Harmattan.
Mbida C.M., Van Neer W., Doutrelepont H., Vrydaghs L. (2000) Evidence for banana cultivation and animal husbandry during the first millennium BC in the forest of southern Cameroon. Journal of Archaeological Science 27: 151–162. http://dx.doi.org/10.1006/jasc.1999.0447
Mohammadou E. (1999) Le poney conquérant des savanes du Cameroun central (c. 1750-1850). In: Baroin C., Boutrais Jean (eds) L’homme et l’animal dans le bassin du lac Tchad. Colloque Réseau Méga: 81–106. Orléans and Paris, IRD.
Mohammadou E. (2004) Climat et histoire en Afrique centrale aux XVIIe et XIXe siècle: l’expansion Baaré-Tchamba de la haute Bénoué (Cameroun). Nagoya, Yoshihito and Djingui, Nagoya University.
Morin-Rivat J., Fayolle A., Gillet J.-F., Bourland N., Gourlet-Fleury S., Oslisly R., Bremond L., Bentaleb I., Beeckman H., Doucet J.-L. (2014) New evidence of human activities during the Holocene in the Lowland forests of the Northern Congo Basin. Radiocarbon 56: 209–220. http://dx.doi.org/10.2458/56.16485
Neumann K., Bostoen K., Höhn A., Kahlheber S., Ngomanda A., Tchiengué B. (2012a) First farmers in the Central African rainforest: A view from southern Cameroon. Quaternary International 249: 53–62. http://dx.doi.org/10.1016/j.quaint.2011.03.024
Neumann K., Eggert M.K.H., Oslisly R., Clist B., Denham T., de Maret P., Ozainne S., Hildebrand E., Bostoen K., Salzmann U., Schwartz D., Eichhorn B., Tchiengué B., Höhn A. (2012b) Comment on “Intensifying weathering and land use in Iron Age Central Africa”. Science 337: 1040. http://dx.doi.org/10.1126/science.1221747
Newbery D.M., Songwe N.C., Chuyong G.B. (1998) Phenology and dynamics of an African rainforest at Korup, Cameroon. In: Newbery D.M., Prins H.H.T., Brown N.D. (eds) Dynamics of tropical communities: 37th Symposium of the British Ecological Society: 267–308. Oxford, Blackwell Science.
Ngomanda A., Chepstow-Lusty A., Makaya M., Favier C., Schevin P., Maley J., Fontugne M., Oslisly R., Jolly D. (2009a) Western equatorial African forest-savanna mosaics: a legacy of late Holocene climatic change? Climate of the Past 5: 647–659. http://dx.doi.org/10.5194/cp-5-647-2009
Ngomanda A., Jolly D., Bentaleb I., Chepstow-Lusty A., M’voubou Makaya Maley J., Fontugne M., Oslisly R., Rabenkogo N. (2007) Lowland rainforest response to hydrological changes during the last 1500 years in Gabon, Western Equatorial Africa. Quaternary Research 67: 411–425. http://dx.doi.org/10.1016/j.yqres.2007.01.006
Ngomanda A., Neumann K., Schweizer A., Maley J. (2009b) Seasonality change and the third millennium BP rainforest crisis in southern Cameroon (Central Africa). Quaternary Research 71: 307–318. http://dx.doi.org/10.1016/j.yqres.2008.12.002
Olivry J.C. (1986) Fleuves et rivières du Cameroun. Paris, MESRES and ORSTOM.
Oslisly R. (1998) Hommes et milieux à l’Holocène dans la moyenne vallée de l’Ogooué (Gabon). Bulletin de la société préhistorique française 95: 93–105.
Oslisly R. (2006) Les traditions culturelles de l’Holocène sur le littoral du Cameroun entre Kribi et Campo. In: Wotzka H.P. (ed.) Grundlegungen. Beiträge zur europäischen und afrikanischen Archäologie für Manfred K.H. Eggert: 303–317. Tübingen, Francke.
Oslisly R., Bentaleb I., Favier C., Fontugne M., Gillet J.-F., Morin- Rivat J. (2013a) West Central African peoples: survey of radiocarbon dates over the past 5000 years. Radiocarbon 55: 1377–1382. http://dx.doi.org/10.2458/azu_js_rc.55.16385
Oslisly R., Peyrot B. (1992) L’arrivée des premiers métallurgistes sur l’Ogooué, Gabon. The African Archaeological Review 10: 129–138. http://dx.doi.org/10.1007/BF01117698
Oslisly R., White L. (2007) Human impact and environmental exploitation in Gabon during the Holocene. In: Denham T.P., Iriarte J., Vrydaghs L. (eds) Rethinking Agriculture; Archaeological and Ethnoarchaeological Perspectives, Walnut Creek: 345–358. California, Left Coast Press Inc.
Oslisly R., White L., Bentaleb I., Favier C., Fontugne M., Gillet J.-F., Sebag D. (2013b) Climatic and cultural changes in the west Congo Basin forests over the past 5000 years. Philosophical Transactions of the Royal Society Biological sciences 368: 20120340. http://dx.doi.org/10.1098/rstb.2012.0304
Oslisly R., White L.J.T. (2003) Etude des traces de l’impact de l’homme sur l’environnement au cours de l’Holocène dans deux régions d’Afrique centrale forestière: la réserve de la Lopé (Gabon central) et le sanctuaire du Banyang Mbo (Ouest- Cameroun). In: Froment A., Guffroy J. (eds) Peuplements anciens et actuels des forêts tropicales: 77–87. Paris, IRD.
Reimer P.J., Bard E., Bayliss A., Beck J.W., Blackwell P.G., Bronk Ramsey C., Buck C.E., Cheng H., Edwards R.L., Friedrich M., Grootes P.M., Guilderson T.P., Haflidason H., Hajdas I., Hatté C., Heaton T.J., Hoffmann D.L., Hogg A.G., Hughen K.A., Kaiser K.F., Kromer B., Manning S.W., Niu M., Reimer R.W., Richards D.A., Scott E.M., Southon J.M., Staff R.A., Turney C.S.M., van der Plicht J. (2013) IntCal13 and Marine13 Calibration Curves, 0–50,000 Years cal BP. Radiocarbon 55: 1869–1887. http://dx.doi.org/10.2458/azu_js_rc.55.16947
Réjou-Méchain M., Pélissier R., Gourlet-Fleury S., Couteron P., Nasi R., Thompson J.D. (2008) Regional variation in tropical forest tree species composition in the Central African Republic: an assessment based on inventories by forest companies. Journal of Tropical Ecology 24: 663–674. http://dx.doi.org/10.1017/S0266467408005506
Reynaud-Farrera I., Maley J., Wirrmann D. (1996) Végétation et climat dans les forêts du Sud-Ouest Cameroun depuis 4770 ans BP: analyse pollinique des sédiments du Lac Ossa. Comptes Rendus de l’Académie des Sciences, sér. IIa, Sciences de la Terre et des Planètes 322: 749–755.
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: 353–361.
Swaine M., Hall J. (1986) Forest structure and dynamics. In: Lawson G.W. (ed.) Plant ecology in West Africa: 47–93. Chichester, John Wiley and Sons.
Swaine M.D. (1996) Rainfall and soil fertility as factors limiting forest species distributions in Ghana. Journal of Ecology 84: 419–428.
Tardy C., Vernet J.-L., Servant M., Fournier M., Leprun J.-C., Pessenda L.C., Sipeddine A., Solari M.-E., Soubies F., Turcq B., Wengler L., Vacher S., Jerémie S., Ceccantini G., Cordeiro R., Scheel R. (1996) Feux, sols et écosystèmes forestiers tropicaux. In: Actes du Symposium ECOFIT, dynamique à long terme des écosystèmes forestiers intertropicaux, Bondy: 101–103. Collection colloques et séminaires ORSTOM-CNRS.
van Gemerden B.S., Olff H., Parren M.P.E., Bongers F. (2003) The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity. Journal of Biogeography 30: 1381–1390. http://dx.doi.org/10.1046/j.1365-2699.2003.00937.x
Verhegghen A., Mayaux P., De Wasseige C., Defourny P. (2012) Mapping Congo Basin vegetation types from 300 m and 1 km multi-sensor time series for carbon stocks and forest areas estimation. Biogeosciences 9: 5061–5079. http://dx.doi.org/10.5194/bg-9-5061-2012
Vincens A., Buchet G., Servant M., ECOFIT Mbalang collaborators (2010) Vegetation response to the “African Humid Period” termination in Central Cameroon (7° N)–new pollen insight from Lake Mbalang. Climate of the Past 6: 281–294. http://dx.doi.org/10.5194/cp-6-281-2010
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., Wirrmann D. (1999) 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: 879–885. http://dx.doi.org/10.1046/j.1365-2699.1999.00333.x
White L.J.T., Oates J.F. (1999) New data on the history of the plateau forest of Okomu, southern Nigeria: an insight into how human disturbance has shaped the African rain forest. Global Ecology and Biogeography 8: 355–361. http://dx.doi.org/10.1046/j.1365-2699.1999.00149.x
Wijma (2007) Plan d’Aménagement Durable de l’Unité Forestière d’Aménagement N°09-024. Douala, Wijma Douala SARL.
Wijma (2011) Révision de Plan d’Aménagement de l’Unité Forestière d’Aménagement N°09-021 (Province du Sud-Arrondissement de Ma’an). Douala, Wijma Cameroun SARL.
Willis K.J., Gillson L., Brncic T.M. (2004) How “virgin” is virgin rainforest? Science 304: 402–403. http://dx.doi.org/10.1126/science.1093991
Wotzka H.-P. (2006) Records of activity: radiocarbon and the structure of Iron Age settlement in Central Africa. In: Wotzka H.-P. (ed.) Grundlegungen. Beiträge zur europäischen und afrikanischen Archäologie für Manfred K. H. Eggert: 271–289. Tübingen, Francke.