South China-Vietnam subtropical evergreen forests
Halong Bay, Vietnam Photograph by © Jack Stein Grove/Zegrahm Expeditions
This large ecoregion extends only partially into the region of analysis considered here, with the majority of the area extending into China. Because the ecoregion lies within two of the most densely populated countries in Asia, very little natural habitat now remains, having been cleared throughout the last several centuries for agriculture.
Location and General Description
This large ecoregion extends from northern Vietnam into southeastern China, including Hainan Island. Only the Vietnamese portion of this ecoregion is considered here.
Vietnam northeast of the Red River forms a part of the South China Platform and is geologically separate from the remainder of southeast Asia. The sediments here consist of a combination of exposed ancient metamorphic basement rock and marine sediments deposited in the late Paleozoic and early Triassic. Many of these sediments are limestones that have been uplifted and weathered to form an extensive karst landscape with steep topography. The highest peak in this region of Vietnam is Tsi Con Ling at 2,531 meters (m), but most of the area is of only moderate relief.
Annual rainfall in this ecoregion varies from a low of about 1,800 millimeters (mm) in the Red River Basin to a high of about 2,850 mm near the Chinese border, where there are only two months with less than 50 mm rainfall and no totally dry months. Temperature regimes in the north have a strong seasonality, with cool winter conditions and hot and humid summers.
Very little pristine forest remains within this ecoregion. Lowland forests growing on limestone substrates commonly reach only 15-20 m in height but grow to 30-35 m on favorable sites. Few emergent trees in most stands suggest past cutting of larger trees. Dominance is mixed among a variety of tree species, with the Lauraceae, Fagaceae, and Meliaceae particularly important. This region shows strong floristic relationships with areas to the north in China, and regional endemism is high.
Biodiversity Features
A complete biodiversity database is being compiled for this ecoregion as part of a large analysis that includes China. However, the area of the ecoregion that extends into northern Vietnam, and thus into this region of analysis, contains four near-endemic mammals (Table 1), an indicator of the biodiversity and endemism levels that can be expected from this ecoregion.
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Family |
Species |
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Cercopithecidae |
Trachypithecus francoisi |
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Cercopithecidae |
Pygathrix avunculus |
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Viverridiae |
Cynogale lowei |
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Muridae |
Dremomys gularis |
Current Status
Almost all of the lowland forests of the northern part of this ecoregion, which falls within a heavily populated section of Vietnam, have been cleared. In Myanmar, in eastern Shan State along the border with Laos and China, very large areas of forest have been cleared, but a few large blocks of habitat remain.
There are sixteen protected areas (in Vietnam only) that cover 1,450 square kilometers (km2) of this ecoregion (Table 2). Most of these protected areas are smaller than 100 km2, and the largest is only 260 km2.
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Protected Area |
Area (km2) |
IUCN Category |
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Pac Bo |
50 |
UA |
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Trung Khanh |
170 |
IV |
|
Nui Pia Oac |
110 |
IV |
|
Ba Be |
170 |
II |
|
Bac Son |
20 |
IV |
|
Tan Trao |
20 |
UA |
|
Huu Lien |
20 |
IV |
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Ai Chi Lang |
30 |
UA |
|
Nui Tam Dao |
260 |
IV |
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Cam Son |
120 |
? |
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Unnamed |
80 |
? |
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Unnamed |
70 |
? |
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Con Son-Kiep Bac |
20 |
UA |
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Unnamed |
70 |
? |
|
Bai Chay |
60 |
UA |
|
category Ba |
180 |
II |
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Total |
1,450 |
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Types and Severity of Threats
Much of the natural habitat has been altered by shifting cultivation and logging. Hunting for the wildlife trade is also a significant threat to conservation of biological diversity.
Additional information on this ecoregion
- For a shorter summary of this entry, see the WWF WildWorld profile of this ecoregion
- To see the species that live in this ecoregion, including images and threat levels, see the WWF Wildfinder description of this ecoregion.
- World Wildlife Fund Homepage
Further Reading
- Campbell, D.G., and H.D. Hammond, editors. 1989. Floristic inventory of tropical countries. The New York Botanical Garden, New York. ISBN: 0893273333
- Davis, S.D., V.H. Heywood and A.C. Hamilton. 1995. Centres of Plant Diversity: a guide and strategy for their conservation, Volume 2: Asia, Australasia and the Pacific. Worldwide Fund for Nature and IUCN – The World Conservation Union. ISBN: 2831701988
- Mackinnon, J., M. Sha, C. Cheung, G. Carey, Z. Xiang, and D. Melville. 1996. A biodiversity review of China. World Wide Fund for Nature, Hong Kong.
- Nowak, R. M. 1991. Walker’s Mammals of the World, Volume II, 5th Edition. Johns Hopkins University Press. Baltimore and London
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