Typological and Floristic Diversity of Fir Stands in the Teberda National Park

The paper presents the results of a study of the floristic and typological diversity of forests with the participation of Abies nordmanniana in the Teberda National Park (North-West Caucasus). Geobotanical descriptions have been carried out on visually homogeneous sample plots measuring 30×30 m using standard methods adopted in geobotany and forest inventory. When classifying forest vegetation, an ecological and phytocenotic approach has been used. Based on the data from the survey of forest areas of the Teberda National Park, a typological scheme of forests with the participation of Nodmann fir has been compiled, and their geobotanical and inventory characteristics have been carried out. The forests under study are represented by 6 groups of forest types, including 11 forest types. 120 species of vascular plants have been identified, belonging to 98 genera and 50 families. The families with the largest number of species are Asteraceae – 13, Rosaceae – 8, Apiaceae – 7, Lamiaceae and Poaceae – 6 each. The distribution of fir stands, in which Betula litwinowii and Populus tremula are significantly involved, has been revealed – fir forests of the wood sorrel, alchemilla-fern and woodruff-fern types, which is due to both the economic load on the indigenous forests of the Teberda National Park and the proximity of the communities to the upper altitudinal boundary of the forest. The presence of reed-green moss and hazel-forb pine forests in the forest cover, which include a significant participation of fir, confirms that the forests of Karachay-Cherkessia represent a zone in which the coniferous forests of the Western Caucasus smoothly merge into the coniferous forests of the Central Caucasus, characterized by a more continental climate. A comparison of the typological diversity of fir forests in the Teberda National Park and other regions of the North Caucasus and Transcaucasia indicates a decrease in variability with a shift in the “spectrum” towards mixed forests in the Teberda National Park. An assessment of the floristic diversity of the living ground cover of the identified forest types has been carried out using the dominance, Shannon, Simpson, Margalef and Menkhinik indices. The floristic diversity of the ground cover in the communities is high, with the exception of medium- and highly closed areas of woodruff-sorrel and wood sorrel fir forests, where insufficient insolation results in low species richness. In reed-green moss pine forests and reed fir forests, the indices of species diversity take on lower values, which is caused by the dominance of one species (Calamagrostis arundinacea) in the ground cover.