Asian Journal of Biological Sciences1996-3351xxxx-xxxxScience International10.3923/ajbs.2009.21.28HeydariM. MahdaviA. 1200921The aim was to study biodiversity of plant species including
trees, shrubs and grasses in related to physiographic factors (aspect,
elevation above sea level and slope percentage) in Melah Gavan protected
area from northwestern Ilam province, Iran. The field data were collected
using a number of 67 field plots in a systematic randomized design (each
covering 20x20 m). The characters including tree and shrub species type,
number and canopy coverage were recorded by measuring their small/large
diameters in each plot. In order to record the herbaceous species, the
Whitaker′s snail plot method was applied and the minimum plot area
81 m2 was determined. Based on the results, there are two tree
species, one Shrub and 74 Grasses (belonging to 71 genus and 29 families)
in the study area. The family Poaceae and the genus Euphorbia sp.
form the most existing plants as well as Therophytes cover (51%)
the most vegetative form in the area. The results obtained from multivariate
Duncan test showed that the biodiversity is maximum in southern aspect
and minimum in eastern aspect. Moreover, plant richness was the most in
southern aspect while it was not significantly different in the other
aspects. Investigation of biodiversity and richness amongst the altitude
classes showed that the low altitudes (1400-1500 and 1500-1600 m ranges)
have the most, while the upper altitudes (1800-1900 and 1900-2000 m ranges)
have the least diversity. The ANOVA results also showed that the slope
percentage had a significant effect on biodiversity and richness of plants.
The results obtained from multivariate Duncan test showed that the biodiversity
and richness are maximum in 0 - 25 slope percentage.]]>Petragilia, A. and M. Tomaselli,2003627178Badano, E.I., L.A. Cavieres, M.A. Molina-Montenegro and C.L. Quiroz,20056293108Barnes, B.V., D.R. Zak and S.H. Spurr,19984th Edn.,pp: 774pp: 774Basiri, R.,2003Quercus libani site by analyzing environmental features in Marivan.]]>2003Boll, T., J.C. Svenning, J. Vormisto, S. Normand, C. Grandez and H. Balslev, 2005213175183Daubenmire, R.F.,197642115143Enright, N.J., B.P. Miller and R. Akhter, 200561397418Chai, M.F. and M. Marvie, 2004shrub species of northern Iran.]]>582535 (In Persian)Fu, B.J., S.L. Liu, K.M. Ma and Y.G. Zhu,20042614754Grytnes, J.A. and O.R. Vetaas, 2002159294304Heydari, M.,20062006Hegazy, A.K., M.A. El-Demerdash and H.A. Hosni, 199838313Jazerehei, M.H. and M. Ebrahimirastaghi,20031st Edn.,pp: 560 (In Persian)pp: 560 (In Persian)Marsh, W.M., 19914th Edn.,pp: 472pp: 472Moustafa, A.E.R.A. and A. Zayed, 199632431443Nuzzo, V.A., 199674607617Perring, F.,195947447481Rikhari, H.C. R.S. Singh and S.K. Tripathi,199117174176Saberyan, G.R.,20002000Sebastia, M.T.,20045331346Shannon, C.E. and W. Weaver,19491st Edn.,Pages: 117 Pages: 117 Shmida, A. and M.V. Wilson, 198512120Christine, J.S. and B.C. McCarthy,2005217229243Sohrabi, H., 200321280293 (In Persian)Tabatabaei, M. and F. Ghasriani,19921st Edn.,pp: 570pp: 570Baker, M.E. and B.V. Barnes,19982814051418