Introduction: Landslides are a common natural phenomenon in forests and are affected by factors such as topography, geological structure, soil depth and texture, humidity, climate, etc. The present study, which was conducted in Hyrcanian forests, investigates the impact of disturbance caused by landslides with a small depth and extent on vegetation cover compared to adjacent areas and the process of vegetation recovery (tree and herbaceous) in the short term.

Material and Methods: This study was conducted in the Zalem-Rud Neka forest and in two landslide areas with ages of nine and eleven years. Which were respectively named A and B and the adjacent two areas as controls named AC and BC. For vegetation sampling, 20 sample plots in each designated area and the plants within them were identified and counted. Diversity and evenness were analyzed with four Shannon-Wiener, Dominance, Equitability and Simpson richness measures.

Results: The results showed that tree and herbaceous species were affected by the landslide compared to the control areas, and the landslide caused a change in the flora and dominance of herbaceous species. The effect and correlation between diversity indices and species and the effect of different ages on each other were also examined using PCA. The results showed that there is a strong correlation between diversity indices and tree species and the total number of tree plants. In the examination of the eigenvectors, the number of tree plants and the Shannon index were in the first component, which indicates the greatest impact of the landslide. In the PCA analysis, it was also determined that area B was closer to the vector center than area A, which indicates an improvement in the indices compared to the landslide area A.

Conclusion: In the short term, despite the observed improvement in vegetation restoration and recovery in terms of biodiversity indicators, there is still a statistically significant difference between landslide areas and control areas in terms of forest regeneration and restoration of valuable native forest species and tree cover in the landslide area. However, the Shannon-Wiener, Simpson, Dominance, and Equability biodiversity indices have been severely affected by the landslide disturbance due to changes in the number and type of species, which indicates a decrease in the number of tree species in disturbed areas and a significant increase in herbaceous species in landslide areas compared to control areas.