The Yapen rain forests is a

tropical moist forest Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature. Description TSMF is generally found in large, discon ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. The ecoregion covers the island of

Yapen Yapen (also Japan, Jobi) is an island of Papua, Indonesia. The Yapen Strait separates Yapen and the Biak Islands to the north. It is in Cenderawasih Bay off the north-western coast of the island of New Guinea. To the west is Mios Num Island a ...

and smaller neighboring islands which lie north of

New Guinea New Guinea (; Hiri Motu Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea). It is a simplified version of ...

Geography

The ecoregion covers the island of Yapen, and the smaller islands of

Mios Num Mios Num (aka: Num, Indonesian language: ''Pulau Mios Num'') is an island of the Yapen Islands group, in Papua Province of Western New Guinea, northeastern Indonesia. It is in Cenderawasih Bay. The Mios Num Strait separates it from Yapen ...

to the northwest and Kurudu to the east. Yapen covers an area of 2,230 km². The island is long and narrow, extending 166 km east and west and only 26 km north to south at the island's widest point. Hills and mountains run the length of the island. The highest peak is 1,430 m.Jared Diamond, K. David Bishop "Origins of the upland avifauna of Yapen Island, New Guinea region," Bulletin of the British Ornithologists’ Club, 140(4), 423-448, (9 December 2020) The surface geology is limestone and plutonic rocks, including outcrops of

ultramafic rock Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are composed ...

. The islands were connected to New Guinea during the ice ages when the sea level was lower, and shares many plants and animals with the adjacent mainland.

Climate

The ecoregion has a tropical rain forest climate.

Flora

The original vegetation was tropical wet evergreen forest. Forests consisted of three main types, alluvial forests in flatlands and river valleys, and hill forest on the hillsides, and montane forests at higher elevations. Dominant trees on the coastal strand are ''

Terminalia catappa ''Terminalia catappa'' is a large tropical tree in the leadwood tree family, Combretaceae, native to Asia, Australia, the Pacific, Madagascar and Seychelles. Common names in English include country almond, Indian almond, Malabar almond, sea almon ...

Barringtonia asiatica ''Barringtonia asiatica'' (fish poison tree, putat or sea poison tree) is a species of ''Barringtonia'' native to mangrove habitats from islands of the Indian Ocean in the west to tropical Asia and islands of the western Pacific Ocean. It is g ...

Calophyllum inophyllum ''Calophyllum inophyllum'' is a large evergreen plant, commonly called tamanu, oil-nut, mastwood, beach calophyllum or beautyleaf. It is native to tropical Asia and Wallacea. Due to its importance as a source of timber for the traditional shipbu ...

Artocarpus ''Artocarpus'' is a genus of approximately 60 trees and shrubs of Southeast Asian and Pacific origin, belonging to the mulberry family, Moraceae. Most species of ''Artocarpus'' are restricted to Southeast Asia; a few cultivated species are more w ...

'' sp., and ''

Casuarina ''Casuarina'' is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, islands of the western Pacific Ocean, and eastern Africa. It was once treated as the sole genus in the fami ...

'' sp. Swamp forests of

Nipa palm ''Nypa fruticans'', commonly known as the nipa palm (or simply nipa, from ms, nipah) or mangrove palm, is a species of palm native to the coastlines and estuarine habitats of the Indian and Pacific Oceans. It is the only palm considered adapte ...

(''Nypa fruticans'') are common behind the shore. ''

Palaquium amboinense ''Palaquium'' is a genus of about 120 species of trees in the family Sapotaceae. Their range is from India across Southeast Asia, Malesia, Papuasia, and Australasia, to the western Pacific Islands. Description Within their range, ''Palaquium'' ...

Octomeles sumatrana ''Octomeles'' is a monotypic genus of plant in family Tetramelaceae. The sole species is ''Octomeles sumatrana'', sometimes written ''O. sumatranum''. ''Octomeles sumatrana'', commonly called Benuang, or Ilimo, is found in Brunei, Indonesia, Ma ...

Intsia bijuga ''Intsia bijuga'', commonly known as Borneo teak, Johnstone River teak, Kwila, Moluccan ironwood, Pacific teak, scrub mahogany and vesi, is a species of flowering tree in the family Fabaceae, native to the Indo-Pacific. It ranges from Tanzania and ...

Ficus benjamina ''Ficus benjamina'', commonly known as weeping fig, benjamin fig or ficus tree, and often sold in stores as just ficus, is a species of flowering plant in the family Moraceae, native to Asia and Australia. It is the official tree of Bangkok. The ...

'', and species of ''

Eugenia ''Eugenia'' is a genus of flowering plants in the myrtle family Myrtaceae. It has a worldwide, although highly uneven, distribution in tropical and subtropical regions. The bulk of the approximately 1,100 species occur in the New World tropics, ...

'' and ''

'' cover lowland slopes. ''Palaquium amboinense, Octomeles sumatrana, Calophyllum'' sp., ''Terminalia'' sp., ''Manilkara'' sp., ''

Pometia acuminata ''Pometia pinnata'' is a large tropical hardwood and fruit tree species, with common names including matoa, taun tree, island lychee, tava, Pacific lychee of the plant family Sapindaceae. Naturally widespread, the trees are native to tropical S ...

'', and ''

Pometia pinnata ''Pometia pinnata'' is a large tropical hardwood and fruit tree species, with common names including matoa, taun tree, island lychee, tava, Pacific lychee of the plant family Sapindaceae. Naturally widespread, the trees are native to tropical So ...

'' predominate in lowland forests further inland, with '' Anisoptera thurifera polyandra'' as an emergent tree in scattered locations. Characteristic trees of the highlands include ''Pometia acuminata, Palaquium amboinense'', and species of ''

Cryptocarya ''Cryptocarya'' is a genus of evergreen trees belonging to the laurel family, Lauraceae. The genus includes more than 350 species, distributed through the Neotropical, Afrotropical, Indomalayan, and Australasian realms. Overview The genus inc ...

, Tristania,'' and ''Calophyllum''. The conifer ''

Araucaria cunninghamii ''Araucaria cunninghamii'' is a species of ''Araucaria'' known as hoop pine. Other less commonly used names include colonial pine, Queensland pine, Dorrigo pine, Moreton Bay pine and Richmond River pine. The scientific name honours the botanist a ...

'' is an emergent tree found in scattered mountain locations above 500 meters elevation. Ultramafic rocks contain concentrations of metals which are toxic to many plants, and the ultramafic outcrops host unique plant communities adapted to ultramafic soils.

Fauna

The ecoregion is home to 37 mammal species.Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). ''Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment.'' Washington, DC: Island Press. Two limited-range species are shared with the

Biak–Numfoor rain forests The Biak–Numfoor rain forests is a tropical moist forest ecoregion in Indonesia. The ecoregion covers the islands of Biak, Supiori, Numfoor, and several smaller islands, which lie in Cenderawasih Bay north of Yapen and New Guinea. Geography B ...

ecoregion, which covers the islands north of Yapen: the

Japen rat The Japen rat (''Rattus jobiensis'') is a species of rodent in the family Muridae found only in Yapen, Biak- Supiori, and Owi islands of West Papua, Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast A ...

(''Rattus jobiensis'') is found on Yapen and the islands of Biak and Supiori, and the

Geelvink Bay flying fox The Geelvink Bay flying fox or Geelvink Bay fruit bat (''Pteropus pohlei'') is a species of flying fox in the family Pteropodidae. It is endemic to the islands of Yapen, Numfor, and Rani, which lie north of New Guinea in Indonesia's Papua Provi ...

(''Pteropus pohlei''), a fruit bat, is found on Yapen and the islands of Numfor and Rani. 147 bird species live in the ecoregion. There are no strictly endemic bird species. About 120 species live in the lowlands, and 26 species live in the uplands. The montane forests are home to the

Green-backed robin The green-backed robin (''Pachycephalopsis hattamensis'') is a species of bird in the family Petroicidae. It is found in New Guinea. Its natural habitats are subtropical or tropical moist lowland forest and subtropical or tropical moist montane ...

(''Pachycephalopsis hattamensis''), which also lives in New Guinea's Central and Vogelkop highlands."Yapen". Birdlife International. Accessed 10 July 2021
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Protected areas

48.31% of the ecoregion is in protected areas. Yapen Tengah Nature Reserve is the largest protected area in the ecoregion, covering 590.0 km² in the center of the island."Yapen Tengah". ''Protected Planet''. Accessed 11 July 2021
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External links

*
Yapen endemic bird area (Birdlife International)

Yapen rain forests (DOPA Explorer)

References

{{reflist Australasian ecoregions Ecoregions of Indonesia Tropical and subtropical moist broadleaf forests Yapen Islands