Comparison of some effective environmental factors on distribution of Dactylis glomerata L. and Thymus kotschyanus Boiss and Hohen. in South of Ardabil province

The purpose of this study was to identify the effects of environmental factors on the distribution of Dactylis glomerata and Thymus kotschyanus in rangelands of Khalkhal and Kosar counties in southern part of Ardabil province. From 111 determined sites random- systematically using five 1m2 plots along a 40 m transect samples were collected. In all sites environmental factors including stone and gravels, bare soil, litter and density of selected species were recorded. Soil samples were taken from the 0 to 30 cm of soil surface of each transect. Soil parameters including pH, OC, K, P, EC, Sand, Clay, and Silt were measured. One way ANOVA was used to study the relationship significance between the effective environmental factors on the presence and absence of the selected species. Duncan's test was used to compare the measured factors. To determine the importance of measured variables on the distribution of selected species and grouping of sampling sites discriminant analysis was used. According to the results of the discriminant analysis, tow functions were explained 77.8 and 22.2%, respectively and totally 100% of the data variance and generally 94/6% of grouped cases, correctly classified. Finally, results demonstrated that EC, litter, precipitation, temperature, elevation, K, silt and bare soil are the most important factors on the distribution of D. glomerata and T. kotschyanus. By considering the results in introducing these species for rangeland restoration and management the appropriate decision could be made.