Change in the group species of plants in relation to environmental and management factors in the Zagros mountainous ecosystems (Case study: Baneh)

This study was conducted to analysis the changes in plant group species (PGS) in relation to environmental and management factors in mountain rangelands of Baneh-Kurdestan, Iran. For this purpose 4 plant group species: shrub, forb, grass and shrub-forb (3sites for each PGS) were defined in the study area. There were established 30 plots (2m2) in each site via classified random method. Also in the center of plots we had 10 soil profiles into sampling in each site. All of vegetation, soil and topography and management (grazing intensity) factors were measured in the plots (in total, 90 plots and 30 soil samples for each PGS). Principal component analysis (PCA) showed that first and second axes, in total, explain 73% of changes in the traits of plant group species. Two PGS of forb and shrub-forb are directly related to clay, organic matter, nitrogen, soil depth, potassium, silt 1th, and the first depth and electrical conductivity 2th and northern aspect. Grasses affected by silt 2th, pH, CaO 2th, southern aspect and shrubs are related to sand, gravel (surface and below ground), southern aspect and grazing intensity. On the other word, topography, grazing intensity, nitrogen, organic matter and soil physical factors were the most important factors in the separation of plant group species. The plant group species that had different functional groups (Shrub and forb) had more production and coverage.