The Hyrcanian forests (; ) are a zone of lush lowland and montane forests covering about near the shores of the

Caspian Sea The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

and

Azerbaijan Azerbaijan, officially the Republic of Azerbaijan, is a Boundaries between the continents, transcontinental and landlocked country at the boundary of West Asia and Eastern Europe. It is a part of the South Caucasus region and is bounded by ...

. The forest is named after the ancient region of

Hyrcania Hyrcania (; ''Hyrkanía'', Old Persian: 𐎺𐎼𐎣𐎠𐎴 ''Varkâna'',Lendering (1996) Middle Persian: 𐭢𐭥𐭫𐭢𐭠𐭭 ''Gurgān'', Akkadian: ''Urqananu'') is a historical region composed of the land south-east of the Caspian Sea ...

. The

World Wide Fund for Nature The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named th ...

refers to the

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

as the Caspian Hyrcanian mixed forests. Since 5 July 2019, the Hyrcanian Forests have been designated a

UNESCO The United Nations Educational, Scientific and Cultural Organization (UNESCO ) is a List of specialized agencies of the United Nations, specialized agency of the United Nations (UN) with the aim of promoting world peace and International secur ...

World Heritage Site World Heritage Sites are landmarks and areas with legal protection under an treaty, international treaty administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural ...

. In September 2023, the heritage site expanded to incorporate portions of the forest located in Azerbaijan.

Geography

In Iran, the Hyrcanian ecoregion comprises a long strip along the southern coast of the Caspian Sea and the northern slopes of the

Alborz The Alborz ( ) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs northeast and merge ...

mountains. It covers parts of five provinces, from east to west: North Khorasan, Golestan ( being its south and southwest plus eastern regions of the Gorgan plain),

Mazandaran Mazandaran Province (; ) is one of the 31 provinces of Iran. Its capital is the city of Sari, Iran, Sari. Located along the southern coast of the Caspian Sea and in the adjacent Central Alborz mountain range and Hyrcanian forests, it is border ...

Gilan Gilan Province () is one of the 31 provinces of Iran, in the northwest of the country and southwest of the Caspian Sea. Its capital is the city of Rasht. The province lies along the Caspian Sea, in Iran's Region 3, west of the province of ...

and

Ardabil Ardabil (, ) is a city in northwestern Iran. It is in the Central District (Ardabil County), Central District of Ardabil County, Ardabil province, Ardabil province, Iran, serving as capital of the province, the county, and the district. The ...

. The Golestan National Park spans the boundary of Golestan and Mazandaran provinces. In the Mazandaran province, where the Hyrcanian forest is estimated at , are used commercially, are protected and the rest are regarded as forest lands or over-used forests. The total of the forest woods used in this province is estimated at . The Kojoor, Dohezar and Sehezar forest watersheds are in Mazandaran province,

Gilan province Gilan Province () is one of the 31 provinces of Iran, in the northwest of the country and southwest of the Caspian Sea. Its capital is the city of Rasht. The province lies along the Caspian Sea, in Iran's Regions of Iran, Region 3, west of ...

(these forests are graded from 1 to 3 with an area of ; and , respectively. The commercial utilization is and the non-commercial utilization is . The Masooleh, Ghaleh Roodkhan and Astara forest watersheds are in Gilan province) and Ardabil Province. At higher elevations to the south, the ecoregion grades into the Elburz Range forest steppe. In southeastern

the ecoregion spans through the

Lankaran Lowland The Lankaran Lowland () is a narrow strip of lowland in southern Azerbaijan by the Caspian Sea. It is the southward extension of the Kura-Aras Lowland which in itself is an extension of the Aral–Caspian Depression. It is named after the city of ...

and the

Talysh Mountains Talysh Mountains (, , ) is a mountain range in far southeastern Azerbaijan and far northwestern Iran within Ardabil Province and Gilan Province. Geography The Talysh Mountains extend southeastward from the Lankaran Lowland in southeastern Azer ...

. The ecoregion's climate is

humid subtropical A humid subtropical climate is a subtropical -temperate climate type, characterized by long and hot summers, and cool to mild winters. These climates normally lie on the southeast side of all continents (except Antarctica), generally between la ...

at lower altitudes; at mid-altitudes it has

oceanic Oceanic may refer to: *Of or relating to the ocean *Of or relating to Oceania **Oceanic climate **Oceanic languages **Oceanic person or people, also called "Pacific Islander(s)" Places * Oceanic, British Columbia, a settlement on Smith Island, ...

features, while in the mountains it is

humid continental Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...

. Summer is a humid but low-precipitation season. Alborz is the highest mountain range in the Middle East and it captures, by

relief precipitation Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as ''oreography'', ''orology,'' or ''oreology'') falls within the broader dis ...

and

dew point The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to produce a relative humidity of 100%. This temperature depends on the pressure and water content of the air. When the air at a temperature above the ...

mists, much of the evaporation of the southern Caspian Sea. Annual rainfall ranges from in the east to in the west, making the forests much lusher than the desert, semi-desert, and steppe regions which it borders.

Flora

The natural forest vegetation is temperate

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

broadleaved forest. 32.7 percent of volume of Hyrcanian forest is of oriental beech (''

Fagus orientalis ''Fagus orientalis'', commonly known as the Oriental beech, is a deciduous tree in the beech family Fagaceae. It is native to Eurasia, in Eastern Europe and Western Asia. Description ''Fagus orientalis'' is a large tree, capable of reaching he ...

''). A main feature of the region is the lack of

conifer Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

s; only relics of coniferous species are present, which include European yew (''

Taxus baccata ''Taxus baccata'' is a species of evergreen tree in the family (botany), family Taxaceae, native to Western Europe, Central Europe and Southern Europe, as well as Northwest Africa, and parts of Southwest Asia.Rushforth, K. (1999). ''Trees of Bri ...

''), junipers (''

Juniperus Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

'' spp.), Mediterranean cypress (''

Cupressus sempervirens ''Cupressus sempervirens'', the Mediterranean cypress (also known as Italian cypress, Tuscan cypress, Persian cypress, or pencil pine), is a species of cypress native to the eastern Mediterranean region and Iran. While some studies show it ha ...

'' var. ''horzontalis'') and Chinese arborvitae ('' Platycladus orientalis''). The Caspian Sea coastal plains were once covered by chestnut-leaved oak ('' Quercus castaneifolia''), European box (''

Buxus sempervirens ''Buxus sempervirens'', the common box, European box, or boxwood, is a species of flowering plant in the genus ''Buxus'', native to western and southern Europe, northwest Africa, and southwest Asia, from southern England south to northern Morocco ...

''), black alder (''

Alnus glutinosa ''Alnus glutinosa'', the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family (biology), family Betulaceae, native plant, native to most of Europe, southwest Asia and northern Africa. ...

''subsp.'' barbata''), Caucasian alder ('' Alnus subcordata''), Caspian poplar (''

Populus alba ''Populus alba'', commonly called silver poplar,Webb, C. J.; Sykes, W. R.; Garnock-Jones, P. J. 1988: Flora of New Zealand. Vol. IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. 4. Christchurch, New Zealand, Botany Division, D.S.I.R. si ...

'' var. ''caspica'') and Caucasian wingnut (''

Pterocarya fraxinifolia ''Pterocarya fraxinifolia'' is a species of tree in the Juglandaceae family. It is commonly known as the Caucasian wingnut or Caucasian walnut. It is native to the Caucasian region Armenia, Azerbaijan, Georgia, Iran, Russia, Ukraine and Turk ...

''), but these forests have been almost entirely converted to urban and agricultural land. (Mosadegh, 2000; Marvie Mohadjer, 2007) The lower slopes of Talysh and Alborz Mountains below harbor diverse humid forests containing chestnut-leaved oak, European hornbeam (''

Carpinus betulus Hornbeams are hardwood trees in the plant genus ''Carpinus'' in the family Betulaceae. Its species occur across much of the temperateness, temperate regions of the Northern Hemisphere. Common names The common English name ''hornbeam'' derives ...

''), Persian ironwood ('' Parrotia persica''), Caucasian zelkova ('' Zelkova carpinifolia''), Persian silk tree (''

Albizia julibrissin ''Albizia julibrissin'', the Persian silk tree, pink silk tree, or mimosa tree, is a species of tree in the Fabaceae family, native to Western Asia, southwestern and East Asia, eastern Asia. Taxonomy It was introduced to Europe in the mid-18th ...

''), and date-plum (''

Diospyros lotus ''Diospyros lotus'', with common names date-plum, Caucasian persimmon, or lilac persimmon, is a widely cultivated species of the genus ''Diospyros'', native to temperate Asia and southeast Europe. Its English name derives from the small fruit, wh ...

'') along with shrubs holly ('' Ilex hyrcana''), '' Ruscus hyrcanus'', '' Danae racemosa'' and '' Atropa pallidiflora'', and lianas '' Smilax excelsa'' and '' Hedera pastuchovii'' (Mosadegh, 2000; Marvie Mohadjer, 2007). Persian Ironwood is endemic to the Talysh Mountains and northern Iran and nearly pure stands of the tree can be particularly dramatic, with lichen-covered branches twisting together and only dead leaves in the deep shade of the forest floor. In addition, the ironwood's yellow leaves turn a faint lilac in the fall. At the medium elevations between , oriental beech is the dominant tree species in this cloudy zone in pure and mixed stands with other noble

hardwood Hardwood is wood from Flowering plant, angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal ecosystem, boreal latitudes they are mostly deciduous, but in tropics and subtropics mostl ...

s such as chestnut-leaved oak, Caucasian oak ('' Quercus macranthera''), European hornbeam (''

''), Oriental hornbeam ('' C. orientalis'') and sweet chestnut (''

Castanea sativa The sweet chestnut (''Castanea sativa''), also known as the Spanish chestnut or European chestnut, is a species of tree in the family Fagaceae, native to Southern Europe and Asia Minor, and widely cultivated throughout the Temperate climate, te ...

''). From its floristic composition, these beech forests are linked with European forests and with affinities to the beech forests of the Balkans. However, local conditions of aspect and

edaphic Edaphology (from Greek , ''edaphos'' 'ground' + , '' -logia'') is concerned with the influence of soils on living beings, particularly plants. It is one of two main divisions of soil science, the other being pedology. Edaphology includes the st ...

factors, such as soil moisture and depth, are all of importance in determining the composition of the vegetation, which leads to the establishment of different beech subcommunities. (Mosadegh, 2000; Marvie Mohadjer, 2007) Upper mountain and subalpine zones are characterized by Caucasian oak, Oriental hornbeam,

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominance (ecology), dominated by shrubs, often also including grasses, herbaceous plant, herbs, and geophytes. Shrubland may either occur naturally o ...

s and

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the tropical and subtropica ...

Alpine tundra Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets ...

and meadows occur at the highest elevations. Other native tree species include Caspian locust (''

Gleditsia caspica ''Gleditsia caspica'', the Caspian locust or Persian honeylocust, is a species of ''Gleditsia'' native to western Asia, in the Caucasus region of Azerbaijan and northern Iran, close to the Caspian Sea.Huxley, A., ed. (1992). ''New RHS Dictionary ...

''), velvet maple ('' Acer velutinum''), Cappadocian maple (''

Acer cappadocicum ''Acer cappadocicum'', the Cappadocian maple, is a maple native to Asia, from central Turkey (ancient Cappadocia) east along the Caucasus, the Himalayas, to southwestern China.Mitchell, A. F. (1974). ''A Field Guide to the Trees of Britain and No ...

''), European ash (''

Fraxinus excelsior ''Fraxinus excelsior'', known as the ash, or European ash or common ash to distinguish it from other types of ash, is a flowering plant species in the olive family Oleaceae. It is native throughout mainland Europe east to the Caucasus and Alb ...

''), Wych elm (''

Ulmus glabra ''Ulmus glabra'', the wych elm or Scots elm, has the widest range of the European elm species, from Ireland eastwards to the Ural Mountains, and from the Arctic Circle south to the mountains of the Peloponnese and Sicily, where the species reach ...

''), wild cherry (''

Prunus avium ''Prunus avium'', commonly called wild cherry, sweet cherry or gean is a species of Prunus subg. Cerasus, cherry, a flowering plant in the rose family, Rosaceae. It is native to Eurasia and naturalized elsewhere. It is an ancestor of ''Prunus c ...

''), wild service tree (''

Sorbus torminalis ''Torminalis'' is a genus of plants in the rose family, Rosaceae. The genus was formerly included within the genus ''Sorbus'' as the Section (biology), section ''Torminaria'', but the simple-leafed species traditionally classified in ''Sorbus'' ...

'') and lime tree (''

Tilia platyphyllos ''Tilia platyphyllos'', the large-leaved lime or large-leaved linden, is a species of flowering plant in the family (biology), family Malvaceae (Tiliaceae). It is a deciduous tree, native plant, native to much of continental Europe as well as sou ...

'').

Fauna

The

Caspian tiger The Caspian tiger was a '' Panthera tigris tigris'' population native to eastern Turkey, northern Iran, Mesopotamia, the Caucasus around the Caspian Sea, Central Asia to northern Afghanistan and the Xinjiang region in western China. Until the Midd ...

(''

Panthera tigris tigris The tiger (''Panthera tigris'') is a large cat and a member of the genus ''Panthera'' native to Asia. It has a powerful, muscular body with a large head and paws, a long tail and orange fur with black, mostly vertical stripes. It is tradition ...

'') was once the apex predator of the biome before its extinction. The remaining large mammals include the Persian/Caucasian leopard (''

Panthera pardus tulliana ''Panthera pardus tulliana'', also called Persian leopard, Anatolian leopard, and Caucasian leopard in different parts of its range, is a leopard subspecies that was first described in 1856 based on a zoological specimen found in western Anato ...

''),

Eurasian lynx The Eurasian lynx (''Lynx lynx'') is one of the four wikt:extant, extant species within the medium-sized wild Felidae, cat genus ''Lynx''. It is widely distributed from Northern Europe, Northern, Central Europe, Central and Eastern Europe to Cent ...

(''Lynx lynx''),

brown bear The brown bear (''Ursus arctos'') is a large bear native to Eurasia and North America. Of the land carnivorans, it is rivaled in size only by its closest relative, the polar bear, which is much less variable in size and slightly bigger on av ...

(''Ursus arctos''),

wild boar The wild boar (''Sus scrofa''), also known as the wild swine, common wild pig, Eurasian wild pig, or simply wild pig, is a Suidae, suid native to much of Eurasia and North Africa, and has been introduced to the Americas and Oceania. The speci ...

(''Sus scrofa''),

wolf The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a Canis, canine native to Eurasia and North America. More than thirty subspecies of Canis lupus, subspecies of ''Canis lupus'' have been recognized, includin ...

(''Canis lupus''),

golden jackal The golden jackal (''Canis aureus''), also called the common jackal, is a wolf-like canid that is native to Eurasia. The golden jackal's coat varies in color from a pale creamy yellow in summer to a dark tawny beige in winter. It is smaller a ...

(''Canis aureus''),

jungle cat The jungle cat (''Felis chaus''), also called reed cat and swamp cat, is a medium-sized cat native from the Eastern Mediterranean region and the Caucasus to parts of Central, South and Southeast Asia. It inhabits foremost wetlands like swamps, ...

(''Felis chaus''), Caucasian badger (''Meles canescens''), and

Eurasian otter The Eurasian otter (''Lutra lutra''), also known as the European otter, Eurasian river otter, European river otter, common otter, and Old World otter, is a semiaquatic mammal native to Eurasia and the Maghreb. The most widely distributed member o ...

(''Lutra lutra''). This ecoregion is the main green resting area for birds migrating between central-northern

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

and

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

and thus is a key habitat for many bird species. Notable birds seen here are the greylag goose ('' Anser anser''), white-fronted goose ('' Anser albifrons''), little bustard (''

Tetrax tetrax The little bustard (''Tetrax tetrax'') is a Aves, bird in the bustard family, the only member of the genus ''Tetrax''. It breeds in Southern Europe and in Western Asia, Western and Central Asia. Taxonomy The little bustard was Species descripti ...

''), glossy ibis ('' Plegadis falcinellus''), Eurasian spoonbill ('' Platalea leucorodia''), night heron ('' Nycticorax nycticorax''), red-breasted goose ('' Branta ruficollis''), peregrine falcon ('' Falco peregrinus''), Dalmatian pelican ('' Pelecanus crispus''), cattle egret ('' Bubulcus ibis''), squacco heron ('' Ardeola ralloides''), greater flamingo ('' Phoenicopterus roseus''), white-headed duck ('' Oxyura leucocephala''), and Caspian snowcock ('' Tetraogallus caspius'').

Endemic species

The Hyrcanian forests are thought to have served as a refugium for certain species during changing climatic conditions. The

Iranian edible dormouse The Iranian edible dormouse or Iranian fat dormouse (''Glis persicus'') is a species of dormouse native to Western and Central Asia. It is one of only two species in the genus ''Glis''. Taxonomy It was long considered conspecific with the Euro ...

(''Glis persicus'') is an

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

of this ecoregion, and is thought to have evolved when mid-

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

climatic change led to the fragmentation of the ancestral ''

Glis Glis is an electronic music project founded in 2001 by Shaun Frandsen of Seattle, WA. The band has experienced several lineup changes and guest appearances, with frontman Shaun Frandsen acting as primary producer, vocalist, songwriter, and inst ...

'' population, with one such population fragment surviving in these forests and evolving into a new species. The bat '' Myotis hyrcanicus'' is likely also endemic to this region. The region is also known to preserve a unique lineage of bicolored shrew (''Crocidura leucodon'') that diverged from the other lineages during the mid-

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

, about 1 million years ago. The Persian mountain salamander (''Paradactylodon persicus'') is an aquatic salamander endemic to high rainfall regions of the Hyrcanian forest. It is primarily known from its aquatic larvae which live in permanent streams with forest cover. This is a very understudied species and very few adults have ever been found. It is under threat from habitat loss due to logging, agricultural development, and urban sprawl.

Protected areas

The diversity and endemism of the species make the Caspian Hyrcanian forests a priority and unique feature for species conservation. Habitats are threatened by conversion into tea, vegetable, fruit, and vine plantations, unsustainable forestry and poaching. Protected areas in Azerbaijan include: *

Gizil-Agach State Reserve Ghzil-Aghaj State Reserve (), meaning golden tree, was established on July 3, 1929, by the Committee on Protection of the Ancient and Art Monuments of Azerbaijan on an area of 884 km2 on Ghizil-Agaj Bay at the southwestern shore of the Caspian Se ...

– * Hirkan National Park - Protected areas in Iran include: * Golestan National Park * Jahan Nama Protected Area * Central Alborz Protected Area * Lisar Protected Area * Siah Keshim Protected Area * Dodangeh Wildlife Refuge * Neka Miankaleh Wildlife Refuge * Selkeh Wildlife Refuge * Dashtenaz Wildlife Refuge

References

External links

* {{DEFAULTSORT:Caspian Hyrcanian Mixed Forests Ecoregions of Azerbaijan Ecoregions of Iran Ecoregions of Asia Ecoregions of Europe Forests of Azerbaijan Forests of Iran * * Alborz (mountain range) Astara District Lankaran District Lerik District Masally District Yardimli District Geography of Gilan province Geography of Golestan province Geography of Mazandaran province Mountain ranges of Azerbaijan Mountain ranges of Iran Palearctic ecoregions Temperate broadleaf and mixed forests Temperate rainforests World Heritage Sites in Iran World Heritage Sites in Azerbaijan