Altitudinal zonation of tree communities along climate and soil gradients in the East African biodiversity hotspot

Document Type : Research paper


Department of Ecosystems and Conservation, Sokoine University of Agriculture, Morogoro, Tanzania


Using climate and soil parameters, zonation of tree communities and species associations were classified along altitudinal gradients of Amani Nature Reserve (ANR) and Udzungwa Mountains (UMF). The plots were sampled from the two mentioned sites and classified separately. In addition, tree communities were named based on dominant and diagnostic species. Along climate gradient, four and five distinct plant communities were identified in ANR and UMF respectively. The communities consisted of typical Miombo species in the lowland forests (lower slopes) of the UMF. Zonation of the tree communities corresponded to a range of edaphic factors. The communities of ANR responded to sand, loamy sand, and sandy clay soil types, while in UMF the communities correlated with sandy loam and loamy sand soil types. All communities correlated with acidic soils in ANR and UMF. This study advances the understanding of drivers of plant community distribution in EAMs and other tropical ecosystems. Variation findings reported in some of the previous studies might be due to different sampling approaches and variables (environmental factors) used in the analysis.

Graphical Abstract

Altitudinal zonation of tree communities along climate and soil gradients in the East African biodiversity hotspot


  • Climate role in the vegetation of wet Montana forests is important.
  • Altitudinal zonation of tree communities along climate and soil gradients was studied.
  • All studied communities correlated with acidic soils in ANR and UMF.
  • Variable results might be due to different sampling approaches and environmental factors used.


Main Subjects

Ashton, P.S., 2003. Floristic zonation of tree communities on wet tropical mountains revisited. Perspect. Plant. Ecol., Evol. Syst., 6, 87-104.
Barelli, C., Mundry, R., Araldi, A., Hodges, K., Rocchini, D., Rovero, F., 2015. Modelling primate abundance in complex landscapes: a case study from the Udzungwa Mountains of Tanzania. Int. J. Primatol., 36, 209-226.
Beck, E., Bendix, J., Kottke, I., Makeschin, F. Mosandl, R., 2008. Gradients in a tropical mountain ecosystem of Ecuador. Springer, 198, 1-542.
Blundo, C., Malizia, L.R., Blake, J.G., Brown, A.D., 2012. Tree species distribution in Andean forests: influence of regional and local factors. J. Trop. Ecol., 28, 83-95.
Brooks, T.M., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A.B., Rylands, A.B., Konstant, W.R., Flick, P., Pilgrim, J., Oldfield, S., Magin, G., Hilton-Taylor, C., 2002. Habitat loss and extinction in the hotspots of biodiversity. Biol. Conserv., 16, 909-923.
Brown, J.H., Gillooly, J.F., Allen, A.P., Savage, V.M., West, G.B., 2004. Toward a metabolic theory of ecology. Ecology, 85, 1771-1789.
Burgess, N.D.,  Butynski, T.M.,  Cordeiro, N.J.,  Doggart, N.H.,  Fjeldså, J., Howell, K.M., Kilahama, F.B., Loader, S.P.,  Lovett, J.C.,  Mbilinyi, B.,  Menegon, M.,  Moyer, D.C.,  Nashanda, E.,  Perkin, A., Rovero, F.,  Stanley,  W.T., Stuart, S.N., 2007. The biological importance of the Eastern Arc Mountains of Tanzania and Kenya. Biol. Conserv., 134, 155-288.
Burgess, N.D., Bahane, B., Clairs, T., Danielsen, F., Dalsgaard, S., Funder, M., Hagelberg, N., Harrison, P., Haule, C., Kabalimu, K., Kilahama, F., Kilawe, E., Lewis, S.L., Lovett, J.C., Lyatuu, G., Marshall, A.R., Meshack, C., Miles, L., Milledge, S.A.H., Munishi, P.K.T., Nashanda, E., Shirima, D., Swetnam, R.D., Willcock, S., Williams, A., Zahabu, E., 2010. Getting ready for REDD+in Tanzania: a case study of progress and challenges. Oryx, 44(3), 339-351.
Currie, D.J., Mittelbach, G.G., Cornell, H.V., Field, R., Guégan, J.F., Hawkins, B.A., Kaufman, D.M., Kerr, J.T., Oberdorff, T., O’Brien, E., Turner, J.R.G., 2004. Predictions and tests of climate-based hypotheses of broad-scale variation in taxonomic richness. Ecol. Lett., 7, 1121-1134.
Givnish, T.J., 1999. On the causes of gradients in tropical tree diversity. J. Ecol., 87, 193-210.
Hawkins, B.A., Diniz-Filho, J.A.F., Weis, A. E., 2004. The mid-domain effect and diversity gradients: Is there anything to learn? Am. Nat., 166, 140-143.
Lieberman, D., Lieberman, M., Peralta, R., Hartshorn, G., 1996. Tropical Forest Structure and Composition on a Large-Scale Altitudinal Gradient in Costa Rica. J. Ecol., 84(2), 137-152.
Lomolino, M.V., 2001. Elevation gradients of species-density: historical and prospective views. Glob. Ecol. Biogeogr., 10, 3-13.
Lovett, J.C., 1999. Tanzanian forest tree plot diversity and elevation. J. Trop. Ecol., 15, 689-694.
Lovett, J.C., Hatton, J., Mwasumbi, L.B., Gerstle, J., 1997. Assessment of the impact of the lower Kihansi hydropower project on the forests of Kihansi Gorge, Tanzania. Biodivers. Conserv., 6, 915-933.
Muenchow, J., Hauenstein, S., Bräuning, A., Bäumler, R., Rodríguez, E.F., von Wehrden, H., 2013. Soil texture and altitude, respectively, largely determine the floristic gradient of the most diverse fog oasis in the Peruvian desert. J. Trop. Ecol., 29, 427-438.
Parmentier, I., Malhi, Y., Senterre, B., Whittaker, R.J., Alonso, A.T.D.N.A., Balinga, M.P.B., Bakayoko, A., Bongers, F., Chatelain, C., Comiskey, J.A., Cortay, R., Kamdem, M.N.D., Doucet, J.L., Gautier, J.L., Hawthorne, W.D., Issembe, Y.A., Kouame, F.N., Kouka, L.A., Leal, M.E., Lejoly, J., Lewis, S., Nusbaumer, L., Parren, M.P.E., Peh, K.S.H., Phillips, O.L., Sheil, D., Sonke, B., Sosef, M.S.M., Sunderland, T.C.H., Stropp, J., Steege, H., Swaine, M.D., Tchouto, M.G.P., van Gemerden, B.S., van Valkenburg, J.L.C.H., Woll, H., 2007. The odd man out? Might climate explain the lower tree alpha diversity of African rain forests relative to Amazonian rain forests? J. Ecol., 95, 1058-1071.
Peña-Claros, M., Poorter, L., Alarcon, A., Blate, G., Choque, U., Fredericksen, T.S., Justiniano, M.J., Leano, C., Licona, J.C.,Pariona,W.,Putz, F.E.,Quevedo, L., Toledo, M., 2012. Soil effects on forest structure and diversity in a moist and a dry tropical forest. Biotropica, 44, 276-283.
Platts, P.J., Gereau, R.E., Burgess, N.D., Marchant, R., 2013. Spatial heterogeneity of climate change in an Afromontane centre of endemism. Ecography, 35, 001-013.
Punyasena, S.W., Eshel, G., McElwain, J.C., 2008. The influence of climate on the spatial patterning of Neotropical plant families. J. Biogeogr., 35, 117-130.
Romdal, T.S., Grytnes, J.A., 2007. An indirect area effect on elevational species richness patterns. Ecography, 30, 440-448.
Slik, J.W.F., Poulsen, A.D., Ashton, P.S., Cannon, C.H., Eichhorn, K.A.O., Kartawinata, K., Lanniari, I., Nagamasu, H., Nakagawa, M., van Nieuwstadt, M.G.L., Payne, J., Purwaningsih, S.A., Sidiyasa, K., Verburg, R.W., Webb, C.O., Wilkie, P., 2003. A floristic analysis of the lowland dipterocarp forests of Borneo. J. Biogeogr., 30, 1517-1531.
Soethe, N., Lehmann, J., Engels, C., 2008. Nutrient availability at different altitudes in a tropical montane forest in Ecuador. J. Trop. Ecol., 24, 397-406.
Tallents, L.A., Lovett, J.C., Hall, J.B., Hamilton, A.C., 2005. Phylogenetic diversity of forest trees in the Usambara mountains of Tanzania: correlations with altitude. Bot. J. Linn. Soc., 148, 217-228.
Tattersfield, P., Seddon, M.B., Ngereza, C., Rowson, B., 2006. Elevational variation in diversity and composition of land-snail faunas in a Tanzanian forest. Afr. J. Ecol., 44, 47-60.
Ter Braak, C.J.F., Prentice, I.C., 2004. A theory of gradient analysis. Adv. Ecol. Res., 18, 271-317.
Ter Steege, H., Pitman, N.C.A., Phillips, O.L., Chave, J., Sabatier, J., Duque, A., Molino, J.F., Prevost, M.F., Spichiger, R., Castellanos, H., von Hildebrand, P., Vasquez, R., 2006. Continental-scale patterns of canopy tree composition and function across Amazonia. Nature, 443, 444-447.
Ter Steege, H., Pitman, N., Sabatier, D., Castellanos, H., van der Hout, P., Daly, D.C., Silveira, M., Phillips, O., Vasquez, R., van Andel, T., Duivenvoorden, J., de Oliveira, A.A., Ek, R., Lilwah, R., Thomas, R., van Essen, J., Baider, C., Maas, P., Mori, S., Terborgh, J., Vargas, P.N., Mogollon, H., Morawetz, W., 2003. A spatial model of tree alpha-diversity and tree density for the Amazon. Biodivers. Conserv., 12, 2255-2277.