Preliminary results of forest structure monitoring in Zagros Vegetation Area

Measurement and monitoring of structural characteristics of forest stands are essential for studying the dynamics of vegetation, as well as planning forestry interventions such as silvicultural operations and restoration activities. This research, conducted within the framework of the comprehensive Zagros Forest Monitoring and Assessment Program, aimed to evaluate the structure of forest stands in the growth area of Zagros, using a total of 34 one-hectare sample plots designed through a location-based monitoring approach. In each location, a randomly selected square-shaped one-hectare sample plot was established. The results demonstrated that the total number of tree and shrub species ranged from a minimum of 1 to a maximum of 6 species, with a density ranging from 18 to 924 stems ha-1. Regarding the tree species composition, the maximum number of branch base stems was 826, and branch base stems were dominant in most sites. The average diameter of branch shoots ranged from 3 to 69 cm, while tree heights ranged from 3 to 10.8 m. Furthermore, the study revealed that the uniform angle index value ranged from 0.469 to 0.086 across different sample plots, indicating a scattered pattern in all stands. The composite index value ranged from 0.2 to 0.5, suggesting that most stands are in a fair to moderate condition in terms of stability. Monitoring the temporal changes in structural characteristics of the studied stands through repeated measurements in the future phases will provide valuable insights into Zagros Forest stands.