Description
Location and General Description
The Qilian Mountain Range rises along the northeastern rim of the Qinghai-Tibet Plateau to a maximum elevation of 5547 m. Northward, mountains fall away to the Alashan Desert. The southern slopes flank the hilly northern part of the Qinghai-Tibet Plateau. Vegetation here consists of extensive alpine meadow and shrub vegetation with isolated areas of subalpine conifer forest, mostly on north-facing slopes. The forests here are defined as a separate ecoregion, Qilian Mountains Coniferous Forests (71).
The alpine region of the Qilian Mountains is divided into two main vegetation types. Meadows occur below 3,300 m and deciduous shrublands above. The extent of the shrub area is probably determined by moisture availability, since extrazonal riparian habitat at a lower elevation also supports shrubs, while drier south-facing slopes support forb/graminoid (grassy) meadows. At elevations above 4,500 m, vegetation is very sparse, dominated by cushion plants such as Androsace spp. on stable soils amidst boulders and scree.
The assemblage of species that comprises the rangelands of this ecoregion is roughly similar to vegetation that covers approximately 35 percent of the total land area of the Qinghai-Tibet Plateau. Dominant shrub species include Potentilla fruticosa, a species abundant throughout the eastern Himalayan alpine scrub and also in the mountains of North America, willow (Salix oritopne), and Caragana spp., a thorny legume more typical of dry steppe habitats. Graminoids include the sedges Kobresia capifolia, K. humilis, and Carex spp. and the grasses Elymus nutans, Festuca ovina, F. rubra, Ptilogrostis coccinna, Poa spp., Helioctron spp., and Stipa purpurea. Forbs here include Oxytropis spp., Lancea tibetica, Pedicularis spp., Potentilla spp., Thalictrum alpinum, and more than ten species of Gentiana.
Biodiversity Features
Several endangered ungulate species and their predators are distributed widely across the eastern part of the Qinghai-Tibet Plateau, confined to the more remote areas where pressures from hunting and livestock-grazing are not too great. These species, adapted to the steppe meadow rangeland habitat, may occur in the Qilian Mountain ecoregions as well. They include snow leopard (Panthera uncia), white-lipped deer (Cervus albirostris), wild yak (Bos grunniens), Tibetan gazelle (Panthalops hodgsonii) and ibex (Capra ibex).
Current Status
The Qilian Shan Nature Reserve (4,790 km2) protects forest, shrublands, and meadow on the northern slope of the range. Because this slope is wetter, it supports a richer community of plants and animals. Protected animals within this reserve include snow leopards, Asiatic wild ass (Equus hemionus), white-lipped deer, argali (Ovis ammon), goitered gazelle (Procapra subgutturosa), and Severtzov’s grouse (Bonasia sewerzowi). Extending this reserve onto the southwest slopes of the range would further enhance its conservation value.
Types and Severity of Threats
Domestic livestock grazing affects plant species composition within the alpine meadows. High-elevation pastures that are heavily grazed during summer have fewer grasses and a higher proportion of unpalatable plant species, such as Morina chinensis, Oxytropis spp., and Stellera chamae-jasme. Forb species that respond favorably to high grazing pressure include Gentiana spp., Gueldenstaedtia diversiloba, Trigonella ruthica, Leotopodium nanum, Anaphalis lactea, Aster flaccidus, Pedicularis spp., Lancea tibetica, and Iris potannini. Graminoid species are similar, but less abundant in the grazed versus the ungrazed sites. The rush, Scirpus distichimus may become abundant in heavily grazed sites. At lower elevations, heavily grazed sites tend to acquire a high abundance of the robust gentian species G. straminea, the roots of which are used medicinally.
Alpine meadow and shrub habitats in this area are used by local people in a variety of ways. Domestic livestock (especially sheep) graze here; and plants are collected for medicinal purposes or for household uses that include insulation, bedding for livestock and as a secondary source of fuel (dung is the main source). The lower elevation meadows are used for winter pasture (allocated by the government to individual families) and may be cultivated in mustard for oil production. Recently there has been an increase in fencing (both wire and earthen fences) which has a potentially disruptive, but as yet unstudied, effect on wildlife.
Local herders report that the quality of the grazing lands has decreased in recent years as the number of domestic livestock has increased. These increases are due to several factors traceable to demographic and economic changes that are occurring throughout western China. More people have moved into the area; each family now owns more animals than in years past; and families are more sedentary which tends to concentrate patterns of summer grazing activity.
Marmot eradication programs have effectively reduced the number of these small mammals, due to concern about their effect on the quality of the meadow for livestock grazing. The effect of these reductions on ecosystem function has not been investigated.
Justification of Ecoregion Delineation
This montane area is located between two desert regions, the Alashan Plateau and Qaidam Basin. The Qilian Mountains serve as a barrier between the desert in the north and the alpine meadow in the south. The boundary is based on montane grassland (41, 48) north of the mountain range, and alpine meadow (68a) according to the CVMCC (1979) Vegetation Map of China. This falls within the Qilian Mountains biogeographic subunit in the Tibetan Plateau according to Mackinnon et al. (1996).
References
Chinese Vegetation Map Compilation Committee (CVMCC). 1979. Vegetation map of China. Map (1:10,000,000). Science Press, Beijing.
Laidler, L. and K. Laidler. 1996. China’s Threatened Wildlife. Blandford, London.
MacKinnon, John. 1996. Wild China. The MIT Press, Cambridge MA.
MacKinnon, J., M. Sha, C. Cheung, G. Carey, Z. Xiang, and D. Melville. 1996. A biodiversity review of China. Worldwide Fund for Nature (WWF) International, Hong Kong.
Steinkraus, D. C., and J. B. Whitfield. 1994. Chinese Caterpillar Fungus and World Record Runners. American Entomologist. Winter.
Xin-Quan Zhao, and Xing-Min Zhou. 1999. Ecological Basis of Alpine Meadow Ecosystem Management in Tibet. Ambio 26(8).
Zhao, Ji. Editor. Zheng Guangmei, Wang Huadong, Xu Jialin. 1990. The Natural History of China. McGraw Hill Publishing Company, New York.
Prepared by: Chris Carpenter
Reviewed by: In progress