Zoning of Decline Potential of Persian Oak by TOPSIS Technique and the Factors Affecting it in Ilam Forests

Over the past decade, the decline phenomenon has affected the valuable forests of this tree in the Zagros region in western Iran. Persian Oak as the most important tree species has been damaged more than any other species. On the other hand, many parameters are involved in this phenomenon. The purpose of this study is to identify areas with high potential for deterioration and determine the most important parameters affecting it.

For this purpose, in this study, using multi-criteria evaluation methods based on GIS - TOPSIS method - and fuzzy logic, in June 2019 the zoning map of decline potential was prepared for the two selected stand of Dalab and Chaghasabz in Ilam city to reveal areas with high risk of decline. Hierarchical analysis process (AHP) was used to determine the weight of the parameters.

The results showed that in Dalab %25 and in Choghasbz about %60 of the stand area as the center of potential for decline, but both selected stands had the potential for decline at all levels. Chaghasabz is more prone to decline due to socio-economic problems. Also rainfall, pests and diseases and socioeconomic parameters have the greatest impact on Oak decline.

These results confirm the need for greater focus of area management on the design of strategic protection plans.