Ecoregions

South China-Vietnam subtropical evergreen forests

August 9, 2012, 3:02 pm
Content Cover Image

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.

 Table 1. Endemic and Near-Endemic Mammal Species.

Family

Species

Cercopithecidae

Trachypithecus francoisi

Cercopithecidae

Pygathrix avunculus

Viverridiae

Cynogale lowei

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.


 Table 2. Protected Areas That Overlap with the Ecoregion.

Protected Area

Area (km2)

IUCN Category

Pac Bo

50

UA

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

Ai Chi Lang

30

UA

Nui Tam Dao

260

IV

Cam Son

120

?

Unnamed

80

?

Unnamed

70

?

Con Son-Kiep Bac

20

UA

Unnamed

70

?

Bai Chay

60

UA

category Ba

180

II

Total

1,450

 

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

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

Disclaimer: This article is taken wholly from, or contains information that was originally published by, the World Wildlife Fund. Topic editors and authors for the Encyclopedia of Earth may have edited its content or added new information. The use of information from the World Wildlife Fund should not be construed as support for or endorsement by that organization for any new information added by EoE personnel, or for any editing of the original content.

 

Glossary

Citation

Fund, W. (2012). South China-Vietnam subtropical evergreen forests. Retrieved from http://www.eoearth.org/view/article/156126

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