Coppice swidden fallows in tropical deciduous forest: Biological, technological, and sociocultural determinants of secondary forest successions
Tóm tắt
Secondary succession in tropical deciduous forest is often characterized by vegetative reproduction, or coppicing. Coppicing is also observed in forest sites that are disturbed by farming activity. This observation raises questions about the role of established management practices in determining the succession of vegetation on farmsites once they are abandoned to fallow. To what extent is the coppicing succession the result of specific aspects of swidden farming technology and management? And what variations in coppice successions occur in swidden sites following deviations from the standard farming practice? In research on swidden farming among the Susu of Sierra Leone, I examined the successional pathway in an age series of forest fallow sites. I show that the standard pattern of minimal cultivation favors the coppicing of felled trees in the subsequent fallow periods. By contrast, deviation from this pattern results in stump deaths and favors the invasion of fallow sites by grasses and vegetatively reproducing pioneer trees from the savanna. Variations in the environmental outcome of disturbance to plant communities, then, are the result of interactions between processes of tropical tree reproduction and the agricultural practices of local farmers.
Tài liệu tham khảo
Brooks, G. E. (1985). Western Africa to ca. 1860 A.D.: A Provisional Historical Schema Based on Climatic Periods. Indiana University African Studies Program Working Papers Series, No. 1, African Studies Program, Indiana University, Bloomington, Indiana.
Brooks, G. E. (1986). A provisional historical schema for western Africa based on seven climatic periods (ca. 9000 B.C. to the 19th century).Cahiers d'Etudes Africaines, Special issue: “Milieux, Historie, Historiographie” 26(1–2): 43–62.
Cline-Cole, R. A. (1987). The socio-ecology of firewood and charcoal on the Freetown Peninsula.Africa 57(4): 457–497.
Conklin, H. C. (1961). The study of shifting cultivation.Current Anthropology 2: 27–61.
DeSchlippe, P. (1956).Shifting Cultivation in Africa. Routledge and Kegan Paul, London.
Ewel, J. J. (1977). Differences between wet and dry successional tropical ecosystems.Geo-EcoTrop 1(2): 103–117.
Ewel, J. J. (1980). Tropical succession: Manifold routes to maturity.Biotropica, Special issue: “Tropical Succession.” Ewel, J. J. (ed.) 12(suppl.): 2–7.
FAO (1985).Tree Growing by Rural People. FAO, Rome.
Gomez-Pompa, A., and Vazquez-Yanes, C. (1974). Studies in the secondary succession of tropical lowlands: The life cycle of secondary species.Proceedings of the First International Congress of Ecology-Structure, Functioning, and Management of Ecosystems. Pudoc, Wageningen, pp. 336–342.
Gomez-Pompa, A., and Vazquez-Yanes, C. (1981). Successional studies of a rain forest in Mexico. In West, C., Schugart, H. H., and Botkin, D. B. (eds.),Forest Succession-Concepts and Application (Chap. 16). Springer-Verlag, New York, pp. 246–266.
Harding, R. S. O. (1984). Primates of the Kilimi area, northwest Sierra Leone.Folia Primatologica 42: 96–114.
Hoskins, M. (1982). Social Forestry in West Africa: Myths and Realities. Paper prepared for the American Association for the Advancement of Science.Workshop on Planning Fuelwood Projects, reader prepared for FAO by the Institute for Development Anthropology, pp. 109–112.
Hutchinson, J., and Dalziel, J. M. (1954–1958, 1963).Flora of West Tropical Africa (Vol. I, revised by R. W. J. Keay; Vol. II, revised by F. N. Hepper). Crown Agents, London.
Janos, D. P. (1980). Mycorrhizae influence tropical succession.Biotropica, Special issue: “Tropical Succession,” Ewel, J. J. (ed.) 12(Suppl): 56–64.
Janzen, D. H. (1975).Ecology of Plants in the Tropics. The Institute of Biology's Studies in Biology, No. 58, Edward Arnold, London.
Janzen, D. H. (1985).Spondias mombin is culturally deprived in megafauna-free forest.Journal of Tropical Ecology 1: 131–155.
Janzen, D. H. (1988). Management of habitat fragments in a tropical dry forest.Annals of the Missouri Botanical Gardens 75: 105–116.
Kartawinata, K., Adisoemarto, S., Riswan, S., and Vayda, A. P. (1981). The impact of man on a tropical forest in Indonesia.Ambio 10(2/3): 115–119.
Lal, R. (1977). Soil-conserving versus soil-depleting crops and soil management for erosion control. In Greenland, D. J., and Lal, R. (eds.),Soil Conservation and Management in the Humid Tropics (Chap. 4.1). John Wiley, New York, pp. 81–86.
Nye, D. H., and Greenland, J. J. (1960).The Soil under Shifting Cultivation. Commonwealth Bureau of Soils, Technical Communication 51, Commonwealth Agricultural Bureaux, Harpenden.
Nye, D. H., and Greenland, J. J. (1964). Changes in the soil after clearing tropical forest.Plant and Soil 21(1): 101–112.
Nyerges, A. E. (1987a). The development potential of the Guinea Savanna: Social and ecological constraints in the West African “Middle Belt.” In Little, P. D., and Horowitz, M. M., Nyerges, A. E. (eds.),Lands at Risk in the Third World-Local-Level Perspectives (Chap. 15). Institute for Development Anthropology, Monographs in Development Anthropology, Westview, Boulder, Colorado, pp. 316–336.
Nyerges, A. E. (1987b). Development in the Guinea savanna (letter).Science 238: 1637–1638.
Nyerges, A. E. (1988a). Swidden Agriculture and the Savannization of Forests in Sierra Leone. Ph.D. dissertation, University of Pennsylvania. University Microfilms, Ann Arbor, Michigan.
Nyerges, A. E. (1988b). Seasonal constraints in the Guinea savanna: Susu ecology in Sierra Leone.MASCA Research Papers in Science and Archaeology, Special issue: “Coping with Seasonal Constraints,” Huss-Ashmore, R., with Cuny, J. J. and Hitchcock, R. (eds.) 5:86–95.
Okigbo, B. N. (1977). Farming systems and soil erosion in West Africa. In Greenland, D. J., and Lal, R. (eds.),Soil Conservation and Management in the Humid Tropics. John Wiley, New York, pp. 151–163.
Phillips, E. A. (1959).Methods of Vegetation Study. Holt, Rinehart, and Winston, New York.
Richards, P. (1986).Coping With Hunger-Hazard and Experiment in an African Rice-Farming System. London Research Series in Geography 11, Allen and Unwin, London.
Richards, P. W. (1979).The Tropical Rainforest. Cambridge University Press, Cambridge.
Spooner, B. (1984).Ecology in Development: A Rationale for Three-Dimensional Policy. The United Nations University, Tokyo.
Spooner, B. (1987). Insiders and outsiders in Baluchistan: Western and indigenous perspectives on ecology and development. In Little, P. D., and Horowitz, M. M., with Nyerges, A. E. (eds.),Lands at Risk in the Third World-Local-Level Perspectives (Chap. 3). Institute for Development Anthropology, Monographs in Development Anthropology, Westview, Boulder, Colorado, pp. 58–68.
Stromgaard, P. (1985). A subsistence society under pressure: The Bemba of Northern Zambia.Africa 55(1): 39–59.
Stromgaard, P. (1986). Early secondary succession on abandoned shifting cultivator's plots in the Miombo of South Central Africa.Biotropica 18(2): 97–106.
Tegler, B. (1983).Environment and Plant Associations in Kilimi, Tambakha Chiefdom, Sierra Leone. Mimeo report to the Director, Outamba-Kilimi National Park.
Uhl, C., and Buschbacher, R. (1985). A disturbing synergism between cattle ranch burning practices and selective tree harvesting in the Eastern Amazon.Biotropica 17(4): 265–268.
Unesco, UNEP, FAO (1978).Tropical Forest Ecosystem-A State-of-Knowledge Report. Unesco, Paris.
Vazquez-Yanes, C., and Segovia, A. O. (1984). Ecophysiology of seed germination in the tropical humid forests of the world: A review. In Medina, E., Mooney, H. A., and Vazquez-Yanes, C. (eds.),Physiological Ecology of Plants of the Wet Tropics. Dr. W. Junk Publishers, The Hague, pp. 37–50.
Vermeer, D. (1970). Population pressure and crop rotational changes among the Tiv of Nigeria.Annals of the Association of American Geographers 60: 299–231.