Abstract
Structure and composition of woody vegetation in Sahelian forest types (not including riparian and riverine types) were studied in Sénégal. The application of classification and ordination resulted in the recognition of seven distinctive woody community types, related to soil and precipitation gradients. The described vegetation types only contained four strictly Saharan species, the rest being of Sahelian and Soudanean affinity, so a floristic change from savanna to desert vegetation after two decades of drought could not be confirmed. Tree density was lower in the northern part than earlier, possibly an indication of degradation. Rejuvenation was greatest at the northernmost arenosolic stations, but low in the southern, ferrouginous areas. This presumably demonstrates the resilience of North-Sahelian vegetation, at the moment being in a dynamic rejuvenation phase, after a period of adverse conditions.
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References
Berry L. 1984. Desertification in the Sudano-Sahelian region 1977–1984. Desertification Control Bulletin 10: 23–28.
Bille J. C. 1972. Recherches ecologiques sur une savane sahelienne du Ferlo Septentrional, Sénégal: Description de la vegetation. La Terre et la Vie 26: 351–365.
Bille J. C. 1974. Recherches ecologiques sur une savane sahelienne du Ferlo septentrional, Sénégal: 1972, annee seche au Sahel. La Terre et la Vie 28: 5–20.
Bourliére F. & Hadley M. 1983. Present-day savannas: an overview.-In: F. Bourliére (Ed.): Ecosystems of the world. Tropical savannas. Elsevier, Amsterdam, Oxford, New York, pp. 1–17.
Cottam G. & Curtis J. T. 1956. The use of distance measures in phytosociological sampling. Ecology 37: 451–460.
GEMS 1988a. Inventory and Monitoring of Sahelian Pastoral Ecosystems. Main report. Global Environmental Monitoring System Sahel Series. UNEP, FAO, Government of Sénégal, Rome 1988.
GEMS 1988b. Inventory and Monitoring of Sahelian Pastoral Ecosystems. Annex 7: woody vegetation in the Sahel. Global Environmental Monitoring System Sahel Series, UNEP, FAO, Government of Sénégal. Rome 1988.
GEMS 1988c. Inventory and Monitoring of Sahelian Pastoral Ecosystems. Annex 2: rainfall in the Ferlo (Sahelian region of North Sénégal) since 1919. Global Environmental Monitoring System Sahel Series. UNEP, FAO, Government of Séńegal. Rome 1988.
Gillet H. 1986. Desert and Sahel, In: Plant Ecology in West Africa. Systems and Processes. G. W. Lawson (Ed), John Wiley & Sons, Chichester, New York, Brisbane, Toronto, Singapore, pp. 151–181.
Hare F. K. 1984. Recent climatic experience in the arid and semi-arid lands.-Desertification Control Bulletin 10: 15–22.
Hill M. O. 1979. Twinspan, a FORTRAN program for arranging multivariate data in an ordered Two-way table by classification of the individuals and attributes. Ecology and systematics, Cornel University, Ithaca, New York.
Hutchinson J. & Dalziel J. M. 1954–1973. Flora of Tropical West Africa 2 Edition, N. Hepper & R. W. J. Keay (Eds), Crown Agents, London.
Klug S. 1982. Inventaire et suivi de la vegetation dans la parcelle délevage a Vindou-Tingoly (Ferlo-Sénégal). Rapport final. GTZ, Hamburg W. Germany.
Le Houérou H. N. 1989. The Grazing Land Ecosystems of the African Sahel. Ecological Studies 75. Springer Verlag, Berlin, Heidelberg, New York, London, Paris, Tokyo, Hong Kong.
Lubke R. A., Clinning C. F. & Smith F. R. 1976. The pattern of the woody species of the Nylsvley savanna ecosystem project area. Proc. Grassld. Soc. Sth. Afr. 11: 29–35.
Lundholm B. 1976. Adaptations in arid ecosystems. In: A Rapp, H. N. Le Houérou & B. Lundholm (eds.): Can desert encroachment be stopped? A study with Emphasis on Africa. Ecoll. Bull. (Stockholm). NFR, Stockholm, pp. 19–27.
Maydell H.-J. von 1986. Trees and shrubs of the Sahel. Their Characteristics and uses. GTZ, Eschborn, W.-Germany.
Menaut J.-C. 1983. The vegetation of African savannas. In F. Bouliére (ed.) Ecosystems of the world. Tropical savannas: pp. 109–149. Elsevier, Amsterdam, Oxford, New York.
Miehe S. & Maydell U. von 1987. Inventur und Uberwachung der Vegetation auf Weideparzellen in Vindou Tiengoly. GTZ, Eschborn, W.-Germany.
Montgomery R. F. & Askew G. P. 1983. Soils of tropical savannas.-In: F. Bourliére (Ed), Ecosystems of the World: Tropical savannas. pp. 63–78 Elsevier, Amsterdam, Oxford, New York.
Nix H. A. 1983. Climate of tropical savannas. In: F. Bourliére (Ed), Ecosystems of the World: Tropical savannas pp. 37–62. Elsevier, Amsterdam, Oxford, New York.
Noy-Meir I. 1982. Stability of Plant-Herbivore Models and possible applications to savanna.-In: B. J. Huntley & B. H. Walker (Eds), Ecology of tropical savannas, ecological studies. Springer. Berlin, Heidelberg, New York, pp. 591–609.
Oldmeyer J. L. & Regelin W. L. 1980. Comparison of 9 methods for estimating density of shrubs and saplings in Alaska. J. Wildl. Manage. 44(3): 662–666.
Poupon H. 1976. La biomasse et l'evolution de sa repartition au corus de la croissance d'Acacia senegal dans une savane sahelienne (Sénégal). Bois et Forêts des Tropiques 166: 23–38.
Poupon H. 1977. Evolution d'un peuplement d'Acacia senegal (L.) Willd. dans une savanne sahelienne au Sénégal de 1972–1976. Cahiers de l'ORSTOM, serie Biologie 12(4): 283–291.
Poupon H. 1980. Structure et dynamique de la strate ligneuse d'une steppe sahelienne au nord du Sénégal. Travaux et documents de l'ORSTOM 115. ORSTOM, PARIS.
Rapp A. 1986. Introduction to soil degradation processes in drylands. Climatic Change 9: 19–31.
Ross J. H. 1979. A conspectus of the African Acacia species. Mem. bot. Surv. S. Afr. 44: 1–155.
Sandford W. W. & Isichei A. O. 1986. Savanna, In: Plant Ecology in West Africa. Systems and Processes. G. W. Lawson (Ed), John Wiley & Sons, Chichester, New York, Brisbane, Toronto, Singapore, pp. 95–149.
Ter Braak C. F. J. 1988. CANOCO — an extension of DECORANA to analyze species-environment relationships. Vegetatio 75: 159–160.
Ter Braak C. F. J. & Prentice C. 1988. A theory of Gradient Analysis. Advances in Ecological Research 18: 271–317. Academic Press. London.
Tybirk, K., Lawesson, J. E. & Nielsen, I. (eds.) 1989. Sahel Workshop 1989, University of Aarhus. AAU reports 19: 1–75.
USAID 1986. Cartographie et teledetection des ressources de la republique du Sénégal. Etude de la geologie, de l'hydrologie, des sols, de la vegetation et des potentiels d'utilisation des sols. US agency for international development, direction de l'amenagement du territorie, Sénégal, RSI. Washington.
Verstraete M. V. 1986. Defining desertification: A review. Climatic Change 9: 5–18.
Walker B. H. & Noy-Meir I. 1982. Aspects of the stability and resilience of savanna ecosystems. In: B. J. Huntley & B. H. Walker (Eds). Ecology of tropical savannas, ecological studies. Springer, Berlin, Heidelberg, New York, pp. 557–590.
White F. 1983. The vegetation of Africa. A descriptive memoir to accompany the Unesco/EATFAT/UNSO vegetation map of Africa. Natural resources research 20. Unesco, Paris.
Wickens G. E. 1976. Jebel Marra. KEW Bull. add. ser. 5: 1–368.
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Lawesson, J.E. Sahelian woody vegetation in Sénégal. Vegetatio 86, 161–174 (1990). https://doi.org/10.1007/BF00031732
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DOI: https://doi.org/10.1007/BF00031732