Deciduousness; Forest management and conservation; Mixed species forest; Monodominant forest; Pioneer; Wood specific gravity
Résumé :
[en] The greater part of the semi-deciduous moist forests of the Congo basin has been given to logging companies for exploitation. In the next decades, very few of these forests will remain intact. In this paper, we aimed to identify large-scale variations in the structure, composition and functioning of African moist forests that could serve as a baseline for both management and conservation purposes. Commercial forest inventory data were assembled for 49,711 0.5-ha plots, covering an area of more than six million hectares, crossing the borders of Cameroon, Central African Republic and Republic of Congo. Floristic composition was analyzed for a subset of 176 genera reliably identified in the field. Three key functional traits of tropical trees: regeneration guild, leaf phenology, and wood specific gravity, were collected at the species
level from various sources, and assigned at the genus level. We first investigated the main variations in forest structure and composition, and identified seven forest types based on these variations. Differences in the percentage of pioneer and deciduous stems, and mean wood specific gravity were tested between forest types. Most of the study area was composed of a mosaic of the structural variations of the forests characterized by the occurrence of Celtis (Ulmaceae) species, which are mostly composed of frequent and abundant genera that formed the common floristic pool of the region. Secondary Musanga (Moraceae) forest is located in repeatedly disturbed areas, along roads and around main cities; mixed Manilkara (Sapotaceae) forest covers a huge area in the southern Central African Republic and in the northern Republic of Congo; and monodominant Gilbertiodendron (Fabaceae) forest is sparsely distributed along
rivers. The contrasted structure, composition, and functioning of the forest types imply pronounced differences in population and ecosystem processes, and call for adapted management and conservation strategies.
Fayolle, Adeline ; Université de Liège - ULiège > Forêts, Nature et Paysage > Gestion des ressources forestières et des milieux naturels
Picard, Nicolas; CIRAD, UPR BSEF, FRANCE > Biens et Services des Ecosystèmes Forestiers Tropicaux
Doucet, Jean-Louis ; Université de Liège - ULiège > Forêts, Nature et Paysage > Laboratoire de Foresterie des régions trop. et subtropicales
Swaine, Michael; University of Aberdeen, United Kingdom > Institute of Biological and Environmental Sciences
Bayol, Nicolas; Forest Ressources Management, Espaces Frejorgues, France
Bénédet, Fabrice; CIRAD, UPR BSEF, FRANCE > Biens et Services des Ecosystèmes Forestiers Tropicaux
Gourlet-Fleury, Sylvie; CIRAD, UPR BSEF, FRANCE > Biens et Services des Ecosystèmes Forestiers Tropicaux
Langue du document :
Anglais
Titre :
A new insight in the structure, composition and functioning of central African moist forests
Date de publication/diffusion :
2014
Titre du périodique :
Forest Ecology and Management
ISSN :
0378-1127
eISSN :
1872-7042
Maison d'édition :
Elsevier Science
Fascicule/Saison :
329
Pagination :
195-205
Peer reviewed :
Peer reviewed vérifié par ORBi
Intitulé du projet de recherche :
ErA Net BiodivERsA CoForChange project (http://www.coforchange.fr)
Organisme subsidiant :
ANR - Agence Nationale de la Recherche NERC - Natural Environment Research Council
Commentaire :
This study is part of the ErA Net BiodivERsA CoForChange project (http://www.coforchange.fr), funded by the National Research Agency (ANR) - France and the Natural Environment Research Council (NERC) - United Kingdom, involving 15 European, African and international partners. We wish to thank the timber companies:
Alpicam, Bois et Placages de Lopola, Danzer, Congolaise Industriale des Bois, Industries Forestieres de Batalimo, Likouala Timber, Mokabi SA. and Vicwood. The consulting firm Foret Resource Management (FRM), facilitated contacts and exchange with several logging companies, participated in data collection and data compiling, and provided inventory data files. A.F. was supported by ANR funding.
Aubréville, A., 1950. Flore forestière soudano-guinéenne: (AOF-Cameroun) (AEF).
Aubréville A., Duvigneaud P., Hoyle A.C., Keay R.W., Mendonca F.A., Pichi-Sermolli R.E.C. Carte de la Végétation de l'Afrique au sud du Tropique du Cancer 1958, AETFAT/UNESCO, Paris, France.
Baccini A., Laporte N., Goetz S., Sun M., Dong H. A first map of tropical Africa's above-ground biomass derived from satellite imagery. Environ. Res. Lett. 2008, 3:045011.
Bégué L. Les Forêts du nord de la République du Congo (Brazzaville). BFT, Chronique Phytogéographique 1967, 111:63-76.
Betbeder, J., Valéry Gond, Frédéric Frappart, Nicolas N. Baghdadi, Gaël Briant, Etienne Bartholomé, 2014. Mapping of Central Africa forested Wetlands using remote sensing. IEEE J. Selected Topics Appl. Observations Remote Sensing.
Boulvert, Y., 1986. Carte phytogéographique de la république centrafricaine. Notice explicative n 104.
Brncic, T., 2002. Ecology and patch dynamics of Megaphrynium macrostachyum (Benth.) Milne-Redh. (Marantaceae) in the south-west Central African Republic. University of Oxford.
Brncic T.M., Willis K.J., Harris D.J., Washington R. Culture or climate? The relative influences of past processes on the composition of the lowland Congo rainforest. Philos. T. R. Soc. B 2007, 362:229-242.
Caballé G. Essai sur la géographie forestière du Gabon. Adansonia 1978, 17:425-444.
Chave J., Coomes D., Jansen S., Lewis S.L., Swenson N.G., Zanne A.E. Towards a worldwide wood economics spectrum. Ecol. Lett. 2009, 12:351-366.
Couteron P., Pelissier R., Mapaga D., Molino J.F., Teillier L. Drawing ecological insights from a management-oriented forest inventory in French Guiana. Forest Ecol. Manage. 2003, 172:89-108.
De Namur, C., 1990. Aperçu sur la végétation de l'Afrique centrale atlantique. Paysages quaternaires de l'Afrique centrale atlantique. ORSTOM, Paris 60-67.
Dufrêne M., Legendre P. Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecol. Monogr. 1997, 67:345-366.
Fayolle A., Engelbrecht B., Freycon V., Mortier F., Swaine M., Réjou-Méchain M., Doucet J.L., Fauvet N., Cornu G., Gourlet-Fleury S. Geological substrates shape tree species and trait distributions in African moist forests. PLoS ONE 2012, 7:e42381.
Gillet, J.-F., 2013. Les forêts à Marantaceae au sein de la mosaïque forestière du Nord de la République du Congo: origines et modalités de gestion (PhD Thesis). Gembloux Agro-Bio Tech, Université de Liège, Gembloux, Belgique.
Gillet J.-F., Doucet J.-L. A commented checklist of woody plants in the Northern Republic of Congo. Plant Ecol. Evol. 2012, 145:258-271.
Gond V., Fayolle A., Pennec A., Cornu G., Mayaux P., Camberlain P., Doumenge C., Fauvet N., Gourlet-Fleury S. Vegetation structure and greenness in Central Africa from Modis multi-temporal data. Philos. T. R. Soc. B 2013, 368:20120309. http://dx.doi.org/10.1098/rstb.2012.0309.
Gourlet-Fleury S., Beina D., Fayolle A., Ouédraogo D.Y., Mortier F., Bénédet F., Closset-Kopp D., Decocq G. Silvicultural disturbance has little impact on tree species diversity in a Central African moist forest. Forest Ecol. Manage. 2013, 304:322-332.
Gourlet-Fleury, S., Mortier, F., Fayolle, A., Baya, F., Ouédraogo, D., Bénédet, F., Picard, N., 2013b. Tropical forest recovery from logging: a 24 year silvicultural experiment from Central Africa. Philos. Trans. R. Soc. B: Biol. Sci. 368.
Gourlet-Fleury S., Rossi V., Réjou-Méchain 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. Environmental filtering of dense-wooded species controls aboveground biomass stored on nutrient-poor soils in African moist forests. J. Ecol. 2011, 99:981-990.
Guillot B. Rendements de la cacaoculture et formations végétales. Essai d'écologie pratique des forêts de la Sangha (Congo) et du Sud-Est du Cameroun. Cahiers ORSTOM (Office de la Recherche Scientifique et Technique d'Outre-Mer). Série Sci. Humaines Bondy 1981, 18:63-106.
Hall J.S., Harris D.J., Medjibe V., Ashton P.M.S. The effects of selective logging on forest structure and tree species composition in a Central African forest: implications for management of conservation areas. Forest Ecol. Manage. 2003, 183:249-264.
Harris D.J. The vascular plants of the Dzanga-Sangha Reserve 2002, Central African Republic, Scripta Botanica Belgica, 23.
Hawthorne, W.D., 1995. Ecological profiles of Ghanaian forest trees, Tropical Forestry Papers. Oxford Forestry Institute, Department of Plant Sciences, University of Oxford, Oxford.
Higgins M.A., Ruokolainen K. Rapid tropical forest inventory: a comparison of techniques based on inventory data from western Amazonia. Conserv. Biol. 2004, 18:799.
Küper W., Sommer J.H., Lovett J.C., Mutke J., Linder H.P., Beentje H.J., Van Rompaey R.S.A.R., Chatelain C., Sosef M., Barthlott W. Africa's hotspots of biodiversity redefined. Ann. Missouri Botanical Garden 2004, 91:525-535.
Lanly J.P. Inventaire Forestier en République Centrafricaine. BFT 1966, 107:33-56.
Lanly J.P. La Forêt dense Centrafricaine. BFT 1966, 108:43-55.
Lebrun J., Gilbert G. Une Classification écologique des fore{ogonek}ts du Congo, Série scientifique 1954, Institut national pour l'étude agronomique du Congo Belge, Bruxelles, Belgique.
Letouzey, R., 1985. Carte phytogéographique du Cameroun.
Lewis S.L., Lopez-Gonzalez G., Sonké B., Affum-Baffoe K., Baker T.R., Ojo L.O., Phillips O.L., Reitsma J.M., White L., Comiskey J.A. Increasing carbon storage in intact African tropical forests. Nature 2009, 457:1003-1006.
Lewis, S.L., Sonke, B., Sunderland, T., Begne, S.K., Lopez-Gonzalez, G., van der Heijden, G.M.F., Phillips, O.L., Affum-Baffoe, K., Banin, L., Bastin, J.-F., 2013. Aboveground biomass and structure of 260 African tropical forests. Philos. Trans. R. Soc. London Ser. B Containing Papers Biol. Character (1896-1934).
Linder H.P. Plant diversity and endemism in sub-Saharan tropical Africa. J. Biogeogr. 2001, 28:169-182.
Maharjan S.K., Poorter L., Holmgren M., Bongers F., Wieringa J.J., Hawthorne W.D. Plant functional traits and the distribution of West African rain forest trees along the rainfall gradient. Biotropica 2011, 43:552-561.
Mayaux P., Bartholomé E., Fritz S., Belward A. A new land-cover map of Africa for the year 2000. J. Biogeogr. 2004, 31:861-877.
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.
Nasi R., Billand A., van Vliet N. Managing for timber and biodiversity in the Congo Basin. Forest Ecol. Manage. 2012, 268:103-111.
Ouédraogo D.Y., Beina D., Picard N., Mortier F., Baya F., Gourlet-Fleury S. Thinning after selective logging facilitates floristic composition recovery in a tropical rain forest of Central Africa. Forest Ecol. Manage. 2011, 262:2176-2186.
Peh K.S.-H., Lewis S.L., Lloyd J. Mechanisms of monodominance in diverse tropical tree-dominated systems. J. Ecol. 2011, 99:891-898.
Putz F.E., Zuidema P.A., Synnott T., Peña-Claros M., Pinard M.A., Sheil D., Vanclay J.K., Sist P., Gourlet-Fleury S., Griscom B., Palmer J., Zagt R. Sustaining conservation values in selectively logged tropical forests: the attained and the attainable. Conservation Lett. 2012, 5:296-303. 10.1111/j.1755-263X.2012.00242.x.
Réjou-Mechain M., Fayolle A., Nasi R., Gourlet-Fleury S., Doucet J.L., Gally M., Hubert D., Pasquier A., Billand A. Detecting large-scale diversity patterns in tropical trees: can we trust commercial forest inventories?. Forest Ecol. Manage. 2011, 261:187-194.
Réjou-Méchain M., Pélissier R., Gourlet-Fleury S., Couteron P., Nasi R., Thompson J.D. Regional variation in tropical forest tree species composition in the Central African Republic: an assessment based on inventories by forest companies. J. Trop. Ecol. 2008, 24:663-674.
Ruiz Pérez M., Ezzine de Blas D., Nasi R., Sayer J.A., Sassen M., Angoué C., Gami N., Ndoye O., Ngono G., Nguinguiri J.C. Logging in the Congo Basin: a multi-country characterization of timber companies. Forest Ecol. Manage. 2005, 214:221-236.
Slik J.F., Bernard C.S., Breman F.C., Van Beek M., Salim A., Sheil D. Wood density as a conservation tool: quantification of disturbance and identification of conservation-priority areas in tropical forests. Conservation Biol. 2008, 22:1299-1308.
Slik J.W.F. Assessing tropical lowland forest disturbance using plant morphological and ecological attributes. Forest Ecol. Manage. 2005, 205:241-250.
Slik J.W.F., Poulsen A.D., Ashton P.S., Cannon C.H., Eichhorn K.A.O., Kartawinata K., Lanniari I., Nagamasu H., Nakagawa M., Van Nieuwstadt M.G.L. A floristic analysis of the lowland dipterocarp forests of Borneo. J. Biogeogr. 2003, 30:1517-1531.
Ter Steege H., Hammond D.S. Character convergence, diversity, and disturbance in tropical rain forest in Guyana. Ecology 2001, 82:3197-3212.
Ter Steege H., Pitman N.C.A., Phillips O.L., Chave J., Sabatier D., Duque A., Molino J.F., Prévost M.F., Spichiger R., Castellanos H. Continental-scale patterns of canopy tree composition and function across Amazonia. Nature 2006, 443:444-447.
Van Gemerden B.S., Olff H., Parren M.P.E., Bongers F. The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity. J. Biogeogr. 2003, 30:1381-1390.
Van Schaik C.P., Terborgh J.W., Wright S.J. The phenology of tropical forests: adaptive significance and consequences for primary consumers. Annu. Rev. Ecol. Evol. S 1993, 24:353-377.
Veenendaal E.M., Swaine M.D., Lecha R.T., Walsh M.F., Abebrese I.K., Owusu-Afriyie K. Responses of West African forest tree seedlings to irradiance and soil fertility. Funct. Ecol. 1996, 10:501-511.
Verhegghen A., Mayaux P., de Wasseige C., Defourny P. Mapping Congo Basin vegetation types from 300m and 1km multi-sensor time series for carbon stocks and forest areas estimation. Biogeosciences 2012, 9:5061-5079.
Viennois G., Barbier N., Fabre I., Couteron P. Multiresolution quantification of deciduousness in West Central African forests. Biogeosci. Discuss. 2013, 10:7171-7200.
White F. The Vegetation of Africa: a Descriptive Memoir to Accompany the UNESCO/AETFAT/UNSO Vegetation Map of Africa 1983, ORSTOM - UNESCO, Paris, France.
White L.J.T., Oates J.F. 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 Ecol. Biogeogr. 1999, 8:355-361. 10.1046/j.1365-2699.1999.00149.x.
Willis K.J., Gillson L., Brncic T.M. How "virgin" is virgin rainforest?. Science 2004, 304:402-403.
Zimmerman B.L., Kormos C.F. Prospects for sustainable logging in tropical forests. BioScience 2012, 62:479-487. 10.1525/bio.2012.62.5.9.
