| Marquesas tropical moist forests | |
|---|---|
 | |
 Map of the Marquesas Islands | |
| Ecology | |
| Realm | Oceanian |
| Biome | tropical and subtropical moist broadleaf forests |
| Geography | |
| Area | 540 km2 (210 sq mi) |
| Country | French Polynesia |
| Administrative subdivisions | Marquesas Islands |
| Conservation | |
| Conservation status | Critical/endangered [1] |
| Protected | 37 km2 (7%) [2] |
The Marquesas tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in the Marquesas Islands of French Polynesia.
The Marquesas Islands include 12 major islands of volcanic origin. They extend northwest to southeast between 8º and 11º S latitude and 139º and 141º W longitude. The islands are part of French Polynesia, lying north of the Tuamotu islands, south of Hawaii, and approximately 5,500 km (3,400 mi) west of South America. [1]
The islands are volcanic in origin, created by the slow west-northwest movement of the Pacific Plate over the Marquesas hotspot. The northwestern islands are approximately 6 million years old, and the southeast islands are younger at 1.3 million years old. [1]
The islands are composed of basalt rock, and have mountainous terrain with sharp ridges, deep canyons, and steep cliffs. The largest and highest islands are:
The islands have a tropical climate. Average annual rainfall varies with elevation and orientation, from 500 mm on leeward lowlands to 4000 mm or more on windward slopes above 1000 meters on the five highest islands. Trade winds blow from the southeast during most of the year, and the windward eastern slopes tend to be wetter than the leeward western slopes. The east-facing mountain slopes are cooler, with mean temperatures of 15º to 25º C, while the hottest mean temperatures (25º to 29°C) are in the dry western lowlands. [1]
The natural vegetation is principally tropical moist forest, which varies in height and species composition with rainfall and elevation. [1]
Lowland forests extend up to about 300 m with areas of up to 2000 mm of annual rainfall. Typical lowland forests are dominated by Pisonia grandis , which forms a canopy up to 15 meters high, along with the trees Thespesia populnea, Calophyllum inophyllum , and Terminalia glabrata . Tropical dry forest occurred on drier leeward slopes of the larger islands, characterized by species of Hibiscus, Pandanus, Thespesia , and Cordia . [1] Native lowland forests have mostly been replaced with introduced trees. Archeological evidence shows that some pre-settlement lowland forest trees are now extinct, including species of Planchonella and cf. Sideroxylon (Sapotaceae), and a species of Allophylus (Sapindaceae) extirpated from Nuku Hiva. [3]
Mid-elevation forests occur between 300 and 800 meters elevation, with annual rainfall of 2,000 to 3,000 mm. Typical trees include Hibiscus tiliaceus, Pandanus tectorius, Alphitonia marquesensis , and Pterophylla marquesana , which form a canopy up to 20 meters high. Understory plants include Angiopteris evecta and Cyclophyllum barbatum . From 800 to 1000 meters elevation, Hernandia nukuhivensis , and the tree ferns Cyathea affinis and Sphaeropteris feani predominate in wet areas, and Metrosideros collina and Pterophylla marquesana on drier slopes. A cloud forest belt occurs above 1000 meters elevation, with a low-canopied forest of Cheirodendron bastardianum, Ilex anomala , and Metrosideros collina, with climbers of Freycinetia spp. [1]
Mountaintops above 1,200 m are drier and windswept, supporting a heathland of low trees and shrubs up to one meter high, including M. collina, Vaccinium cereum, Styphelia tameiameiae , and Bidens spp., interspersed with grasses and ferns. [1]
42% of the 320 native vascular plant species are endemic. [1]
The ancestors of the Marquesas' native fauna arrived via long-distance dispersal from other islands, and evolved into distinct forms over millions of years. [1]
The ecoregion has 19 breeding seabird species and 11 resident land birds, including ten endemic bird species. Endemic species include the Marquesas ground dove (Gallicolumba rubescens), Marquesas kingfisher (Halcyon godeffroyi), Fatuhiva monarch (Pomarea whitneyi), Iphis monarch (P. iphis), and Marquesas monarch (P. mendozae). Most endemic species have been decimated by introduced rats, which prey on eggs and chicks. The Nuku Hiva pigeon (Ducula galeata) is now limited to a few hundred individuals on Nuku Hiva. The ultramarine lory (Vini ultramarina) once ranged across the archipelago, but predation by introduced black rats reduced its range to Ua Huka island. The birds were reintroduced on Fatu Hiva in conjunction with a rat control program. The red-moustached fruit dove (Ptilinopus mercierii) is now extinct. [1]
The Marquesas are home to at least 78 species of land and freshwater snails. [1]
There are 1198 species of terrestrial arthropods in the Marquesas, 681 (53%) of which are considered endemic to the islands, 138 (11.5%) are introduced, and the remainder mostly native with some of uncertain status. The majority of the endemic insect species are contained in five orders: Coleoptera (beetles), Diptera (flies), Hemiptera (true bugs), Hymenoptera (wasps, bees and ants), and Lepidoptera (butterflies and moths). Many of the endemic species are native to a single island. [4] Insect genera which have significant radiations of endemic species in the Marquesas include Asymphorodes (Lepidoptera, 21 spp.), Prochaetops (Diptera, 15 spp., possibly not all endemic), Campsicnemus (Diptera, 15 spp.), Pacificola (Coleoptera, 13 spp.), Dichelopa (Lepidoptera, 13 spp.), Sierola (Hymenoptera, 12 spp.), and Campylomma (Hemiptera, 11 spp.). [5]
Humans have altered landscape and flora and fauna of the islands since the arrival of Polynesians in the 11th and 12th centuries. Polynesian settlers introduced 33 to 37 species of plants to the islands, [4] Including the coconut palm (Cocos nucifera), breadfruit tree (Artocarpus altilis), candlenut tree (Aleurites moluccana), Tahitian chestnut ( Inocarpus fagifer ), Malay apple ( Syzygium malaccense ), paper mulberry (Broussonetia papyrifera), and Polynesian bamboo ( Schizostachyum glaucifolium ), some of which have naturalized across the archipelago, as well as pigs and the Polynesian rat (Rattus exulans). [6] [1] Much of the native lowland forest vegetation was replaced with traditional agroforestry systems centered on the introduced breadfruit and coconut. [7] These agroforestry landscapes provide food, fiber, and building materials while largely preventing soil erosion and nutrient depletion. [6]
Europeans started visiting the islands in the 18th century and later conquered and settled there. Europeans brought with them many more exotic plants and animals, including black rats (Rattus rattus) which have decimated the islands' birds. [1] Introduced sheep and goats have denuded some areas of vegetation, particulary in drier parts of the islands. Introduced grasses, shrubs, and trees are often fast-growing and adapted to grazing and fire, and can outcompete native species. [4] By the 19th century commercial coconut plantations occupied much of the lowlands. [7]
Relatively intact natural vegetation covers about 43% of the ecoregion's area. [2] Most of the lowlands are used for agriculture and pasture, and very little natural lowland forest remains. [1]
A 2017 assessment found that 37 km2, or 7%, of the ecoregion is in protected areas. [2]
The Vanuatu rain forests are tropical and subtropical moist broadleaf forests ecoregion which includes the islands of Vanuatu, as well as the Santa Cruz Islands group of the neighboring Solomon Islands. It is part of the Australasian realm, which includes neighboring New Caledonia and the Solomon Islands, as well as Australia, New Guinea, and New Zealand.
The Madagascar subhumid forests are a tropical moist broadleaf forest ecoregion that covers most of the Central Highlands of the island of Madagascar. They are included in the WWF's Global 200 list of outstanding ecoregions. Most of the original habitats have been lost due to human pressure.
The Hawaiian tropical rainforests are a tropical moist broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of 6,700 km2 (2,600 sq mi) in the windward lowlands and montane regions of the islands. Coastal mesic forests are found at elevations from sea level to 300 m (980 ft). Mixed mesic forests occur at elevations of 750 to 1,250 m, while wet forests are found from 1,250 to 1,700 m. Moist bogs and shrublands exist on montane plateaus and depressions. For the 28 million years of existence of the Hawaiian Islands, they have been isolated from the rest of the world by vast stretches of the Pacific Ocean, and this isolation has resulted in the evolution of an incredible diversity of endemic species, including fungi, mosses, snails, birds, and other wildlife. In the lush, moist forests high in the mountains, trees are draped with vines, orchids, ferns, and mosses. This ecoregion includes one of the world's wettest places, the slopes of Mount Waiʻaleʻale, which average 373 in (9,500 mm) of rainfall per year.
Ua Huka is one of the Marquesas Islands, in French Polynesia, an overseas territory of France in the Pacific Ocean. It is situated in the northern group of the archipelago, approximately 25 mi (40 km) to the east of Nuku Hiva, at 8°54′S139°33′W.
The São Tomé, Príncipe, and Annobón forests, also known as the São Tomé, Príncipe, and Annobón moist lowland forests, is a tropical moist broadleaf forest ecoregion that covers the islands of São Tomé and Príncipe, which form the island nation of São Tomé and Príncipe, as well as the island of Annobón, which is part of Equatorial Guinea.
The Marquesan monarch is a species of bird in the family Monarchidae. It is endemic to French Polynesia. Its natural habitats are subtropical or tropical dry forest, subtropical or tropical moist lowland forest, and subtropical or tropical moist montane forest. It is threatened by habitat loss.
Metrosideros collina is a species of flowering plant in the family Myrtaceae. It is a tree or shrub native to French Polynesia, the Cook Islands, and the Pitcairn Islands.
The Samoan tropical moist forests are a tropical moist broadleaf forest ecoregion in the Samoan Islands of the Pacific Ocean.
The Puerto Rican moist forests are a tropical moist broadleaf forest ecoregion in Puerto Rico. They cover an area of 7,544 km2 (2,913 sq mi).
Northern Zanzibar–Inhambane coastal forest mosaic, also known as the Northern Swahili coastal forests and woodlands, is a tropical moist broadleaf forest ecoregion of coastal East Africa. The ecoregion includes a variety of habitats, including forest, savanna and swamps.
The Fiji tropical moist forests is a tropical moist forest ecoregion in Fiji and Wallis and Futuna. It covers the windward sides of Viti Levu and Vanua Levu, Fiji's largest islands, as well as the smaller Fijian islands and the three islands that make up Wallis and Futuna, an overseas territory of France.
The Tongan tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion that includes the Tonga archipelago and Niue.
The Cook Islands tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion that covers the Southern Cook Islands in the Cook Islands.
The Tubuai tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in French Polynesia. It covers the Austral Islands.
The Society Islands tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in the Society Islands of French Polynesia.
The Tuamotu tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in the Tuamotu Archipelago of French Polynesia and the Pitcairn Islands.
The Western Polynesian tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in Polynesia. It includes Tuvalu, the Phoenix Islands in Kiribati, Tokelau, and Howland and Baker islands, which are possessions of the United States.
The Carolines tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in Micronesia. It includes the central and eastern Caroline Islands in the Federated States of Micronesia.
Pterophylla marquesana, formerly known as Weinmannia marquesana, is a species of plant in the family Cunoniaceae. It is a shrub or tree endemic to the Marquesas Islands of French Polynesia.
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