However, both statistical and other information usually considers the Caucasus in terms of its political and administrative borders. In this respect, there are traditionally three South or Trans-Caucasus countries: Armenia, Azerbaijan and Georgia, and autonomous republics and krays (regions) of the North Caucasus: Krasnodar and Stavropol krays, and the republics: Adigeya, Karachaevo-Cherkessia, Kabardino-Balkaria, North Ossetia, Ingushetia, Chechnya and Dagestan, which are the parts of the Russian Federation. Thus, in the CEO report the Caucasus is treated from this viewpoint.

There are changes recently ongoing in sub-dividing the Caucasus into the "North Caucasus" and "Trans-Caucasus". For specialists from Russia and other northern neighbouring countries who study Caucasus issues, Armenia, Azerbaijan and Georgia are located beyond the Greater Caucasus. That is why the region was traditionally called "Trans-Caucasus". However, after the break-up of the Soviet Union, there appears to be another geographical understanding of the location of these three countries. That is why frequently scientific and political publications refer to the region as the "South Caucasus", involving the territory of three new independent states. The name "Trans-Caucasus" remains only in a physical-geographic sense, and its border is located at the Main Caucasus Range. In this respect, part of the Russian Federation (the Black Sea coastline) is in the Trans-Caucasus and the regions of North Georgia (upstream of the rivers Terek, Assa, Argun and Andian Koisy) and northeast Azerbaijan (the city of Kuba and adjacent to it Mukhtadir, Divichi, Siazan and Kusary regions) belong to the North Caucasus.

The Russian Federation is now consists of seven federal districts (okrugs). Krays and republics of the North Caucasus are within the South Federal District. Rostov, Astrakhan and Volgograd regions (oblasts) and the Republic of Kalmykia are included in it. If the entire South Federal District of the Russian Federation belonged to the Caucasus, its border would move sharply to the north and the territories added to the Caucasus would have nothing in common with the Caucasus itself, in a physical-geographical and environmental sense.

The North Caucasus involves two completely different parts. The first is represented mainly by pre-Caucasian plains, and in the majority of cases is settled by Russians. There are two krays (regions) of the Russian Federation: Krasnodar and Stavropol. It is one of the richest regions of the Russian Federation, and is characterised by relative political stability.

The other part is connected with the North Caucasus autonomies (Adigeya, Karachaevo-Cherkessia, Kabardino-Balkaria, North Ossetia, Ingushetia, Chechnya and Dagestan), mostly located in the mountains and foothills of the Greater Caucasus. They have diverse ecological and geographic conditions, with their population consisting of local ethnic groups and the regions differing in terms of political stability.

A "backbone" of the Caucasus is the Main Caucasus Range, which extends from the Taman peninsula on the Black Sea, to Absheron peninsula on the Caspian Sea. This range has a direction from northwest to southeast and is 1,500 km. in length. Its highest peak is located in the central part (Mt. Elbrus). Unlike the Alps, the Main Caucasus Range does not have easily accessible passes. The Jvari (Cross) pass is an only motorway laid in the high mountainous part of the Central Greater Caucasus, and thus the Main Caucasus Range remains a difficult barrier to cross.

It is noteworthy that there are many commonalties in the economic and socio-cultural aspects of its northern and southern slopes. Hence, the Greater Caucasus is often considered a single geographic region.

Geopolitical Location and Ethnic Composition. On the west, the Caucasus is washed by the Black and Azov Seas. The northern border passes the Kuma-Manich depression. Therefore, the North Caucasus joins the rest of the Russian Federation. To the east, there is the Caspian Sea, on the eastern coast of which Kazakhstan and Turkmenistan are located and on the southern coast Iran. On the southern border of the Caucasus lie Iran and Turkey.

The national and religious composition of the neighbouring countries has a great influence on the geo-political situation of the Caucasus.

Along with Georgians, the Caucasian language family involves Abkhazs, Chechens, Circassians, Kabardins, and the major ethnic groups of Dagestan.

The Indo-European language family involves Slavs (Russians, Ukrainians, Bulgarians), ethnic Iranian groups (along with Persians, there are Kurds and Ossetians) and Armenians.

The Turkish language group (the majority of population of Turkey, Azerbaijan, Central Asian republics and some minorities of the North Caucasus: Karachais and Balkars) belongs to vast Altai language family.

The Caucasus is located in the geopolitical region where Christian and Moslem worlds are closely inter-related. Religion has a great influence on ongoing political processes in the Caucasus and its surroundings.

Key transport corridors are located in the Caucasus, with the shortest route from Middle and Central Asia to Europe passing through the Caucasus.

The transport lines connecting Russia with Turkey and Iran also pass via the Caucasus, and are of great importance as well. Nevertheless, use of the favourable geographical position of the Caucasus for transport is complicated by political and ethnic conflicts. Due to this, many routes traversing the Caucasus remain blocked.

The Caucasus environment is much influenced by existing and planned oil and gas pipelines. The struggle for access to the region’s natural resources and adjacent territories considerably influences the political situation in the Caucasus.

Major Physical-Geographic Characteristics. The Caucasus is in the central part of the Alpine-Himalayas mountain chains, starting on the coast of the Atlantic Ocean, embracing the Mediterranean Sea and Middle East, and via the Caucasus leading to the Himalayas.

In terms of climate, the Caucasus is at the junction of sub-tropical and moderate zones. The border between them passes along the Main Caucasus Range.

Among six floristic worlds globally, the largest area is the Holartic, embracing a greater part of the entire Northern Hemisphere; the Caucasus is located in its southern part. In terms of its vegetation cover as well, the Caucasus is at the junction of the sub-tropical and temperate zones.

In terms of its fauna, the Caucasus belongs to the Arctoge, which coincides with the Holartic world with some exceptions.

There are eight physical-geographical regions in the Caucasus. The Pre-Caucasus (or North Caucasus plain) is fully located within the Russian Federation and consists of lowlands and lower elevations. The Greater Caucasus is represented by high, difficult to pass mountains. The highest among them Mt. Elbrus reaches 5,642 m. The Trans-Caucasian Depression represented by the humid sub-tropical Colchida and relatively arid East Trans-Caucasus is located to the south. The moderately elevated Likhy (Suram) Range serves a natural divide and is important as a climatic determinant. The Lesser Caucasus consists of relief of medium elevation and generally encloses the arid Armenian Highlands. There are two small, but very specific physical-geographic regions: the North Black Sea (with features of Mediterranean Climate) and Hyrcan (with humid sub-tropical climate and extremely distinct Hyrkan flora) at the northwest and southeast frontiers.

The Place of the Caucasus in the World. Table below presents some important characteristics of the Caucasus. For comparative purposes, average world data and deviations of the Caucasus region from these are given. Analysis of this table enables one to estimate the Caucasus contribution to global processes.

Within the scale of the entire planet, the Caucasus is a medium-sized region. Its total area makes up less than half a percent of the land area of the Northern Hemisphere.

Although the Caucasus is considered a highland region, its average height is 268 m less than the global average. However, if only the Greater and Lesser Caucasus geographical regions are considered, these are 638 m higher than the global average.

In terms of thermal conditions, on average, it is colder in the Caucasus than in other regions of the same latitude. It is as if the Caucasus was actually located several degrees of latitude further northward. It is colder by 4.5 C in January and by 2.8 C in July in the Caucasus. Only in Colchida are the January temperatures close to mid-latitude ones. In the remaining regions, it is relatively colder, with the cooling influence of the powerful Siberian anti-cyclone and results of penetration of cold arctic masses into the Caucasus.

In summer, the temperature of the Caucasus overall is close to mid-latitude values, and in the regions with a relatively continental climate (East Trans-Caucasus), it is 3-5 C higher. The average annual temperature in the Caucasus is 3-5 C lower than that in the same latitudes.

On average, it is drier in the Caucasus than across the globe, with the difference in precipitation reaching nearly 400 mm. If one compares the Caucasus values with mid-latitude precipitation, the Caucasus varies from the global average value by nearly 200mm.

Usually, there is higher humidity in landscapes of Colchida and the Greater and Lesser Caucasus than that in other mid-latitude regions. At the same time, in other Caucasus regions, it is 1.5-2 times more arid.

In terms of thermal and water regimes, the Caucasus overall lags behind average world values, and therefore is like an island of cold and of relative (but not absolute) dryness on our planet.

The Caucasus receives less solar radiation than other mid-latitude regions. However, the difference in this index is less notable than those for thermal and moisture indices. It is noteworthy that lower temperatures compensate for the insufficient amount of precipitation and thus, in the light of the difference in radiation balance, average values of heat for evaporation for the Caucasus and other mid-latitude regions are practically equal to each other.

In terms of radiation balance, only Colchida may be considered a sub-tropical region with landscapes characteristic of such regions (the radiation balance is more than 50 kcal/cm sq.). East Trans-Caucasus and part of the Armenian Highlands are characterised by landscapes ranging from temperate to subtropical.

With values similar to mid-latitude values for evaporation, water flow in the Caucasus is nearly two times lower than average latitude values. Consequently, the heat and water balance is maintained mostly through evaporation, which is close to average latitude indices. Lower values of radiation balance are compensated for by low turbulent heat exchange values. A reduction of water flow, rather than a reduction of evaporation compensate for lower precipitation.

Specific Features and Key Problems. One of the major peculiarities of the Caucasus is high landscape diversity of the region. By this index, the Caucasus occupies one of the highest ranks in the world. A broad spectrum of landscapes is found in the region, starting from humid to arid, from sub-tropical to glacial-nival and from low- to highlands. Based on rough calculations, over 40% of landscape types are existent in the Caucasus, which occupies only 0.5% of the global land area. The Caucasus is thus truly a “landscape laboratory” of the world.

Figure “Relief of landscapes diversity of the Northern Hemisphere”, or landscape diversity calculated by a five-degree latitude-longitude grid, shows the relief of diversity in the form of a volumetric diagram. On its X and Y-axes, latitudes and longitudes of the Northern Hemisphere are plotted respectively. The height of separate cells corresponds to their landscape diversity, the diversity peaks being easily visible. As it is clear from the figure, the highest level of diversity is characteristic of the Caucasus, the Black Sea region and the north-eastern part of the Himalayas. These regions greatly surpass other parts of the world in terms of landscape diversity, and thus represent “peaks” of landscape diversity globally.

Similarly, the world map of the number of landscapes on a 10 degree-step grid shows that the Caucasus falls into the category of regions with the highest landscape diversity, Georgia being within the group of the first ten countries. By the number of landscapes per unit of area (10,000 km sq.), Georgia appears in first place, far ahead of all other countries.

In terms of biological diversity, the Caucasus lags behind tropical countries, but occupies first place among other regions of the same latitude. The Caucasus is characterised by a high level of endemism: nearly one-fourth of all species are endemic. The Caucasus flora and fauna include many relict species, which have been preserved and inherited from warmer and more humid periods.

The high biological diversity of the Caucasus is determined by the region being situated at the junction of temperate and sub-tropical zones, and being affected by both mild Atlantic air masses and the dry continental air of Eurasia. Because of this and its unique natural history, the Caucasus represents a remarkable sub-region in terms of biodiversity.

One further major peculiarity of the Caucasus is the existence of a comparatively large amount of intact ecosystems and even virgin landscapes. Such landscapes occupy nearly one-tenth of the Caucasian land area.

Overall, the Caucasus is a region, with a relatively clean environment and few environmental “hot spots”.

Finally, one of the specific features of the Caucasus is the high ethno-cultural mosaic of its territory. Many ethnic groups live in the Caucasus, which profess different religions and have quite specific ethno-cultural traditions. In Dagestan alone, in an area of less than 50,000 km sq., there are more than 40 ethnic groups speaking different languages. Very often villages located in neighbouring river gorges do not understand one another, and their populations can only communicate in Russian, which is a state language there.