Ecological Diversity

The Caucasus region has been identified by the World Wide Fund for Nature as a Global 200 Ecoregion, based on selection criteria such as species richness, levels of endemism, taxonomic uniqueness, unusual evolutionary phenomena, and global rarity of major habitat types. Moreover, Conservation International has identified the region as a global “hotspot” — that is, one of the 25 most biologically rich and most endangered terrestrial ecosystems in the world. These hotspots have been identified based on three criteria: the number of species present, the number of those species found exclusively in an ecosystem and the degree of threat they face. The Caucasus region is an Endemic Bird Area, with several bird species and subspecies endemic to the region.

Georgia, a mountainous country covering 70,000 km2 with a population of 5.5 million people, is situated between the south slope of the Caucasus Mountains, the east coast of the Black Sea, and the northern edge of the Turkish Anatolia plain. Forests cover 40 percent of the country (2.8 million ha), largely in the Greater Caucasus Mountains (Georgia’s northern border), the Lesser Caucasus (its southern border), and in intervening lowlands and foothills. The principal landscapes of the Caucasus include foothill and mountain forests and subalpine meadows of the Greater and Lesser Caucasus, treeless mountain upland plateaus of the Lesser Caucasus, humid lowland forests of western Georgia, and the arid steppe and deserts of eastern Georgia.

Located at a biogeographical crossroads where the flora and fauna of at least three biogeographic provinces converge, Georgia has high levels of biodiversity. In this region are found species typical of Europe (e.g., bear, lynx, chamois, red deer), Central Asia (e.g., Caucasian tur or mountain goat, leopard), and the Middle East regions (e.g., striped hyena, Persian gazelle); many of these species are threatened elsewhere in their ranges. The varied terrain and climatic conditions contribute to a diversity of ecosystems and species. The Georgian forests of the Caucasus Mountains contain more than 200 plant community associations, and 120 species of tree, 250 bushes, and 4,500 species of vascular plants. Among vascular plants, 9 percent are endemic to Georgia and 14 percent are endemic to the Caucasus region. There are 572 vertebrate species (348 species of birds, 95 mammals, 52 reptiles, 13 amphibians, and 64 fishes). The diverse and threatened large mammal fauna includes three species of wild goats, chamois, red and roe deer, and their predators, including wolf, lynx, wild cats, and possibly leopard. Some of these species (e.g., wild goats, deer, and wolf) undertake large-scale annual movements, increasing their susceptibility to habitat loss, degradation, and fragmentation, overhunting, and competition with domestic livestock for forage.

Georgia also possesses rich agricultural biodiversity that is gradually being replaced by more cosmopolitan varieties. The list of Georgian plant genetic resources includes varieties and subspecies, some endemic to the Caucasus region, which are close relatives of domestic food plants. The Caucasus region also harbors several wild close relatives of domestic food plants such as wild rye, wheat, barley, millet, wild pears, cherry, and more than 200 varieties of grapes as well as at least nine important domestic animal breeds.

Main Landscape Zones

Georgia’s ecosystems include alpine and subalpine meadows, lowland steppe grasslands, coastal, mountain and inland wetlands, coniferous and beech forests, oak woodlands and mixed deciduous forests, wetland forests, arid light woodlands, riparian shrub, and forest vegetation along rivers.

Considerable differences between the climates of western and eastern Georgia have led to significant differences in ecosystems and vegetation types. Semi-arid and arid woodlands do not exist in western Georgia. There are four main altitudinal zones in western Georgia: forests (up to 1,900 m), subalpine (1,900 to 2,500 m); alpine (2,500 to 3,100) and nival (> 3,100). In contrast, there are six zones in Eastern Georgia: semi-desert; dry grassland (steppes) and arid woodland (150 to 600 m); forest (600 to 1,900 m); subalpine (1,900 to 2,500 m) alpine (2,500 to 3,000 m); sub-nival (3,000 to 3,500 m) and nival (> 3,500). In mountain forests and alpine zones, treeless formations of semi-arid ecosystems are also found.

Semi-desert habitats are restricted to the extreme southeast of Georgia and are dominated by wormwood Artemisia fragrans, either alone or associated with saltwort (Salsola sppi), or Bothriochloa. Pockets of more typical desert vegetation also occur in this area.

Steppe vegetation occurs the lowlands and foothills around 300 to 700 m and is largely the result of human influence on woodland and shrub habitats. The dominant species are grasses (Bothriochloa spp). Rich floristic communities have developed in the Bothriochloa ischaemum/Glycyrrhiza glabra steppes of the lowlands. On the foothill slopes, Bothriochloa ephemerosa is mixed with other grasses such as Festuca sulcata and Stipa spp. Thorny shrubs, notably Christ’s Thorn (Paliurus spina-christii), are typical. Mountain steppes are found between 1,800 to 2,500 m, and Stipa spp and Festuca spp are dominant. Meadows are often formed, with a tall, rich herbaceous component.

Semi-arid woodlands occur on the plains and foothills of East Georgia. Communities are of three main types:

  • Pistachio (Pistachia mutica) woodlands, with quite a rich understorey of shrubs and grasses
  • Juniper (Juniperus spp) woodlands in mountainous areas
  • Open woodlands dominated by species of Pyrus and Celtis

Lowland forests. Alder (Alnus barbata) forests are characteristic of swampy regions of the lowlands and are floristically rich. Riparian forest, with wing-nut (Pterocrya pterocarpa), lowland oaks (e.g., Quercus imeretina) and white poplars (Populus alba) are found along river banks or in floodplain areas. Their extent has been much reduced because of their accessibility. A unique area of relic Carpinus orientalis-Zelkova carpinifolia forest exists in East Georgia between the Alzani and Stori rivers. A characteristic community of the Black Sea coast is the tall Pinus pityusa forests, sometimes mixed with broadleaved species.

Particularly interesting are the endemic mixed broad-leaved forests of western Georgia that have developed in areas of high rainfall (2,500 mm/yr). These are very rich floristically and contain many rare and relic species and communities from the Tertiary period. A rich understorey and the presence of many vines and ferns characterize these threatened rainforests. Many of these forests have been cleared for agricultural crops such as tea, citrus, and tobacco. This has been accompanied by the spread of aggressive weed species, often non-native.

Mountain forests. Forests cover almost 40 percent of Georgia’s territory, but are unevenly distributed and include areas with low tree cover.

In western Georgia, lowland forests give way on southern slopes to oak/hornbeam forests dominated by Georgian oak (Quercus iberica), Q. hartwissiana and hornbeam (Carpinus caucasica). At 600 to 700 m, beech (Fagus orientalis) forests appear, mixed with Caucasian fir (Abies nordmanniana). Forests of Caucasian spruce (Picea orientalis) and fir occur at 1,200 to 1,300 m, with subalpine forests of spruce and birch (Betula medwedewii). On the northern slopes, the oak forest is replaced by hornbeam and sweet chestnut (Castanea sativa), with beech forests dominating at higher altitudes. In some areas (Svaneti), beech forests begin to dominate at 600 m, with an understorey of Rhododendrum ponticum. Fir trees appear with the beech trees at 1,300 m, and Acer trautvetteri becomes dominant in the subalpine zone.

In eastern Georgia, semi-desert and steppe areas are replaced by forests of Georgian oak and hornbeam (Carpinus orientalis) on southern slopes. There is a narrow band of beech-hornbeam forest around 1,300 m, with forests of broad-leaved oak (Q. macranthera) at higher altitudes. On northern slopes, beech forests occupy extensive areas from 600 to1800 m above the Georgian oak/hornbeam forests. The maple (Acer trautvetteri) is also found in these beech forests, which are replaced at higher altitudes by birch forests, and finally by Rhododendron scrub above tree level. The high-altitude beech and birch forests are often characterized by their “crookstem” appearance.

Subalpine zone (1,900 to 2,500 m). Near the timberline, straight trunk forests reach their climatic limit and are replaced by low (“elfin”) forests of spruce, pine, fir, and beech in relatively dry and sunny areas, and by crookstem forests in moister areas, typically birch (Betula litwinowii), service tree (Sorbus aucuparia) and beech. All these forests are very diverse and floristically rich, including the regionally endemic birch species (Betula medwedewii and B. megrelica), and Pontic oak (Quercus megrelica).

Under certain conditions, a tall herbaceous vegetation, including several species of Aconitum, Cicerbita, Delphinium, Heracleum and Senecio occurs in the subalpine zone. This is unique among mountain ecosystems, including the Alps, Himalayas, and Pamir ranges. More typically, the vegetation of the subalpine zone consists of grass and grass/forb meadows. Dominant species are Calamagrostris arundinacea, Poa longifolia and Festuca varia.

Alpine zone (2,500 to 3,000 m). This zone is characterized by the dominance of short-grass meadows, the so-called “carpet-like” alpine meadows, alternating with thickets of Rhododendron caucasicum and rock scree vegetation. Above the alpine zone, in the sub-nival zone, environmental conditions are extreme. Nevertheless, more than 300 plant species occur here, with more than 100 of those being characteristic of the zone, mostly associated with rock and talus substrates.

Wetlands are represented primarily by the swamp forests and bogs of the western Georgia lowlands. Peat bogs are characteristic of the Kolkheti lowlands, but are also found at higher altitudes. In the lowlands, such bogs contain a number of relic and endemic plant species. Lakes and marshes, typically with reeds Phragmites and cattail Typha are found in the lowlands and along river valleys.

Flora

The flora of Georgia contains between 4,200 and 4,500 species of vascular plants. Of these, 9 percent are endemic to Georgia and 14 percent are endemic to the Caucasus. This is a high proportion compared with other, larger countries of Europe and Asia. There are a number of unique and representative plant communities and ecosystems of high biodiversity importance. More than 2,000 species are of direct economic importance, for timber, edible fruits and nuts, forage and fodder, medicine, industry and essential oil production. In addition, there are many rare and traditional cultivars and wild relatives of cultivated species. Ten species of vascular plants are known to have become extinct in Georgia. In addition, 50 are critically endangered, 300 are classified as rare, and 140 have undergone significant decline.

For Georgia’s forests, the following species are dominant: Eastern beech, 1,164,000 ha (42 percent); hornbeam, 298,000 ha, (11.8 percent); oak, 281,000 ha, (11.2 percent); alder, 200,000 ha, (7.2 percent); sweet chestnut, 105,000 ha, (3.8 percent); coniferous species, (fir, spruce, and pine), 455,000 ha, (17.4 percent).

Twenty-two (22) percent of Georgia’s forests are found at altitudes from 0 to 500 m, 24 percent from 500 to 1,000 m, 17 percent from 1,000 to 1,500 m, 17 percent from 1,500 to 2,000 m, and 20 percent above 2,000 m.

Most forests of the country are on the slopes of Great and Lesser Caucasus. Four percent of the forest area is on slopes from 0 to 10o, 16 percent on 11 to 20o, 17 percent on 21 to 25o, 19 percent on 26 to 30o, 20 percent on s 31 to 35o, and 24 percent on slopes steeper than 35o.

Broadleaved forests characterize Georgian forests (80 percent of the area and 69 percent of the volume). Beech (Fagus orientalis) is the dominant species, occupying 50 percent of the forested area. The second species group in terms of area coverage (10 percent) are the oaks (Querqus iberica, Q. cerris, Q. suber) followed by firs (9 percent), primarily Abies nordmanniana. Other important species are hornbeam (Carpinus spp.), spruce (Picea orientalis), pine (Pinus nigra, P. pinaster, P. silvestris), Birch (Betula spp.), Chestnut (Castanea sativa) and alder (Alnus spp.).

Relic and endemic species are widely distributed in Georgian forests, among them yew (Taxus baccata), Bichvinta Silver fir (Pinus pithycesa), Pterocaria fraxinifolia, Georgian hazelnut (Corylus iberica), Imeretian oak (Quercus imeretina), Zelkova carpinifolia, Pistacea mutica, Georgian maple (Acer iberica), etc. In total, 1,000 plant species are considered endemic. Of more than 400 species of trees, 60 naturally occur only in Georgia and another 43 only in the Caucasus region.

Fauna

The fauna of Georgia consists of species characteristic not only of Georgia and the Caucasus, but also of their areas of origin, such as southwestern Asia and the Middle East/east Mediterranean regions.

Invertebrates

Five hundred (500) representatives of butterflies and moths (Macrolepidoptera) have been described in Georgia, nearly a third of them endemic or relic species. Seven species of the family Papilionidae (swallowtails) occur in the country, including two endemics. Sixty-five (65) insect species from Georgia were included in the most recent Red Data book of the Soviet Union.

Vertebrates

Freshwater fish. Throughout Georgia there are 84 species of freshwater fish. Twenty-nine species are found in the basin of the Caspian Sea, of which 11 are also found in Black Sea basins. Twelve (12) of the native species are found only in the basin of the Mtkvari river, and 9 of these are endemic to this river and its tributaries. There are also 9 introduced fish species. Throughout the basin of the Black Sea, there are 66 species of fish, including 2 introduced species. Six are endemic to the Kolkheti region, including the economically important Varicorhinus spp. The conservation status of most Georgian fish is not known. Acipenser sturio (sturgeon) and Salmo trutta labrax (salmon) were included in the Soviet Red Data book. Other sturgeon and trout species are also likely to be under threat. The status of the endemic species of the river Mtkvari and of Kolkheti needs further study.

Amphibians. Four species of newts and nine species of frogs and toads are found in Georgia. One species is endemic to Georgia and two to the Caucasus. Recently, the range of Pelobates syriacus has declined alarmingly, and that of Triturus vittatus ophryticus is also decreasing.

Reptiles. Fifty-three (53) reptile species occur throughout Georgia, consisting of 3 tortoises, 27 lizards and 23 snakes. Of these, 3 snakes and 12 lizards are endemic to the Caucasus. Six reptiles are included in the Georgian Red Data book. Seven reptiles having the largest part of their range in Georgia are vulnerable. The ranges of Vipera lebetina, Eumeces schneider and Eryx jaculus have been declining for the past 10 years.

Birds. Three-hundred-and-sixty (360) bird species have been recorded in Georgia. Because of their mobility, there is a lower level of endemism among birds compared to other groups. Caucasian snowcock (Tetraogallus caucasicus) and Caucasian black grouse (Tetrao mlokosiewiczi) are alpine species endemic to the Caucasus. Disjunct populations of great rosefinch (Carpodacus rubicilla) and Guldenstadt’s redstart (Phoenicurus erythrogaster) occur in the Caucasus, where they breed at high altitudes, but winter in alpine valleys. Here they appear to be dependent on thickets of berry-bearing shrub, Hippophae rhamnoides, which are threatened with overcutting by local shepherds. Some 100 species are migratory and appear in the country on passage or during the winter. Many species are dependent on wetland habitats, which are under severe threat in Georgia and the region. Birds of prey, including vultures, are well represented in Georgia, which is also an important migratory pathway. The smaller species of hawks are regularly trapped in the migration period. Seventeen (17) bird species are globally threatened and included in the IUCN Red Data list.

Mammals. There are 68 species of small mammals in Georgia. Nineteen (19) of these species are endemics. Fifteen (15) of them have not had their conservation status evaluated, and for about 30 further species there is not enough information to assign them to a category. Seven species are endangered and five are vulnerable, with 20 classified as being out of danger. Large mammals include 27 species of carnivores and ungulates. Up to the beginning of this century, these species were widely distributed across the country. For example, the ranges of the Asian leopard (Panthera pardus), lynx (Felis lynx), and wolf (Canis lupus) covered practically the whole country. The striped hyena (Hyaena hyaena) was common in all arid zones of the country. In the Black Sea, three species of dolphins and porpoises are found.

Agrobiodiversity

Agriculture in Georgia can be traced back to the 5/6th millennium B.C., when Kartvelian (Georgian) tribes began to domesticate basic crops such as wheat, barley, oat, rye, and grain legumes (pea, chickpea, lentil, fava bean), as well as fruit species (plum, cherry, quince, grape) and other crops.

Having first developed the concept of centers of crop plant biodiversity in 1926, the Russian agricultural scientist Vavilov described Georgia as being part of a Southeast Asian Center of Agrobiodiversity (containing the Caucasian Center, the Near Eastern Center and the Northern Indian Center). More recent studies have placed Georgia in an enlarged Near Eastern Center, which includes the Fertile Crescent, the Caucasus, and all of Turkey. It is important to note that whichever center description is used, the different authors all agree that Georgia, with 23 soil-climatic zones in only 70,000 km2, possesses a unique plant diversity and a species composition that significantly differs from that of its southern neighbor Armenia.

Indeed, Georgia has a very rich flora of crop plants, both in terms of number of crop species (about 100 families and 350 local species of grain-crops) as well as in terms of intraspecific variability. There are numerous endemic cultivated taxa, such as Triticum karamyshcevii, Pisum sativum, Staphylea colchica, Triticum carthlicum, Vicia faba, Triticum timophevii, Staphylea pinata, Vitex agnus-castus, Trieicum macha, and Trieicum zhukovskyi.

The variability within crop species is significant and well documented for some indigenous varieties (Triticum aestivus, Vitis vinifera, etc.) as well as for introduced species (Phaseolus vulgaris, Glycine max, Zea mays, etc). As far as the latter is concerned, Georgia is a secondary center of diversity. For instance, the garden bean (P. vulgaris), introduced in the second half of the 16th century, shows a striking variability in growth form, leaf shape and size, flower coloration, color and structure of pod, as well as in time of maturity. For example, 48 seed variants have been detected in the East Georgian province of Kakhetia.

Georgia’s rich agrobiodiversity is threatened by the introduction of cultivars of a few popular species, and by the erosion of traditional knowledge and practices for conserving agrobiodiversity.

There is also a rich diversity of fruit trees. This group of plants is composed of more than 100 species of seed and stone fruit trees, nuts, and wild berries. Among others of particular importance, the group includes Amyygdalus communis, Cerasus mahaleb, M. pumila, Pyrus communis, and Cydonia oblonga. Of an estimated 500 local varieties of grapes, only 300 still exist in seed or live collections in scientific research institutes and peasant farms.




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