Stepanov. Endemism of boreal rainforest regions of the Sayan mountains. In: The East Asian Flora: and its role in the formation of the world’s vegetation

Endemism of boreal rainforest regions of the Sayan mountains

Nikolay STEPANOV
Siberian Federal University, Krasnoyarsk, Russia

The level of endemism of flora characterizing the humid areas of Sayan mountains (area occupied by boreal rainforests) is highly unusual. Of the total 849 species in the Western Sayan over 15 % are endemic. Among the many endemic relic species, indicating the age of the flora, are Chrysosplenium filipes, Ch. ovalifolium, Ch. sedakowii, Fritillaria dagana, Brunnera sibirica, etc. However, much of species are neoendemic, recently separate from the mother taxa. These include: Corydalis sajanensis, Betula rotundifolia, Pilosella kebeshensis and among several others. The endemic chorological structure is dominated by species common throughout South Siberia (12 %). Noticeably fewer local taxa: endemic of Western Sayan, Altai-Sayan and others make up just over 3 %. According to zonal-structure of flora alpine endemics (30 %) predominate, penetrating from highlands to the woodlands, and sometimes in the lower zonebelts: Veronica sajanensis, Aconitum tanzybeicum, Aquilegia borodinii etc. Quite rich are nemoral (20 %) montane (16 %) and light-coniferous-forest (10 %) zonal groups. A similar pattern is observed in the East Sayan. In general, a complex structure and richness of endemic species points to a long and complicated history of the formation of rain forest flora of Sayan.