Patterns of Tropical Tree Species Richness along Elevational Gradients of Mountain Afadjato, Ghana
This paper evaluates the effect of altitude on tree species richness, diversity, growth pattern and tree abundance to assess the responses of tree species to environmental changes. The highest mountain in Ghana, Afadjato, was categorized into three namely, lower elevation (200m -400m ASL), middle elevation (400m-600m ASL) and from 600m ASL and above the mountain as upper elevation. On five transects running from the bottom to the top of the mountain, two 20m by 20m squared plots were laid in each category on any 20m rise in altitude along the gradient of the mountain. All trees greater than 5cm in diameter at 1.3m above ground were identified and measured. The species richness, basal areas of trees and diversity differed in all the three levels of elevation. Tree abundance was found to decrease with increasing altitude. It was thought that these variations could be attributed to the various micro-environmental differences that might have occurred as a result of edaphic and climatic factors. Recommendations have been made for future studies.
Austrheim, G. (2002). Plant diversity patterns in semi-natural grasslands along an elevational gradient in Southern Norway. Plant Ecology 161:193-205.
Brown, J. (2001). Mammals on mountain sides: elevational patterns of diversity. Global Ecology and Biogeography, 10:101-109.
Davis, B.A.S., Brewer, S., Stevenson, A.C. & Guiot, J. (2003). The temperature of Europe during the Holocene reconstructed from pollen data. Quatern. Sci. Rev., 22: 1701€“1716.
Ford, W.M. & Rodrigue, J. L. (2001). Sorcid abundance in partial overstorey removal harvests and riparian areas in an industrial forest landscape of the central Appalachians. Forest Ecology and Management, 152:159-168.
Grytnes, J.A., & Vetaas, O.R. (2002). Distribution of vascular plant species richness and endemic richness along the Himalayan elevation gradient in Nepal. Global Ecology and Biogeography 11: 291-301.
Harrison, E. A., Mclntyre, B.M. & Dueser, R.D. (1989). Community dynamics and topographic controls on forest pattern in Shenandoah National Park, Virginia. Bulleting of the Torrey Botanical Club 116:1-14.
Lomolino, M.V. ( 2001). Elevation gradients of Species €“ density; historical and prospective view. Global Ecology and Biogeography, 10:3-13.
MA (Millenium Ecosystem Assessment). (2005). Ecosystems and Human Well- Being: Current State and Trends. Washington, DC: Island Press.
Mills, H.H. & Stephenson, S.L. (1999). Forest vegetation and boulder streams in the central Appalachian Valley and Ridge province , Southwestern Virginia. Journal of the Torrey Botanical Society 116:15-24.
Ntaimoa-Baidu, Y., Owusu, E. H., Daramani, D. & Nuoh, A. A. (2001). Ghana. In Important Bird Areas in Africa and Associated Islands: Priority Sites for Conservation. (L. D. C. Fishpool and M. I. Evans, ed. (2001) Pisces Publications and Birdlife International Newbury and Cambridge. Birdlife Conservation Series No.11.
Owusu, E. H. (2001). Community-based conservation in Ghana: the potential of the Afadjato and Agumatsa Range for ecotourism. (PhD Thesis.), University of Kent, Canterbury, Kent.
Pagels, J. F. & Handley, C.O. (1989). Distribution of the south eastern shrew, Sorex longirostris Bachman, in western Virginia. Brimleyana, 15:123-131.
Rahbek, C. (1995). The elevational gradients of species richness: a uniform pattern? Ecography 18: 200-2005.
Sanders, N. J., Jorrold, M. & Wagner, D. (2003). Patterns of ant species richness along elevational gradient in an arid ecosystem. Global ecology and biogeography 12: 93-102.
Whitney, H.E. & W.C. Johnson. (1984) Ice storms and forest succession in south-western Virginia. Bulleting of the Torrey Botanical Club 111:42-56.
Whittaker, R.H. (1956). Vegetation of the Great Smoky Mountains. Ecological Monographs 26:1-80
Yu, H. (2004). Distribution of Plant Species Richness along Elevation Gradient in Hubei Province, China. Nanjing University, International Institute for Earth System Science (ESSI).