Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-20T09:30:42.176Z Has data issue: false hasContentIssue false

Patterns of forest diversity along the Tana River, Kenya

Published online by Cambridge University Press:  10 July 2009

Kimberly E. Medley*
Affiliation:
Department of Botany and Plant Pathology, Michigan State University, East Lansing, Michigan 48824, USA

Abstract

Tropical forest vegetation occurs within a narrow corridor along the semi-arid lower floodplain of the Tana River, Kenya. An inventory of the woody flora and ecological study of 12 forest areas in the Tana River National Primate Reserve (TRNPR) describe the composition and structure of this riverine forest ecosystem and identify patterns of regional and local diversity. Only 175 species in 49 families are recorded in the woody flora, but the geographic affinities of 98 species are from four major floristic regions in Africa: Zanzibar-Inhambane (31%), Somalia-Masai (16%), Guinea-Congolian (12%), and Zambezian (1%). Ten species are rare and/or disjunct. Forests have a disturbed physiognomy characterized by a low mean height (14.4 m), high species importance attributable to a few trees, low density (409 ha−1) and coverage (23.1 m2 ha−1) of trees > 10 cm dbh, and an abundance of palms and lianes. Changes along the river in sediment deposition and hydrology explain the high diversity of landforms and corresponding forest types in the TRNPR vicinity, but the absence of trees which are most important near Bura, Acacia elalior, and near Wema, Barringtonia racemosa, suggests that the regional diversity of the ecosystem is inadequately protected. Preservation of key resources, such as the endangered primates, should be coupled with protection of the forest heterogeneity that characterizes this dynamic landscape.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1992

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

1

Present address: Department of Geography, 217 Shideler Hall, Miami University, Oxford, Ohio 45056, USA.

References

LITERATURE CITED

Andrews, P., Groves, C. P. & Horne, J. F. M. 1975. Ecology of the lower Tana River floodplain (Kenya). Journal of East African Natural History Society and National Museums 151:131.Google Scholar
Beentje, H. J. 1988a. Atlas of the rare trees of Kenya. Utafiti 1(3):71123.Google Scholar
Beentje, H. J. 1988b. A new species of Cynometra (Caesalpiniaceae) from Kenya. Utafiti 1(3): 124125.Google Scholar
Bogden, A. V. 1958. Some edaphic vegetational types of Kiboko, Kenya. Journal of Ecology 46:115126.CrossRefGoogle Scholar
Burtt, B. D. 1942. Some East African vegetation communities. Journal of Ecology 30:65146.CrossRefGoogle Scholar
Chapman, J. D. & White, F. 1979. The evergreen forests of Malawi. Commonwealth Forestry Institute, Oxford.Google Scholar
Dale, I. R. & Greenway, P. J. 1961. Kenya trees and shrubs. Buchanan's Kenya, Estates Limited, Kenya, in association with Hatchards, London.Google Scholar
FAO. 1984. Agriclimatological data for Africa. (Volume 2). Countries south of the equator. FAO Plant Production and Protection Series. No. 22. FAO, Rome.Google Scholar
Gichathi, F. N., Alakoski-Johansson, G. & Johansson, S. 1987. A check-list of indigenous trees and shrubs of Bura, Tana River District, Kenya with Malakole, Orma and Somali Names. Bura Forestry Research Project. Technical Report No. 6.Google Scholar
Greenway, P. J. 1973. A classification of the vegetation of East Africa. Kirkia 9:168.Google Scholar
Greig-Smith, P. 1983. Quantitative plant ecology. (3rd Edition). University of California Press, Berkeley.Google Scholar
Guy, P. R. 1977. Notes on the vegetation types of the Zambezi Valley, Rhodesia, between the Kariba and Mpata gorges. Kirkia 10:543557.Google Scholar
Hall, J. B. & Swaine, M. D. 1981. Distribution and ecology of vascular plants in a tropical rain forest. Dr Junk Publishers, Boston.CrossRefGoogle Scholar
Hamilton, A. 1974. The history of vegetation. Pp. 188209 in Lind, E. M. & Morrison, M. E. S. (eds). East African vegetation. Longman Group Limited, London.Google Scholar
Hart, T. B. 1985. The ecology of a single-species-dominant forest and of a mixed forest in Zaire, Africa. PhD Dissertation, Michigan State University.Google Scholar
Hart, T. B. 1990. Monospecific dominance in tropical rain forests. Trends in Ecology and Evolutionary Biology 5(1): 611.CrossRefGoogle ScholarPubMed
Hill, M. O. 1979. Decorana. A FORTRAN program for detrended correspondence analysis and reciprocal averaging. Ecology and Systematics, Cornell University, Ithaca, New York.Google Scholar
Hill, M. O. & Gauch, H. G. Jr. 1980. Detrended Correspondence Analysis: an improved ordination technique. Vegetatio 42:4758.CrossRefGoogle Scholar
Holdridge, L. R. 1967. Life zone ecology. (Revised Edition). Tropical Science Center, San Jose, Costa Rica.Google Scholar
Holdridge, L. R., Grenke, W. C., Hatheway, W. H., Liang, T. & Tosi, J. A. Jr. 1971. Forest environments in tropical life zones. Pergammon Press, New York.Google Scholar
Homewood, K. M. 1976. Ecology and behaviour of the Tana mangabey (Cercocebus galeritus galeritus). PhD Dissertation, University of London.Google Scholar
Homewood, K. M. 1978. Feeding strategy of the Tana mangabey (Cercocebus galeritus galeritus) (Mammalia: Primates). Journal of Zoology (London) 186:375391.CrossRefGoogle Scholar
Homewood, K. M. & Rodgers, W. A. 1981. A previously undescribed mangabey from southern Tanzania. International Journal of Primatology 2(1): 4755.CrossRefGoogle Scholar
Hughes, F. M. R. 1985. The Tana River fioodplain forest, Kenya: ecology and the impact of development. PhD Dissertation, University of Cambridge.Google Scholar
Hughes, F. M. R. 1988. The ecology of African floodplain forests in semi-arid and arid zones: a review. Journal of Biogeography 15:127140.CrossRefGoogle Scholar
Hughes, F. M. R. 1990. The influence of flooding regimes on forest disbtribution and composition along the Tana River, Kenya. Journal of Applied Ecology 27:475491.CrossRefGoogle Scholar
Hutchinson, J. 1973. The families of flowering plants: arranged according to a new system based on their probable phylogeny. Third Edition. Clarendon Press, Oxford.Google Scholar
Livingstone, D. A. 1975. Late Quaternary climatic change in Africa. Annual Review of Ecology and Systematics 6:249280.CrossRefGoogle Scholar
Madwick, J. 1986. Ecology of riverine forest in the Jubba Valley. Pages 2351 in Madwick, J., Wood, B., Varty, N. & Maunder, M. (eds). 1986 Somalia research project. (Final Report). University College London.Google Scholar
Marsh, C. W. 1976. A management plan for the Tana River Game Reserve. Report to the Kenya Department of Wildlife Conservation and Management, Nairobi. New York Zoological Society.Google Scholar
Marsh, C. W. 1978. Ecology and social organization of the Tana River red colobus, Colobus badius rufomitratus. PhD Dissertation, University of Bristol.Google Scholar
Marsh, C. W. 1981. Diet choice among red colobus (Colobus badius rufomitratus) on the Tana River. Folia Primatology 35:147148.CrossRefGoogle ScholarPubMed
Marsh, C. W. 1986. A resurvey of Tana River primates and their forest habitat. Primate Conservation 7:7281.Google Scholar
Medley, K. E. 1990. Forest ecology and conservation in the Tana River National Primate Reserve, Kenya. PhD Dissertation, Michigan State University.Google Scholar
Medley, K. E., Kinnaird, M. F. & Decker, B. S. 1989. A survey of the riverine forests in the Wema/Hewani vicinity, with reference to development and the preservation of endemic primates and human resources. Utafiti 2(1): 16.Google Scholar
Muchena, F. N. 1987. Soils and irrigation of three areas in the lower Tana Region, Kenya. University of Wageningen, The Netherlands.Google Scholar
Pichi-Sermolli, R. E. 1955. Tropical East Africa (Ethiopia, Somaliland, Kenya, Tanganyika). Pp. 302360 in Arid zone research VI, plant ecology UNESCO, Paris.Google Scholar
Pires, J. M. 1978. The forest ecosystems of the Brazilian Amazon: description, functioning, and research needs. Pp. 607627 in Tropical forest ecosystems. UNESCO, Paris.Google Scholar
Richards, P. W. 1957. The tropical rainforest. Cambridge, Cambridge University Press.Google Scholar
Simpson, C. D. 1975. A detailed vegetation study on the Chobe River in northeast Botswana. Kirkia 10:185217.Google Scholar
Turrill, W. B., Milne-Redhead, E. & Polhill, R. M. (eds). 19521990. Flora of tropical East Africa. In fascicles. Crown Agents, London (from 1980, Balkema, Rotterdam).Google Scholar
Vollesen, K. 1980. Annotated check-list of the vascular plants of the Selous Game Reserve, Tanzania. Opera Botanica 59:1117.Google Scholar
White, F. 1979. The Guineo-Congolian region and its relationship to other phytochoria. Bulletin Jarden Botanica National Belgium (Bulletin National Plantentuin Belgium) 49:1155.Google Scholar
White, F. 1983. The vegetation of Africa. UNESCO, Paris.Google Scholar