SPECIES RICHNESS, DIVERSITY AND DISTRIBUTION OF AMPHIBIANS ALONG ELEVATIONAL GRADIENT ON MOUNTAIN AFADJATO, GHANA

Yıl 2013, Cilt: 1 Sayı: 2, 68 - 76, 16.06.2013

Daniel Agyei , Edward Wiafe

Öz

 Numerous studies have confirmed Altitudinal gradients and physical environment as the major factors that affect species richness and distribution. The world's biodiversity are not evenly distributed due to the variations in biogeographically conditions. The West African tropical rain forest ecosystem host about two- thirds of the earth's biodiversity however, little information is known about this rich biodiversity especially the factors that link species  richness and distribution. In this study, the richness and distribution of amphibians were investigated. In this regard, systematic sampling was used as a method to determine amphibian species richness and distribution along the three levels of elevation. Litter levels were also recorded to determine the effect of litter levels as ecological variable on amphibian's richness and distribution. The instruments used include GPS, ruler, a hundred meter line tape and compass. The result reveals a significant variation of amphibian's richness and diversity along elevational gradient. However there was a negative relationship between amphibian species and litter levels along the lower, middle and upper elevational levels.

Anahtar Kelimeler

Amphibian, Elevation, Leaf litter, Afadjato, Ghana

SPECIES RICHNESS, DIVERSITY AND DISTRIBUTION OF AMPHIBIANS ALONG ELEVATIONAL GRADIENT ON MOUNTAIN AFADJATO, GHANA

Öz

Bu çalışmada amfibi tür çeşitliliği ve dağılımını incelemek üzere sistematik örnekleme yapılarak, amfibi türlerinin üç yükseltideki dağılımı incelenmiştir. Elde edilen bulgulara göre; tür zenginliği ve dağılımı yükselti boyunca anlamlı bir şekilde değişirken, tür çeşitliliğinin yükseltiye göre değişmediği tespit edilmiştir. Ayrıca Arthroleptis spp. ve Phrynobatracus calcaratus türlerinin Afadjato dağında en fazla yaygınlık gösteren ve yaşam rekabetinde üstünlük gösteren türler olduğu sonucuna varılmıştır. Yükselti boyunca ölü örtü seviyesi ile amfibi türlerinin yaygınlığı arasında negatif bir ilişki olduğu görülmüştür. Yükselti boyunca artış gösteren ölü örtü miktarına karşın amfibi tür sayısının azalması ile Afadjato dağında amfibilerin ölü örtünün fazla olduğu yerleri tercih etmediği sonucuna varılmıştır.

Anahtar Kelimeler

Amfibi, Yükselti, Ölü örtü, Afadjato, Gana

Kaynakça

• References
• Adams, M.J. (1999). Correlated factors in amphibian decline: exotic species and habitat change in western Washington. Journal of wildlife management. 63:1162-1171.
• Araujo, M. B., and R. G. Pearson. (2005). Equilibrium of species'distributions with climate. Ecography 28:693€“695
• Bakarr, M., B. Bailey, D. Byler, R. Ham, S. Olivieri & M. Omland (2001, Eds.): From the forest to the sea: Biodiversity connections from Guinea to Togo, Conservation Priority- SettingWorkshop, December 1999, Conservation International, Washington D.C.
• Buckley, L. B., and Jetz, W. (2007). Environmental and historical constraints on global patterns of amphibian richness. Proc. R. Soc. B 274: 11671173.
• Brown, W. C., & Alcala, A. C., (1961). Populations of amphibians and reptiles in the submontane and montane forests of Cuernos de Negros, Philippine Islands. Ecology, 42 (4): 628-636.
• Crump M.L, Scott N.J (1994). Visual Encounter Surveys, In Heyer WR Donnelly MA McDiarmid RW Hayek LC Foster MS (Eds) Measuring and Monitoring Biological Diversity, Standard Methods for Amphibians, Smithsonian Institution, Washington DC, USA. pp. 84- 92.
• Currie, D. J. (1991). Energy and large-scale patterns of animal and plant- species richness. Am. Nat. 137: 2749.
• Durand JR, Skubich M (1982). Lagoons of Ivory Coast. Aquaculture, 27: 211-250
• Frempong, E. (1995): Limnological research and training in Ghana: The past, present and perspectives for future development. €“ In: GOPAL, B. & R.G. WETZEL (Eds.): Limnology in developing countries: 1-39.
• Fishpool, L. D. C. and Evans, M. I., eds. (2001) Important Bird Areas in Africa and associated islands: Priority sites for conservation. Newbury and Cambridge, UK: Pisces Publications and BirdLife International (BirdLife Conservation Series No. 11)
• Fauth, J. E., B. I. Crother, and J. B. Slowinski. (1989). Elevational patterns of species richness, evenness, and abundance of the Costa Rican leaf-litter herpetofauna. Biotropica 21: 178- 185.
• Fisher BL, and Robertson H. 2002. Comparison and origin of forest and grassland ant assemblages in the high plateau of Madagascar. Biotropica 34: 155-167.
• Fu, C., Hua, X., Li, J., Chang, Z., Pu, Z. & Chen, J. (2006). Elevational patterns of frog species richness and endemic richness in the Hengduan Mountains, China: geometric constraints, area and climate effects. Ecography, 29 (6): 919-927.0
• Gifford, M.E, and Kozak, K.H. (2011). Islands in the sky or squeezed at the top? Ecological causes of elevational range limits in montane salamanders. Ecography. DOI: 10.1111/j.1600- 0587.2011.06866. Publishe online, 07/14/2011
• Grau, O., Grytnes, J. A., & Birks, H. (2007). A comparison of altitudinal species richness patterns of bryophytes with other plant groups in Nepal, Central Himalaya. Journal of Biogeography,
• Grytnes, J. A. & Vetaas, O. R. (2002). Species richness and altitude: a comparison between null models and interpolated plant species richness along the Himalayan altitudinal gradient, Nepal. American Naturalist: 294-304.
• Gibbons JW, Scott DE Ryan TJ, Buhlmann KA, Tuberville TD, Metts BS, Greene JL,Mills T, Leiden Y, Poppy S, Winne CT (2000). The global decline of Reptiles, déjà vu amphibians. Bioscience, 50: 655- 666.
• Hammer, Ø., Harper, D.A.T., Ryan, P. D. (2001). PAST: Paleontological statistics software package for education and data analysis. Palaeontologia Electronica 4(1): 9pp. http://palaeo-electronica.org/2001_1/past/issue1_01.htm
• HEYER, W.R., M.A. DONNELLY, R.W. MCDIARMID, L.-A.C. HAYEK, & M.S. FOSTER (1994): Measuring and monitoring biological diversity, standard methods for amphibians. €“ Washington D.C. (Smithsonian Institution Press).
• Heinen, J. T. (1992). Comparisons of the leaf litter herpetofauna in abandon cacao plantations and primary rainforest
• HUGHES, B. (1988): Herpetology in Ghana (West Africa).- Brit. Herp. Soc. Bull., 25: 29-38.
• Korner, C. (2000). Why are there global gradients in species richness? Mountains might hold the answer. Trends in Ecology and Evolution, 15 (12): 513-514.
• Khatiwada, J. R. (2011): amphibian species richness and composition along an elevational gradient in chitwan, Nepal Norwegian University of Life Sciences
• Lomolino, M. V. (2001). Elevation gradients of species-density: historical and prospective views. Global Ecology and Biogeography, 10: 3-13.
• Lomolino, M. & Weiser, M. (2001). Towards a more general species-area relationship: diversity on all islands, great and small. Journal of Biogeography: 431-445.
• MacArthur, R. H. 1972. Geographical ecology: patterns in the distribution of species. Harper and Row.
• McCain, C. M. (2005). Elevational gradients in diversity of small mammals. Ecology, 86(2): 366- 372.
• McCain, C. M. (2007). Area and mammalian elevational diversity. Ecology, 88 (1): 7686.
• McCallum, M. L. (2007). "Amphibian Decline or Extinction? Current Declines Dwarf Background Extinction Rate". Journal of Herpetology 41 (3): 483€“491.
• Monney, K.A., Darkey, M. L and Dakwa, K. B. (2011). Diversity and distribution of amphibians in the Kakum National Park and its surroundings. International Journal of Biodiversity and Conservation Vol. 3(8), pp. 358-366
• Nagy, L. & Grabherr, G. (2009). The biology of alpine habitats: Oxford University Press, USA.
• Naniwadekar, R. & Vasudevan, K. (2007). Patterns in diversity of anurans along an elevational gradient in the Western Ghats, South India. Journal of Biogeography (J. Biogeogr.), 34: 842-853
• Ntiamoa-Baidu, Y., Owusu, E.H., Daramani, D.T. & Nuoh, A.A. (2001) Important Bird Areas of Ghana. In: L.D.C. Fishpool & M.I. Evans (Eds.). Important Bird Areas in Africa and Associated Islands: Priority Sites for Conservation. Pp. 367-389
• Owusu E.H., (2010), Community based conservation in Ghana : A case of local Management of the Afadjato and Agumatsa forest conservation in Ghana In: Natural Resources in Ghana: Management, Policy and Economics (eds. D. M Nanang nad T.K Nunifu,), pp 183-203, nova publishers
• Patterson, B.D., P.L. M Eserve & B.K. L Ang. (1989). Distribution and abundance of small mammals along an elevational transect in temperate rainforests of Chile. J. Mamm. 70:67-78
• Pounds, J. A., Fogden, M. P. L. & Campbell, J. H. (1999) Biological response to climate change on a tropical mountain. Nature 398, 611€“615. (doi:10.1038/19297)
• Rahbek, C. (1995). The elevational gradient of species richness: a uniform pattern? Ecography, 18 (2): 200-205.
• Rahbek C, Graves GR (2001) Multiscale assessment of patterns of avian species richness. Proc Natl Acad Sci USA 98:4534€“4539
• Scott, N. J. 1976. The abundance and diversity of the herpetofaunas of the tropical forest litter.
• Biotropica 8: 41-58
• RÖDEL, M.-O. & R. ERNST (2004): Measuring and monitoring amphibian diversity in tropical forests. An evaluation of methods with recommendations for standardization. €“ Ecotropica, 10: 1- 14.
• Rödel, M. O, Gil M., Agyei A.C., Leache, A.D., Diaz, R. E., Fujita, M. K, Ernst, R. (2005). The amphibians of the forested parts of south western Ghana. Salamandra, 41: 107-127
• Whittaker, R. J., Willis, K. J. & Field, R. (2001). Scale and species richness: towards a general, hierarchical theory of species diversity. Journal of Biogeography, 28 (4): 453 470.