Determination of environmental factors affecting the distribution of plant species in northern Zagros forests (Case study: Armardeh Forest, Baneh)

Northern Zagros forests are one of the most important ecosystems in Iran from ecological and socio-economic points of view. This study was done to determine the most important gradients affecting on plant species distribution by using ordination methods. Environmental variables including inclination, slope aspect, elevation, litter depth, bare soil percentage, soil organic carbon, available P, K, N, soil texture, pH and EC were measured in 60 plots along with vegetation data and canopy cover. Redundancy detrended analysis (RDA) was performed to identify the main environmental gradients. 90 plant species belonging to 75 genus and 32 families were determined. Species belonging to Asteraceae, Apiaceae, Poaceae, and Fabacea families had the most contribution in floristic composition. RDA results showed that with considering spatial autocorrelation of sample plots as covariate, slope aspect, litter depth, canopy cover, C/N, elevation and outcrop explained 30% of the total variations in floristic composition. The results of this study can be used to do more efficient management of these fragile ecosystems.