The flora of Buryatia as a part of the spacious Siberian territory has been researches since 1724. The first works about it are connected with the names of D.G. Messerschmidt and I.G. Gmelin. Their first expeditions not only gave a scientific description of the virgin Baikal land nature, but also created the first chronicle of the land’s vegetation world.
By the present day the flora has been researched quite well, a great role in it has been played by outstanding botanists of the 20th century – M.G. Popov and L.P. Sergiyevskaya, as well as their disciples, G.A. Peshkova, L.I. Malyshev, M.A. Reshchikov, M.M. Ivanova, N.S. Vodopyanova and others.
2,006 species of higher vascular plants are recorded on the territory of Buryatia. They are united into 559 genera and 123 families. In comparison with the adjacent territories, the Chita (1,692 species) and the Irkutsk (1,827 species) regions on the territory of Buryatia more species grow which is considerably determined by the region buffer situation at the junction of many provinces (Namzalov, 1995).
The peculiarities of the relief, the climatic and soil condition influenced the richness and vegetation variety of the region. The originality of the Buryatia flora is caused by relic forest-steppe complexes, on the one hand, and on the other hand, by high-grass taiga rich in relic and endemic plants species. The flora of the highlands is as original, it includes the tundra, the steppe and the Alpine-meadow elements.
Out of 10 leading families only the Cruciferae and the clove-like have no multi-species genera. Ancient Mediterranean and east-Asian families are quite representative by the number of species: the buckwheats, the Labiatae and the umbellate. Among the latter the most remarkable ones are: Atraphaxis of the buckwheats, Dracocephalum and Lophantus of the Labiatae and Shaposhnikovia, Bupleurum and Aegopodium of the umbellate which also play a great role in the formation of the vegetation cover.
It is necessary to mention some other genera from the leading group, they are the violet, the saxiphrage and the onion. The significance of these genera in the Zabaikalye flora demonstrates the complex ways of the region vegetation world formation.
The Role of Separate Systematic Plant Groups in the Flora of Buryatia
In the family of the cereals which play an especially significant role in the vegetation cover, the feather-grass (Stipa) distinguishes. The neighbouring Mongolia including a part of the southern Buryatia is considered to be the centre of the feather-grass formation (Stipa capillata s.l.).
Among other cereals forming the cenosis such species of the fescue - Festuca genus should be mentioned as F. lenensis, F. pseudosulcata, F. dahurica, F. ovina and F. brachyphylla. The two latter ones dominate in the cenosis of the mountainous tundra and Alpine waste grounds. On the meadows and in the grass forests F. pratensis (the meadow fescue) often dominates.
The genera very significant for the Transbaikal land vegetation cover are Poa (a very significant role is played by the endemic Poa ircutica on the sub-Alpine Khamar-Daban meadows) and Calamagrostis, especially in the meadow-taiga ecosystems.
The representatives of the carex family take especially remarkable positions in the highlands vegetation – the Alpine and sub-Alpine meadows, lichen and dryad tundras. In the communities of the taiga forests the role of the carex is less significant. There Carex macroura, C. amgunensis, C. caryophyllea and others are characteristic. The cenosis role of the carex is especially significant in the herbage of the marshlands in the river flood-lands.
The family of the leguminous plants is mostly represented by astragals and some others. Only caraganas are of landscape significance in the cavities, forming its communities on the sands (C. microphylla), in dry steppes (C. pygmaea), in meadow steppes and forests (C. arborescens), on the river valleys terraces thickets of caragana (C. spinosa) are common. It is necessary to mention that in the Sayans highlands the original kind of caragana (C. jubata) is often found.
The most common species of the Rosaceae family are those of Potentilla genus – P. acaulis, P. bifurca, P. tanacetifolia, P. sericea, which are most common in the steppe phytocenosis, as well as representatives of Chamaerhodos genus – C. altaica and C. trifida.
In the light coniferous and deciduous forests not only Potentilla (P. fragarioides, P. evestita, P. nudicaulis) are recorded but also strawberries (Fragaria orientalis), the dog-rose (Rosa acicularis) and species of Spiraea (Spiraea media, S. salicifolia).
In the rivers flood-lands among the shrubs very frequently the Kuril tea (Pentaphylloides fruticosa) is found, it often dominates. In the highlands the dryad (Dryas oxyodonta, D. grandis) is very common, forming the tundra shrub communities. Especially original representatives of Rosaceae are groups of Armeniaca sibirica which can be found on the stony slopes in the southern Buryatia (near the Selenga).
The family of Compositae is the most numerous one by the number of species. In the steppes very often the wormwoods predominate, in the highlands steppes cenosis they are A. depauperata, A. dolosa. The most remarkable ones are the original cenosis former of the Dauria steppes, they are Filifoliae (Filifolium sibiricum), Arctogeroneae (Arctogeron gramineum) and Artemisia subviscosa. The latter is the Baikal land endemic.
Among the multi-species families there ones which are very rare to be the dominants or the main cenosis formers. They are the buttercups, the Cruciferae and some others. However, the plants of these families are equally included into the herbage of all the Transbaikal land ecosystems, starting with the steppes and to the mountain tundra.
To sum it up let us mention the representatives of the arboreous species of the region. The species of the coniferous family are most characteristic. The main kind of them is the Siberian larch (Larix sibirica) which makes up the taiga forests in the mountains of the Baikal Siberia, in the west (the Sayan, the Dzhida highlands, the Khamar-Daban). On the ranges and highlands of the North Transbaikalye (the Stanovoye highlands, the Vitim plateau) the larch forests are formed by the Gmelin larch (Larix gmelinii).
In the dark coniferous forests the cedar-tree (Pinus sibirica), the abies (Abies sibirica) and the fir-tree (Picea obovata) predominate. The most heat-loving tree of the coniferous is the pine which forms forests on sands, grass forests in the cavities and the taiga pine-trees forests on the mountain slopes.
The deciduous forests belong to three families, they are the willows (the poplar species - Populus), the birches (Betula genus), the elms (Ulmus genus). The most dignificant ones are the birch (B. plathyphylla) forests, in the highlands – the species of the dwarf birches (B. Nana subsp. rotundifolia, B. Middendorfii, B. divaricata) form the characteristic landscape. The poplars are represented by two species – P. lauriifolia and P. sauveolens. They are often combined with willows, the thickets of the bird cherry and the Siberian apple-tree. Among the deciduous kinds we should mention the participation of the low elm (Ulmus pumila) in the development of groves on the slopes of low mountains in south Buryatia.