Southern Vietnam lowland dry forests | |
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Ecology | |
Realm | Indomalayan |
Biome | Tropical and subtropical dry broadleaf forests |
Geography | |
Area | 35,000 km2 (14,000 sq mi) |
Country | Vietnam |
Coordinates | 13°15′N109°06′E / 13.25°N 109.1°E |
The Southern Vietnam lowland dry forests ecoregion (WWF ID: IM0211) 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. [1] [2] [3] 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 coast in this ecoregion is a series of alluvial plains separated by ridges extending down from the Annamite Range on the west. The separating hills rise to 1,000 meters, and are typically granite or rhyolite. The region stretches for 750 km from Da Nang in the north to the edge of the Mekong River delta in the south, and averages about 50 km wide. Mean elevation is 200 meters. [3]
The climate of ecoregion is Tropical savanna climate - dry winter (Köppen climate classification (Aw)). This climate is characterized by relatively even temperatures throughout the year, and a pronounced dry season. The driest month has less than 60 mm of precipitation, and is drier than the average month. [4] [5] Annual rainfall is less than 1,500 mm in most of the region, and as low as 800 mm. [1]
Nearest the beach are extensive dunes of red sand, with woody thickets giving way to evergreen forest cover on coastal hills and higher elevations. [1] Two endemic species of trees on these dunes are the critically endangered Hopea cordata and Shorea falcata . The most common trees in this region are Cinnamomum cassia, Durio zibethinus, Garcinia mangostana, Artocarpus heterophyllus, Ficus benghalensis, Gnetum gnemon, Mangifera indica, Toona ciliata, Toona sinensis, Cocos nucifera, Tetrameles nudiflora, Ginkgo biloba, Shorea robusta, Prunus serrulata, Camphora officinarum, Tsuga dumosa, Ulmus lanceifolia, Tectona grandis, Quercus acutissima, Terminalia elliptica , Terminalia bellirica , and Nypa fruticans .
Where freshwater gathers at the base of the dunes there are communities of Phreatophytes (plants that maintain constant contact with ground water) that create forest cover up to 12 meters in height. At semi-arid higher elevations of the coastal slopes are forest and thicket stands that support other endemic species but are under human pressure.
The Aravalli West Thorn Scrub Forests, formerly known as Northwestern thorn scrub forests, is a xeric shrubland ecoregion of Pakistan and Northern India, stretching along the border lowlands and hills between the two countries. Once covered in deciduous forest, this ecoregion has been degraded through agriculture and the extraction of timber so that it currently has a scanty covering of thorny scrub dominated by such trees as Acacia senegal, Acacia leucophloea and Prosopis cineraria. Where the soils are particularly saline, there are patches of semi-desert. A number of mammals are found in this habitat, including about four hundred species of bird. Some small areas are protected but the collection of firewood and the conversion of the land to subsistence farming continues.
The Southeastern Indochina dry evergreen forests are a tropical dry broadleaf forest ecoregion of Indochina.
The Cardamom Mountains rain forests is a tropical moist broadleaf forest ecoregion in Southeast Asia, as identified by the WWF. The ecoregion covers the Cardamom Mountains and Elephant Mountains and the adjacent coastal lowlands in eastern Thailand and southwestern Cambodia, as well as the Vietnamese island of Dao Phu Quoc.
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 Caspian lowland desert ecoregion covers the north and southeast coasts of the Caspian Sea, including the deltas of the Volga River and Ural River in the northern region. While the region gets relatively low amounts of precipitation, wildlife is supported by the river estuaries and the sea itself. The wetlands are an internationally important area for bird nesting and migratory resting. The ecoregion is in the Palearctic realm, and the deserts and xeric shrublands biome. It has an area of 267,300 square kilometres (103,200 sq mi).
The Changjiang Plain evergreen forests ecoregion covers the plain of the Yangtze River (Changjiang) from where it leaves the mountains at the Three Gorges in the west, to the mouth of the Yangtze at the East China Sea. This plain is one of the most densely populated areas on Earth, and most of the original oak and conifer forests have long been converted to agriculture. Extensive wetlands, however, provide habitat for migratory waterfowl and for diverse aquatic species.
The Hainan Island monsoon rain forests ecoregion covers mountainous interior of Hainan Island in China. The tropical forests receive over 1,000 mm/year of rain, heavily concentrated in the summer rainy season. The island has high levels of biodiversity, with over 4,200 plant species, 630 of which are endemic to the island. The region is under ecological pressure from deforestation for agriculture and timber extraction.
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 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 Northern Vietnam lowland rain forests ecoregion covers the central-eastern coast of Vietnam from the Red River delta in the north to Tam Kỳ in the center of the country and neighboring adjacent parts of Laos. The region is one of the wet evergreen forests, with rain over 50 mm in every month. The forests have been highly degraded by human use, and the high levels of biodiversity have been pushed back into relatively small protected areas like Pu Mat National Park.
The Southern Annamites montane rain forests ecoregion covers a region of high biodiversity in the central and southern mountains of the Annamite Range in Vietnam. Terrain ranges from wet lowland forest to evergreen hardwood and conifer montane rain forest. There is a short dry season centered on January–February, but fog and dew are common throughout the year and support a lush forest character.
The Red River freshwater swamp forests ecoregion covers the freshwater portion of the Hong 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. 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 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 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 lowland rain forests ecoregion covers the lowland forests running the length of the island of Sumatra in Indonesia. The region is one of exceptionally high biodiversity, similar to Borneo and New Guinea islands. Many endangered mammals species are present, and over 450 species of birds have been found in the region. In recent years, illegal logging and human encroachment have put great strain on this ecoregion.
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 rain 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 Isthmian–Pacific moist forests ecoregion covers the lowland tropical evergreen forests on the Pacific side of the central mountains of southern Costa Rica and western Panama. As the meeting zone between North and South American floral communities, the area is one of very high biodiversity. Much of the rainforest has, however, been cleared for subsistence agriculture and cattle grazing.
The Baluchistan xeric woodlands ecoregion covers the middle elevations of a series of mountain ranges of western Pakistan and northeastern Afghanistan, reaching 1,200 kilometres (750 mi) from the Arabian Sea in the south to the Hindu Kush Mountains and the Himalayas in the north. The characteristic vegetation is xeric (dry) woodlands of shrubs and herbaceous cover. The region has rich biodiversity but relatively few endemic species.