The Marianas Islands extend 900 km north and south. The islands were formed by the subduction of the Pacific Plate under the Mariana Plate, and the Marianas Trench, the world's deepest, lies immediately east of the islands. The nine northern islands are volcanic and relatively young; Farallon de Pájaros, the northernmost, is an active stratovolcano. Several of the northern islands have experienced recent volcanic activity. Anatahan erupted in 2003, Pagan in 1981, and Asuncion and Guguan in 1906.[4]
The southern islands are older, and are composed of volcanic rocks and marine limestone uplifted by the colliding plates. Guam, the southernmost island, is the largest. Other southern islands include Saipan, Tinian, and Rota.[citation needed]
The climate of the Mariana Islands is tropical. Temperature varies little from season to season, and average monthly temperatures range from 24º to 27º C. Rainfall averages 2,000 and 2,500 mm annually and is strongly seasonal, with a wet season from July through October. Easterly trade winds are fairly constant, with an occasional weak westerly monsoon influence during the summer months.[2]
Flora
Plant communities on the northern islands include grassland on young volcanic soils. Older and lower-elevation lava flows are colonized by the tree Casuarina equisetifolia, known locally as gagu, and the fern Nephrolepsis hirsutula. Small patches of Pisonia grandis forest can be found on the four younger islands which are free of grazing goats.[2]
The four larger northern islands, Agrihan, Pagan, Sarigan, and Anatahan, are home to remnant Aglaia–Elaeocarpus forests. The characteristic trees are mapunyao (Aglaia mariannensis) and yonga (Elaeocarpus joga). Mapunyao is endemic to the Marianas, and yonga is endemic to Micronesia. Mapunyao is dominant in the forest understory on both limestone and volcanic soils. Yonga is a large tree with a spreading crown, although the Marianas' frequent typhoons often limits their growth to 15 meters. Yonga's fleshy bright-blue berries are an important food for forest birds, particularly fruit doves.[2]
Asuncion has a Terminalia forest, unique in the archipelago, whose principal species are endemic.[2]
Most of the natural vegetation on the older southern islands has been cleared or altered by humans, but areas of primary and secondary forest remain. The plant communities vary with elevation and soils.[2]
Areas with volcanic substrates have highly weathered lateritic clays (oxisols or ultisols) or very young inceptisols. The limestone terrain has thin to moderately thick soils, with areas of bare stone.[2]
Most of Guam is covered by secondary forest. Patches of primary forest survive on the northern plateau and in inaccessible areas.[2]
The limestone forests are of five types. In Artocarpus-Ficus forests, the tall wild breadfruit Artocarpus mariannensis and the banyan Ficus prolixa are co-dominant. Lower-stature Mammea forests, dominated by Mammea odorata, are found on the eastern escarpment. Cordia forests, dominated by Cordia subcordata, are found on steep slopes and cliffs. Merrilliodendron-Ficus forest is dominated by Merrilliodendron megacarpum and Ficus prolixa which form a canopy 30 to 45 meters high. Pandanus forest is dominated by Pandanus tectorius.[2]
Vegetation on volcanic soils is predominantly grassland with forests growing in ravines. Ravine forest trees include Pandanus tectorius, P. dubuis, Hibiscus tiliaceus, Ficus prolixa, Glochidion marianum, and Premna serratifolia. Dense thickets of Leucaena leucocephala, a South American tree widely planted after World War II, are common.[2]
Limited-range species include the White-throated ground dove (Alopecoenas xanthonurus) of the Marianas and Yap; the Micronesian myzomela (Myzomela rubratra) of the Marianas, Caroline Islands, and Palau; the Caroline swiftlet (Aerodramus inquietus) of the Marianas and Carolines; and the Micronesian starling (Aplonis opaca) of the Marianas, Carolines, and Palau.[5]
The endangered Marianas megapode (Megapodius laperouse laperouse) and the skink Emoia slevini are now found only in the Terminalia forests of Asuncion.[2] However, there have been recent megapode sightings on Saipan and its adjacent islet of Managaha.
Guam's native bird and lizard species have been decimated by the Australasianbrown tree snake (Boiga irregularis), which was introduced in the 1940s.
The two extant native mammal species are bats. The Marianas flying fox (Pteropus mariannus) lives on inaccessible vegetated limestone cliffs and volcanic ravine forests. The only Pacific sheath-tailed bats (Emballonura semicaudata) in the Marianas are found on Aguijan. The Guam flying fox (Pteropus tokudae) was last seen in the 1960s and is presumed extinct.[2]
The Northern Mariana Islands, officially the Commonwealth of the Northern Mariana Islands, is an unincorporated territory and commonwealth of the United States consisting of 14 islands in the northwestern Pacific Ocean. The CNMI includes the 14 northernmost islands in the Mariana Archipelago; the southernmost island, Guam, is a separate U.S. territory. The Northern Mariana Islands were listed by the United Nations as a non-self governing territory until 1990.
The Northern Mariana Islands, together with Guam to the south, compose the Mariana Islands. The southern islands are limestone, with level terraces and fringing coral reefs. The northern islands are volcanic, with active volcanoes on Anatahan, Pagan and Agrihan. The volcano on Agrihan has the highest elevation at 3,166 feet (965 m). About one-fifth of the land is arable; another tenth is pasture. The primary natural resource is fish, some of which are endangered species, which leads to conflict. Also, development has created landfills which have contaminated the groundwater on Saipan, which could lead to disease.
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 Solomon Islands rain forests are a terrestrial ecoregion covering the Solomon Islands archipelago.
The Mariana mallard or Oustalet's duck is an extinct species of duck of the genus Anas that was endemic to the Mariana Islands. Its taxonomic status is debated, and it has variously been treated as a full species, a subspecies of the mallard or of the Pacific black duck, or sometimes as a subspecies of the Indian spot-billed duck.
Rota, also known as the "Friendly Island", is the southernmost island of the United States Commonwealth of the Northern Mariana Islands (CNMI) and the third southernmost of the Marianas Archipelago. In early Spanish records it is called "Zarpana"; the name Rota may have come from the Spaniards possibly naming the island after the municipality of Rota, Spain. It lies approximately 40 nautical miles (74 km) north-northeast of the United States territory of Guam. Sinapalo village is the largest and most populated, followed by Songsong village (Songsong). Rota also functions as one of the four municipalities of the CNMI.
The Ogasawara subtropical moist forests is a terrestrial ecoregion which encompasses the Ogasawara Archipelago of Japan. The Ogasawara Archipelago lies in the Pacific Ocean south of Honshu, Japan's largest island, and north of the Marianas Islands. The ecoregion includes the Bonin Islands and Volcano Islands chains. The islands are volcanic in origin, and have never been linked to a continent. They are home to distinct plants and animals including many endemic species.
Asuncion is an island in the Northern Mariana Islands chain in the Pacific Ocean. The island is uninhabited. Asuncion is situated 101 kilometers (63 mi) northwest of Agrihan and 37 km (23 mi) southeast of the Maug Islands.
The Micronesian megapode or Micronesian scrubfowl is an endangered megapode which inhabits islands of the Western Pacific Ocean.
Aglaia mariannensis, is a tree endemic to the Mariana Islands and Guam with large dark green, glossy pinnately compound leaves, densely arranged on stems. Terminal leaf buds are often orange and fuzzy and look like praying hands.
The Mariana crow is a species of the crow family from the tropical Western Pacific. It is a glossy black bird about 15 inches (38 cm) long and known only from the islands of Guam and Rota.
Serianthes nelsonii is a large tree endemic to Guam and Rota of the Mariana Islands. Only one mature tree exists on Guam, while 121 mature trees have been identified on Rota since 1984.
The Mariana swiftlet or Guam swiftlet is a species of swiftlet in the family Apodidae.
The bridled white-eye is a species of white-eye native to the Mariana Islands and formerly Guam. The species' natural habitat is tropical forests, shrublands and urban areas.
The following is an alphabetical list of articles related to the Commonwealth of the Northern Mariana Islands.
Star Marianas Air, Inc. is a U.S. commuter airline headquartered at Tinian International Airport in Tinian Municipality, Northern Mariana Islands. It operates scheduled and charter passenger service in the Commonwealth of the Northern Mariana Islands and Guam, both U.S. territories in the Pacific Ocean.
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 Tuamotu tropical moist forests is a tropical and subtropical moist broadleaf forests ecoregion in the Tuamotu Archipelago of French Polynesia and the Pitcairn Islands.
Syzygium thompsonii is an endemic tree of the Mariana Islands of Guam, Rota, and Saipan with a striking appearance due to its abundance of white flowers and edible fruit that grow directly from the trunk. It is related to the Malay apple but bears smaller tart fruit.
↑ Williams, Laura & Radley, Paul & Castro, Tony & Vogt, Scott. (2009). Wildlife and Vegetation surveys of Asuncion Island, Technical Report #15, 2009. 10.13140/RG.2.1.1175.7600.
1 2 BirdLife International (2020) Endemic Bird Areas factsheet: Mariana Islands. Downloaded from http://www.birdlife.org on 29/11/2020.
↑ UNEP-WCMC (2020). Protected Area Profile for Northern Mariana Islands from the World Database of Protected Areas, November 2020. Available at: www.protectedplanet.net
↑ UNEP-WCMC (2020). Protected Area Profile for Guam from the World Database of Protected Areas, November 2020. Available at: www.protectedplanet.net
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