The Caucasus Biodiversity Hotspot is one of 36 hotspots in the world and the region of Aragvi is a part of it. The Caucasus hotspot has the greatest biological diversity of any temperate forest regions in the world, incl. more than 6500 species of vascular plants, at least 1600 of which (25 %) are endemic. Its forests, high mountains, wetlands, steppes and semi-deserts contain more than twice the plant and animal diversity found in adjacent regions of Europe and Asia.
The extraordinary vertical span (840–3842 m asl) gives the Aragvi PL wide range of habitats and high species diversity. The PL is covered by one of the Priority Conservation Areas in Georgia – Khevi-Tusheti, and partially overlaps with the Important Bird Area of Khevsureti. Two Special Protection Areas (SPAs) for birds are proposed along the northern border of the Aragvi PL – SPA 8 Khevsureti-Tusheti and SPA 9 Khevi.


Landscape and its habitats

Mountainous landscape of the Aragvi PL has been formed by various natural processes and human activities, and is covered by broad-leaved forests, montane meadows, subalpine shrubs, subalpine and alpine grasslands, subnival and nival areas, and historical settlements. Typical landscape character of the Aragvi PL, esp. the mosaic of small settlements, hay meadows, fields, pastures and forests, was modified by long-lasting pastoral activities. Crucial components of the landscape, creating its unique features, are sharp peaks in the north of the Aragvi PL (the Chaukhi massif), rounded ridges and deep valleys with wild rivers.
Habitat diversity is very high thanks to the vertical span of the region reaching almost 3000 m. The following habitat classification was largely based on physical features and visual characteristics, as well as on a rough classification of vegetation.

Flora
The level of endemism is particular¬ly high among plant species here. Pshav-Khev¬sureti flora comprises of 212 Caucasian en¬demic species, which means that 8 out of 17 genera spread throughout the Cau¬casus are found here; accordingly, 34.4 % of the plant species found in Pshav-Khev¬sureti are Caucasian endemics.
Flora of the Aragvi PL is rich particularly because of wide altitudinal range of the protected area. While relatively thermophilous plant species typical for the Caucasus foothills can be found in lowest parts, at elevations of about 1000 m asl on southern slopes of the Sharakhevi valley, some rare orchid species may occur on hay meadows and pastures in the montane vegetation belt in middle elevations. Many alpine species typical for the highest parts of the Greater Caucasus Range have their habitats in the subalpine, alpine or even subnival vegetation belts.
Flora of the Aragvi PL has not been mapped in detail yet, e.g. such species as Orchis ustulata or parasitic Phelypaea coccinea that grow some hundreds meters out of the PL may occur also inside its area. Orchis caucasica and O. mascula ssp. longicalcarata are sparsely found in mixed oak-hornbeam forests of lower elevations. Whilst Gentiana cruciata and G. septemfida are the typical representatives of the flora of traditionally used montane pastures, Anacamptis pyramidalis belongs to the rarest and the most threatened species occurring in this type of habitat. Ferns such as Asplenium viride and Phylitis scolopendrium occurring in forests indicate soils and rocks rich for calcium. Matteucia struthiopteris makes undergrowth of well-preserved and not grazed alder alluvial forests along the Pshavi Aragvi River and some of its tributaries. Early spring aspect on wet subalpine grasslands is represented by Primula algida and Trolius patulus that flower there shortly after snowmelt.
Gadelia (Campanula) lactiflora, Senecio platyphylloides, Cephalaria gigantea and Gentiana asclepiadea can be mentioned as typical representatives of species-rich subalpine tall-herb vegetation which can descend from the subalpine to the montane belt along avalanche tracks. Valeriana tiliifolia, Telekia speciosa and Heracleum sosnowskyi can be found in wet forest openings or along streams. Swertia iberica grows along small streams and in spring areas of the subalpine vegetation belt. Presence of Rhododendron caucasicum usually indicates low grazing pressure; large and more or less continuous growths occur on north-facing slopes at altitudes of 2200–2800 m asl. Rhododendron luteum makes usually an aspect of undergrowth, locally in open subalpine birch forests.
Many species of genus Campanula, Saxifraga and Draba can be found in the alpine vegetation belt (particularly in rock and scree habitats and in so-called alpine carpets) as well as a typical example of Caucasian endemic species, Pseudovesicaria digitata. Scabiosa caucasica – a flagship species of Central and Eastern parts of the Caucasus – grows in regularly grazed subalpine and alpine grasslands.
The species mentioned above represent only a very small proportion of flora of the Aragvi PL. In summary, species richness of vascular plants in the area is enormous, and it is not aim of this chapter to prepare a more comprehensive overview.

Fauna
Fauna of the Aragvi PL is poorly known, but thanks to diverse landscape features and various habitats it is expected to be diverse as well. As regards the best known groups of vertebrates, there are 55 mammal, 132 bird, 9 reptile and 6 amphibian species mentioned for the Pshav-Khevsureti National Park. About a similar number of species can be expected in the Aragvi PL, bordering the national park from the south, with some high altitude species probably missing and some species of lower elevations occurring.

Large carnivores belong to the most important mammal species – the brown bear (Ursus arctos), the grey wolf (Canis lupus) and the lynx (Lynx lynx); other predators and indicator species – the wild cat (Felis silvestris) and the Eurasian otter (Lutra lutra), cannot be neglected as well. Among ungulates, the endemic Caucasian subspecies of the chamois (Rupicapra rupicapra caucasica) is the most valuable. Potential occurrence of two other ungulate species – the East Caucasian tur (Capra cylindricornis) and the bezoar goat (Capra aegagrus), is mentioned for the Aragvi PL. However, if there is any, it is probably very scarce and occasional. Several endemic species of small mammals (esp. shrews and voles) can be expected in the territory of the PL.

Important birds are represented by two endemic galliform species – the Caucasian snowcock (Tetraogallus caucasicus) and the Caucasian black grouse (Tetrao mlokosiewiczi), by large birds of prey – esp. the griffon vulture (Gyps fulvus), the black vulture (Aegypius monachus), the bearded vulture (Gypaetus barbatus) and the golden eagle (Aquila chrysaetos) (all of them listed in the Georgian Red List), or by several endemic species of passerines (e.g. warblers Phylloscopus nitidus and Ph. lorenzii). It is worth mentioning also some other birds of higher altitudes – the Güldenstädt’s redstart (Phoenicurus erythrogastrus), the great rosefinch (Carpodacus rubicilla), the wall creeper (Tichodroma muraria), the horned lark (Eremophila alpestris) or the red-fronted serin (Serinus pusillus). The area is also important for birds during migration (esp. concentrations of migrating raptors).

There are several reptiles found in the region, e.g. the spiny-tailed lizard (Darevskia rudis), vipers Vipera kaznakovi or V. dinniki, etc.
However, it is obvious that even lists of well-known groups (e.g. reptiles, birds or small mammals) are still very incomplete and basic data on many other groups of animals, esp. invertebrates (e.g. important bioindication groups such as butterflies or grasshoppers), are nearly or completely missing.

The following species were chosen as the key/target ones for the Aragvi PL. Majority of vertebrates are mentioned as priority species of the Caucasus ecoregion and listed among the Georgian Red List species (except the snowcock and the cat). Moreover, many of them are also target species of the adjacent national park. Their distribution, as important “umbrella species”, was taken into account when preparing the zoning of the Aragvi PL.

Yew (Taxus baccata)
This Georgian Red List species is rarely distributed within mixed broad-leaved forests of middle mountain altitudes. In the Aragvi PL it occurs naturally in forests below Apsho village and on steep western slopes just above the main road in the 1st zone segment no. 4 (Sharakhevi valley and adjacent forests) near Kanatia.
All found yew trees are quite young. This fact could indicate that in the past the yew was probably object of selective logging to use its timber. Although the local yew populations are quite small and trees are young, it seems they are not directly threatened currently. Anyway, any logging of full-grown trees (and young individuals as well) must by strictly prohibited.

Pyramidal orchid (Anacamptis pyramidalis)
The species, sensitive to the way and intensity of meadow management, indicates appropriately managed grasslands with moderate grazing pressure in middle mountain altitudes. So far, only two places of its occurrence are known – meadows above Chargali and pastures above Khomi.
Threatening factors are intensive grazing, or abandonment of grasslands and subsequent overgrowing by shrubs and trees.

Butterflies of the genus Parnassius
Three species of the genus may occur in the wider area – Parnassius apollo, similarly coloured but smaller P. nordmanni and P. mnemosyne. The last one is related mainly to light broadleaf and mixed forests with undergrowth of Corydalis species, which its caterpillars are feeding on. P. nordmanni also feeds on different Corydalis species and occurs on scree and stony slopes and in alpine meadows up to 3 000 m asl.
Habitats of P. apollo include stony places, rocks and similar habitats with sparse vegetation, which caterpillars feed on (Sedum and Sempervivum sp., Hylotelephium caucasicum). Adults occur mainly in species-rich meadows up to 2000 m asl. We confirmed this species both in Pshav-Khevsureti (subalpine meadows above Chalisopeli, Barisakho and Matura) and Gudamakari (subalpine meadows above Bursachili).
All three species are very sensitive to changes in traditional management and intensification of forestry and agriculture. For example, P. apollo needs both disturbed places with sparse vegetation for caterpillars (danger of overgrowing by shrubs and trees) and species rich meadows with sufficient amount of nectar for adults in June and July (danger of overgrazing on the one hand, and abandonment of pasturing and haymaking on the other).

River trout (Salmo fario)
The Georgian Red List species occupies running waters and can serve as a good indicator of water quality in them.
It is threatened especially by deteriorating water quality, fragmentation of water bodies and illegal fishing.

Caucasian snowcock (Tetraogallus caucasicus)
The endemic species, living in the Greater Caucasus only, occurs along the highest mountain ridges, esp. in rocky habitats, and winters in lower altitudes.
In the Aragvi PL, occurrence of the snowcock is well known from the highest altitudes of the whole territory, but especially along the northern border of the PL.

Caucasian black grouse (Tetrao mlokosiewiczi)
This endemic species inhabits areas above the timberline and prefers especially a mosaic of alpine grasslands with shrub vegetation (e.g. stands of rhododendrons). The most significant threats for the species include habitat loss and fragmentation due to unsustainable land use, poaching and human disturbance.
Potential occurrence of the black grouse in the Aragvi PL is expected in all suitable habitats along and above the timberline.

Brown bear (Ursus arctos)
Important indicator species that reflects state of ecosystems and biodiversity, and stands as a top predator in the food chain in most habitats of the Caucasus. It occupies forests from lower elevations up to the timberline, but it occurs also in high mountain grasslands. Its Caucasian population has declined drastically in recent decades, with poaching and habitat loss being the main threats.
In the Aragvi PL, the brown bear occurs in the whole territory, but it prefers especially the mosaic of forests, shrubberies and grasslands in remote valleys.

Eurasian lynx (Lynx lynx)
One of the three top predators in the Caucasus, together with the brown bear and the wolf. Its exact distribution, population numbers and trends are not known, but it is considered one of the priority species in Georgia. Poaching could be the main threat for the lynx.
In the Aragvi PL, the distribution of the lynx is expected in all suitable habitats throughout the whole area.

Wild cat (Felis silvestris)
This species indicates deciduous and mixed forests of good quality, with an appropriate tree species composition, space and age structure and a presence of dead wood (important for many other species of invertebrate and vertebrate animals).
Regular occurrence of the wild cat is expected in all aged beech and mixed forests in lower elevations of the Aragvi PL (own observations).

Eurasian otter (Lutra lutra)
The Georgian Red List species that occupies running waters and serves, together with the river trout, as another good indicator of river ecosystem quality.
Its occurrence is expected in all suitable rivers and brooks with sufficient food supply (i.e. fish populations), especially in lower and middle elevations of the Aragvi PL.

Caucasian chamois (Rupicapra rupicapra caucasica)
The endemic subspecies occurs in the highest elevations of both the Greater and the Lesser Caucasus, and its population numbers has decreased drastically over the past century. The greatest threat comes from poaching and habitat loss.
Occurrence of the chamois in the Aragvi PL is mentioned from higher altitudes in the whole area, but especially along the northern border of the PL.

In addition to biodiversity of wild species, the Aragvi PL is also important due to unique agrobiodiversity, incl. local fruit trees, crops and animal breeds.
As far as stock raising, presence of the local breed (the Georgian mountainous cow) is very important. Though the breed has almost vanished in its pure form, recent projects are trying to trace and revive it. The Georgian mountainous grey bee has one of its distribution centres in Pshavi and Khevsureti as well.

As regards grain growing, several ancient varieties of wheat are attested in the Aragvi area – e.g. asli (Triticum dicoccum) and dika (T. carthlicum). Historically, millet culture (kvrima – Setaria moriver troutcharica) and more variegated growing of legumes (e.g. lentils) are attested as well.

Some local cultivars or varieties could be found among plenty of cultivated fruit trees in the area (Malus sp. div., Prunus sp. div., Pyrus sp. div.). However, deeper knowledge of diversity of fruit trees grown in the mountains needs further research.