Effects of grazed exclosure on some of nutrient elements of aerial and underground organs of Artemisia sieberi , Stipa hohenacheriana and Salsola rigida

Abstract Grazing management is increasingly aimed at the restoration of rangelands ecosystems. Animal grazing is a global, dominant land use covering more than 25% of the terrestrial surface of the globe and a larger geographic area than any other land use. Overgrazing reduces the usefulness, productivity, and biodiversity of the land and is one cause of rangelands degradation, desertification and erosion. One of the methods of rangelands management and improvement is Exclosure. Exclosure is one of the simplest methods of rangelands improvement. It is considered as an alternative to restore vegetation in degraded rangelands in this region. We studied the effects of 20 years of rangeland exclosure on some of nutrient elements of Artemisia sieberi, Stipa hohenacheriana and Salsola rigida in Roodshoor region, Saveh, Iran. Sampling in exclosure and control treatments was conducted using a systematic randomized method. Four 300-m long transects were randomly located in each area. Plant organs sampling was conducted in first, middle and end of each transect. In both grazing exclusion and control sites two, plant organs samples were taken from aerial (herbage) and underground (roots) organs. Samples in the laboratory were placed in the oven for 24 hours. Then the samples were milled. The plants samples for each organ per site were analyzed in the laboratory of the department of Natural Resources, Tehran University, Iran. In general, results of this study were showed livestock grazing exclosure had no significantly effects on nutrients of NPK and C in plants Salsola, Stipa and Artemisia. Grazed exclosure increase amounts of Na, Ca and Mg on organs of these plants.