CHANGES OF VEGETATION STRUCTURE AND BIOMASS IN RESPONSE TO THE LIVESTOCK GRAZING IN STEPPE RANGELANDS OF IRAN

This paper provides basic information on the response of steppe rangelands to different grazing regimes in steppe rangelands of Saveh, Iran. Data were collected from four rangelands including: a: Exclosure: for four years, b: Nemati Rangeland: rotation grazing system for six months, c: Chagneh Rangeland: continuous grazing for 6 months and d: Shirali Rangeland: continuous grazing throughout the year. Collected data included species composition, canopy cover percentage, production, and species height. Our results showed that continuous grazing throughout the year had negative effect on species composition and production, as the class-III species formed the main composition of Shirali Rangeland. On the other hand, exclosure for four years increased the canopy cover percentage and production of the species with a positive effect on rangeland. However, grazing management plans should include economic and biological considerations. Consequently, rotation grazing system and observing the grazing capacity could have positive effects on the vegetation and soil of rangelands.