Background and objectives: Background and objectives: Understory vegetation in forests directly interacts with the type and ecological conditions of forest stands and plays a vital role in maintaining ecological balance. Therefore, identifying and studying the flora of the understory is essential. This study aimed to investigate and identify the similarities and differences in plant species, their life forms, and chorological characteristics in different Persian oak stands within the protected forests of Ghalaje, Kermanshah Province.
Materials and methods: The forest stands were categorized based on their regeneration forms (high stand, coppice stand, and high–coppice stand). Subsequently, in each stand, three one-hectare sample plots were randomly established. The structural attributes of all trees and coppice groups were measured and recorded, including species identity, growth form, number of sprouts per coppice group, diameter at breast height (DBH), tree height, dominant height of coppice groups, and two perpendicular crown diameters. For the assessment of understory vegetation, ten 100 m² subplots were randomly selected within each main plot, and four 1 m² quadrats were established at the corners of each subplot.
Results: The results showed that a total of 146 vascular plant species belonging to 35 families and 104 genera were identified in the understory. Of these, 124 species from 33 families and 88 genera were found in coppice stands, 103 species from 31 families and 83 genera in high–coppice stands, and 108 species from 33 families and 83 genera in high stands. Analysis of life forms using Raunkiaer’s method indicated that therophytes were dominant in all three stands, while phanerophytes had the lowest representation. In all stands, dicotyledons constituted more than 75% of the plant species. Chorological analysis using Zohary’s approach showed that, in coppice, seed–coppice, and seed-origin stands, respectively 25%, 25.71%, and 30% of the species belonged to the Irano-Turanian region; 30.6%, 30.5%, and 32.7% occurred in two phytogeographical regions; 20.9%, 22.8%, and 16.8% occurred in three regions; and 22.5%, 20%, and 21.6% were multi-regional elements. Cosmopolitan species accounted for less than 1% in all three stands. Overall, the findings suggest that the Persian oak stands in the study area show no considerable differences in species richness, life-form composition, phytogeographical distribution, or family representation.
Conclusion: Overall, the results indicate that the differences in floristic composition, life-form structure, and sub-canopy chorological patterns among the different oak stands in the Ghalajeh Protected Area reflect habitat homogeneity and the relative stability of ecological conditions in the region. The dominance of therophytes across all stands demonstrates the vegetation’s adaptation to dry and semi-arid climatic conditions and seasonal fluctuations. This feature can also serve as an indicator of the ecosystem’s response to environmental stress, and this dominance was higher in the coppice stands than in the other stands.
