The Short-term effect of disturbance on forest structure in Darmazo (Quercus infectoria Oliv.): Shineh Qallaei, Lorestan

The composition and diversity of plant and animal communities change over time due to environmental changes and disturbances. In this study, the impact of short-term disturbance on forest structure in the Daramazu Reserve, located in the Shineh Qallaei region of Lorestan Province, was investigated. For this purpose, 8 forest stands affected by landslides with a total area of 4.5 hectares were identified, and the quantitative and qualitative characteristics of trees (in 4 damage classes) were recorded. Subsequently, changes in tree density, species diversity, and distribution were evaluated. Based on the results, after the disturbance and landslides, half of the trees are in moderate and severe damage classes, and 17.2% of tree bases, as well as 4.1% of canopy cover, have been lost, mostly affecting young trees. Regarding structural indices, species diversity and evenness had a decreasing trend, while the Smith-Wilson index and uniform angle index increased. Despite not observing statistically significant differences in structural indices, the combination of consecutive droughts, irregular and intense rainfall, degradation, and subsequent landslides has led to noticeable changes in the forest structure over a short period of time, and unfortunately, this trend continues. Therefore, it is essential to implement further conservation measures and forest restoration, especially in areas affected by disturbances, to mitigate or halt the destruction of this valuable ecosystem.