Degrading Wetlands of the Tibetan Plateau

Every year on February 2, World Wetlands Day is celebrated internationally which marks the anniversary of the signing of the Convention on Wetlands of International Importance (Ramsar Convention) in Ramsar, Iran, on 2 February 1971. The international theme for World Wetlands Day 2012 is ‘Wetlands and Tourism’.

Presently the parties of the Ramsar Convention have 160 contracting members including China who joined the Convention in 1992. The list of Wetlands of International Importance includes 1994 wetlands, with a total area of about 192 million hectares. Out of this 41 sites are located in China, covering an area of 3,709,853 hectares. 

The wetland is known as the "kidney of the earth" and is one of the three major ecosystems along with forest and ocean. The wetland plays a key role in flood control, water conservation, pollution control, environment regulation and so on. It is deemed as a warehouse with water and food for humans as well as a habitat for rare wildlife to overwinter and reproduce. 

Wetlands of the Tibetan Plateau

Known as ‘the third pole’ and ‘the water tower of Asia’, Tibetan Plateau has 1,33,000 sq. km of alpine freshwater wetland, which functions as a source of major rivers of Asia, biological species gene pool, oxygen supply, a potential carbon sink, and a critical factor maintaining the stability of water table and the balance of diverse alpine ecosystems in the Tibetan Plateau. 

The wetlands on the Tibetan Plateau are distributed mainly in three kinds of areas including:

 (1) Source region of rivers that provide life-giving waters to over a billion people and flow into sea directly or indirectly, e.g. lake Wetland, river wetland and swamp wetland distributed in the source area of Drichu (Yangtse River) and Machu (Yellow river).

(2) The hinterland of the Tibetan plateau with very high altitude or inland water in basins among mountains, e.g. inland river or lake wetlands in the Northern Tibet’s Jhangthang Plateau, A-chen Gang-gyal (Kekexili) and Tso-ngon (Qinghai Lake).

(3) Flat and lower elevation areas such as Dzoge (Ruergai), Tsaidam (chaidamud) and permafrost. Besides, backwater areas adjacent to alpine glacier and snow cover, and swampy wetlands exist extensively in these flat regions of the Tibetan Plateau.

Three-river Source Region (Tib: རྨ་འབྲི་རྫ་གསུམ།), which is located in the south of Tso-ngon (Qinghai Province), is the source of Machu (Yellow River), Drichu (Yangtse) and Zachu (Lancangjiang). Plateau wetland ecosystem in Three-river Source Region is the largest with the highest altitude above sea level in the world, the total area of which is 7.33×106 ha. It supplies an estimated 25%, 49% and 15% of Drichu, Machu and Zachu’s total water volume, respectively.

 Another important wetlands distribution area in the Plateau is Ruergai with altitude ranging from 3400 to 3900 m, where the wetland is the largest Plateau peat swamp remaining in China with a total area of 1.6 × 10⁶ ha. Ruergai wetland ecosystem is a critical water conservation of Yellow River and is the concentrated distribution area of plateau swamp vegetation and main breeding habitat of Grus nigricdlis (black-necked Crane) and its common plant species are Carex muliensis and Clinelymus nutans.

The scientific name of Tibetan Black-Necked Crane is Grus Nigricollis (Latin), and belongs to the Gruidae family of Gruiformes order. Source: wwfchina.org/birdgallery

Lhalu Wetland located in the north of the city of Lhasa, covers an area of 12.2 sq. km. With an average elevation of 3545 meters, it is highest altitude wetland in the world. It had been reported that the wetland has 52 geneses of 30 plant families, 43 species of terrestrial wildlife, 152 species of aquatic wildlife and 101 species of insect. Black-necked cranes, Bearded vultures and Himalayan Griffon are some of the important species found in this wetland.

The most notable feature in this image of the Lhasa city (Tibet) is the Lhalu Wetland Nature Reserve on the northern side of the city. The reserve is red-brown with black smudges where water darkens the surface. The natural wetland influences Lhasa’s climate, adding humidity to the city. The plants are also an important source of oxygen to a city with a thin, high-altitude atmosphere. The Lhalu Wetland Nature Reserve provides habitat for a wide range of birds. (Picture taken on 26 September 2009 from NASA Earth Observatory)

 

Degradation of the Alpine Wetlands of the Tibetan Plateau

Diverse wetland ecosystems in the Tibetan Plateau have been playing an important role in maintaining the healthy performance of other kinds of ecosystem and regulating water resources. These wetlands are also home to many species of birds, mammals, and fish, as well as being critical grazing areas for Tibet's traditional nomadic livestock herders.

However, the Tibetan Plateau's wetlands are now seriously threatened by human intervention and global climate change. Due to various natural and human factors, typical alpine wetland has degraded extensively with its area shrinking an estimated 10% in the Tibetan Plateau. The ecosystem shifting in the western and northern part of Three-river Source Region, which involves water ecosystem shifting to bottomland ecosystem and wetland shifting to grassland, occurred during 1975 to 2004, resulting in the shrinking of the aerial extend of the water and wetland over the years.

The greatest such degradation occurred in the Source Region of Drichu where swampy wetland shrank by 29% and nearly 17.5% of lakes had dried up. Similarly, 38.9% of total lake dried up from 1985 to 2000 in Dzoge Region, at a rate of around 56.13 ha per year. 

Degradation of plateau wetlands led to alteration of their hydrological functions. In the source region of the Drichu and the Dzoge region, where the wetlands declined more severely, the frequency of the perennial low water runoff decreased while the rare larger runoff increased. Besides, water regulation capacity of all the wetlands was declined.

Climate change has been an important cause of wetland degradation in the Tibetan Plateau. Due to the increased irregularity of annual precipitation, the prolonged duration of sunshine, and the rising air and soil temperature, there has been adverse effects of water loses and the degradation of plateau wetlands. 

Furthermore, another driving force for wetland degradation has been the small-scale changes of the temporal and spatial distribution of key climatic factors and alteration of local climate characteristics. Meanwhile, human activity plays an important role as amplifiers and accelerators in wetland degradation processes.

Protection of the wetlands of the Tibetan Plateau

China’s efforts to portray itself as the protector of its bio-diversity and ecology is evident from the lengthy white paper about its "Policies and Actions for Addressing Climate Change" and series of Xinhua reports bragging its "initiatives" and  "achievements". 

Xinhua, the official mouthpiece of China recently quoted a spokesperson of its State Forestry Administration who boasted that they, “carried out 42 wetland protection projects, increased 330,000 hectares of protected wetland areas, added four wetlands of international importance and 68 national wetland parks.” These "initiatives" and "achievements" may be a step towards the right direction but addressing the critical problem of wetland degradation, which threatens the sustenance of over a billion people, entails urgent and sincere efforts from peoples of all sectors. 

To protect and restore wetlands in the Tibetan Plateau, a vital and immediate step that the Chinese government must take is to reduce and restrict negative effects of human activities in wetland areas caused by the construction of railways and roadways, deforestation, desertification and mining. 

At the same time, putting ecological compensation into practice may boost the positive effect of human activities on the protection of plateau wetland ecosystems. Additionally, further research on wetland science in the Tibetan Plateau is urgently needed to ensure that conservation of the Tibetan Plateau’s Wetlands are seriously considered as a priority rather than just an empty rhetoric that are usually based on some questionable figures.