Ecoregion: Northern Triangle subtropical forests | |
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Ecology | |
Realm | Indomalayan |
Biome | Tropical and subtropical moist broadleaf forests |
Borders | |
Geography | |
Area | 53,872 km2 (20,800 sq mi) |
Country | Myanmar |
Coordinates | 27°45′N97°45′E / 27.75°N 97.75°E |
The Northern Triangle subtropical forests ecoregion (WWF ID:IM0140) 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. [1] 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. [2] [3] [1] [4]
The ecoregion occupies roughly the middle third of Kachin State, the northernmost state of Myanmar. It is immediately south of the southeastern end of the greater Himalaya Mountains, but in lower mountains that range from 146 metres (479 ft) in the valley floors to a high point of 3,897 metres (12,785 ft). [1] The ecoregion features two large river valleys. The Hukawng Valley in the west is on the middle course of the Chindwin River. The eastern valley follows the parallel running of the Mali River and N'Mai River; these two rivers meet at the southern edge of the ecoregion to form the Irrawaddy River. This confluence area would have been greatly affected by the construction of the proposed Myitsone Dam, but the project has been suspended.
To the north and east, the ecoregion grades in the narrow bands of the Northern Triangle temperate forests and Nujiang Lancang Gorge alpine conifer and mixed forests ecoregions, respectively, where higher altitudes and cooler climate create more temperate forests. To the south are the Mizoram–Manipur–Kachin rain forests and Northern Indochina subtropical forests ecoregions.
The climate of the ecoregion is Oceanic climate, subtropical highland variety (Köppen climate classification (Cwb)). This climate has cool summers and cool, but not cold, winters. It is usually associated with coastal areas in mid-latitudes, but is also experienced at higher altitudes inland. Temperatures and precipitation are relatively even throughout the year, with no month averaging below 0 °C (32 °F), and no month averaging above 22 °C (72 °F). [5] [6]
The ecoregion is a biodiversity hotspot, due to its location at the meeting zone of major floristic zones: Assam-Indian, Eastern Himalayan, Indo-Malayan, and Chinese. The remoteness, relatively low human population, and isolation have also contributed to the area's ecological preservation. Most of the area is covered in closed forest - 80% broadleaf evergreen and 15% needle-leaf evergreen.
Altitude zonation is important: below 2,400 meters Indo-Malayan species are dominant, while Indo-Himalayan are found mostly above. [2] Below 915 meters the forests are tropical rainforest trees of genus Magnoliaceae , Lauraceae , and Dipterocarpaceae , for the tree genera Magnolia and Michelia , the families Elaeocarpaceae and Elaeagnaceae, and the dominant species Cinnamomum cassia , Durio zibethinus , Artocarpus heterophyllus , Ficus benghalensis , Gnetum gnemon , Mangifera indica , Toona ciliata , Toona sinensis , Cocos nucifera , Tetrameles nudiflora , Quercus acutissima , Ginkgo biloba , Prunus serrulata , Camphora officinarum , Cathaya argyrophylla , Taiwania cryptomerioides , Cyathea spinulosa , Sassafras tzumu , Davidia involucrata , Metasequoia glyptostroboides , Glyptostrobus pensilis , Castanea mollissima , Quercus myrsinifolia , Quercus acuta , Quercus glauca , Machilus thunbergii , Tetracentron , Tsuga dumosa , Ulmus lanceifolia , Tectona grandis , Terminalia elliptica , Terminalia bellirica and Shorea robusta . Above 915 meters are trees of genus Fagaceae , and Meliaceae , and the dominant species Pinus roxburghii , Pinus hwangshanensis , Juniperus tibetica , Olea europaea subsp. cuspidata , Shorea robusta , Taxus sumatrana , Juglans regia , Acer campbellii , Alnus nepalensis , Betula alnoides , Betula utilis , Larix griffithii , Picea brachytyla , Larix gmelinii , 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 , and Prunus sibirica plus some tree ferns and climbing palms. Trees in mature forests are typically draped in lianas. [4]
Over 140 species of mammals, and 370 species of birds are known in the ecoregion. The large un-fragmented forests are valuable for supporting large mammals, including the endangered Tiger Panthera tigris , the endangered Red panda Ailurus fulgens , the endangered Asian elephant Elephas maximus , and vulnerable Takin Budorcas taxicolor . [2]
Officially protected areas cover over 35% of the ecoregion, [1] including:
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 Eastern Himalayan broadleaf forests is a temperate broadleaf forest ecoregion found in the middle elevations of the eastern Himalayas, including parts of Nepal, India, Bhutan, Myanmar and China. These forests have an outstanding richness of wildlife.
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 Qionglai-Minshan conifer forests are a World Wide Fund for Nature ecoregion in Southwest China. These forests are classified as temperate coniferous forests and are part of the Palearctic realm.
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 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 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 Central Korean deciduous forests is a temperate broadleaf and mixed forests ecoregion on the Korean Peninsula, covering portions of South Korea and North Korea.