Ecoregion: Red River freshwater swamp forests | |
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Ecology | |
Realm | Indomalayan |
Biome | Tropical and subtropical moist broadleaf forests |
Geography | |
Area | 10,877 km2 (4,200 sq mi) |
Country | Vietnam |
Coordinates | 20°30′N106°15′E / 20.5°N 106.25°E |
The Red River freshwater swamp forests ecoregion (WWF ID:IM0147) covers the freshwater portion of the Hong River ("Red River") delta in northern Vietnam. The ecoregion is separated from the sea by a thin coastal strip of the saltwater mangroves of the Indochina mangroves ecoregion. [1] [2] [3] Very little of the little ecosystem remains; most of the delta has been converted to urbanization, industry, or agriculture. Less than 1% of the ecoregion is protected in significantly sized tracts.
The ecoregion is relatively small, just under 11,000 km2, limited to the flat river delta of the Hong River, centered on the cities of Hanoi in the center and Haiphong at the river mouth. The ecoregion is separated from the actual sea coast by a thin strip of the Indochina mangroves ecoregion in the saltwater-affected zone. [1] To the north is the South China-Vietnam subtropical evergreen forests ecoregion, and to the west are the Northern Indochina subtropical forests and Northern Vietnam lowland rain forests ecoregions.
The climate of the ecoregion is Dry-winter humid subtropical climate (Köppen climate classification (Cwa)). This climate is characterized as having no month averaging below 0 °C (32 °F), at least one month averaging above 22 °C (72 °F), and four months averaging over 10 °C (50 °F). Precipitation in the wet summer months is ten time or more the average of the winter months. [4] [5]
Inland of the saltwater mangroves are the freshwater swamp forests, at least in the areas not converted to human use. The forest cover is generally limited to strips along the rivers. Only about 1% (about 100 km2) of the ecoregion is in a core natural state, although 17% is in some form of forest cover, mostly of open evergreen broadleaf trees. [3]
The Paramaribo swamp forests (NT0149) is an ecoregion in the coastal plain of Suriname covering a strip of land that is almost always flooded by fresh waters. It transitions into saline mangrove swamps towards the coast, and into submontane forests towards the interior.
The South China-Vietnam subtropical evergreen forests ecoregion covers the mountainous coastal region of southeastern China and northeastern Vietnam. The ecoregional also covers the coastal plain along the South China Sea and Hainan Island. The area has significant biodiversity and ecological importance, with high levels of both endemic and threatened species. Rapid urban expansion is reducing biologically-rich forests and wetlands. Ecologically, the subtropical forests are at the northeastern extent of the Indomalayan realm.
The Qin Ling Mountains deciduous forests ecoregion covers the Qin Mountains, which run west-to-east across central China. The mountains effectively divide the biological regions of China into north and south. To the north is the Yellow River basin, a loess-soil region of temperate deciduous forests. To the south is the Yangtze River basic, a subtropical forest region. In between, the Qin Mountains support many rare and endemic species, including the Giant panda and the Sichuan snub-nosed monkey.
The Jiang Nan subtropical evergreen forests ecoregion covers the mountainous divide between the lower Yangtze River and the coastal plain of South China. The region is also a climatic divide between the temperate valleys of the north and the subtropical forests of the south. The region is important for biodiversity and endemic species. The rugged limestone karst hills have been relatively protected from conversion to agriculture, and support specialized plant and animal communities.
The Luang Prabang montane rain forests ecoregion covers elevations over 800 meters in the Luang Prabang mountains that straddle the border between northern Thailand and north-central Laos, and the highlands that stretch eastward across north-central Laos. While much of the forest cover has been degraded, there are still large areas of relatively untouched forest.
The Northern Annamites rain forests ecoregion covers the rugged and relatively unexplored northern Annamite Mountains of central Laos and Vietnam. There are high numbers of endemic plant species, and the relative remoteness and isolation of the area supports many rare and endangered animals. Rainfall is somewhat less than the lowland rainforest of the lower elevations in Vietnam, and the temperatures slightly cooler due to the higher elevation.
The Southern Vietnam lowland dry forests ecoregion covers the low, relatively arid coastal strip of southern Vietnam on the South China Sea. The region is in the rain shadow of the Southern Annamite Range, which blocks humid air from the west. Although approximately half of the ecoregion is forested to some degree, most has at some point been cleared for agriculture or degraded by extraction of hardwoods. There are few protected areas.
The Tonle Sap freshwater swamp forests ecoregion covers the seasonally flooded forests surrounding Tonlé Sap, the largest lake in Cambodia, and the floodplains of its connections to the Mekong River. Over 35% of the ecoregion experiences flooding during the wet season.
The Tonle Sap-Mekong peat swamp forests ecoregion covers a patchwork of areas permanently inundated with fresh water along the Tonle Sap River and Mekong River floodplains in Cambodia and Vietnam. The terrain is mostly flat, with extensive agricultural fields, reed beds, and degraded shrub forest. Less than 10% of the region is in its original state, and less than 1% is protected. Habitat in the region is distinguished from the Tonle Sap freshwater swamp forests ecoregion that runs through the middle, as that ecoregion is only seasonally flooded.
The Northern Thailand–Laos moist deciduous forests ecoregion follows the upper course of the Nan River in northern Thailand and the Mekong River in Laos. This area has the highest proportion of tree cover in Thailand, with many forests dominated by Teak. The river valleys have been under pressure from human use: agriculture, teak plantations, and hunting have reduce plant and animal presence.
The Irrawaddy freshwater swamp forests ecoregion covers the freshwater portion of the delta of the Irrawaddy River, set back an average of 70 km from the Bay of Bengal by the saltwater mangroves. To the north is a rainforest belt with less inundated land. The region is extremely fertile due to the river-borne silt, but nearly-total conversion to agriculture has degraded the ecology. There are no fully protected areas in this ecoregion.
The Northern Triangle subtropical forests ecoregion covers remote, mountainous terrain in the far north of Myanmar. Due to the regions isolation it is relatively untouched and unexplored by humans. Over 95% of the ecoregion is covered with closed evergreen forest, and importantly for conservation, these forests exist in large contiguous blocks. As of the late 1990s, 140 mammal species were known to be in the region, and new species, such the Leaf muntjac discovered in 1997, are still being found.
The Sumatran peat swamp forests ecoregion covers the low-lying peat swamp forests along the northeast coast of the island of Sumatra in Indonesia. As is typical for peat swamp forests, this ecoregion lies between a thin strip of saltwater-affected mangroves on the coast, and freshwater swamps and lowland rainforest forest on better drained soils further inland. Because the peat soil has relatively low nutrient levels, this ecoregion has been less used for agriculture, but burning and clearance has degraded half of the forest.
The Southwest Borneo freshwater swamp forests ecoregion covers a number disconnected patches of freshwater swamp forest along the southwestern coasts of Borneo. The swamps are generally set back a few kilometers or two from the sea by the saltwater-affected Sunda Shelf mangroves The relatively fertile, flat soil has led to much of this ecoregion being converted to agriculture.
The Moist Pacific Coast mangroves ecoregion covers a series of disconnected mangrove sites along the Pacific Ocean coast of Costa Rica and Panama. These sites occur mostly on coastal flatlands around lagoons, particularly where rivers from the inland mountains reach the sea, bringing fresh water to the coastal forests. The area is in a transition zone from the drier coastline to the north; rainfall in this ecoregions is over 2,000 mm/year, and reaches over 3,600 mm/year at the southern end.
The Mayan Corridor mangroves ecoregion covers the mangrove habitats along the Caribbean Sea coast of the state of Quintana Roo in southern Mexico and a narrow strip on the north of Belize. The region is named for the Maya Civilization archeological sites along the coast. Biodiversity in the area high due to the interactions of different environments - coastal lagoons, river estuaries, coral reefs, and barrier beaches. The ecoregion supports Mexico's largest population of crocodiles.
The Rio Negro-Rio San Sun mangroves ecoregion covers a series of small of discontinuous mangrove forests on the Caribbean Sea coast of Costa Rica, from a small portion inside the border with Nicaragua in the west to the border with Panama in the east. The coast on this stretch is a flat, alluvial plain, and mangroves are only a small part of a diverse patchwork of local habitats including swamps, mixed rainforests, coastal lagoons, sea grass beds, and sandy beaches. Much of the territory is "blackwater river" in character - slow-moving channels in wooded swamps with water stained by decayed matter. These mangroves are periodically damaged by hurricanes, such as in 1988 from Hurricane Joan, but are able to regenerate.
The Trinidad mangroves ecoregion covers the separate mangrove forest areas on the coast of the island of Trinidad, in the country of Trinidad and Tobago. The character of the mangroves is affected by the large amount of fresh water flowing out of the Orinoco River and Amazon River to the south, which flow northwest around the island. The mangroves of Trinidad are found on all coasts, and are usually in the estuaries of rivers, but also found in coastal lagoons.
The Trinidad and Tobago moist forests ecoregion covers most of Trinidad Island and Tobago Island near the coast of South America where the southeastern Caribbean Sea meets the Atlantic Ocean. Small portions of the islands around river estuaries and coastal lowlands are mangroves or dry forests. Species diversity is very high, in particular for plants and birds. Tobago, being much smaller, has fewer species.