Habitat characteristics effective in the distribution of exclusive and gypsum species in western Semnan

Digging a large number of gypsum mines in the west of Semnan has caused the removal of native western Iran gypsum species from habitats. In this regard, limited studies on the ecological compatibility of species in such habitats have been conducted in order to be able to take effective and extensive scientific actions to "protect", "rehabilitate" and "exploit" rangeland ecosystems as three components of the approach related to rangeland management. In this regard, soil and plant sampling was performed in 38 stations and 115 plots at different altitudes in a hypothetical triangle between Lasjerd and Mo'menabad at low altitudes and Aftar at higher altitudes. Soil pH, electrical conductivity of EC and other soil characteristics were analyzed. CCA internal correlations were used to assess the importance of environmental variables.  The results of the study of the relationship between the distribution of gypsum species with the topographic and soil characteristics of the mentioned habitats indicate that height, amount of gypsum with sodium content, electrical conductivity (EC) and acidity (pH), have an effective role in adaptability and survival of gypsum species. Four habitats of After, Lasjerd and Mo'menabad, calcareous and saline were identified in the studied area.