The Western Polynesian tropical moist forests is a

tropical and subtropical moist broadleaf forests 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 ...

Polynesia Polynesia () "many" and νῆσος () "island"), to, Polinisia; mi, Porinihia; haw, Polenekia; fj, Polinisia; sm, Polenisia; rar, Porinetia; ty, Pōrīnetia; tvl, Polenisia; tkl, Polenihia (, ) is a subregion of Oceania, made up of ...

. It includes

Tuvalu Tuvalu ( or ; formerly known as the Ellice Islands) is an island country and microstate in the Polynesian subregion of Oceania in the Pacific Ocean. Its islands are situated about midway between Hawaii and Australia. They lie east-nor ...

, the

Phoenix Islands The Phoenix Islands, or Rawaki, are a group of eight atolls and two submerged coral reefs that lie east of the Gilbert Islands and west of the Line Islands in the central Pacific Ocean, north of Samoa. They are part of the Republic of Kiri ...

Kiribati Kiribati (), officially the Republic of Kiribati ( gil, ibaberikiKiribati),Kiribati
''The Wor ...

Tokelau Tokelau (; ; known previously as the Union Islands, and, until 1976, known officially as the Tokelau Islands) is a dependent territory of New Zealand in the southern Pacific Ocean. It consists of three tropical coral atolls: Atafu, Nukunonu, a ...

, and Howland and Baker islands, which are possessions of the United States.

Geography

The islands are mostly atolls, low islands of coralline sand ringing a central lagoon, or raised platforms of coralline limestone. The ecoregion includes three archipelagos along with some scattered islands. Tuvalu, formerly known as the Ellice Islands, includes nine atolls between 6º to 9º S latitude and 176º to 180º E longitude. The Phoenix Islands include eight atolls between 2º to 5º S latitude and 171º to 175º W longitude. They are part of Kiribati, and mostly uninhabited. Tokelau includes three inhabited atolls, Atafu, Nukunonu, and Fakaofo, and uninhabited Swain's Island, which is disputed with

American Samoa American Samoa ( sm, Amerika Sāmoa, ; also ' or ') is an unincorporated territory of the United States located in the South Pacific Ocean, southeast of the island country of Samoa. Its location is centered on . It is east of the Internationa ...

. Tokelau lies between 8º to 12º S latitude and 170º to 173º W longitude. Howland and Baker islands lie north of the Phoenix Islands.

Climate

The climate of the islands is tropical, with little seasonal variation in temperature. Tuvalu and Tokelau are in the trade wind belt, and average annual rainfall ranges 1,500 to 3,500 mm, falling relatively consistently from month to month and year to year. Most of the Phoenix Islands and Howland and Baker islands receive less than 1,000 mm of rain annually, with a March through June dry season. Rainfall on these islands is also more variable from year to year, with droughts during

El Niño El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date ...

cycles.

Flora

Native vegetation on the wetter islands is principally tropical moist forest, with shrub and herbaceous plant communities in rocky areas and shoreline areas exposed to salt spray. Characteristic canopy trees include ''

Pisonia grandis ''Pisonia grandis'', the grand devil's-claws, is a species of flowering tree in the ''Bougainvillea'' family, Nyctaginaceae. Description The tree has broad, thin leaves, smooth bark and bears clusters of green sweet-smelling flowers that matu ...

'' up to 25 meters high, '' Cordia subcordata'', and ''

Tournefortia argentea ''Heliotropium arboreum'' is a species of flowering plant in the borage family, Boraginaceae. It is native to tropical Asia including southern China, Madagascar, northern Australia, and most of the atolls and high islands of Micronesia and Polyn ...

'' in single-species or mixed stands, with ''

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 shi ...

Pandanus tectorius ''Pandanus tectorius'' is a species of ''Pandanus'' (screwpine) that is native to Malesia, Papuasia, eastern Australia, and the Pacific Islands. It grows in the coastal lowlands typically near the edge of the ocean. Common names in English incl ...

, Hernandia nymphaeifolia,

Ficus tinctoria ''Ficus tinctoria'', also known as dye fig, or humped fig is a hemiepiphytic tree of genus ''Ficus''. It is also one of the species known as '' strangler fig''. It is found in Asia, Malesia, northern Australia, and the South Pacific islands. ...

'', and ''

Guettarda speciosa ''Guettarda speciosa'', with common names sea randa, or zebra wood, is a species of shrub in the family Rubiaceae found in coastal habitats in tropical areas around the Pacific Ocean, including the coastline of central and northern Queensland an ...

''. Understory plants include the shrubs '' Suriana maritima'' and '' Pemphis acidula'', the fern '' Asplenium nidus'', and the vine '' Ipomoea tuba''. Forests are interspersed with areas of '' Scaevola taccada'' and '' Morinda citrifolia'' scrub. The drier islands are covered with low plants, including sparse grassland dominated by ''

Lepturus repens ''Lepturus'' (common name thintail) is a genus of plants in the grass family, native to Asia, Africa, Australia, and various islands in the Indian and Pacific Oceans. ; Species * '' Lepturus anadabolavensis'' A.Camus - Madagascar * '' Lepturus a ...

'', the creepers ''

Portulaca ''Portulaca'' (, is the type genus of the flowering plant family Portulacaceae, with over 100 species, found in the tropics and warm temperate regions. They are known as the purslanes. Common purslane (''Portulaca oleracea'') is widely consume ...

'' spp., ''

Sida fallax ''Sida fallax'', known as yellow ilima or golden mallow, is a species of herbaceous flowering plant in the ''Hibiscus'' family, Malvaceae, indigenous to the Hawaiian Archipelago and other Pacific Islands. Plants may be erect or prostrate and are ...

'', and ''

Sesuvium portulacastrum ''Sesuvium portulacastrum'' is a sprawling perennial herb that grows in coastal areas throughout much of the world. It is commonly known as shoreline purslane or (ambiguously) "sea purslane," in English, ''dampalit'' in Tagalog and 海马齿sl in ...

'', the grass '' Eragrostis whitneyi'', and occasionally the shrubs ''Cordia subcordata, Abutilon asiaticum, Suriana maritima, Pemphis acidula'', and '' Tribulus cistoides''. The flora is mostly of widespread coastal Indo-Pacific species, with relatively few endemic species.

Fauna

The native vertebrates are mostly seabirds, who roost in large numbers on many of the islands. The only forest birds are the Pacific pigeon (''Ducula pacifica''), a year-round resident, and the migratory

long-tailed cuckoo The Pacific long-tailed cuckoo (''Urodynamis taitensis''), also known as the long-tailed cuckoo, long-tailed koel, sparrow hawk, home owl, screecher, screamer or in Māori, is a species of the Cuculidae bird family (the cuckoos). It is a migrat ...

(''Urodynamis taitensis''), which winters in the tropical Pacific and breeds in New Zealand during the spring and summer. There are no native non-marine mammals or amphibians.

Polynesian rat The Polynesian rat, Pacific rat or little rat (''Rattus exulans''), known to the Māori as ''kiore'', is the third most widespread species of rat in the world behind the brown rat and black rat. The Polynesian rat originated in Southeast Asia, ...

(''Rattus exulans'') and house cats have been introduced to several islands, and prey heavily on native birds. Banded rails (''Hypotaenidia philippensis'') from Fiji have recently colonized Niulakita in Tuvalu.

Protected areas

64.3% of the ecoregion is in protected areas. Protected areas include the

Phoenix Islands Protected Area The Phoenix Islands Protected Area (PIPA) is located in the Republic of Kiribati, an ocean nation in the central Pacific approximately midway between Australia and Hawaii. PIPA constitutes 11.34% of Kiribati's exclusive economic zone (EEZ), an ...

References

External links

*{{WWF ecoregion, name=Western Polynesian tropical moist forests, id=oc0117
Western Polynesian tropical moist forests (DOPA)

Western Polynesian tropical moist forests (Encyclopedia of Earth)
Ecoregions of Kiribati Ecoregions of the United States Biota of Tuvalu Environment of Tuvalu Geography of Tuvalu Oceanian ecoregions Tropical and subtropical moist broadleaf forests Ecoregions of American Samoa