Caucasian Oak-Hornbeam Forest

The remaining natural or semi-natural remnants of these forests such as in Greater Caucasus around Tbilisi show that they had an upper canopy dominated by the endemic or near endemic Carpinus caucasica (Betulaceae) and Quercus iberica (Fabaceae) reaching heights of up to about 10 m. A sub-canopy about 6 m high largely dominated by Carpinus caucasica is usually present. Shrub layer species include Acer campestris, Cornus mas, Corylus avellana, Crataegus monogyna, Malus orientalis, Prunus divaricata, Rosa canina, Viburnum avellana and the endemic Lonicera caucasica (Caprifoliaceae) and Pyrus caucasica (Rosaceae) and generally reach a height of about 3 m. Below this is a rich herb layer comprising species like Arum albispathum, Campanula rapunculoides, Geum urbanum, Polygonatum verticillatum and the endemic Cyclamen vernum (Primulaceae), Galanthus caucasicum (Alliaceae) and Primula woronowii (Primulaceae). However, much of these forests have now been converted to secondary deciduous scrub with species such as Berberis vulgaris, Cotinus coggygria, Paliurus spina-christi, Spiraea hypericifolia and the endemic Amygdalus georgica (Rosaceae).

 

Caucasian Arid Pistacia-Juniperus Woodland

Woodland dominated by Juniperus foetidissima, J. polycarpus, J. rufescens and the deciduous Pistacia mutica are important in the dryer eastern areas, especially in eastern Georgia. They also extend westward to Tbilisi and on through the Mtkvari River Valley to the Meskheti region. They are largely composed of small trees (ca. 8 m) and usually have a well-developed shrub layer up to 3 m high. Typical shrubs are Cerasus microcarpa, Paliurus spina-christi, Berberis iberica, jasminum fruticans, Lonicera iberica and Rhamnus pallasii. Among the many herbaceous ground layer species are Campanula hohenackeri, Cleistogenes bulgarica, Helianthemum salicifolium, Falcaria vulgaris, Lasiagrostis bromoides and the endemic Dictamnus caucasicus (Rutaceae) and Polygala transcaucasica (Polygalaceae). However, these woodlands rarely have a closed canopy and often have a parkland character especially on flatter terrain.

 

Caucasian Steppe Meadow

Steppe vegetation is only characteristic of the dryer eastern areas but good natural examples are now confined to relatively small areas such as the in the Vashlovani Reserve in Kiziki. These are forb-rich grasslands that can grow to about 1 m in height. The dominant grass species here is Botriochloa (Andropogon) chaemum, but several feather grasses, such as Stipa pulcherrima, are also common. These grasslands undergo a continuing flora metamorphosis during the growing season, mainly from April to June. Early forbs are initially replaced by taller forbs and these eventually give way to the dominant species of summer. Among the rich forb assemblage are many endemic species such as Bellevalia wilhelmsii (Liliaceae), Dianthus inamoenus (Caryophyllaceae), Malabaila sulcata (Apiaceae), Muscari caucasicum (Liliaceae), Onosma armeniaca (Boraginaceae), Polygala transcaucasica (Polygalaceae), Scutellaria orientalis (Lamiaceae), Seseli grandivittatum (Apiaceae) and Thymus serpyllacea (Lamiaceae).

 

Caucasian Sub-Alpine Grassland and Thicket

These range in altitude from about 2300-2500 m, and on Mount Kazbegi in the Great Caucasus can be broadly divided into four types. At the lowest part of the altitudinal range thicket dominated by Vaccinium myrtillus and the endemic Rhododendron caucasicum (Ericaceae) often predominate. These stands are fairly homogenous in structure with few associated species but may include Geranium sylvaticum, Oxalis acetosella, Solidago virgaurea and the endemic Empetrum caucasicum (Empetraceae) and Dolichorrhiza caucasica (Asteraceae). At similar altitudes there are forb dominated stands characterized by Taraxacum stevenii and Veratrum lobelianum. The latter can reach heights of 2 m and its presence is thought to indicate a lack of grazing by cattle.  Also its broad ground-leaves protect nearby areas from grazing favouring the occurrence of Arenaria rotundifolia, Gentiana aquatica and the endemic Anthriscus ruprechtii (Apiaceae). Tussocks of Nardus strictus, however, invariably dominate the lower layers. On south and southeast slopes up to about 2490 m grassland characterized by the endemic or near endemic Bromopsis variegata and Festuca woronowii (Poaceae) predominate. Other constant species here are Campanula stevenii, Kobresia persica, Minuartia oreina, Potentilla crantzii, Trifolium canescens and the endemic Plantago caucasica (Plantaginaceae). Finally at the highest part of this altitudinal range often on exposed ridges with clear evidence of frost action (e.g. soil polygons) grass becomes less conspicuous and the short forbs Chamaesciadium acaula and Polygonum viviparum become two of the main species. Associated species are Festuca woronowii, Thalictrum alpinum and the endemic Alchemilla caucasica (Rosaceae) and Androsace lehmanniana (Primulaceae). All of these sub-alpine communities are usually subject to varying degrees of grazing by domestic stock.

Further information required.

 

References

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