The Effect of Altitude and Aspect on Rangeland Plant Diversity (Case Study: Dashte Zahab, Kermanshah, Iran)

Recognizing the herbaceous plant species diversity could use as an important indicator applied for the rangeland and forests management. Considering the presence of vegetation and animal husbandry in Zagros region, Iran, being aware of the diversity and richness of plant species is necessary to management or the destructed vegetation restoration. In order to study the effect of aspect and elevation on species diversity of herbaceous plants 160 four m2 quadrates were sampled via transect method in the Dasht e Zahab in Kermanshah, Iran. In each quadrate a list herbaceous species plants, altitude and aspect were recorded. After the inventory, the plant diversity indices were calculated and compared in three elevation classes (low: <800 m, moderate: 800 to 1200 m and high: >1200 m) and four aspect classes (North, South, East and West) using Shannon-Wiener diversity and Margalef richness indices. One-way ANOVA was used to investigate the effect of independent variables (altitude and aspects) on dependent variable (species diversity and richness). The results showed a significant effect of aspect and altitude on the diversity and richness of herbaceous plants (P<0.05). The maximum and minimum diversity and species richness were observed on the northern aspect coupled with middle elevation and on the southern aspect with low elevation, respectively.