Description
Location and General Description
The Guizhou Plateau, 1000 to 1400 m in elevation, is characterized by karst limestone arranged in blocked hills and intermontane basins. It lies to the east of the higher Yunnan Plateau and to the south of the Changjiang (Yangtze) River. Mountains here consist of steep hills, and isolated pinnacles deeply dissected by river valleys. The area is riddled with caves and sinkholes, and many local rivers are partially subterranean. The limestone is of Paleozoic origin. It was uplifted during the Tertiary by the tectonic collision of India and Asia, recently exposed and chemically eroded to its present form. The porous substrate, and mild, cloudy weather (more than 200 overcast days per year) account for the distinctive ecology of the ecoregion. Although the plateau receives ample precipitation and high cloud cover, areas of karst are still prone to drought stress because karst limestone has a poor water-holding capacity. Water that might be stored in granitic soils quickly filters through the porous limestone and becomes unavailable to plants.
Vegetation consists of subtropical evergreen broadleaf forest comprised of species tolerant of limestone. The original forest (now mostly extirpated) was dominated by trees in the oak (Castanopsis, Quercus, Cyclobalanopsis), laurel (Phoebe, Eugenia), and tea (Schima, Camellia) families. At lower elevations, taxa more characteristic of seasonal tropical forest (Sterculia, Erythrina, Ficus, Euenia, and Helicia) or secondary forest (Albizzia, Rhus, Cornus, Liquidamber) are present.
Warm conifer forests occur in the eastern and northern regions of the Guizhou Plateau ecoregion. Important species include Chinese red pine (Pinus massoniana) in the north and east and Yunnan pine (P. yunnanensis) in the south. "Chinese fir" (Cunninghamia lanceolata) occurs in the northern region, with spruce (Picea) and fir (Abies) at the higher elevations. Mountain tops in places like Fanjing Shan support Himalayan-type conifer-hardwood forests comprised of Tsuga chinensis, Acer flabellatum, Rhododendron hypoglaucum, Enkiartos chinensis, Prunus serrulata, and a fir taxon that has recently been described as Abies fanjingshanensis (Huang, Tu and Fang 1984), although it is possible that this might be a subspecies of the more widespread A. fargesii.
Biodiversity Features
Guizhou Province as a whole supports 64 species of endangered and protected plants, although data as to the number of species within the plateau ecoregion is not available. The Guizhou Plateau supports four plants that are regarded as first-class protected species: the subtropical conifers Cathaya argyrophylla and Taiwania flousiana, the tree fern Cyathea spinulosa, and the dove tree Davidia involucrata. The latter species is revered in China for its curious inflorescence in which bracts up to 30 cm long subtend the flowers.
The Guizhou Plateau and surrounding valleys support 8 of China’s first-class protected mammals: Assamese macaque (Macaca assamensis), Francois’ leaf monkey (Presbytis francoisi), Guizhou snub-nosed monkey (Rhinopithecus brelichi), clouded leopard (Neofelis nebulosa), leopard (Panthera pardus), tiger (P. tigris amoyensis), Sika deer (Cervus nippon), and red goral (Naemorhaedus cranbrookeii).
The Guizhou snub-nosed monkey is of particular significance, as it is an endemic primate restricted to the Fanjing Shan National Nature Reserve where an estimated 300-500 individuals occur. Fanjing Shan, a mountainous area (maximum elevation 2575 m) located in the northeastern part of the ecoregion, holds special significance because it supports intact forest over much of its 419 km2, especially at the higher elevations, and conserves other rare species including the giant salamander (Megalobatrachus davidiana) and dove tree. Fanjing Shan is also a UNESCO Man And Biosphere Reserve.
Current Status
Today the original forest vegetation across the Guizhou Plateau has been largely replaced by a secondary scrub or sparse woodland association that consists of taxa in the heath family (Rhododendron, Vaccinium), and Quercus, Eurya, Myrica, and Myrsine
Original forest types exist within the protected areas, but are almost completely gone outside, except for small patches on the most remote and inaccessible limestone hills, such as those found in the scenically spectacular Wuyang River Valley and Zhangjia Jie in the northern part of the ecoregion.
Types and Severity of Threats
These include habitat conversion, hunting, and inadequate management of existing nature reserves.
Justification of Ecoregion Delineation
Ecoregion boundaries were derived from the CVMCC (1979) Vegetation Map of China. Due to overexploitation, shrubland and sparse woodland (32a, 33) have replaced much of the originally predominant evergreen broadleaf forests (21a,b) and patches of warm-temperate conifers (8b, 10). This area is comparable to the Guizhou Plateau biogeographic subunit in the Central Chinese Subtropical Forests according to Mackinnon et al. (1996).
References
Chinese Vegetation Map Compilation Committee. 1979. Vegetation map of China. Map (1:10,000,000). Science Press, Beijing, China.
Farjon, A. 1990. Pinaceae: drawings and descriptions of the genera Abies, Cedrus, Pseudolarix, Keteleeria, Nothotsuga, Tsuga, Cathaya, Pseudotsuga, Larix and Picea. Koeltz Scientific Books, Königstein.
Jablonski, N.G., editor. 1998. The Natural History of the Doucs and Snub-nosed Monkeys. World Scientific Press.
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.
MacDonald, D. editor. 1999. The Encyclopedia of Mammals. Barnes and Noble Books.
MacKinnon, J. 1996. Wild China. The MIT Press, Cambridge MA.
Zhao J., editor. Z. Guangmei, W. Huadong, X. Jialin. 1990. The Natural History of China. McGraw Hill Publishing Company, New York.
Prepared by: Chris Carpenter
Reviewed by: In process