Anthropogenic influence on the Tibetan Plateau

Table of content

1. Introduction

2. Geographic Classification of the Tibetan Plateau

3. Traditional Nomad pastoralism on the Tibetan Plateau

4. Soil degradation
4.1 Deforestation
4.2 Soil erosion
4.3 Desertification

5. Conclusion

6. References

1. Introduction

The Tibetan Plateau is probably the most important and one of the most fragile areas in the world. With its enormous tectonic geomorphology forms and its unique ecosystem the Tibetan Plateau has an huge impact on the asian continent and even on the whole global climate (Cui/Graf 2009:49). For hundred of years this area was inhabited by few nomads, who practiced a sustainable approach of life in this space. Initiating with the reforms of " the Great Leap Forward, the Opening Door Policy and the Globalisation" an imigration flow began to discover and settle down. Those human activities had an influence on the climate change and land-cover change. The consequences resulting thereoff are evident and measurable and the aftereffects of that development cant yet be foreseen in their whole scale.

The purpose of this study is to examinethe anthropogenic influence on the Tibetan Plateau in recent years. The structure applied to this paper begins with a geographic classification of the Tibetan Plateau with its geographical, geomorphological and climatical charecteristics. The second part discribes the anthropogenic influence on the Plateau area and its demographical and agricltural development since the 1950s. The impacts of this influence on the vegetational and soil change are being discribed in the third part and the conclusion finalises this study.

2. Geographic Classification of the Tibetan Plateau

The Tibetan Plateau is a "huge mountainous area of the Eurasian continent with an average altitude of 4,000m" above sea level (Cui,Graf 2008:48). It is often recalled the "Roof of the World" and it accomodates the "(...) largest glaciated area outside the Polar Region(...)" and therefore "(...) plays an important role in regional and glo- bal atmospheric circulation." (Lehmkuhl/Schlütz 2009:1449). The Plateau stretches between the 28 and 40 degrees North Latitude and 70 to 110 degrees East Latitude. The territorium spreads for about 1280 km from north to south and 1600 km from east to west. Fig.1 describes the geographical and geomorphological characteristica of this area. It includes the Tibetan Autonomous Region, Qinghai province, parts of Sichuan and Gansu provinces, and parts of the Xinjiang Uygur Autonomous region (Chen et al. 2006:34). According to Lehmkuhl/Schlütz (2009:1449) "The Plateau and the bordering mountain ranges are influenced by five major climatc systems: the mid-lattitude westerlies, the South and East Asian monsoons, the Siberian high- pressure system and the El Niño Southern Oscillation (ENSO)."

Summertime consists the most precipitation on while winters are commonly cold and dry. The precipitation decreases from southeast to northwest and hence is responsible for a moisture gradient from humid to arid with an allocation of land co- vers from forest, grasland, shrubland, glaciers, meadow, desert and steppe (Cui 2005:7, Cui/Graf 2009:49). The Tibetan Plateau, or the so called Qinghai Xizang Pla- teau, is "the source region for several major rivers in southeastern and eastern Asia. Including the Yellow River, Yangtze River, Mekong River, and Salween River (Cui/Graf 2009:49). Therefore this region has an immense importance for the surrounding areas.

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Fig. 1 Geographic Map of the Tibetan Plateau (Harris 2010:2)

3. Traditional Nomad pastoralism on the Tibetan Plateau

According to Harris (2010:1) "Livestock grazing is the dominant form of land use in arid biomes worldwide, and grazing lands of the Qinghai-Tibetan plateau." and therefore plays an important role for the landscape development and the transforma- tion to a domesticated ecosystem (Lehmkuhl/Schlütz 2009:1450). The climatic circumstances of the grasslands with its sparse flora and its huge expanse of land are suitable for pastoral farming. The extensive livestock farming is being performed for thousands of years by the Nomadic inhabitants of the Tibetan Plateau (Miller 2007:2). Lehmkuhl/Schlütz state (2009:1450) that the anthropogenic influence of the Titbetan nomadic culture changed the natural grazing system, inhabited by only wild herbivores, to an anthropozoogenic system. Over the past centuries the residents enveloped a sustainable approach for range and livestock farming under those difficult circumstances. According to Miller (2007:3) the Tibetan nomads graze their cattles at altitudes from 3,000 to 5,000 meters in environmental conditions that are too cold for crop cultivation and therefore dont compete with other agricultural pursuits. According to (Lehmkuhl/Schlütz 2009:1455) the pasturing has a significant influence on the "composition and structure of the vegetation.", resulting in a change of the vegetation types through the grazing intensity. Plants species like Anemone, Bistorta and Poaceae are suppressed and overcome by species like Leontopodium, Saussurea and Ligularia, which are more grazing resistent, in due to an increasing grazing pressure and therefore change the natural Biomass diversity through nomadical induced land-use. According to Lehmkuhl/Schlütz (2009:1468) the biomass diversity change in due to the transformation of the plants species have important influence in the local and regional climate and therefore "it is highly likely, that the anthropo-zoogenic vegetation hanges have affected synoptic conditions."

The economic growth of the VR China, during the intensive phase of mobilization, the Great Leap (1958/59) and the Opening Door Policy (1978), caused interventions in the traditional system of rotation, the transformation of grasslands into crop land and the market-oriented organization of the livestock production (Shen et al. 2008:56). This led to a development driven by the planned economy of the VR China and an increasing demand for livestock and agricultural goods. In addition to that it put the traditional sustainable system under pressure to support the market with those kinds of products. "Since 1978, when China initiated economic reform and an open-door policy, rapid land use and land cover change has taken place in most of its territory." (Weng 2002 cit. in Shen et al. 2008:56). The effect of that was the tremendous increase in livestock numbers, as stated by Du et al. (2004 cit. in Chen et al. 2006:35), "Over the last 30 years, livestock numbers across the TP have increased more than 200% due to inappropriate land management practice.", and the enormous impact on the ecological equilibrium wich had consequences on the climate system in addition (Lehmkuhl/Schlütz 2009:1450).

This overdevelopment of the already fragile ecosystem of the Tibetan Plateau leads to some extensive intrusion in the climatic change and degradation of soil and vege- tation. One of the main problems of the livestock increase was the traditional farmers attitude (Bai et al. 2002 cit. in Harris 2010:7). Large numbers of farm animals are synonymous for the amount of wealth and financial securiy therefore large livestock numbers assure the farmers the possibility for unanticipated loss or outfalls of the productive livestock. Fig.2 illustraes the enormous increase in the livestock producti- on of sheep and cattles in Tibet during 1978 and 1999. The amount of sheep increased for almost 110% and that of cattes for 250% by comparison to the referen- ce year of 1978.

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Fig. 2 Increase oflivestock prodction in Tibet (Du et al.2004:243)

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