ffective ecological Factors in the Distribution and Diversity of Astragalus verus and Astragalus glaucops in West of Iran

The objective of this research was to study the relationships between environmental factors and distribution of Astragalus verus and Astragalus glaucops in order to find the most effective factors in the distribution of Astragalus verus and Astragalus glaucops in west of Iran. Sampling of soil and Floristic composition were performed with Eco-phytosociology method. Floristic composition data including density and cover percentage were estimated quantitatively within each releve, and using Anaphyto (F.C.A, A.H.C and Boules optimmsees methods), and Floristic composition was classified into different groups. The topographic conditions were recorded in releve locations. Soil samples were taken in 0-30cm depth in each releve. The measured soil variables included texture, acidity (pH) and electrical conductivity (EC). Multivariate techniques including Factorielle Correspondence Analysis (F.C.A), Principles component Analysis (PCA) and Canonical Correspondence Analysis (CCA) were used to analyses the collected data. The results showed hat the Astragalus verus and Astragalus glaucops distribution pattern was mainly related to elevation. Totally, considering the habitat conditions, ecological needs and tolerance range each both species has a significant relation with elevation and soil properties.