Study of Effective Environmental Factors on Distribution of Plant Communities in Middle Taleghan Basin

The main objective of this study was to classify the plant communities and the most effective environmental factors on distribution of plant communities in Taleghan region. To achieve these objectives، plant sampling was done by randomized–systematic method in index region of each vegetation type. Plot and sample sizes were determined by minimum area and vegetation cover changes، respectively. Then، vegetation cover classification was performed by TWINSPAN analysis. In order to study the effects of soil properties on distribution of plant communities، at the first and end of every transect، soil sampling was done and soil factors in depth of 0-30 centimeter including soil texture، phosphorous، potassium، nitrogen، lime، pH and EC were measured. Principal component analysis (PCA) indicated that there is significant relation between distribution of plant communities and environment factors. Also، the result showed that aspect of slope، elevation، soil texture، lime and potassium percentages، and soil depth have meaningful impacts on distribution of plant communities.