central Africa; archaeology; history; paleoecology; dendrology; environment; ecology; light-demanding trees; logging; Cameroon; Republic of the Congo; Central African Republic; European colonization; 19th century; human impact; tropical forest; modelisation; radiocarbon; endangered species; land-use; disturbances; global change; sustanability; intact forest
Abstract :
[en] The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future.
Disciplines :
History Life sciences: Multidisciplinary, general & others Environmental sciences & ecology Phytobiology (plant sciences, forestry, mycology...) Arts & humanities: Multidisciplinary, general & others Archaeology
Fayolle, Adeline ; Université de Liège > Ingénierie des biosystèmes (Biose) > Gestion des ressources forestières et des milieux naturels
Favier, Charly; ISEM -Montpellier
Bremond, Laurent; ISEM - Montpellier
Gourlet-Fleury, Sylvie; CIRAD
Bayol, Nicolas; FRM
Lejeune, Philippe ; Université de Liège > Ingénierie des biosystèmes (Biose) > Gestion des ressources forestières et des milieux naturels
Beeckman, Hans; Musée royal de l'Afrique centrale
Doucet, Jean-Louis ; Université de Liège > Ingénierie des biosystèmes (Biose) > Laboratoire de Foresterie des régions trop. et subtropicales
Language :
English
Title :
Present-day central African forest is a legacy of the 19th century human history
Publication date :
17 January 2017
Journal title :
eLife
eISSN :
2050-084X
Publisher :
eLife Sciences Publications, Cambridge, United Kingdom
Pages :
e20343
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture [BE] Fonds Léopold III pour l'Exploration et la Conservation de la Nature [BE] ANR - Agence Nationale de la Recherche [FR] NERC - Natural Environment Research Council [GB]
Aleman JC, Blarquez O, Bentaleb I, Bonte P, Brossier B, Carcaillet C, Gond V, Gourlet-Fleury S, Kpolita A, Lefevre I, Oslisly R, Power MJ, Yongo O, Bremond L, Favier C. 2013. Tracking land-cover changes with sedimentary charcoal in the afrotropics. The Holocene 23:1853-1862. doi: 10.1177/0959683613508159
Anhuf D, Ledru M-P, Behling H, Da Cruz FW, Cordeiro RC, Van der Hammen T, Karmann I, Marengo JA, De Oliveira PE, Pessenda L, Siffedine A, Albuquerque AL, Da Silva Dias PL. 2006. Paleo-environmental change in Amazonian and African rainforest during the LGM. Palaeogeography, Palaeoclimatology, Palaeoecology 239: 510-527. doi: 10.1016/j.palaeo.2006.01.017
Bayliss A. 2009. Rolling out revolution: using radiocarbon dating in archaeology. Radiocarbon 51:123-147. doi: 10.1017/S0033822200033750
Biwolé A, Morin-Rivat J, Fayolle A, Bitondo D, Dedry L, Dainou K, Hardy OJ, Doucet JL. 2015. 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. Plant Ecology and Evolution 148:19-28. doi: 10.5091/plecevo.2015.1011
Bostoen K, Clist B, Doumenge C, Grollemund R, Hombert J-M, Muluwa JK, Maley J. 2015. Middle to late holocene paleoclimatic change and the early bantu expansion in the rain forests of Western Central Africa. Current Anthropology 56:354-384. doi: 10.1086/681436
Brňić TM. 2003. Ecology and Patch Dynamics of Megaphrynium Macrostachyum (Marantaceae) in the Rain Forest of Central African Republic. D.Phil. Thesis. Oxford, UK: Oxford University.
Brňić TM, Willis KJ, Harris DJ, 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 B: Biological Sciences 362:229-242. doi: 10.1098/rstb.2006.1982
Brňić TM, Willis KJ, Harris DJ, Telfer MW, Bailey RM. 2009. Fire and climate change impacts on lowland forest composition in northern Congo during the last 2580 years from palaeoecological analyses of a seasonally flooded swamp. The Holocene 19:79-89. doi: 10.1177/0959683608098954
Burnham P. 1996. Political relationships on the eastern marches of Adamawa in the late nineteenth century: a problem of interpretation. In: Fowler I, Zeitlyn D (Eds). African Crossroads: Intersections of Ethnography and History in Cameroon Studies. p 45-61.
Carrière SM, Letourmy P, McKey DB. 2002. Effects of remnant trees in fallows on diversity and structure of forest regrowth in a slash-and-burn agricultural system in southern Cameroon. Journal of Tropical Ecology 18:375-396. doi: 10.1017/S0266467402002262
Clark DA, Clark DB. 1992. Life history diversity of canopy and emergent trees in a neotropical rain forest. Ecological Monographs 62:315-344. doi: 10.2307/2937114
Copet-Rougier E. 1998. Politico-economic history of the Upper-Sangha. In: Eves HE, Hardin R, Rupp S (Eds). region of Equatorial Africa: histories, knowledge forms, and institutions. New Haven, CT: Yale School of Forestry and Environmental Studies, Vol. 102. Trinational Sangha river: Resource use in the. p 51-71.
Coquery-Vidrovitch C. 1998. The Upper-Sangha in time of the concession companies. In: Eves HE, Hardin R, Rupp S (Eds). region of Equatorial Africa: histories, knowledge forms, and institutions. New Haven, CT: Yale School of Forestry and Environmental Studies, Vol. 102. Trinational Sangha river: Resource use in the. p 72-84.
De Ridder M, Trouet V, Van den Bulcke J, Hubau W, Van Acker J, Beeckman H. 2013a. A tree-ring based comparison of Terminalia superba climate-growth relationships in West and Central Africa. Trees 27:1225-1238. doi: 10.1007/s00468-013-0871-3
De Ridder M, Van den Bulcke J, Van Acker J, Beeckman H. 2013b. Tree-ring analysis of an African long-lived pioneer species as a tool for sustainable forest management. Forest Ecology and Management 304:417-426. doi: 10.1016/j.foreco.2013.05.007
De Ridder M, Toirambe B, van den Bulcke J, Bourland N, van Acker J, Beeckman H. 2014. Dendrochronological potential in a Semi-Deciduous rainforest: The case of Pericopsis elata in Central Africa. Forests 5:3087-3106. doi: 10.3390/f5123087
DeMenocal P, Guilderson T, Adkins J, Sarnthein M, Baker L, Yarusinsky M. 2000. Abrupt onset and termination of the african humid period: rapid climate responses to gradual insolation forcing. Quaternary Science Reviews 19:347-361. doi: 10.1016/S0277-3791(99)00081-5
Doucet JL, Ntchandi Otimbo PA, Boubady AG. 2004. Comment assister la Régénération naturelle de l’okoumé dans les concessions forestières? Bois et Forêts des Tropiques 279:59-71.
Durrieu de Madron L, Forni E. 1997. Aménagement forestier dans l’est Du Cameroun: structure Du Peuplement etpériodicité d’exploitation. Bois et forêts des tropiques 254:39-50.
Engone Obiang NL, Ngomanda A, Hymas O, Chézeauxl Éric, Picard N. 2014. Diagnosing the demographic balance of two light-demanding tree species populations in central africa from their diameter distribution. Forest Ecology and Management 313:55-62. doi: 10.1016/j.foreco.2013.10.045
Fairhead J, Leach M. 1998. Reframing deforestation, global analyses and local realities: Studies in West Africa. London: Routledge, UK.
Fay JM. 1997. The ecology, social organization, populations, habitat and history of the western lowland gorilla (Gorilla gorilla gorilla Savage and Wyman 1847). PhD Thesis. USA: Washington University.
Fayolle A, Engelbrecht B, Freycon V, Mortier F, Swaine M, Réjou-Méchain M, Doucet JL, Fauvet N, Cornu G, Gourlet-Fleury S. 2012. Geological substrates shape tree species and trait distributions in African moist forests. PLoS One 7:e42381. doi: 10.1371/journal.pone.0042381
Fayolle A, Picard N, Doucet J-L, Swaine M, Bayol N, Bénédet F, Gourlet-Fleury S. 2014a. A new insight in the structure, composition and functioning of Central African moist forests. Forest Ecology and Management 329: 195-205. doi: 10.1016/j.foreco.2014.06.014
Fayolle A, Swaine MD, Bastin J-F, Bourland N, Comiskey JA, Dauby G, Doucet J-L, Gillet J-F, Gourlet-Fleury S, Hardy OJ, Kirunda B, Kouamé FN, Plumptre AJ. 2014b. Patterns of tree species composition across tropical African forests. Journal of Biogeography 41:2320-2331. doi: 10.1111/jbi.12382
Freed L. 2010. Networks of (colonial) power: roads in French Central Africa after World War I. History and Technology 26:203-223. doi: 10.1080/07341512.2010.498637
Gendreau F. 2010. The demographic challenges. In: Deveze JC (Ed). Challenges in African Agriculture. p 9-33. doi: 10.1596/9780821384817_ch01
Giles-Vernick T. 2000. Doli: translating an African environmental history of loss in the sangha river basin of equatorial Africa. The Journal of African History 41:373-394. doi: 10.1017/S0021853700007702
Gillet J-F, Doucet JL. 2012. A commented checklist of woody plants in the Northern Republic of Congo. Plant Ecology and Evolution 145:258-271. doi: 10.5091/plecevo.2012.648
Gond V, Fayolle A, Pennec A, Cornu G, Mayaux P, Camberlin P, Doumenge C, Fauvet N, Gourlet-Fleury S. 2013. Vegetation structure and greenness in central Africa from modis multi-temporal data. Philosophical Transactions of the Royal Society B: Biological Sciences 368:20120309. doi: 10.1098/rstb.2012.0309
Goucher CL. 1981. Iron is irontil it is rust: Trade and ecology in the decline of West African iron-smelting. The Journal of African History 22:179-189. doi: 10.1017/S0021853700019393
Gourlet-Fleury S, Rossi V, Rejou-Mechain M, Freycon V, Fayolle A, Saint-André L, Cornu G, Gérard J, Sarrailh J-M, Flores O, Baya F, Billand A, Fauvet N, Gally M, Henry M, Hubert D, Pasquier A, Picard N. 2011. Environmental filtering of dense-wooded species controls above-ground biomass stored in African moist forests. Journal of Ecology 99:981-990. doi: 10.1111/j.1365-2745.2011.01829.x
Greve M, Lykke AM, Blach-Overgaard A, Svenning J-C. 2011. Environmental and anthropogenic determinants of vegetation distribution across africa. Global Ecology and Biogeography 20:661-674. doi: 10.1111/j.1466-8238.2011.00666.x
Hall JS, Harris DJ, Medjibe V, Ashton PMS. 2003. The effects of selective logging on forest structure and tree species composition in a Central African forest: implications for management of conservation areas. Forest Ecology and Management 183:249-264. doi: 10.1016/S0378-1127(03)00107-5
Harris DJ. 2002. The vascular plants of the Dzanga-Sangha Reserve, Central African Republic. National Botanic Garden 23:274.
Hérault B, Bachelot B, Poorter L, Rossi V, Bongers F, Chave J, Paine CET, Wagner F, Baraloto C. 2011. Functional traits shape ontogenetic growth trajectories of rain forest tree species. Journal of Ecology 99:1431-1440. doi: 10.1111/j.1365-2745.2011.01883.x
Kaspi A. 1971. French war aims in Africa 1914-1919. In: Gifford P, Louis W. M. R (Eds). France and Britain in Africa. Imperial Rivalry and Colonial Rule. Yale University Press, New Haven and London. p 368-396.
Kay AU, Kaplan JO. 2015. Human subsistence and land use in sub-Saharan Africa, 1000BC to AD1500: A review, quantification, and classification. Anthropocene 9:14-32. doi: 10.1016/j.ancene.2015.05.001
Lanfranchi R, Ndanga J, Zana H. 1998. New carbon 14C datings of iron metallurgy in the Central African dense forest. In: Eves HE, Hardin R, Rupp S (Eds). Region of Equatorial Africa: Histories, Knowledge Forms, and Institutions, New Haven, CT: Yale School of Forestry and Environmental Studies, Vol. 102. Trinational Sangha river: Resource use in the. p 41-50.
Laporte NT, Stabach JA, Grosch R, Lin TS, Goetz SJ. 2007. Expansion of industrial logging in Central Africa. Science 316:1451. doi: 10.1126/science.1141057
Laraque A, Pouyaud B, Rocchia R, Robin E, Chaffaut I, Moutsambote JM, Maziezoula B, Censier C, Albouy Y, Elenga H, Etcheber H, Delaune M, Sondag F, Gasse F. 1998. Origin and function of a closed depression in equatorial humid zones: The lake télé in north Congo. Journal of Hydrology 207:236-253. doi: 10.1016/S0022-1694(98)00137-1
Lupo KD, Schmitt DN, Kiahtipes CA, Ndanga JP, Young DC, Simiti B. 2015. On intensive late holocene iron mining and production in the northern Congo basin and the environmental consequences associated with metallurgy in central Africa. PLoS One 10:e0132632. doi: 10.1371/journal.pone.0132632
Lézine A-M, Holl AF-C, Lebamba J, Vincens A, Assi-Khaudjis C, Février L, Sultan Émmanuelle. 2013. Temporal relationship between holocene human occupation and vegetation change along the northwestern margin of the central african rainforest. Comptes Rendus Geoscience 345:327-335. doi: 10.1016/j.crte.2013.03.001
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. doi: 10.1111/j.1759-5436.2002.tb00003.x
Maley J, Giresse P, Doumenge C, Favier C. 2012. Comment on “Intensifying weathering and land use in Iron Age Central Africa”. Science 337:1040. doi: 10.1126/science.1221820
Manning P, Akyeampong E. 2006. Slavery and slave trade in West Africa, 1450-1930. Themes in West Africa’s history 99.
Meyer S, Meister C, Eggert M. 2009. Preliminary report on the excavations at Bagofit and Mampang, East Province, Cameroon. Nyame Akuma 72:67-73.
Moga J. 2008. La métallurgie Du fer en centrafrique: premiers éléments de synthèse. Rev Centrafr Anthropol 1.
Morin-Rivat J, Fayolle A, Gillet JF, Bourland N, Gourlet-Fleury S, Oslisly R, Bremond L, Bentaleb I, Beeckman H, Doucet JL. 2014. New evidence of human activities during the holocene in the lowland forests of the northern Congo basin. Radiocarbon 56:209-220. doi: 10.2458/56.16485
Morin-Rivat J, Biwole A, Gorel A-P, Vleminckx J, Gillet J-F, Bourland N, Hardy OJ, Smith AL, Dai nou K, Dedry L, Beeckman H, Doucet J-L, Livingstone Smith A, Daïnou K. 2016. High spatial resolution of late-Holocene human activities in the moist forests of central Africa using soil charcoal and charred botanical remains. The Holocene 26:1954-1967. doi: 10.1177/0959683616646184
Neumann K, Eggert MK, Oslisly R, Clist B, Denham T, de Maret P, Ozainne S, Hildebrand E, Bostoen K, Salzmann U, Schwartz D, Eichhorn B, Tchiengué B, Hohn A. 2012. Comment on “Intensifying weathering and land use in Iron Age Central Africa”. Science 337:1040. doi: 10.1126/science.1221747
Neumer M, Becker E, Runge J. 2008. Palaeoenvironmental studies in the Ngotto Forest: alluvial sediments as indicators of recent and Holocene landscape evolution in the Central African Republic. In: Runge J (Ed). Palaeoecology of Africa, Vol. 28. p 122-137.
Oslisly R, White L, Bentaleb I, Favier C, Fontugne M, Gillet JF, Sebag D. 2013a. Climatic and cultural changes in the west Congo basin forests over the past 5000 years. Philosophical Transactions of the Royal Society B: Biological Sciences 368:20120304. doi: 10.1098/rstb.2012.0304
Oslisly R, Bentaleb I, Favier C, Fontugne M, Gillet JF, Morin-Rivat J. 2013b. West central African peoples: Survey of radiocarbon dates over the past 5000 Years. Radiocarbon 55:1377-1382. doi: 10.2458/azu_js_rc.55.16385
Parmentier I, Malhi Y, Senterre B, Whittaker RJ, ALONSO A, Balinga MPB, Bakayoko A, Bongers F, Chatelain C, Comiskey JA, Cortay R, KAMDEM M-ND, Doucet J-L, Gautier L, Hawthorne WD, Issembe YA, Kouamé FN, Kouka LA, Leal ME, Lejoly J, et al. 2007. The odd man out? Might climate explain the lower tree? diversity of African rain forests relative to Amazonian rain forests? Journal of Ecology 95:1058-1071. doi: 10.1111/j.1365-2745.2007.01273.x
Picard N, Gourlet-Fleury S. 2008. Manuel de référence pour l’installation de dispositifs permanents en forêt de production dans le Bassin du Congo. COMIFAC and CIRAD. http://hal.archives-ouvertes.fr/cirad-00339816/
Pinçon B. 1990. La métallurgie du fer sur les plateaux Teke (Congo). Quelles influences sur l’évolution des paysages au cours des deux derniers millénaires. In: Lanfranchi R, Schwartz D (Ed). Paysages quaternaires de l’Afrique Centrale Atlantique. p 479-492.
Pourtier R. 1989. Le Gabon: espace-histoire-société, t. 1. Paris: L’Harmattan, France.
Reimer P. 2013. IntCal13 and Marine13 radiocarbon age calibration curves 0-50,000 Years cal BP. Radiocarbon 55:1869-1887. doi: 10.2458/azu_js_rc.55.16947
Robineau C. 1967. Contribution à l’histoire du Congo: la domination européenne et l’exemple de Souanké (1900-1960). Cahiers D’études Africaines 7:300-344. doi: 10.3406/cea.1967.3099
Runge F, Fimbel RA. 2001. Opal phytoliths as evidence for the formation of savanna islands in the rain forest of Southeast Cameroon. In: Heine K (Ed). Palaeoecology of Africa and the surroundings islands, Vol. 27. p 171-189.
Runge J, Nguimalet C-R. 2005. Physiogeographic features of the oubangui catchment and environmental trends reflected in discharge and floods at Bangui 1911-1999, Central African Republic. Geomorphology 70:311-324. doi: 10.1016/j.geomorph.2005.02.010
Runge J. 2008. Remote sensing based forest assessment: recent dynamics (1973-2002) of forest-savanna boundaries at Ngotto Forest, Central African Republic (CAR). In: Runge J (Ed). Palaeoecology of Africa, Vol. 28. p 237-244.
Runge J, Sangen M, Neumer M, Eisenberg J, Becker E. 2014. Late Quaternary valley and slope deposits and their palaeoenvironmental significance in the Upper Congo Basin, Central Africa. In: Runge J (Ed). Palaeoecology of Africa, Vol. 32. p 53-90.
Réjou-Méchain M, Pélissier R, Gourlet-Fleury S, Couteron P, Nasi R, Thompson JD. 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. doi: 10.1017/S0266467408005506
Sangen M, Eisenberg J, Kankeu B, Runge J, Tchindjang M. 2011. New findings from geological, geomorphological and sedimentological studies on the palaeoenvironmental conditions in Southern Cameroon. In: Runge J (Ed). Palaeoecology of Africa, Vol. 30. p 165-188.
Sangen M. 2012. Late Quaternary Palaeoenvironments in Southern Cameroon as evidenced by alluvial sediments from the tropical rain forest and savanna domain. In: Runge J (Ed). Palaeoecology of Africa, Vol. 31. p 137-236.
Stock R. 2013. Texts in Regional Geography. Africa South of the Sahara: A Geographical Interpretation, 3rd edn. Guilford Press.
Tovar C, Breman E, Brňić T, Harris DJ, Bailey R, Willis KJ. 2014. Influence of 1100 years of burning on the Central African rainforest. Ecography 37:1139-1148. doi: 10.1111/ecog.00697
van Gemerden BS, Olff H, Parren MPE, 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. doi: 10.1046/j.1365-2699.2003.00937.x
Vennetier P. 1963. Les hommes et leurs activités dans le nord du Congo-Brazzaville. PhD Dissertation. France: University of Bordeaux.
Vleminckx J, Morin-Rivat J, Biwolé AB, Daïnou K, Gillet JF, Doucet JL, Drouet T, Hardy OJ. 2014. Soil charcoal to assess the impacts of past human disturbances on tropical forests. PLoS One 9:e108121. doi: 10.1371/journal.pone.0108121
White F. 1983. The Vegetation of Africa. Paris: UNESCO.
White LJT, Oates JF. 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. doi: 10.1046/j.1365-2699.1999.00149.x
Willis MKJ, Gillson L, Brňić TM. 2004. How “virgin” is virgin rainforest? Science 304:402-403. doi: 10.1126/science.1093991
Worbes M, Staschel R, Roloff A, Junk WJ. 2003. Tree ring analysis reveals age structure, dynamics and wood production of a natural forest stand in Cameroon. Forest Ecology and Management 173:105-123. doi: 10.1016/S0378-1127(01)00814-3
Wotzka HP. 2006. Records of activity: radiocarbon and the structure of iron age settlement in Central Africa. Grundlegungen. Beitrage Zur Europaischen Und Afrikanischen Archaologie Fur Manfred KH Eggert:271-289.
