Flora, Biological Form, and Geographical Distribution of Plants in the Darabkola Educational and Research Forest

Extended Abstract Background: Identifying and studying the plant species of a region, as a fundamental aspect of ecology, yield insights into biodiversity and the reactions of biological communities to prevailing environmental conditions while also providing a thorough understanding of the evolutionary history of plants and the ecological potential of that area. The Darabkla forest in the southeast of Sari City is one of the forests in the lower parts of the Hyrcanian forest zone. Despite the very high importance of studying the flora of plants, there has not been a detailed and focused study related to the flora, biological form, and geographical distribution of plants in this region and this altitude range of the Hyrcanian forest until now. Therefore, this research aimed to identify and introduce the plant species of the region, especially the floor covering this forest, for optimal management and protection of this natural ecosystem. Moreover, providing information on flora, biological form, and geographical distribution of plants can be a basis for conducting other studies, including plant sociology in the region. Methods: The present study was conducted in the Darabkola educational and research forest (area 2612 hectares) located in watershed 74 of the Natural Resources Organization of Mazandaran Province. This area is located in the southeast of Sari City. To identify and introduce the flora of the region, plant species were collected from the entire study area using the Braun-Blanquet method and 400 square meter sample plots with 400-meter grid dimensions, as well as the field survey method, from the beginning of October 2018 to the end of September 2019. The samples were identified with the Flora Iranica, and the biological forms of plants were determined based on the Raunkiaer classification. Results: In total, 141 plant species belonging to 122 genera and 60 plant genera were identified in the floristic study of the educational and research forest of the faculty of Natural Resources, Sari, Darabkola. The Asteraceae family with 13 plant species, the Poaceae family with 12 plant species, and Lamiaceae, and Rosaceae and Fabaceae families with 9, 8, and 7 plant species, respectively, were introduced as the richest plant families in the Darabkla forest. In total, they include 35% (50 plant species) of all species. The genera Carex with 4 species and Hypericum with 3 species were the most diverse plant genera regarding the number of species in the Darabkla forest. The study of the biological forms of the species in the region using the Raunkiaer method showed that cryptophytes  (28% with 40 species), phanerophytes (26% with 36 species), trophytes (23% with 32 species), and hemi-cryptophytes (21% with 30 species) were respectively the main biological forms of the vegetation composition of the Darabkella forest. Chamaephytes were the rarest biological form in the region (2% with 3 species). The results of the geographical distribution of plant species in the region showed that most of the plant species belonged to the PL region (48 species) and the ES region (34 species), which is more than 58% (n = 81) of the species assigned to themselves. These were followed by the species of ES/IT/M (16 species, 11%), ES/IT (15 species, 11%), COS (15 species, 10%), and vegetation ES/M (11 species, 8%) . The vegetative regions of IT and IT/M, each with one species, showed the lowest presence in the region. Conclusion: As a habitat rich in biodiversity, the Darabkola educational and research forest provides a valuable opportunity for ecological research. The floristic study in this research showed the identification of 140 plant species belonging to 121 genera and 59 families, which shows the high diversity of this region. In particular, Asteraceae, Poaceae, and Lamiaceae were recognized as the richest plant families, which indicates the high compatibility of these species to the environmental conditions of the region. Morphological analysis shows that cryptophytes and phanerophytes, as the two dominant groups, play an important role in adapting to the ecological conditions of the Darabkla forest. These findings can be a sign of the stability of this ecosystem against environmental changes. The geographical distribution of plants also showed that more than half of the species belong to multi-zones and the European-Siberian vegetation zone. This geographical distribution can help better understand ecological patterns and ecological interactions in these forests. Considering the ecological and scientific value of the Darabkla forest, it is necessary to protect this habitat. The implementation of conservation programs to prevent forest destruction, reduce grazing pressure by livestock, and protect biodiversity should be considered the main priorities. These measures not only help preserve forest ecosystems but also provide an opportunity for future research in the field of ecology, forest management, and climate change. In general, floristic identification and analysis is an efficient tool for understanding the status and biodiversity of forests and can be the basis for deeper research in various fields related to ecology and natural resource management.