The Hengduan Mountains (
simplified Chinese: 横断山脉;
traditional Chinese: 橫斷山脈;
pinyin: Héngduàn Shānmài) are a group of mountain ranges in
southwestChina that connect the southeast portions of the
Tibetan Plateau with the
Yunnan–Guizhou Plateau. The Hengduan Mountains are primarily large north-south mountain ranges that effectively separate lowlands in northern
Myanmar from the lowlands of the
Sichuan Basin. These ranges are characterized by significant vertical relief originating from the
Indian subcontinent's collision with the
Eurasian Plate, and further carved out by the major rivers draining the eastern Tibetan Plateau. These rivers, the
Yangtze,
Mekong, and
Salween, are recognized today as the
Three Parallel Rivers UNESCO World Heritage Site.
The Hengduan Mountains cover much of western present-day
Sichuan province as well as the northwestern portions of
Yunnan, the easternmost section of the
Tibet Autonomous Region, and touching upon parts of southern
Qinghai. Additionally, some parts of eastern
Kachin State in neighbouring Myanmar are considered part of the Hengduan group. The Hengduan Mountains are approximately 900 kilometres (560 mi) long, stretching from 33°N to 25°N. Depending on extent of the definition, the Hengduan Mountains are also approximately 400 kilometres (250 mi) wide under the narrowest definition, ranging from 98°E to 102°E. The area covered by these ranges roughly corresponds with the Tibetan region known as
Kham.
The Hengduan Mountain system consists of many component mountain ranges, most of which run roughly north to south. These mountain ranges, in turn, can be further divided into various subranges. The component ranges of the Hengduan are separated by deep river valleys that channel the waters of many of Southeast Asia's great rivers.[1] The core of the Hengduan Mountains can be divided into four major component ranges, described below.[2]
Moving eastward, the next major subsection of the Hengduan Mountains is the range running between the Mekong (Lancang) and
Yangtze (Jinsha) Rivers. The northernmost parts of this range are called the
Mangkam Mountains, the middle section is known as the
Ninchin Mountains, and the southern end is called the
Yun Range. The
Yulong Mountains are a subrange of this system and the highest peak here is
Jade Dragon Snow Mountain's Shanzidou.
Eastern Himalaya, part of larger
Himalaya mountains, is Hengduan Mountain's immediate neighbor to its west.
The third primary component of the Hengduan ranges is the section running between the Yangtze (Jinsha) and
Yalong Rivers. This section is known for almost its entire length as the
Shaluli Mountains except for the northernmost subrange that is called the
Chola Mountains. The highest point of this entire section is the
Ge'nyen Massif.
The easternmost of the Hengduan core ranges is the
Daxue Mountains between the Yalong River and
Dadu River. This range is dominated by
Mount Gongga, the highest peak in the entire Hengduan group as well as the highest peak east of the
Himalayas.[3]
In addition to the four core systems, described above, some adjacent ranges are also sometimes included as part of the Hengduan group. To the west, the
Gaoligong Mountains form an additional barrier along the Salween's western edge, but are more accurately described as an extension of the
Baxoila Range connecting with the eastern
Nyenchen Tanglha Mountains across central
Tibet. To the east, the
Qionglai Mountains and the
Min Mountains are sometimes included as part of the Hengduan Mountains as these two ranges form the eastern edges of the Tibetan Plateau.
Ecosystems
The Hengduan Mountains support a range of
habitats, from subtropical to temperate to montane
biomes. The mountains are largely covered by
subalpineconiferous forests.[4][5] Elevations range from 1,300 to 6,000 metres (4,300 to 19,700 ft). The dense, pristine forests, the relative isolation, and the fact that most of the area remained free from
glaciation during the
ice ages provides a very complex habitat with a high degree of
biological diversity.
The
ecoregions that coincide with the Hengduan Mountains are:
Additionally, the lowest elevation portions of the Jinsha (Yangtze) River and Nu (Salween) River valleys in the southern Hengduan ranges are classified by the Chinese government as a
tropical savanna environment.[6]
The easternmost ranges of the Hengduan are home to the rare and endangered
giant panda. Other species native to the mountains are the
Chinese yew (Taxus chinensis) and various other rare plants, deer, and primates.