Title
Northwest Caucasian krummholz and open woodlands (Betula litwinowii, Fagus sylvatica subsp. orientalis, Acer trautvetteri), scrub (Rhododendron caucasicum), tall-herb communities (Heracleum mantegazzianum, Galega orientalis, Milium schmidtianum) and grasslands (Calamagrostis arundinacea, Poa longifolia, Poa iberica)
Geographical distribution
Country/territory
Russia: west-exponated areas at the northwards aligned flanks of the Greater Caucasus (Stavropol region, Karachai-Cherkesian, Adigea-autonomy region)
area frequency
3 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 herbs and subalpine grasslands (Doluchanov et al. 1942) = Betulo-Adenostyletea Braun-Blanquet & R. Tüxen 1943; Calluno-Ulicetea Braun-Blanquet et R. Tüxen ex Westhoff et al. 1946; Caricetea curvulae Braun-Blanquet 1948; Molinia-Arrhenatheretea R. Tüxen 1937.
Structural feature of the main community(ies) (layers, life-forms, etc.)
Combination of krummholz and open forests (northern slopes, flat surfaces), Rhododendron caucasicum scrub, tall-herb communities and grass communities. In the lower belt (up to an altitude of 2000 m), two- to three-layered beech-krummholz forests (up to 16 m) with good rejuvenation; open, two-layered maple forests with a tall-herb synusium (average height of 15-17 m). At 2000-2400 m two- to three-layered birch-krummholz forests (average height of 6-8 m) with good rejuvenation, as well as evergreen, low-lying, monodominant Rhododendron communities (average height 40-50 cm, in the underwood 60-80 cm), tall-herb communities (up to 2100 m) with an average height of 150 to 300 cm (leaves of Heracleum spp. 120-150 cm long) and grass communities: mainly interspersed grasslands with several dominant species and an average height of 10-15 cm (grass meadows).
Dominant and most frequent species in different layers
Tree layer
birch-krummholz forests: Betula litwinowii, Sorbus aucuparia, Acer trautvetteri, Populus tremula, Salix caprea; beech forests: Fagus sylvatica subsp. orientalis, Acer trautvetteri, Sorbus aucuparia; maple forests: Acer trautvetteri
Shrub layer
birch-krummholz forests: Rhododendron caucasicum or Lonicera caucasica, Ribes biebersteinii, Salix kazbekensis; beech forests: Vaccinium arctostaphylos, Rhododendron luteum, Rhododendron caucasicum, Prunus laurocerasus; Rhododendron communities: Rhododendron caucasicum
Herb layer
birch-krummholz forests: Vaccinium myrtillus, Calamagrostis arundinacea, Aconitum orientale, Adenostyles platyphylloides; beech forests: Calamagrostis arundinacea, Polygonatum verticillatum, Symphytum asperum, Athyrium distentifolium; maple forests: Symphytum ibericum, Arato nordmanniana, Doronicum macrophyllum, Corydalis caucasica; Rhododendron communities: Empetrum hermaphroditum, Veronica gentianoides, Deschampsia flexuosa; tall herb communities: Heracleum mantegazzianum, Heracleum asperum, Galega orientalis, Milium schmidtianum, Anthriscus sylvestris; grasslands: Calamagrostis arundinacea, Poa longifolia, Poa iberica, Bromus variegatus, Agrostis planifolia, Stachys macrantha, Anemone fasciculata
Moss layer (incl. lichens)
Rhododendron communities: Dicranum scoparium, Rhytidiadelphus triquetrus, Hylocomium splendens, Polytrichum juniperinum, Cetraria islandica
Diagnostically important species
krummholz forests: Dryopteris oreades, Athyrium distentifolium, Oreopteris limbosperma, Sorbus aucuparia, Salix kazbekensis, Swertia iberica; Rhododendron communities: Empetrum hermaphroditum; tall herb communities: Heracleum spp.; grasslands: Poa iberica, Festuca djimilensis, Anemone fasciculata, Leontodon hispidus, Agrostis planifolia, Inula grandiflora, Linum hypericifolium, Trifolium trichocephalum
Ecological variants
---
Geographical variants (geogr. differential species)
Vaccinium arctostaphylos, Rhododendron ponticum, Prunus laurocerasus.
Natural accompanying vegetation (most important units in complex with the name giving mapping unit, scientific names)
Beech-fir forests with Abies nordmanniana up to 1900-2000 m; pine forests with Pinus kochiana; meadows with Festuca woronowii; dry grassland with Carex humilis, Salvia verticillata, Stachys discolor; Juniperus communis subsp. hemisphaerica scrub; rock and rubble vegetation with Campanula aucheri, Gypsophila tenuifolia, Sempervivum tectorum, Saxifraga flagellaris etc.
Adjoining climax and permanent vegetation (with numbers of mapping units)
alpine grasslands (B56), fir and mixed fir forests (D32, D33), pine forests (D64), Oriental beech forests (F164), mixed hornbeam-oak forests (F167).
Land use, substitute communities
forestry (substitute communities, plantations of economic tree-species, scrub)
No plantations
grassland (meadows, pastures, herb-rich communities)
Grass meadows, pastures (natural grassland).
arable land (characteristic weed communities)
Cultivation of potatoes, barley.
settlements (typical ruderal vegetation)
Communities with Veratrum lobelianum, Cirsium spp., Rumex acetosa, Polygonum aviculare, Polygonum cognatum, Capsella bursa-pastoris, Alchemilla persica, Rumex pseudoalpinus, Rumex arifolius, Plantago spp.
Site conditions of the mapping unit
Landscape type, geomorphology
high-mountain regions (steep slopes, heavily engraved relief), characterised by erosion and denudation as well as glacial forms (moraines, boulders and U-shaped trough valleys etc.)
Altitudinal belt and/or altitudinal range
subalpine; 1800(1900)-2400 m
Geology (bedrock)
predominately slate and sandstone, partly also limestone and chalky clay (Cretaceous, Jurassic)
soil type, also the depth of fine textured earth (soil), stone content; (international nomenclature)
mountain-meadow soils (highland mull-gley), highland forest-meadow soils (transitions between mull-gley and brown soils, brown forest soils (brown soils, burozem), partly humus carbonate soil and lithosol; (lithic, rendzic and umbric leptosols; humic and dystric cambisols)
soil moisture, water balance
moist to dry (at southern and eastern slopes: moderately dry, partly dry; mostly fresh at all remaining slope expositions; mostly moist below krummholz forests)
soil reaction
acidic to neutral (in Rhododendron caucasicum communities and krummholz forests with Rhododendron: acidic; in remaining formations: moderately acidic, partly neutral)
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
3-4 °C
average annual precipitation
1200-2000 mm
average temperature of the warmest month
13-14 °C
average temperature of the coldest month
-8 to -6 °C
local climate or other climatic peculiarities
moist climate with long, cold winters (4-5 months) and short, warm summers (2-2,5 months) in the highlands. In gorges there is a different air humidity to be found, which decreases from west to east. Climatic influence of the Black Sea and the Sea of Asov in the west.
Importance for nature protection
Present state and development trend of natural vegetation (degree of endangerment)
The tree line today lies about 200 m lower. Most subalpine forest communities have disappeared. A natural regeneration of the subalpine forests 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 forest types (krummholz forests, maple and pine forests), tall herb communities.
causes of endangerment
Intense grazing, hay and timber usage by the resident population for private use; tourism.
required measures for protection and restitution
The remaining areas with semi-natural subalpine forests must be completely protected (protection by establishment of nature reserves), controlled grazing, restoration of the subalpine forests by replantation.
Localities of representative stands (loci typici) with state of protection
of the natural vegetation
Russia: in the catchment area of Laba and Belaja (in the Caucasian biosphere reserve and the Teberda reserve).
of characteristic substitute communities worthy of protection
---
Most important references (author, year)
Alper 1960; Altuchov 1967; Elenevskij 1949; Golgofskaja 1967a; Golgofskaja 1967b; Tumadžanov 1960; Vorobjova 1966
Compiled by
N. Zazanašvili
