Nazimova et al. Biodiversity of chern forest ecosystems in the perhumid climate of the Sayan mountains. In: The East Asian Flora: and its role in the formation of the world’s vegetation

Biodiversity of chern forest ecosystems in the perhumid climate of the Sayan mountains

Dina NAZIMOVA¹, Dilshad DANILINA¹, Nikolay STEPANOV² & Elena BORISOVA²
¹ Sukachev Institute of Forest SB RAS, Krasnoyarsk, Russia
² Siberial Federal University, Krasnoyarsk, Russia

The biodiversity of chern mixed forest and chern taiga of the Sayan mountains have been investigated since 1960 and especially the past decade. Diversity of formations, forest types and series is viewed in charts of climatic ordination and in maps of test areas, made with the help of GIS. To estimate climatic indices of forest vegetation belts, special climatology investigations were conducted. The most important determinant of the distribution of mountain forest ecosystems is that of altitudinal differences of climate which are comparable with zonal ones and even exceed them. Formations of chern forests (with Pinus sibirica, Abies sibirica, Populus tremula but no Picea obovata) represent a separate class of ecosystems which occupy a specific place on the transition line of boreal and cool-temperate orobiomes within Altai-Sayan ecoregion: it is characterized by some unique features of biogeography, physiognomy and functioning under different warmth supply (1800-1200° growing-degree day). Forests are wet enough (700-1500 mm precipitation per year) to qualify them as barrier rainforest ecosystems located on windward slopes of West and East Sayan (350-1300 m a.s.l.). These forests represent relic biota of modern refugia that occur locally also in low-and mid-elevation mountains of Altai and Salair-Kuznetskiy provinces. Some features of structure are similar to Far Eastern subnemoral coniferous forest ecosystems, in spite of differences in Quaternary history and modern regime of climate. Most nemoral species occurring in these forests (Brunnera sibirica, Galium odoratum, Cruciata krylovii, Daphne mezereum, Festuca altissima, Frangula alnus, and Stachys sylvatica) belong to European and / or Mediterranean flora at the eastern edge of their distributions. However, some Tertiary relicts (Anemone baicalense, Menispermum dahuricum and Waldsteinia ternata) are of East Asian origin. The data base on 560 vascular species forming the chern forest communities contains original data on their occurrence, and on the species belonging to taxonomic, areal, zonal, biomorphological, ecological groups.