an application of fuzzy topsis method for plant selection in rangeland improvement (case study: boroujerd rangeland, lorestan province, iran)

species selection based on a new method such as a fuzzy method is one of the most important stages in the successful plantation management planning as choosing a suitable species for the site can be the key to success. this paper is based on a fuzzy extension of the technique or order preference which is similar to ideal solution (topsis) method. the purpose of this paper is to develop fuzzy topsis method to improve the quality of decision making for species selection. for this propose, the selection of range species was done using fuzzy-topsis techniques in 2012 in sarab sefid rangeland in boroujerd, lorestan province, iran. in this method, the ratings of various species versus subjective criteria and weights of all criteria were assessed by linguistic variables represented by fuzzy numbers. fuzzy numbers try to resolve the ambiguity of concepts that are associated with man judgments. a set of pre-defined linguistic variables parameterized by triangular fuzzy numbers was used by the group to evaluate the weights of various criteria and the ratings of each species. to determine the order of species, the closeness coefficient was defined by calculating the distances to fuzzy positive ideal solution (fpis) and fuzzy negative ideal solution (fnis). finally, for the application and verification, an empirical study was performed to demonstrate the model and identify the suitable species. results show that fuzzy-topsis method is useful for species selection decision making and the proposed system can provide accurate results. based on this method, bromus tomentellus was the best species from frequency viewpoint for the range management.