The Effects of Quercus brantii Lindl. Decline on Forest Structure in the West Iranian Forests

Abstract The deterioration of trees in arid and semi-arid regions within the Zagros forests presents a significant challenge that imperils ecosystem integrity. This study aims to assess alterations in vegetative elements’ structures and the potential provision of biological indicators following the onset of decay in Quercus brantii Lindl. (Persian Oak) over a 10-year period in Lorestan Province forests. To achieve this objective, four distinct regions were identified: three experiencing decline (MelehShabanan, Shineh-Qalaei, and Dadabad) and one unaffected region (Warak). Within each region, a comprehensive resurvey covering a 5-hectare area, with prior information availability, was conducted. Trees were categorized into four classes based on crown condition deterioration. Vegetation cover analysis involved sampling thirty 1.5 × 1.5 m2 plots within each area, utilizing the Brown–Blanquet method to document species characteristics. Subsequently, various forest attributes (e.g., density, species diversity, dimensional diversity, and distribution pattern) were determined and compared across two stages: pre- and post-deterioration occurrence. The results indicate non-significant disparities in species diversity, dimensional diversity, and distribution pattern categories. Ecological species analysis delineated three distinct groups, classified as herbaceous species, with one group observed exclusively in the undeteriorated area, while two were identified in the deteriorated zones. Diversity indices analysis revealed significant distinctions between the deteriorated regions and the control area. The observed impacts on forest stand density and quality in the deteriorated areas are indicative of severe warnings. Without intervention or alteration of current conditions, forest regression rates are likely to intensify. Cite this article as: Akhtari, M., Mataji, A., Babaie Kafaki, S., & Kiadaliri, H. (2025). The effects of Quercus brantii Lindl. decline on forest structure in the west Iranian forests. Forestist, 75, 0063, doi:10.5152/ forestist.2024.23063.