Effect of Physiographic Factors on Plant Biodiversity in the Central Zagros Forests (Case Study: Educational Forest of Razi University of Kermanshah)

Ecological condition including physiographic factors have impact bon plant species diversity. There for it is necessary to investigate at the ecological condition in other to achieve sustainable development and natural ecosystem conservation. The present study aim is investigate the effect of physiographic factors (altitude and geographic directions) on the biological diversity of plant species in the middle Zagros forests. The investigate was conducted in Research and Education Forest at Razi university located in between the west cities of Kerend Gharb and Sarpole Zahab, in Kermanshah province. The studied area was divided into three elevation class including less than 1000 m, 1000 to 1500 m and more than 1500 m asl. In each class of elevation and direction, respectively 32 and 48 plots of circular shapes of 1000 square meters in random- systematics were taken. In order to study the shrub layer in each circular sample plot, a plot of 25 m2 and a microplate of one square meter to study the herbaceous diversity were taken. The results showed that the highest values of diversity indices for tree, shrub and herbaceous cover in altitudes from (1500-1000) were observed and ANOVA test showed significant different between diversity index in three elevation classes. The results of compare biodiversity index in two main aspect showed that in trees and shrubs layer maximum of diversity index observed in the northern slopes, but for herbaceous layer, maximum of diversity index showed in southern slopes and T-test showed significant different of biodiversity index in two aspect direct.  Overall results showed that the physiographical parameter (Elevation and aspect) are a significant effect on diversity condition.