| Located in northwest China and the hinterland of the Qinghai-Tibetan Plateau, Qinghai Province is where the Yangtze, Yellow and Lancangjiang/Mekong Rivers originate. The ecological conditions in Qinghai directly affect the economy of the immediate area, its sustainable development and also the areas in the lower reaches of the three rivers. Qinghai Province is722,300km2in size. There are36.47million ha of rangeland in the province, which is50.5%of its total land area. About80%of its territory is highlands with elevations of>3000m above sea level (masl). Due to its unique environmental conditions, the majority of land is only suitable for the pastoral livestock industry. Livestock production plays an extremely important role in the economy of the province, especially for the ethnic groups. However, the harsh natural conditions and environment limit the rangeland productivity. In addition, long-term overgrazing has contributed to rangeland degradation and erosion, thus the ecosystem of the alpine pastoral area is now very fragile and environmental protection has become more important. In the special ecosystem of the alpine pastoral area, the factors of poverty, environmental deterioration and frequent natural disasters (e.g. severe snow disaster and spring drought) are particularly pronounced. They severely jeopardize the livelihoods and production activities of local herders, and also restrain sustainable development of the local economy and threaten societal stability.The research work carried out in the Qilian County located in Three River Region of Qinghai province. The new grassland productivity monitoring method was used to evaluate the grassland condition and production. The research work about the influence factors to aboveground biomass of nature grassland were carried out. The grassland productivity and forage production livestock structure and grassland carrying capacity were analysis and evaluated, the final research results show that:(1) The situation of nature grassland condtion and resources was invesgatived and evaluated in Qillian County. The main grassland type is alpine meadow which is89.97%of total nature grassland in Qilian County, the main dominant species were Kobresia pygmaea, Kobresia humilis, Kobresia tibetica, Kobresia capillifolia, Poa pratensis, Carex tristachya, Salix cupulari. The main soil types are alpine meadow soil. The average height of grass is3-7cm, and the average coverage is about70%. The nature grassland was divided into summer pasture and winter pasture for livestock grazing. The research results show that winter pasture provided the grass about62.02%of total grass to livestock intake, and the summer pasture provided grass about37.72%of total grass to livestock intake, there are just0.26%of total grass forage provided by oats planting and supplementary feed. Which indicated that the livestock intake of grass forage is mainly comes from the nature grassland. This lead to the serious grazing pressure to nature grassland in Qilian County, especially in winter pasture.(2) According to the investigation and evaluation of livestock resources in Qilian County. The main livestock type is yak, Tibetan sheep and horse in Qilian County. The research results show by RAPS that the percentage of dry ewes, dry mature cows and male yaks are very high, which will take the more forage intake and lead the seriously grazing pressure to nature grassland. So we suggest to reduce the number of dry ewes, dry mature cows and male yaks, and increase the number of ewes and mature cows. To improve the livestock productivity and increase the herder’s income by feeding the good and suitable number of livestock.(3) According to the analysis and evelation, the research results indicated that the overgrazing is very serious in Qilian County, especially in winter pasture, the overgrazing is about86.23%in the summer pasture, and the overgrazing is about281.76%in winter pasture, and the long time overgrazing lead to the serious grassland degradation in this area. The suitable carrying capacity is about1.05-10.9sheep unit/ha in Qilian County.(4) The changes in grassland productivity could be influenced by the characteristics of vegetation community and environmental conditions, includes geomorphology, temperature, precipitation, soil nutrient and human disturbance. Our research results indicated that aboveground biomass of alpine grassland was easy influenced by average annual temperature. Precipitation is also an important factor for grassland productivity, the relationships of the precipitation with the grassland aboveground biomass showed positive correlation. The grassland productivity was influenced by climates, geomorphology, soil nutrition, etc, but in the same condition, when the climates, geomorphology, soil nutrition is same, the grazing activities become a major factors for grassland productivity. The research results of grazing trial showed that nature grassland aboveground biomass decreased along with the increased of grazing intensity. The relationships of the species diversity, richness and evenness with the total aboveground biomass showed positive correlation, which indicated that the species diversity and richness can cause the high grassland productivity. The relationships of the total aboveground biomass with altitude showed unimodal distribution patterns, which indicated that the middle level altitude with the highest aboveground biomass in this area.(5) RAPS evaluation system was used to evaluate the grassland condition and carrying capacity, the results indicated that this system can be used effectively in Qinghai-Tibetan plateau. We found that RAPS is more comprehensive, scientific and advanced for estimations of livestock carrying capacity for a single year or a series of years subject to variations in forage production. It cans evaluation of forage development and management options, especially their impact on forage resources and livestock productivity at the system level. Evaluation of the impact of changes in livestock type and livestock production objectives. Monitoring of trends in forage productivity and model-estimated forage consumption etc. All these data can provide the useful information to take effectively measurement for livestock production management scientifically, and to maintain the sustainable development of livestock production and ecological protection. The electronic pasture meter was used to assess standing biomass of pastures. The meters work by sensing the amount of above-ground moisture contained within the herbage. The level of moisture is then related to dry matter using statistical regressions. The assessment results by electronic pasture meter and manual determination in the field indicated correlation coefficients R of0.914, which suggested that the electronic pasture meter was a very useful technique, providing data of the type required by the pastoral resource assessment techniques, the potential for sampling large areas quickly, and will significantly reduce labor requirements in the field.(6) The scientific grassland carrying capacity, grazing management method, effective livestock structure and measurements to reduce the grazing pressure were provide to improve the livestock development and protect the nature environment, keep the livestock sustainable development.All the research methods were taken to analysis the condtion and resource of grassland and livestock in Qilian County, and the final results will provide the scientific support to the livestock sustainable development to local area and Qinghai Tibetan plateau. |
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