A high altitude mire in the Qomolangma National Nature Preserve, Tibet Autonomous Region

by Esther Blom

Until today, not many scientists and nature conservationists have had access to the Tibet Autonomous Region (TAR) of the People’s Republic of China. Therefore, only little is known about the biodiversity of this region. This especially applies to the wetlands in TAR: although there are numerous lakes and marshes, they are only rarely described in literature. Therefore the Qomolangma Conservation Programme (QCP) decided to study a number of lakes and marshes in the Qomolangma National Nature Preserve (QNNP), a unique area of nature on the foot of the Mount Everest (Qomolangma in Tibetan). The QNNP is located in the south of TAR with a total area of around 35,000 km². Five of the world’s 14 peaks above 8000 m are found in this reserve. A special characteristic of this reserve is the giant variation in altitude and the related high diversity of ecosystems. Although in general biodiversity of Tibet is under great threat, in QNNP quite some interesting species are still to be found, like the snow leopard (Uncia uncia), the Tibetan brown bear (Ursus arctos pruinosus), the Tibetan wild ass (Equus hemionus kiang), and the black-necked crane (Grus nigricollis).

The aim of the wetland study (May-July 2003) was to gain insight in the socio-economic and ecological values of the wetlands in the reserve and to increase the awareness on their importance among the staff of the reserve and the NGO and among the local people. To reach these goals, wetlands training was given and four wetland areas were studied. All the selected areas were located in the dry steppes, on an altitude from 4300 to 4700 m.a.s.l.

Three of the wetlands studied were lakes: Pelkutso, Garuwokyema, and Dingmutso. Pelkutso is a very large, alkaline, salt lake with the shape of a kidney. This holy lake is deep and contains only little vegetation. South of the lake four permanent inlets are found surrounded by marshy areas. Although the whole area has a very low population density, these marshes, as well as the grasslands somewhat more upslope, are visited by herders with their numerous sheep and yak resulting in overgrazed vegetation. Abundant mammals are the Wild ass, the Himalayan marmot (Marmota himalayana), the Tibetan sandfox (Vulpes ferrilata), and the Tibetan gazelle (Pantholops hodgsoni). Also the snowleopard is supposed to reside in the hills surrounding the lake. Birds that were spotted were Grus nigricollis (also breeding), large groups of Pallals’ gull (Larus ichthyaetus), common merganser (Mergus merganser), and, in a village nearby, the Eurasian eagle owl (Bubo bubo).

The other two lakes, Garuwokyema en Dingmutso, are shallow (max depth 30 cm) and both around 5 km². They are highly alkaline, with a pH up to 10,3, but the lakes still contain fish and plants. Especially Dingmutso but also Garuwokyema contain high bird densities, among which the great crested grebe (Podiceps cristatus) and common terns (Sterna hirundo) which both nest on the isles of salt and plant debris. Bluesheep (Pseudois nayaur) are hunted and peat of the surrounding wet grasslands is collected as fuel and construction material. Around Garuwokyema a thick layer of salt can be found. Herders specifically visit this area to collect the salt as detergent for their clothes and to feed the salt to the cattle. Both lakes are shrinking. One lake that used to be close to Garuwokyema even disappeared completely.

Chhui Chhang, the fourth wetland under consideration, is a river floodplain consisting of several small permanent and temporary lakes and alkaline sedge marshes, with a total of around 40 km². Several permanent and temporary rivers irrigate the area, as well as two mountain springs. The wetland is located in a bowl-shaped area, on the north side directly bordered by hills and on the south side (further away) by mountains over 8000 m high, which are the most important water supply of the marsh. Several migratory birds like the bar-headed goose (Anser indicus) and Grus nigrocollis use this area, the latter also for breeding. The area is very popular for grazing (mostly horses, which can endure the wet conditions). The peat that can be found in the very wet as well as the somewhat drier areas is collected by the local people and used as fuel as well as building material for the corrals. 

A most interesting type of wetland is found in the very wet area of the floodplain: here a floating fen can be found with a peat layer of around 35 cm, followed subsequently by a layer of water and ooze (mud with a very high organic material content). The most abundant plant species is Hippuris vulgaris. An interesting research question would be how this type of wetland (with a low decomposition rate) can find its origin in such dynamic conditions as a river floodplain and high pH values (8-9). Possible answers are the high altitude of this wetland (4300 m.a.s.l.) and a consequent low oxygen content of the water, low temperature, and a lack of nutrients. Also the water supply by the underground mountain spring might contribute to a constant low nutrient and oxygen supply.

In summary, it can be stated that wetlands play an important role in the lives of the people in QNNP; the highest population density is mostly found around the lakes and river floodplains. The most important function is the influence of the wetlands on the grass quality and quantity, thereby providing many opportunities for grazing. The high grazing pressure is also one of the most important threats to the flora and fauna around the wetlands. Other pressures on the wetlands are the digging of clay and peat and the shrinking of the lakes. 61 species of birds, among which many wetland dependent species, were identified during the visits to the wetlands. The most threatened species is the black-necked crane of which only 5000 to 6000 individuals are left worldwide. According to many herders interviewed, the bird density has severely decreased in the last years. A general inference is that research to high wetlands worldwide should have a high priority, before these valuable areas are unrestorably damaged, or even completely disappeared.

Esther Blom, The Mountain Institute (Currently working for the Small grants for Wetlands Programme, NC-IUCN, esther.blom@nciucn)