Detection of high potential areas of Persian oak forests decline in Zagros, Iran, using topsis method

Abstract

Background: During the past decade, the phenomenon of Oak decline has affected valuable Zagros Oak Forests in western Iran. Quercus brantii as the most important tree species of these forests has been damaged more than any other species. Many factors are involved in this phenomenon. The purpose of this study was to identify areas with high potential for decline and determine the most important factors affecting it. In this study, using multi-criteria evaluation methods based on the Geographic Information System (GIS) Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method and fuzzy logic, the map of decline potential of two selected stands (Dalab and Cheghasabz) in Ilam Province was prepared to reveal the highrisk areas of decline. The analytical hierarchical process was used to determine the weight of the factors. Results: The results showed that both selected stands had decline potential. However, the Dalab stand at 25% and the Cheghasabz, at approximately 60% of the stand has an extreme potential for decline. Rainfall factors, pests, and diseases also have the greatest effect on Oak forest decline. Conclusion: Due to socio-economic problems such as land use change, fire, tourism, grazing, and pruning, the Cheghasabz is more prone to decline than the Dalab, which was a forest reserve. The multicriteria evaluation model used in the study can be a guide in identifying high-risk areas in other parts of the Zagros forests. The large area of critical areas in these two regions reveals the need for planning to implement support operations to reconstruct damaged ecosystems.