Hard natural climatic and mountain-formation processes promoted favorable penetration of plant and animal species from neighboring botanical and geographical zones, hybridization, and appearance of new species. Numerous types of ecotopes, biocoenosis, and ecosystems, in contrast combination, were formed in this environment of a relatively small area. Later, as a result of the climate aridization, in a short period of time, the unique ecosystems appeared under the extreme conditions of development in restricted mountainous area with high anthropogenic load. Many natural ecosystems have a considerable anthropogenic impact, some are endangered to complete degradation; a threat to their ecological balance disturbance is growing.
Mountain ecosystems include: nival-glacier, high-mountain-desert, meadow-desert, forest, most of wetland, ruderal, and, sometimes, urban ecosystems.
More than 80% of natural watercourses of the country are located in high mountainous areas. The foothills contain a small part of meadow-steppe ecosystems, situated in the lower reaches of the Pyandj, Vakhsh, Kafirnigan, Zeravshan, and Syrdarya rivers. Relatively young ecosystems, with a small number of species, are formed in the artificial watercourses.
Agricultural, ruderal-degraded, and partly urban ecosystems occur in all mountain zones, except for nival.
The main species of valuable forest and meadow communities are accumulated in mid-high and high-mountain zones. The latter contain larger mammals, reptiles, and birds.
Geographically, the ecosystems of Tajikistan are subdivided into mountain and foothill-plain ecosystems
Mountain ecosystems occupy the altitudes from 600 to 7000 masl. This zone contains over 90% of mountain communities. Water resources are formed in mountain ecosystems; over 80% of biodiversity are accumulated here. Most of the areas are highly productive summer pastures.
Foothill-plain ecosystems are located on the flat areas of mountain zones and include: foothill semidesert-desert, wetland, agricultural, urban, and ruderal-degraded ecosystems.
According to their use, ecosystems are subdivided into natural and anthropogenic. The interrelation of ecosystems dependent on the areas and the number of population is shown in figure 1.11.
A considerable part of the country possesses natural and relatively undisturbed ecosystems due to their isolation. Though some small fragments of ecosystems are observed at easily accessible places.
1. Nival glacier ecosystemsoccupy high-mountain landscapes of the country, considerable part of the Eastern and Western Pamirs. They are of great importance for climate formation and ecology at the regional and global level. The main water resources of Central Asian region are formed here. The cold glacial rocky landscapes of these ecosystems contain 16-17 species of flowering plants: ragged robin (Melandrium apetalum), whitlow grass (Draba altaica), milk vetch (Astragalus nivalis), Saussurea glacialis, etc. Rare and endangered large mammals listed in the Red Data Book - argali (Ovis ammon polii), snow leopard (Uncia uncia), and Siberian ibex (Capra sibirica) - are found at the lower boundaries of these ecosystems.
These are areas of world mountain-climbing, tourism and international hunting. The long-term tourist and mountain-climbing activity resulted in the area pollution with garbage producing a negative effect on the quality of water in the below rivers.
2. High mountain desert ecosystems occupy the vast areas of the Eastern and Western Pamirs; fragmentarily, they occur in the Zeravshan River Valley. They are used for summer pasturing, tourism, and international hunting. Vegetation consists mostly of teresken (Сeratoides Krascheninnikovia), wormwoods (Artemisia pamirica, A.Korshinskyi), Ajania tibetica, feather-grasses (Stipa glareosa), Oxytropis immerse, Acantholimon diaspensioides, A.pamiricum. They sustain the ecological balance and are used as forage areas. The most valuable communities are wormwood-teresken and meadow-steppe. They include some endemic, rare, and endangered plants - Badakhshan dandelion (Taraxacum badachschanicum), Pamir desederia (Desideria pamirica), etc.
The main background animals are: argali (Ovis ammon), snow leopard (Uncia uncia), Siberian ibex (Cаpra sibirica), red marmot (Marmota caudata), and Syrrhaptes tibetana, as well as some nature embellishing butterflies: machaon (Papilio machaon), apollo (Parnassius apollo), and alexanor (Papilio alexanor).
As the anthropogenic impact on the vegetation and animal worlds is increasing, pastures are degrading, causing reduction of the areas and populations of wild animals. In recent ten years, poaching alone caused a drop in numbers of argali and Siberian ibex by 50%.
The current measures on animal and plant conservation are low-efficient. Even the creation of the National Park, comprising nearly 40% of these ecosystems, cannot improve their condition.
3. High-mountain meadow and steppe ecosystems occur fragmentarily, sometimes as wide belts, in all mountain ranges of Tajikistan and are of great ecological importance. The great part of the ecosystems includes habitats of rare endemic mammals, birds, insects, and valuable vegetation communities. Grass productivity of meadow and meadow-steppe ecosystems is 5-6 times higher as compared to others. They make over 90% of summer pastures.
The main coenosis-forming species of this type of ecosystem are: fescue (Festuca alaica, F.pamirica), feather grass (Stipa kirghisorum), meadow grass (Poa alpina), sedge (Carex melanantha, C.stenocarpa), cobresia (Cobresia stenocarpa), Oxytropis savellanica, thyme (Thymus seravshanicus), etc. The most valuable communities include forbs meadow and steppe, and thyme swamp, most common in the high mountains of the Eastern and Western Pamirs. The forbs meadow-steppe and thyme ecosystems are typical for Central and Northwestern Tajikistan. In overgrazing areas, the ecosystems are strongly degraded (over 30% of the total area), the grass productivity being reduced from 20-25 to 10-12 centners per ha. Periodically, the communities lose the most valuable species, including at least 150 rare and endangered species. The animal world of these ecosystems includes: snow leopard (Uncia uncia), argali (Ovis ammon polii), red marmot (Marmota caudata), Syrrhaptes tibetana, Siberian ibex (Capra sibirica), Tibetian snow partridge (Tetrogallus tibetanus), etc.
This type of ecosystems is an intermediate link between forest (low borders), subnival and nival ecosystems (top borders). Many communities of this type become secondary due to the anthropogenic impact.
4. Mid-mountain conifer forest ecosystems compose nearly 50% of the total forested areas of the country. They are common in northern Tajikistan, within the Kuramin, Turkestan, and Zeravshan ranges. In small fragments, they occur in Central, Southwestern Tajikistan, and in the Western Pamirs mountains. Juniper and light forests are important for regulating and conserving water resources, protecting slope soils, fortifying river banks, and preventing mudflows.
Juniper forests and light forests are represented by 4 species: Juniperus seravschanica, J.turkestanica, J.semiglobosa and J.sibirica, among which Zeravshan juniper (J.serav-schanica), Turkestan j. (J.turkestanica), and semicircular j. (J.semiglobosa) are forest-forming species.
There are some rare and endangered animal species in the juniper forests: Tien Shanian brown bear (Ursus arctos), urial (Ovis vignei bochariensis), Tajik markhur (Capra falconeri), Vipera lebetina, and ring dove (Columba palumbus).
The most valuable communities are motley-shrub-steppe and forbs-meadow juniper forests.
The main juniper and light forest areas are annually reduced by 2-3%. Nearly 30% of their specific diversity is endangered.
The main reasons for worsening the state of juniper forests are:
5. Mid-mountain mesophyllic forest ecosystems are represented by maple-walnut and willow-poplar-birch forests with light forest mesophyllic shrubs. They are important for the socio-economic activity (gathering fruit and berries) and sustain the ecological balance. These forests contain a considerable number of rare endemic species of animals and plants. They are suitable for an optimal life and recreation zones. They are common all over the country, except for northern and southern Tajikistan.
The most valuable communities of these ecosystems - broad-leaf mesophyllic relict forests: walnut (Juglans regia) and maple (Acer turkestanicum) - are widespread in Central Tajikistan. Great areas of small-leaf forests - birch (Betula tianschanica) - occur in the Zeravshan River Valley, within the Karateghin Range, and in the Western Pamirs; mesophyllic shrubs are mainly observed in Central Tajikistan.
The most valuable walnut-maple forests are located in the Sarikhosor, Childukhtaron, and Dashti-Jum zakazniks. These forests include a considerable number of rare and endangered species of flora and fauna. Among plants, there are: Victor's ungernia (Ungernia Victoris), magnificent ostrowskia (Ostrowskia magnifica), cousinia darvazica (Cousinia darwasica, Cousinia leptocampyla), Hissar iskandera (Iskandera hissarica), Yagnob feather grass (Stipa jagnobica); mammals: weasel (Mustela pallida, М.n.heptneri), Turkestan lynx (Felis lynx), snow leopard (Uncia uncia), urial (Ovis vignei bochariensis), Tien Shan brown bear (Ursus arctos), yellow porcupine (Hystrix leucura); birds: ring dove (Columba palumbus), pheasant (Phasianus colchicus), golden eagle (Aquila chrysaetus), and Egyptian vulture (Neophron percnopterus), etc.
The forest vegetation communities have a considerable number of wild relatives of fruits: apple (Malus), pear (Pyrus), cherry plum (Prunus), hawthorn (Crataegus), barberries (Berberis), and other species, which form a favorable environmental niche for large mammals, including rare and endangered species.
Forested areas are annually reduced, while no restoring work is carried out. Nearly 50% of flora and fauna species are endangered
6. Mid-mountain xerophytic light forest ecosystems occupy vast areas of southern and western Tajikistan; small fragments occur in northern Tajikistan. They include: pistachio, forbs wormwood, almond. In dry hot regions, pistachio forest's function is to regulate water resources; they also are an optimal habitat for wild animals from arid zones. No natural restoration of pistachio forests occurs due to their intensive use as pastures and haylands. Vast areas (80%), earlier occupied by pistachio communities, are now overgrown with shrubs.
The animal world of this ecosystem type is much richer than that of others. Of large mammals, there are: Persian gazelle (Gazella subgutturosa), urial (Ovis vignei bochariensis), wolf (Canis lupus), fox (Vulpes vulpes); reptiles: Central Asian cobra (Naja oxiana), and steppe tortoise (Testudo horsfieldi).
This type of ecosystems contains wild relatives of barley (Hordeum spontaneum), vetch (Vicia tenuifolia), almond (Amygdalus bucharica), persimmon (Diospyros lotus), jujube (Zizyphus jujuba), pomegranate (Punica granatum), grapes (Vitis vinifera), etc. They become secondary communities due to intensive cuttings. Large areas of winter pastures, non-irrigable crops, and settlements, situated in these ecosystems, cause a reduction of xerophytic light forest areas.
In order to preserve and sustainably manage this type of ecosystems, cattle grazing in young pistachio forests has to be completely stopped, protected area should be created to preserve the unique high-altitude communities and rare endemic animals (urial, Tajik markhur, Persian gazelle, etc.)
7. Mid-low mountain semisavanna (savannoide) ecosystems are widespread in southern and northern Tajikistan. They develop under hot climatic conditions.
Here, a considerable part of animals and insects with summer aestivation period dwell. High-productive winter pastures and leguminous crops are common. Vast areas of these ecosystems (40-50%) have degraded pastures, thus became low-productive.
The main valuable communities of this type are high-grass and forbs-shrub communities. The dominant species are: barley (Hordeum bulbosum), meadow grass-sedge (Poa bulbosa, Carex pachystylis), ferule (Ferula kokanica, F.kuhistanica), Jerusalem sage (Phlomis bucharica), etc.
The animal world, except for insects, is presented by a small number of species with summer and winter aestivation periods. Background amphibians are: steppe tortoise (Testudo horsfieldi) and Ophisaurus apodus. Rare and endemic species are also found here : seesee partridge (Ammoperdix griseogularis), white bustard (Otis tarda), skink (Eumeces schneideri), Persian gazelle (Gazella subgutturosa), Turkestan saker falcon (Falco cherrug), and golden eagle (Aquila chrysaetus).
Vast areas of these ecosystems (70%) are strongly degraded. The main reasons of the degradation are:
8. Foothill semidesert-desert ecosystems occupy high terraces of the plains in the lower reaches of large rivers: Pyandj, Vakhsh, Kafirnigan, Syrdarya, and Zeravshan.
The major communities of this type are: saxaul, black saxaul, calligonums, and perennial saltwort thickets. They play an important role in protecting soils, preventing erosion, and providing winter pasturing. These ecosystems include 30-40% of the total winter pasture areas, most of which are degraded and cultivated for irrigable agricultural crops. One can find here endemic animal species of regional and global value, many of which are endangered.
The vegetation dominants are: saxaul (Haloxylon persicum), calligonum (Calligonum litvinovii), saltwort (Salsola richteri), wormwood (Artemisia tenuisecta), harmel (Hammada leptoclada), sedge (Carex physodes), halostachys (Halostachys belangeriana), halocharis (Halocharis hispida).
The animal world of the ecosystems is represented by unique species which are adapted solely to open areas, with rare vegetation and hot and dry climate. Mammals are represented mainly by: Persian gazelle (Gazella subgutturosa), jakal (Canis aureus), big-eared hedgehog (Paraechinus hynomelus), and steppe cat (Felis libyca).Of reptiles, there are: steppe agama (Agama sanguinolenta), gray monitor lizard (Varanus griseus), shaft-snake (Taphrometopon lineolatum), and sand echis (Echis carinatus); of insects the xerophyllous species prevail.
In southern Tajikistan, nearly 30 thousand hectares of this ecosystem type are near-protected areas of the Tigrovaya Balka Reserve. Considerable areas of the sand-desert ecosystems are cultivated for cotton growing.
9. Wetland ecosystems include tugai (sometimes tugai forests), meadow-swamp (the river lower reaches), and wetland ecosystems.
They are very important for the preservation of the global ecological balance, particularly for regulating the numbers of waterfowls of Eurasia, as some waterfowls of the continent hibernate here. Due to the worsening state of the Aral Sea, numerous waterfowls (from the Amudarya River lower reaches), among which there are rare and relict species, have found "shelter" and new habitats in the tugai of the Tigrovaya Balka Reserve.
The watercourses of the southern landscapes of Tajikistan are the base of water game species development and provide sustainable reproduction of fish, fur-bearing animals, and birds
In the presence of biomass, tugai ecosystems equal subtropical forests of South Asia.
The world intact tugai ecosystems have been preserved only in the Tigrovaya Balka Reserve. 645 plant species, over 70% of which are assigned solely to tugai, and nearly 30% are common of meadow-swamp and sand-desert ecosystems, are defined here.
The main vegetation dominants are: Populus pruinosa, elaeagnus (Elaeagnus angustifolia), desert thorn (Lycium dasystemum), macereed (Typha angustifolia), alang grass (Imperata cylindrica), bur reed (Phragmites communis), sugarcane (Saccharum spontaneum), Kashgar tamarisk (Tamarix hispida), black grass (Juncus articulatus), etc.
The animal world of the tugai is much richer than that of the sand-desert ecosystems. Many of the animals find shelter in the tugai, where the following bird species hibernate: white and gray herons (Egretta alba, Ardea cinerea), bittern (Botaurus stellaris), garganey teal (Anas querguedula), European teal (A.crecea), marsh harrier (Circus aeruginosus), mud hen (Rallus aquaticus), moor hen (Gallinula chloropus), pheasant (Phasianus colchicus), pygmy cormorant (Pholacrocarax pugmeus), great cormorant (Ph.carbo), serpent eagle (Circaetus ferox), etc. The background species of the tugai mammals are: jungle cat (Felis cnans), jakal (Canis aureus), Bukhara Red deer (Cervus elaphus), etc.
The biodiversity specific composition of watercourses is usually variable. Mountain and high-mountain water reservoirs mainly contain the Arcto-alpine species of sedge (Carex diandra, C.oliveri, C.stenocarpa, C.parva), cobresia (Cobresia pamiroalaica, C.capillifolia, C.persica, C.stenocarpa), meadow grass (Ranunculus songoricus), primrose species (Primula capitellata, P.Kaufmanniana, P.algida, P.farinose, etc.). The low-mountain and plain reservoirs are characterized by the presence of common horsetail (Equisetum arvense), macereed (Typha angustifolia), potomogeton (Potomogeton crispus), anagalis (Anagalis arvensis), sedge (Carex orbicularis), bur reed (Phragmites communis), and many others.
Nearly 330 species of higher plants inhabit water reservoirs of Tajikistan; 145 of these are typical solely of the mountain and high-mountain areas, others are water and wetland in the low-mountain and plain areas of the country.
The biodiversity of wetland ecosystems is very important for keeping the natural balance and improving the socio-economic situation in the country. The vegetation and animal organisms inhabiting the reservoirs form organic and mineral complexes. They promote water purification, regulate the mountain water regime, enrich both water and air with oxygen. Many wetland plants are used as haylands, pastures and forage for cattle, though the overgrowing of plain water areas with thick grass is harmful for some fish species raising.
Currently, the biodiversity of foothill wetland ecosystems is in the most critical state, as they are contaminated with a great volume of water flowing from irrigated lands.
These ecosystems include agricultural, urban, and ruderal-degraded areas. Over 30% of the country area has been transformed into anthropogenic systems which meet the general needs of the population. Increasing the anthropogenic impact on the environment, without considering its capacity, is dangerous for the socio-economic development. It is particularly well observed in the mountain agricultural areas.
10. Agroecosystems (agricultural ecosystems) are located in all natural zones, from hot foothills (300 masl) to high-altitude deserts of the Eastern Pamirs (3000-3500 masl). The main varieties of agricultural crops, local species of wild relatives of cereals, leguminous, industrial, vegetation and melon, and forage plants (genetic resources) grow on unprotected areas.
In recent decade, the area of the agricultural ecosystems has been considerably increased, particularly due to the development of rain-fed and irrigable lands, which, together with pastures, are estimated at slightly over 4 m. ha. 1550 varieties of fruits and berries, 463 - vegetable and melon, 46 - cereal, 39 - leguminous, 25 - industrial, 39 - forage, and about 1850 decorative crops are raised and adapted to local environment within wide range of soil and climatic conditions. Nearly 50% of the cultivated crops are local varieties. There are about 30 breeds of domestic animals.
Most vivacious example of conservation of the animals genetic pool is the extension of yaks habitats within mountainous Tajikistan.
Violation of the regulations of agricultural irrigational technologies and crop rotation results in annual destruction of soil fertile layer, salinization and swamping of some areas; this is primarily due to the destruction of soil-forming fauna and flora. Steep-sloped lands are prone to landslides.
11. Urban ecosystems comprise the cities of Dushanbe, Khudjand, Isfara, Kanibadam, Istravshan, Kulyab, Kurgan-Tybe, Tursunzade, large settlements, and industrial enterprises. They are located in the most vulnerable environmental areas (forests, river banks, lakes, ponds, etc.). Here, the main structure of natural ecosystems is completely destructed, the process being irreversible. The urban zone around the cities is being increased, new system of water supply, central heating, sanitary-purifying zones, and green plantations, which is to be maintained artificially, being created. The ecological load on the area unit is increasing annually, while measures on stabilization get more complicated. The majority of introducent species are found in urban ecosystems including cities.
12. Ruderal-degraded ecosystems occur in all zones of human activity, being particularly well observed in cattle breeding areas. Stable communities adapted to external impacts are formed locally in high-mountain pastures and in low-mountain areas.
On the pastures and sown areas, the most dangerous plants for people and animals are: colchicum (Colchicum luteum), Thermopsis dolichocarpa, Trichodesma incanum, heliotrope (Heliotropium dasicarpum), and some wormwood species (Artemisia). The main dominant communities of ruderal ecosystems are the representatives of compositae (Compositae), cereals (Gramineae), buckwheats (Polygonaceae), meadow grasses (Ranunculaceae), St. John's-worts (Guttiferae), and often labiates (Labiatae).
Ruderal ecosystems of the foothills are generally represented by one species open plant communities: caper (Capparis spinosa), fragments of wall barley (Hordeum leporinum), annual saltworts (Salsola pestifera, S.turkestanica, S.forcipitata), and camel's thorn (Alhagi kirghisorum).
Ruderal communities of the low-mountain zone are represented by Cynodon dactilon, Prosopis farcta, cousinia (Cousinia Olgae, C.polycephala, C.ambigens, C.dichromata, C.microcarpa, C.radians, C.pseudoarctium, etc.), and forbs.
Licorice, together with reed (Saccharum spontaneum) and camel's thorn (Alhagi kirghisorum), are formed after cuttings in the forest ecosystem zone. Imperata cylindrica is usually formed in the deserted fallow lands of the light forest zone.
In the sites of long-term pasturing in the sub-alpine zone, Rumex Paulsenianus and Polygonum coriarum are formed.
In the alpine zone, ecosystems are represented by wormwood species, combined with meadow-steppe vegetation.
The ruderal type is characterized by a displacement of typical zonal ecosystems to interzonal, in most cases from the lower belts. The flora of the ruderal ecosystems consists of 690 species and 30 communities.
The weed-ruderal species and communities are very dangerous for the forest communities, preventing the restoration of wood varieties. The low-mountain areas are characterized by monodominant communities of dwarf shrubs and rude grass, which hamper the development of leguminous crops and valuable forb grass