Introduction: Vegetation, as one of the main components of ecosystems, plays an important role in explaining other ecosystem functions and is always dynamic. Understanding vegetation and monitoring it is key and important for understanding the relationships between ecosystem components. Given the limited studies conducted on vegetation monitoring in Irano-Turanian forests, the present study investigates this issue in Juniperus excelsa M.B. forests in Parvar Protected Area, Semnan Province.
Materials and Methods: To carry out the present study, two permanent one-hectare square-shaped sites in this area were considered. In each of the sites, vegetation study and monitoring were conducted using 16 micro-plots (with dimension of 2×2 m) within 4 sample plots (with dimension of 10×10 m). Vegetation data were collected in mid-May and in two years 2022 and 2024. Quantitative and qualitative characteristics of vegetation including area, species composition, life form, density, frequency and biodiversity indices were calculated and analyzed. Comparisons of the studied variables were performed using the Friedman and Wilcoxon non-parametric tests.
Results: According to the results, the vegetation area at both sites in 2024 was significantly higher than in 2022. In the first site, 68 plant species were identified, belonging to 53 genera and 21 plant families. The Poaceae family was the largest plant family with 9 species. Thirty-eight percent of the species had a hemicryptophyte life form, 32 percent were annual plants (therophyte) and 18 percent were camophyte (shrubs). At the second site, 76 plant species were identified, belonging to 58 genera and 19 families. The families Caryophyllaceae, Asteraceae and Lamiaceae were the largest plant families with 9 species each. Thirty-nine percent of the plants were therophyte, 35% were hemicryptophyte, 14% were camophyte and 10% were cryptophyte. At both sites, species density in 2024 was higher than in 2022, but the difference was significant only at the first site. At both sites, more than half of the species present were present in less than 20% of the micro-plots. Also, at both sites, the ground cover in 2024 was more diverse and richer than in 2022, which was significant for most biodiversity indices.
Conclusion: The results of the present study confirmed both spatial and temporal changes in vegetation characteristics in the study area. In general, the vegetation cover condition in 2024 was better than in 2022. Repeating the sampling in future years can lead to more accurate and complementary results.