Altai-Sayan Vegetation

Plant Formations in the Altai-Sayan BioProvince

Peter Martin Rhind

Altai-Sayan Betula pendula - Pinus sylvestris Mesic Hemiboreal Forest These forests are found, for example, in the fairly warm northern foothills of western Sayan such as in the Dzhoiskii Range and the Yenisei Valley. The dominant trees Betula pendula and Pinus sylvestris may be accompanied by species such as Larix sibirica and Populus tremula. A shrub layer is usually present but rarely exceeds about 25% land cover. Typical species include Caragana arborescens, Cotoneaster melanocarpus, Ribes spicatum and Sambucus sibirica. The ground layer, on the other hand, is well developed with up to 80% coverage. Most of the species are herbs and graminoids typical of meadow steppe and have a Euroasian temperate distribution. Carex pediformis often dominates while other species include Crepis sibirica, Brachythecium starkei, Heracleum dissectum, Primula macrocalyx, Trollius asiaticus and the endemic Lathyrus frolovii (Fabaceae).

Altai-Sayan Larix sibirica Dry Hemiboreal Forest Forests dominated by Larix sibirica can be found at mid-elevations (600-1800 m) throughout the Altai-Sayan mountain system. Other trees may include Betula pendula, Pinus sibirica and P. silvestris. In fact, the latter species becomes a major component in places. Both Larix sibirica (Siberian larch) and Pinus sibirica (Siberian pine) are adapted to grow at extremely low temperature and appear in places very close to the climatic limit for forest. The shrub layer can be sparse but in places pure stands of Rhododendron dauricum can develop. Other shrub species include Betula nana, Caragana frutex, Padus avium, Rhododendron parvifolium, Rosa acicularis, Sambucus racemosa, Spiraea chamaedryfolia, Viburnum opulus and the endemic or near endemic Lonicera altaica (Caprifoliaceae). The herb layer usually has good cover (up to 80%) and in places is dominated by Iris ruthenica. However, there are usually many other species such as Aconitum barbatum, Actaea erythrocarpa, Allium victorialis, Cerastium pauciflorum, Crepis lyrata, Heracleum sibiricum and several Tertiary relicts like Asarum europaeum, Festuca gigantea and Stachys sylvatica.

Altai-Sayan Pinus sylvestris Dry Hemiboreal Forest These forests are usually confined to steep, south-facing slopes with rocky outcrops and can be found, for example, in northern and central Western Sayan. The tree canopy is typically open with admixtures of Betula pendula, Larix sibirica and Pinus sibirica. The shrub layer, on the other hand, is usually well developed and often dominated by Caragana arborescens and Rhododendron dauricum. Herb layer cover ranges from about 20-50% and mainly contains draught and frost adapted species. The main ones are Calamagrostis pavlovii, Carex pediformis and Iris ruthenica, while other common species include Aster alpinus, Bupleurum scorzonerifolium, Galium paniculatum, Kitagawia baiacalensis, Schizonepeta multifida and the endemic or near endemic grass Helictotrichum altaicum (Poaceae).

Altai-Sayan Abies sibirica-Betula pendula Wet Taiga Confined to the relatively warm, high precipitation areas such as north and central Western Sayan, these forests are largely confined to lower slopes and river valleys. Abies sibirica often comprises up to 60% of the canopy layer and in addition to Betula pendula, Pinus obovata and Pinus sibirica are often present, while Sorbus sibirica is a typical subcanopy species. The shrub layer has variable cover and is often dominated by Duschekia fruticosa, while less common shrubs are Ribes spicatum and Sambucus sibirica. The herb layer, however, is species-rich and often dense with up to 90% land cover, and typically Copyright © 2010 Peter Martin Rhind dominated by tall ferns such as Athyrium filix-femina, Diplazium sibiricum, Dryopteris expansa and Matteuccia struthiopteris and the tall grass Calamagrostis obtusata. A lower herb layer is often dominated by Carex pediformis, while others include Aquilegia sibirica, Atragene sibirica, Lactuca sibirica, Poa sibirica and the endemic or near endemic Anemonoides altaica (Ranunculaceae) and Euphorbia alpina (Euphorbiaceae). Several of these species are also common to other local conifer forests.

Altai-Sayan Abies sibirica-Pinus sibirica Mesic Taiga Forest dominated by Abies sibirica, Pinus sibirica and to a less extent Populus tremula is thought to represent the oldest coenotic relict of the dark conifer forests of the Paleocene and Neogene periods. They have features in common with vanished forests recently reconstructed from the fossil record of the full-glacial period in eastern Central Europe. Today they are scattered throughout the mountainous region of this BioProvince including the Altai, East and West Sayan and the Chamar-Daban Mountains, but are mainly confined to north-facing slopes at altitudes ranging from about 1000-1500 m. Canopy cover ranges from 20-50% and may also include admixtures of Picea obovata. The shrub layer is often characterized by the endemic Lonicera altaica (Caprifoliaceae), while other shrubs include Ribes nigrum and Sorbus sibirica. The ground layer tends to be species- poor and often dominated by Bergenia crassifolia and Vaccinium myrtillus and most of the ground flora has a boreal distribution. However, these forests also support a number of relict species including nemoral Atlantic relicts like Asarum europaeum, Campanula trachelium, Circaea lutetiana, Epilobium montanum, Festuca silvatica and Sanicula europaea; nemoral Eurasia relicts like Asperula odorata, Cardamine impatiens, Carex silvatica and Listera ovata. There are also some ancient Mediterranean elements like Brunnera sibirica, Dentaria sibirica and Galium krylovii.

Altai-Sayan Pinus sibirica-Picea obovata Continental Taiga These forests occur throughout this BioProvince on slopes of different inclination and aspect. In the Western Sayan Mountains they range from about 600 m to near the timberline at 1650-1950 m. Pinus sibirica is usually the dominant tree with up to 40% coverage but with a constant admixture of Picea obovata and in places Larix sibirica. The shrub layer is sparse and often dominated by Rhododendron dauricum, while other shrubs include Caragana arborescens, Cotoneaster melanocarpus, Ribes nigrum, Rubus matsumuranus and Spiraea media. Ground layer coverage ranges from 30-60% and is often dominated by Vaccinium vitis-idaea. Other ground layer species include Empetrum nigrum, Equisetum scirpoides, Lupinaster pentaphyllus, Lycopodium annotinum, Polypodium sibiricum and Vicia unijuga. There is also a good variety of bryophytes and macro lichens of the genus Cladonia.

Altai-Sayan Scree Vegetation In the semi-arid and arid climatic sectors Artemisia santolinifolia and Berberis sibirica usually dominate mountain mobile screes of various lithology. A feature of this formation is the predominance of draught-adapted shrubs and semi-shrubs. Other species include Artemisia rutifolia and the Siberian endemic Atraphaxis laetevirens (Polygonaceae). The former often dominates the most draught prone areas. Associated herbaceous species typical include xerophytes like Elytrigia geniculata, Erysimum flavum, Panzerina canescens, Seseli buchtormense, Vicia costata, Vincetoxicum sibiricum and the endemic Euphorbia tshuiensis (Euphorbiaceae). On moderately dry screes in the forest-steppe and steppe belts Grossularia acicularis and Berberis sibirica are often the characteristic species, while others include Artemisia gmelinii, Cotoneaster melanocarpus, Galium verum and Spiraea media, but here the most draught-adapted species are usually absent. This formation is typically found on steep south-facing slopes in the narrow parts of large

Copyright © 2010 Peter Martin Rhind river valleys. A different community can be found on south facing gravel screes in Western Sayan. Here species such as Elytrigia geniculata and Artemisia santolinifolia are typical together with Achnatherum sibiricum, Artemisia frigida, Caragana pygmaea, Chamaerhodos erecta, Cleistogenes squarrosa, Goniolimon speciosum, Poa transbaicalica, Potentilla acaulis and the endemic or near endemic Helictotrichum altaicum (Poaceae) and Schizonepeta annua (Lamiaceae). In places, however, the obligate petrophytic shrub Artemisia santolinifolia can form almost monodominant stands. On the most humid screes in, for example, the forest-steppe belts of northern Altai, Sambucus sibirica and Grossularia acicularis usually become the main species while others include Humulus lupulus, Rosa acicularis, Rubes idaeus, Senecio nemorensis and Urtica cannabina.

Altai-Sayan Rock Crevice Formations In the most humid northern and northwestern peripheral parts of the Altai-Sayan mountain system succulents like Sedum hibridum and to a lesser extent Hylotelephium ewersii dominate rock crevice and stable screes. Other characteristic succulents may include Hylotelephium populifolium and Orostachys spinosa, while typical non-succulents are Dracocephalum nutans, Galium paniculatum, Kitagawia baicalensis, Phlox sibirica, Veronica spicata and the endemic or near endemic Euphorbia altaica (Euphorbiaceae). In the more draught prone areas in southern West Sayan, Selaginella sanguinolenta becomes one of the main rock crevice species. Others include Aster alpinus, Galium coriaceum, Pulsatilla turczanovii, Woodsia ilvensis and the Siberian endemic or near endemic Achnatherum sibiricum (Poaceae), Eritrichium pectinatum (Boraginaceae), Helictotrichon altaicum and Poa transbaicalica (Poaceae). This association is widespread in Western Sayan, where it occurs on south-facing slopes, but appears to be absent from the Altai.

Altai-Sayan Steppe (information required)

Altai-Sayan Alpine Meadows and Tundra (information required)

Further information required.

References

Altangadas, O. 2002. Vegetation in the vicinity of Takhin Tal area. Masters Degree. Mongolian State National University.

Botch, M. S. & Masing, V. V. ed.1983. Mire Ecosystems in the USSR. In: Ecosystems of the World 4B. Mires: swamps, bogs, fen and moor. Ed. A. J. P. Gore. Elsevier Scientific Publishing Company.

Chytry, M., Danihelka, J., Kubesová, S., Lustyk, P., Ermakov, N., Hájek, M., Hájkova, P., Koci, M., Otypkova, Z., Rolecek, J., Reznícková, M., Smarda, P., Valachovic, M., Popov, D. & Pisút, I. 2008. Diversity of forest vegetation across a strong gradient of climatic continentality: Western Sayan Mountains, southern Siberia. Plant Ecology, 196: 61-83.

German, D., Neuffer, B., Friesen, N. & Hurka, H. 2003. Contribution to the knowledge of the flora of the Mongolian Altai II. Feddes Repertorium, 114: 632-637.

Knystautas, A. 1987. The Natural History of the USSR. Century Hutchinson Ltd.

Neuffer, B., Oyuntsetseg, B., Schamsran, Z., Friesen, N. & Hurka, H. 2003. Contribution to the knowledge of the flora of the Mongolian Altai. Feddes Repertorium, 114: 358-371.

Nikolai Ermakov, Novosibirsk. 1998. The Altaian relict subnemoral forest belt and vegetation of pre-Pleistocene mountainous landscapes. Phytocoenologia, 28: 31-44.

Nikolai Ermakov, Novosibirsk, Milan Chytyr, Borno, and Milan Valachovic, Bratislava. 2006. Vegetation of the rock outcrops and screes in the forest-steppe and steppe belts of the Altai and Western Sayan Mts., southern Siberia. Phytocoenologia, 36: 509-545.

Paetzold, H. 1989. Shrublands of the USSR in Asia. In: The Biology and Utilization of Shrubs. Ed. C. M. McKell. Academic Press, Inc.

Pyak, A. I., Shaw, S. C., Ebel, A. L., Zverev, A. A., Hodgson, J. G., Wheeler, B. D., Gaston, K. J., Morenko, M. O., Revushkin, A. S., Kotukhov, Yu. A. & Oyunchimeg, D. 2008. Endemic Plants of the Altai Mountain Country. WildGuides Ltd, Hampshire, UK.

Vlasenko, V. & Parfenova, E. 2005. Biodiversity of Sayano-Shushensky Nature Reserve. Ekologia-Bratislava, 24: 80-88.