Title
North-east Caucasian krummholz and open woodlands (Betula litwinowii, Acer trautvetteri, partly Pinus kochiana) with Betula raddeana, scrub (Rhododendron caucasicum, Juniperus communis subsp. hemisphaerica), tall-herb communities (Heracleum sosnowskyi, Delphinium flexuosum) and grasslands (Festuca woronowii, Bromus variegatus), alternating with dry grasslands (Festuca ovina, Carex humilis)
Geographical distribution
Country/territory
Russia: north-east-exponated flanks of the central and eastern Greater Caucasus (Autonomy Republics of Kabrdino-Balkarskaja, north Ossetia, Ingushetia-Chechnya and Daghestan); Georgia: Greater Caucasus at the border to Daghestan; Azerbaijan: border to Daghestan
area frequency
14 polygons.
Scientific names of main plant communities and their most common synonyms (with author citation)
Formation groups of subalpine krummholz forests, subalpine open woodlands, altimontane prostrate shrubs, of tall herb communities and subalpine grasslands (Doluchanov et al. 1942), of subalpine meadow steppes (Lavrenko 1940) = Betulo-Adenostyletea Braun-Blanquet & R. Tüxen 1943; Calluno-Ulicetea Braun-Blanquet & R. Tüxen ex Westhoff et al. 1946; Caricetea curvulae Braun-Blanquet 1948; Festuco-Brometea Braun-Blanquet & R. Tüxen in Braun-Blanquet 1949; Molinio-Arrhenatheretea R. Tüxen 1937.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Birch- krummholz forests: northern slopes at altitudes of 2000-2600 (2700) m, average height 6-8 m, good regeneration, diameter of the shoots 5-15 cm, density 0.4-0.6 (0.8); Pine forests: mainly at southern and eastern slopes, average height 14-16 m, diameter of stems aged 130-140 years 30-36 cm, varied density from 0.4 to 0.8; Maple forests, rhododendron and tall-herb communities: see C41. Juniper communities: low (on average 50 cm high), creeping, individual shrubs occurring in groups, the entire community has an open structure, frequently on rock and rubble. Grass communities of Festuca woronowii on steep slopes (35-50°), average height 50 cm with a total biomass of about 7-8 tonnes/ha, tussock-cushion structure with a degree of coverage of 80-90 %. Dry grassland: at usually steep southern and eastern slopes, average height of 20-30 cm, total phytomass of 1-2 tonnes/ha, 50‑60% degree of coverage.
Dominant and most frequent species in different layers
Tree layer
birch-krummholz forests: Betula litwinowii, Betula raddeana, Sorbus aucuparia, Acer trautvetteri, Populus tremula, Salix caprea, partly Pinus kochiana; Pine forests: dry type with Pinus kochiana, mesophilous type with Pinus kochiana, Betula spp., Sorbus aucuparia, Salix caprea
Shrub layer
birch-krummholz forests: Rhododendron caucasicum, Salix apoda, Salix kazbekensis, Lonicera caucasica, Ribes biebersteinii; Pine forests: dry type with Juniperus communis subsp. oblonga, Juniperus communis subsp. hemisphaerica, mesophilous type with Lonicera caucasica, Ribes biebersteinii; dry grassland: partly Juniperus communis subsp. hemisphaerica, Spiraea hypericifolia
Herb layer
birch-krummholz forests: Calamagrostis arundinacea, Platanthera chlorantha, Milium effusum, Galanthus caucasicus, Campanula alliariifolia, Dryopteris oreades etc.; Pine forests: dry type with Festuca ovina, Koeleria macrantha, Dracocephalum ruyschiana, mesophilous type with Vaccinium myrtillus, Vaccinium vitis-idaea, Rubus saxatilis, Oxalis acetosella, Pyrola media, Geranium sylvaticum; dry grassland: Festuca valesiaca, Festuca ovina, Bromus variegatus, Koeleria macrantha, Carex humilis, Astragalus captiosus, Oxytropis albana, Thymus spp., Dianthus cretaceus; grasslands: Festuca woronowii, Bromus variegatus, Hordeum violaceum, Onobrychis biebersteinii, Trifolium ambiguum, Totorta carnea, Anemone fasciculata, Stachys macrantha etc.; tall herb communities: Heracleum sosnowskyi, Heracleum asperum, Delphinium flexuosum, Aconitum orientale etc.
Moss layer (incl. lichens)
Pine forests: mesophilous type with Hylocomium splendens, Pleurozium schreberi
Diagnostically important species
Sorbus aucuparia, Salix kazbekensis, Heracleum sosnowskyi, Geranium ibericum, Astragalus captiosus, Carex humilis, Onobrychis biebersteinii
Ecological variants
Dry and mesophilous types of pine forests.
Geographical variants (geogr. differential species)
Betula raddeana, Astragalus captiosus.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Stipa pulcherrima steppes (up to an altitude of 1900-2000 m), rock and rubble vegetation.
Adjoining climax and permanent vegetation (with numbers of mapping units)
alpine grasslands (B56, B57), krummholz and open woodlands (C41, C44), pine forests (D64), Oriental beech forests (F164), hornbeam-oak forests (F167, F170), forest steppes (L8), steppes (M4), thorn-cushion vegetation (N7).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
No plantations.
grassland (meadows, pastures, herb-rich communities)
Grass meadows and pasture lands.
arable land (characteristic weed communities)
Potato, barley cultivation.
settlements (typical ruderal vegetation)
Communities with Veratrum lobelianum, Cirsium spp., Rumex spp., Verbascum spp.; Polygonum aviculare, Polygonum cognatum, Capsella bursa-pastoris, Plantago spp., Alchemilla persica, Rumex pseudoalpinus, Rumex arifolius.
Site conditions of the mapping unit
Landscape type, geomorphology
High-mountain regions with steep slopes and severely engraved relief, shaped by erosion and denudation; glacial forms (moraines, boulders, U-shaped trough valleys etc.), sometimes relief types of volcanic origin (lava flows etc.)
Altitudinal belt and/or altitudinal range
subalpine; 1800-2400(2600) m
Geology (bedrock)
clay-slate, sandstone (Jurassic), furthermore Pleistocene basement rock of volcanic origin (mostly andesite), partly limestone (Jurassic, Cretaceous)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
mountain-meadow soils (mull-gley), forest-meadow soils of the highlands (transition between mull-gley and brown soils), brown forest soils (brown soils, burozem), partly andosol, humus carbonate soil and lithosol; (dystric and humic cambisols; umbric, lithic and rendzic leptosols; andosols)
soil texture
loamy, clayey, stony
soil moisture, water balance
moist to moderately dry (dry) (at southern and eastern slopes: moderately dry, partly dry; at the remaining slopes mostly fresh; below krummholz forests mostly moist)
soil reaction
acidic to neutral (acidic soils below Rhododendron communities and below forests with Rhododendron, otherwise moderately acidic to neutral soils)
soil fertility
mesotrophic (high content of humus (10 % or more), high to moderately high content of nitrogen, moderately high content of potassium, low content of phosphorus)
Climate incl. local climate
climate type (following Walter & Lieth)
X
average annual temperature
4-5 °C
average annual precipitation
550-700 mm (eastern part), 800-1000 mm (western part)
average temperature of the warmest month
13-15 °C
average temperature of the coldest month
-8 to -6 °C
local climate or other climatic peculiarities
moderately moist high mountain climate with long winters (4-5 months) and short summers (2-2,5 months) with a minimum of precipitation in winter. In gorges there is a different air humidity; it decreases generally from the west to the east.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
Areas with subalpine forests have been reduced to the extreme; the tree line now lies around 200-300 m (sometimes 400 m) lower than it used to. A natural regeneration of the subalpine forest is not possible since a grassland soil horizon has formed under the secondary grass communities.
endangered communities, species worthy of protection in natural vegetation
All subalpine types of forest, tall herb communities.
causes of endangerment
Intensive grazing, hay and timber harvesting by the resident population, infrastructure development (streets, gas pipelines etc.), tourism.
required measures for protection and restitution
Protection of still remaining remnants of the subalpine forests, controlled grazing measures, restoration of the subalpine forests by replantation of tree species local to the sites, anti-erosion measures (e. g. establishment of protection forests).
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Russia: in the catchment area of the Bacsan (high mountain reserve in Kabardino-Balkarskaja), of the Ardon and Fiagdon (reserve in north Ossetia); Georgia: catchment area of the Andian Koisu (Tusheti reserve).
of characteristic substitute communities worthy of protection
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Most important references (author, year)
Grossgejm 1925; Kimeridze 1965; Lvov 1969; Šiffers 1953; Tumadžanov 1938
Compiled by
N. Zazanašvili
