[en] Timber exploitation is rapidly expanding throughout the Congo Basin. Forest areas assigned to timber harvesting have sharply expanded over the decades and logging concessions now largely overlap with the range of western lowland gorilla (Gorilla gorilla gorilla Savage & Wyman, 1847). However this species, which is considered as critically endangered by IUCN, could play an essential role in maintaining the structure and composition of tropical rainforest notably through seed dispersal services. This is likely due to its frugivorous diet, high stomach capacity and ability to swallow seeds of variable sizes. Moreover gorillas have a long gut retention time of ingested food, travel long daily distances and deposit most ingested seeds in suitable habitats for plant development (such as logging gaps). Consequently, the preservation of the role of gorilla in forest regeneration is essential in the context of logged forest ecosystems. Timber harvesting has two major opposing impacts on gorilla populations: on the one hand, gorillas benefit from growth of herbaceous vegetation (e.g. Marantaceae and Zingiberaceae) following forest canopy opening, as such herbs provide both staple food and nest-building materials; on the other hand, gorilla populations suffer with the rise in hunting associated with logging activity, especially with road network installation. Considering the potential negative knock-on effects of logging concessions on the ecological function of western lowland gorilla, the implementation of timber harvesting methods that preserve gorilla populations is a considerable challenge for forest sustainability, as well as for gorilla’s conservation.
Disciplines :
Sciences du vivant: Multidisciplinaire, généralités & autres
Auteur, co-auteur :
Haurez, Barbara ; Université de Liège - ULiège > Forêts, Nature et Paysage > Laboratoire de Foresterie des régions trop. et subtropicales
Arnhem E., 2008. Réponse éco-éthologique des grands singes et autres mammifères à l'exploitation forestière sélective au Cameroun. Thèse de doctorat: Université Libre de Bruxelles (Belgique).
Beckman N.G. & Muller-Landau H.C., 2007. Differential effects on hunting on pre-dispersal seed predation and primary and secondary seed removal of two Neotropical tree species. Biotropica, 39(3), 328-339.
Bennett E.L. et al., 2007. Hunting for consensus: reconciling bushmeat harvest, conservation, and development policy in West and Central Africa. Conserv. Biol., 21(3), 884-887.
Cipolletta C., 2004. Effects of group dynamics and diet on the ranging patterns of a western lowland gorilla group (Gorilla gorilla gorilla) at Bai Hokou, Central African Republic. Am. J. Primatol., 64, 193-205.
Clark C.J., Poulsen J.R., Malonga R. & Elkan P.W., 2009. Logging concession can extend the conservation estate for Central African tropical forests. Conserv. Biol., 23(5), 1281-1293.
Cousins, 1978. Man's exploitation of the gorilla. Biol. Conserv., 13, 287-297.
Doran-Sheehy D.M., Greer D., Mongo P. & Schwindt D., 2004. Impact of ecological and social factors on ranging in western gorillas. Am. J. Primatol., 64, 207-222.
Fa J.E. & Brown D., 2009. Impacts of hunting on mammals in African tropical moist forests: a review and synthesis. Mammal Rev., 39(4), 231-264.
FSC, 2012. Global FSC certificates: type and distribution-December 2012, http://ic.fsc.org/facts-figures.19.htm, (06/12/2012).
Goldsmith M.L., 1999. Ecological constraints on the foraging effort of western lowland gorillas (Gorilla gorilla gorilla) at Bai Hoköu, Central African Republic. Int. J. Primatol., 20(1), 1-23.
Hardus M.E., Lameira A.R., Menken S.B.J. & Wich S.A., 2012. Effects of logging on orangutan behavior. Biol. Conserv., 146, 177-187.
Holbrook K.M. & Loiselle B.A., 2009. Dispersal in a Neotropical tree, Virola flexuosa (Myristicaceae): does hunting of large vertebrates limit seed removal? Ecology, 90(6), 1449-1455.
Johns A.D., 1985. Selective logging and wildlife conservation in tropical rain-forest: problems and recommendations. Biol. Conserv., 31, 355-375.
Laurance W.F. et al., 2006. Impacts of roads and hunting on Central African rainforest mammals. Conserv. Biol., 20(4), 1251-1261.
Linder J.M. & Oates J.F., 2011. Differential impact of bushmeat hunting on monkey species and implications for primates conservation in Korup National Park, Cameroon. Biol. Conserv., 144, 738-745.
Malcolm J.R. & Ray J.C., 2000. Influence of timber extraction routes on Central African small-mammal communities, forest structure, and tree diversity. Conserv. Biol., 14(6), 1623-1638.
Matthews A. & Matthews A., 2004. Survey of gorilla (Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes troglodytes) in Southwestern Cameroon. Primates, 194, 179-194.
Mehlman P.T., 2008. Current status of wild gorilla populations and strategies for their conservation. In: Stoinski T.S., Steklis H.D. & Mehlman P.D. Conservation in the 21st century: gorilla as a case study. New York, USA: Springer, 296-314.
Morgan D. & Sanz C., 2007. Best practice guidelines for reducing the impact of commercial logging on great apes in Western Equatorial Africa. Gland, Switzerland: IUCN SSC Primate Specialist Group (PSG).
Muller-Landau H.C., 2007. Predicting the long-term effects of hunting on plant species composition and diversity in tropical forests. Biotropica, 39(3), 372-384.
Nasi R., Billand A. & Van Vliet N., 2012. Managing for timber and biodiversity in the Congo Basin. For. Ecol. Manage., 268, 103-111.
Nellemann C., Redmond I. & Refisch J., eds, 2010. The last stand of the gorilla-environmental crime and conflict in the Congo Basin. A rapid response assessment. Arendal, Norway: United Nations Environment Program, GRID-Arendal.
Nuñez-Iturri G. & Howe H.F., 2007. Bushmeat and the fate of trees with seeds dispersed by large primates in a lowland rain forest in western Amazonia. Biotropica, 39(3), 348-354.
Oates J.F., 1996. Habitat alteration, hunting and the conservation of folivorous primates in African forest. Aust. J. Ecol., 21, 1-9.
Peres C.A. & Palacios E., 2007. Basin-wide effects of game harvest on vertebrate population densities in Amazonian forests: implications for animal-mediated seed dispersal. Biotropica, 39(3), 304-315.
Poulsen J.R., Clark C.J. & Smith T.B., 2001. Seed dispersal by a diurnal primate community in the Dja Reserve, Cameroon. J. Trop. Ecol., 17, 787-808.
Poulsen J.R., Clark C.J., Mavah G. & Elkan P.W., 2009. Bushmeat supply and consumption in a tropical logging concession in Northern Congo. Conserv. Biol., 23(6), 1597-1608.
Remis M.J. & Kpanou J.B., 2010. Primate and ungulate abundance in response to multi-use zoning and human extractive activities in a Central African reserve. Afr. J. Ecol., 49, 70-80.
Rieu L. & Binot A., 2006. « Des agoutis entre les sapellis... » La faune sauvage dans l'aménagement des forêts d'Afrique Centrale. In: Nasi R., Nguinguiri J.C. & Ezzine de Blas D. Exploitation et gestion durable des forêts en Afrique Centrale: la quête de la durabilité. Paris: Éditions L'Harmattan, 267-298.
Robbins M.M. et al., 2004. Social structure and life-history patterns in western gorillas (Gorilla gorilla gorilla). Am. J. Primatol., 64, 145-159.
Rogers M.E. et al., 1998. Lowland gorillas and seed dispersal: the importance of nest sites. Am. J. Primatol., 45, 45-65.
Sanz C., Morgan D., Strindberg S. & Onononga J.R., 2007. Distinguishing between the nests of sympatric chimpanzees and gorillas. J. Appl. Ecol., 44, 263-272.
Stokes E.J., 2008. Conservation through scientific collaboration: case study-Western-gorilla. org. In: Stoinski T.S., Steklis H.D. & Mehlman P.T. Conservation in the 21stcentury: gorillas as a case study. New York, USA: Springer, 296-314.
Stokes E.J. et al., 2010. Monitoring great ape and elephant abundance at large spatial scales: measuring effectiveness of a conservation landscape. Plos One, 5(4), 1-18.
Tutin C.E.G., 2001. Saving the gorillas (Gorilla g. gorilla) and chimpanzees (Pan t. troglodytes) of the Congo Basin. Reprod. Fertil. Dev., 13, 469-476.
Tutin C.E.G., Parnell R.J., White L.J.T. & Fernandez M., 1995. Nest building by lowland gorillas in the Lopé Reserve, Gabon: environmental influences and implications for censuring. Int. J. Primatol., 16(1), 53-76.
van Kreveld A. & Roerhorst I., 2009. Great apes and logging. Zeist: World Wide Fund for Nature, http://awsassets.panda.org/downloads/3617_wnf_mensapen_en_fsc_eng_v7.pdf, (05/15/2013).
Vanthomme H., Bellé B. & Forget P.M., 2010. Bushmeat hunting alters recruitment of large-seeded plant species in Central Africa. Biotropica, 42(6), 672-679.
Van Vliet N. & Nasi R., 2008. Mammal distribution in a Central African logging concession area. Biodivers. Conserv., 17, 1241-1249.
Voysey B.C. et al., 1999. Gorillas and seed dispersal in the Lopé Reserve, Gabon II: survival and growth of seedlings. J. Trop. Ecol., 15, 39-60.
Walsh P.D. et al., 2003. Catastrophic ape decline in western equatorial Africa. Nature, 422, 611-614.
Walsh P.D. et al., 2008. Gorilla gorilla. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.1., http://www.iucnredlist.org/details/9404/0, (05/15/2013).
Wang B.C., Sork V.L., Leong M.T. & Smith T.B., 2007. Hunting of mammals reduces seed removal and dispersal of the afrotropical tree Antrocaryon klaineanum (Anacardiaceae). Biotropica, 39(3), 340-347.
Wilkie D.S., Sidle J.G. & Boundzanga G.C., 1992. Mechanized logging, market hunting, and a bank loan in Congo. Conserv. Biol., 6(4), 570-580.
Wilkie D.S. et al., 2000. Roads development and conservation in the Congo Basin. Conserv. Biol., 14(6), 1614-1622.
Wright S.J., 2003. The myriad consequences of hunting for vertebrates and plants in tropical forests. Perspect. Plant Ecol. Evol. Syst., 6(1-2), 73-86.
Wright S.J. et al., 2007a. The plights of large animals in tropical forests and the consequences for plant regeneration. Biotropica, 39(3), 289-291.
Wright S.J., Hernandéz A. & Condit R., 2007b. The bushmeat harvest alters seedling banks by favouring lianas, large seeds, and seed dispersal by bats, birds, and wind. Biotropica, 39(3), 363-371.
