The investigation of some Environmental Factors affecting on Thymus kotschyanus Boiss in Polur Summer rangelands

In this research, habitat of Thymus kotschyanus was studied ecologically. This species hasspread into an area of 4600 ha within Polur in Mazandaran province and the relation between T. kotschyanus with some environmental factors (soil characteristics, slope, aspect and elevation) and the most important effective factors was investigated. Sampling method was randomized-systematic and vegetation types were studied by physiognomic- floristicmethod in the field. Within each unit along three 100 meter transect 10 plots (1m2) established along each transect in 10 meter distances. Three soil samples in each area collected in 0-30 cm and parameters such as N, P, organic material, pH, EC and texture were determined. To compare the mean canopy cover and density of T. kotschyanus between elevation and slop classes and different aspects interactions, multi-way analysis of variance was used and to compare means of interior classes of factors and existence significant difference among them, one-way analysis of variance and homogeneity Duncan test with software SPSS was employed. Results showed that topographic factors and their interaction effects and soil characteristics in different aspects had significant effect on cover percentage and density of T. kotschyanus. The maximum of canopy cover percentage and density of T. kotschyanus respectively related to western and eastern aspect, slope class of >45 and elevation of 2200-2500 m, changes of canopy cover had the most relationship to OC, N, pH and P. changes of density had the most relationship to EC, litter and stone.