Changjiang Plain evergreen forests | |
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Ecology | |
Realm | Palearctic |
Biome | Temperate broadleaf and mixed forest |
Geography | |
Area | 437,967 km2 (169,100 sq mi) |
Countries | China |
Coordinates | 30°30′N117°45′E / 30.500°N 117.750°E |
The Changjiang Plain evergreen forests ecoregion (WWF ID: PA0415) 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. [1] [2]
The Yangtze River Plain stretches 1,000 km from the Three Gorges to the sea. The terrain is mostly flat or low alluvial hills, with numerous shallow lakes. Large lakes include Poyang Lake, the largest freshwater lake in China, and Dongting Lake which was formerly the largest but has seen significant conversion to farmland over the years. The floodplain lakes grow and shrink dramatically with the seasons - Dongting Lake grows from 3,700 km2 to 13,000 km2 in the summer (and its depth increases by 10 meters).
The climate of the ecoregion is Humid subtropical climate, warm wet summer (Köppen climate classification (Cfa)). This climate is characterized by large seasonal temperature differentials. No month averages below 0 °C (32 °F), at least one month averages above 22 °C (72 °F), and four months average over 10 °C (50 °F). Precipitation is relatively even throughout the year. [3] [4]
The plain was once home to extensive evergreen oak (Cyclobalanopsis) or chinquapin ( Castanopsis ) forests and both forests are predominant by these trees, Cathaya argyrophylla , Taiwania flousiana , Cyathea spinulosa , Sassafras tzumu , Metasequoia glyptostroboides , Glyptostrobus pensilis , Davidia involucrata , Tetracentron , Cercidiphyllum japonicum , Emmenopterys henryi , Eucommia ulmoides , Castanea mollissima , Quercus myrsinifolia , Quercus acuta , Quercus glauca , Ilex integra , Machilus thunbergii , Juglans regia , Larix gmelinii , Juglans regia , Larix sibirica , Larix × czekanowskii , Betula dahurica , Betula pendula , Pinus koraiensis , Pinus sibirica , Pinus sylvestris , Picea obovata , Abies sibirica , Quercus acutissima , Quercus mongolica , Ginkgo biloba , Prunus serrulata , Prunus padus , Tilia amurensis , Salix babylonica , Acer palmatum , Populus tremula , Ulmus davidiana , Ulmus pumila , Pinus pumila , Haloxylon ammodendron , Elaeagnus angustifolia , Tamarix ramosissima , Prunus sibirica , Cinnamomum cassia , Durio zibethinus , Garcinia mangostana , Artocarpus heterophyllus , Ficus benghalensis , Gnetum gnemon , Mangifera indica , Toona ciliata , Toona sinensis , Cocos nucifera , Tetrameles nudiflora , Shorea robusta , Camphora officinarum , Tsuga dumosa , Ulmus lanceifolia , Tectona grandis , Terminalia elliptica , and Terminalia bellirica ; but the flat areas have mostly been converted to rice paddies. Better drained hills once supported conifers, but these areas are now mostly scrub or developed. Seasonal flooding of the river and surrounding wetlands provide habitat for waterfowl and aquatic life.
Aquatic life includes endangered species, such as the Chinese sturgeon ( Acipenser sinensis ) and the Chinese alligator ( Alligator sinensis ).
The Himalayan subtropical pine forests are a large subtropical coniferous forest ecoregion covering portions of Bhutan, India, Nepal, and Pakistan.
The Northeast India-Myanmar pine forests is a montane subtropical coniferous forest ecoregion in the mountains of Northeastern India and adjacent portions of Myanmar.
The Himalayan subtropical broadleaf forests is an ecoregion that extends from the middle hills of central Nepal through Darjeeling into Bhutan and also into the Indian States of Uttar Pradesh and Bihar. It represents the east–west-directed band of subtropical broadleaf forest at an altitude of between 500 and 1,000 m along the Outer Himalayan Range, and includes several forest types traversing an east to west moisture gradient.
The Taiwan subtropical evergreen forests is an ecoregion that covers most of the island of Taiwan, with the exception of the southern tip of the island, which constitutes the South Taiwan monsoon rain forests ecoregion. The island's concentrated steep mountains host a range of forest types, from subtropical forests in the lowlands to temperate and alpine or montane forests.
The Northern Indochina subtropical forests are a subtropical moist broadleaf forest ecoregion of northern Indochina, covering portions of Vietnam, Laos, Thailand, Myanmar, and China's Yunnan Province.
The Mizoram–Manipur–Kachin rain forests is a subtropical moist broadleaf forest ecoregion which occupies the lower hillsides of the mountainous border region joining Bangladesh, China's Yunnan Province, India, and Myanmar. The ecoregion covers an area of 135,600 square kilometres (52,400 sq mi). Located where the biotas of the Indian Subcontinent and the Indochinese Peninsula meet, and in the transition between subtropical and tropical regions of Asia, the Mizoram–Manipur–Kachin rain forests are home to great biodiversity. The WWF rates the ecoregion as "Globally Outstanding" in biological distinctiveness.
The Taiheiyo evergreen forests is a temperate broadleaf forest ecoregion of Japan.
The Western Himalayan broadleaf forests is a temperate broadleaf and mixed forest ecoregion which is found in the middle elevations of the western Himalayas, including parts of Nepal, India, and Pakistan.
The Southern Korea evergreen forests is a temperate broadleaf and mixed forests ecoregion at the southern end of the Korean Peninsula.
The Sichuan Basin evergreen broadleaf forests are a critically endangered WWF ecoregion. The ecoregion occupies the Sichuan Basin in China and covers an area of 9,816,054 ha. The broadleaf forest habitat once covered the Sichuan Basin, but today is limited to mountains and preserved temple grounds in the basin and around the basin's rim. An especially well-preserved example of remaining forest exists on Mount Emei at the western edge of the Sichuan Basin. The original forests are thought to have been made up of subtropical oaks, laurels, and Schima. Much of the remaining Sichuan Basin has been converted to anthropogenic agricultural use in the last 5,000 years.
The Daba Mountains evergreen forests are a Global 200 endangered ecoregion located on the Daba Mountains in China. The forests are part of temperate broadleaf and mixed forests containing both coniferous and broadleaf trees covering a swath of Central China. Forests here provide a transitional area between evergreen forests to the south and deciduous forests to the north. The Daba Mountains evergreen forests cover areas of northeast Sichuan Province, southern Shaanxi Province, the northern half of Chongqing Municipality, and western Hubei Province.
The Yunnan Plateau subtropical evergreen forests is an endangered ecoregion in southwestern China. These forests once covered the western parts of the Yungui Plateau but have been significantly reduced and replaced with agricultural land uses. The Yunnan evergreen forests and the neighbouring Guizhou Plateau broadleaf and mixed forests are the only two ecoregions in the Palearctic realm to be classified as part of tropical and subtropical moist broadleaf forests biome.
The Guizhou Plateau broadleaf and mixed forests are a subtropical moist broadleaf forest ecoregion in the Yungui Plateau of China. Much of the original forest has been replaced by secondary forests.
The Qilian Mountains Conifer Forests ecoregion is an ecoregion that consists of a series of isolated conifer forests on the northern slopes of the Qilian Mountain Range, on the northeast edge of the Tibetan Plateau in Qinghai and Gansu provinces of north-central China.
The Central China Loess Plateau Mixed Forests ecoregion covers an elongated plateau across north-central China, characterized by accumulated soils of wind-blown dust known as loess and glacial till. The yellowish soil imparts its color to the Yellow River and Yellow Sea downstream. The ecoregion is located west of the lower Yellow River basin and the North China Plain.
The Huang He Plain mixed forests ecoregion covers the flat lower ranges of the Yellow River. This area is generally known as the North China Plain. While there is some forest habitat, the region has mostly been converted to agriculture, being one of the most populous areas in the world.
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 Nihonkai evergreen forests ecoregion covers a thin strip of land on the western coast of the island of Honshu in Japan. It is bounded on the east by the Nihonkai montane deciduous forests 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.