About relict larches of mountain forest steppe of South Siberia

¹ State Scientific Institution “Buryat Research Institute of Agriculture”, 670045, Tretiakova str. 25z, Ulan-Ude, Russia
² Tuva State University, 667000, Lenin str. 36, Kyzyl, Russia

^* Corresponding author: namzalov@rambler.ru

Abstract

The paper provides original information about relict phenomena in the structure of the forest component of the mountain forest-steppe of Southern Siberia (SS). Larch (Larix sibirica Ledeb.) shrub-grass forests are a characteristic element of vegetation in the forest-steppe of the SS. The oldest are the Pliocene, the most thermophilic analogues of the modern forest-steppe, noted in the foothills of the Western Tannu-Ola ridge (natural boundary Khorlety) – is a small-leaved honeysuckle-wormwood larch forest with participation in the community of highland-Asian elements of ancient Middle-earth – Lonicera microphylla, Cotoneaster megalocarpus, Spiraea hypericifolia. In the conditions of Western Transbaikalia, in the spurs of the Malyi Khamar-Daban ridge (natural boundary Inzagatuy) described the relict sedge-needlegrass larch forest with the participation of characteristic species of the periglacial Pleistocene complex such as Helictotrichon altaicum, Festuca sibirica, Artemisia commutata and others. In the Quaternary period – especially in the xerothermic phases of the Holocene, as mountain glaciers were deglaciated and a relatively warm and temperate climate develops, conditions are created for the formation of a modern mountain forest-steppe in the conditions of the semi-humid climatic regime of the SS.