Determination of plant species index at different stages of succession in semi-steppe rangelands of Chaharmahal Bakhtiari province

One of the strategies for restoration and reclamation of arid and semi-arid rangelands is introducing t species which is compatible with the characteristics of these areas. This introduction is possible by the recognition, identification and properties of plants in rangeland ecosystems. Understanding the stages of succession and index species in each stage will help us in the proper management of these areas. This study was done in Karsanak rangelands in the Chaharmahal Bakhtiari province in order to recognizes property- plant index first three regions with different sequence including (1) 3-5 years-it was sown and abandoned; (2) 10-15 years; (3) more than 25 years, as well as a control area were selected then the experiment was followed by transecting and sampling by means of systematic random –method in order to determine vegetation percentage. Indicator Species Analysis (ISA) was used to determine the index species in the each steps of the succession. Non-Metric Multi dimensional Scaling (NMS) was used for separating the species groups of each stage. The results showed, that the highest number of index species was related to the sequence of more than 25 years, and the control group; each of them had 10 index species. And this could be the result of vegetation return after removing destructive agents while the lowest number of index species was related to the sequence of 3-5 years with 7 species. Groups of index species of each step were separated by NMS test results it was observed there was a significant difference among four studied - areas in terms of species composition and index species.