The estimation of forage yield in three rangeland plant species withregard to their height, canopy cover and volume plant in shrublands dry area (Case Study: SorkhDeh, Damghan shrublands, Semnan Province)

One of the goals of targets ecologist is to determine accurate, fast and low cost method to determine the yield of rangeland plants which are interesting for them and the lencwledge of the amount of vegetation changes. Measurement of vegetation cover is easy but measurement of yield in plants is difficult. The aim of this research is to determine the relationships between variables vegetation cover with dominated and important shrubs yeild in dry rangeland of Sorkhdeh of Damghan provice. First 30 individual of 3 species of Artemisia aucheri, Salsola dendroides and Salicornia herbacea with different size. Were selected therefore small and large diameter variables and height of species were calcutated. The present yield was measured by clipping and weighting method. Regression relationship was determined between the independent variables including height, canopy cover and volume shrubs and dependent variable including yield. Regression analysis showed that there ware significant line relationship between independent variables and dependent variables in all species. Result according to information of models and coefficient of determination showed that variables of vegetation cover of species of Salsola dendroides and Salicornia herbacea well can be estimated yield in species we can develop this model in the study area. But this model of information of Artemisia aucheri cannot be estimated yield in the study area.Therefore this models cannot be developed and suggested in the study area.