From the "Green Great Wall" of more than 160 kilometers on both sides of the the Yarlung Zangbo River, to the endless alpine grassland in Naqu, from the Kegula Pass, which is more than 5200 meters above sea level, to the rippling Ge Rencuo, the snow covered plateau in August, where highland barley is abundant, pastures are like grass, sheep are abundant... The plateau is full of life, and a picture of "drunk beauty" is slowly unfolding in the "third pole" of the earth. This picture is the fruitful result of the construction of Xizang's national ecological security barrier. "Our latest assessment shows that from 2000 to 2020, Xizang has achieved remarkable benefits in ecological protection, and is still one of the regions with the best ecological environment quality in the world." Wang Xiaodan, a researcher of the Chinese Academy of Sciences and the Chengdu Mountain Disaster and Environment Research Institute of the Ministry of Water Resources (hereinafter referred to as the "Chengdu Mountain Institute"), told the reporter. To provide scientific and systematic solutions, starting from Lhasa and heading southeast, it takes about two hours to reach Shannan City, which is located in the middle and south of Xizang and the middle reaches of the the Yarlung Zangbo River. Here, the reporter saw that the valley of the the Yarlung Zangbo River is blue and green, with poplar and willow forests stretching. However, here used to be a place where 'looking up into the distance, one could see a piece of sand, but with strong winds, one could not see home.' Due to its geographical location and climate, every winter and spring season, the strong winds in the river valley would raise fine sand in the sky. Since the 1980s and 1990s, Shannan City has actively carried out afforestation and windbreak and sand fixation work. The Qinghai Tibet Plateau is known as the 'third pole' of the Earth and serves as the 'stabilizer' of China's and even the world's climate system. Xizang is the main body of the Qinghai Tibet Plateau. Planting trees, preventing wind and fixing sand here sounds simple, but it is actually a technical job. We need a scientific and systematic solution to the problems of what trees to plant, how to plant them, and how to prevent land desertification Wang Xiaodan said. In the comprehensive demonstration zone for ecological management of desertified land in Sangye Town, Zhanang County, Shannan City, the reporter saw that grids measuring 1 meter square were neatly arranged among the sand slopes, and experimental plants such as Badong drunken fish grass, silk haired rose, and tree pheasant were planted in the grids. We are conducting stress resistance transplantation experiments on shrub and grass plants here, evaluating their growth and overwintering survival rates, and ultimately selecting some plant varieties suitable for growing in high-altitude sandy areas Researcher Zhou Ping from Chengdu Mountain Institute said. In recent years, the scientific research team of Chengdu Mountain Institute has carried out a comprehensive survey of sandy land in the middle and upper reaches of the the Yarlung Zangbo River basin, and combined with climate, terrain, soil, vegetation, degree of desertification and other factors, determined the control points and demonstration areas of sandy land with different degrees of desertification in the southern part of the the Yarlung Zangbo River basin, built an ecological control model of degraded sandy land based on the "burying - spreading - blocking - storing" ecological water and soil layer, and carried out experimental demonstration of ecological control of sandy land based on microhabitats in combination with the germplasm resources initially selected and bred. In the future, we will strengthen regular monitoring of the complete life history process of local plant reproductive bodies, young plant supplementation, and settlement, quantitatively evaluate their ecological suitability and benefits, in order to provide new ideas for the ecological governance of degraded sandy land on the Qinghai Tibet Plateau Zhou Ping said. By relying on both feet to find the pattern of ecological changes on the plateau, the reporter left the comprehensive demonstration area for ecological governance of desertified land in Shannan City and arrived in Shenzha County, Nagqu City. There is currently the highest comprehensive ecological monitoring station in the world - Chinese Academy of Sciences Shenzha Alpine Grassland and Wetland Ecosystem Observation Station (hereinafter referred to as "Shenzha Station"). Another identity of Wang Xiaodan is the head of Shenza Station. He has worked on the plateau for more than 20 years since he first visited Xizang at the age of 27. "Xizang has various ecological types such as forests, shrubs, meadows, grasslands, deserts, etc. It is necessary to rely on both feet to find the law of changes in plateau ecology from the long environmental changes." Every year, Wang Xiaodan has nearly six months to carry out field surveys on the Qinghai Tibet Plateau. When working in the field, Wang Xiaodan encountered many dangers. Once, on the way to the Ali area, there was a problem with the car, and we waited on the road for 5 days before we received rescue During this time, Wang Xiaodan and his team members relied on canned food and instant noodles to satisfy their hunger during the day, and stayed in tents at night. However, these experiences did not stop Wang Xiaodan from leading his team to carry out scientific research on the plateau. The grassland area of the Qinghai Tibet Plateau is very vast, accounting for more than 60% of the total area of the Qinghai Tibet Plateau, so monitoring the grassland is very important. "Wang Xiaodan said that after multiple investigations, they finally chose to establish the Shenzha Station in the high-altitude grassland lake basin area in the southern part of the Qiangtang Plateau. Shenzha Station focuses on alpine grasslands and alpine wetlands as the main research objects, and the response of alpine ecosystems to global changes and human activities as the main research content. It monitors and evaluates the effects of human activities on the natural environment and ecosystems, predicts the impact of changes in plateau environment and ecosystem functions on ecological security in China and even Asia. The station has three professional laboratories for biology, soil, and moisture, as well as comprehensive observation sites, including over 500 acres of high-altitude grassland comprehensive observation sites and 100 acres of high-altitude swamp wetland comprehensive observation sites. After years of monitoring, we have successfully revealed the relationship between plant root architecture and nutrient utilization efficiency in high-altitude freeze-thaw zones, and explored the adaptation mechanism of high-altitude plants from a new perspective of root nutrient absorption preferences Wang Xiaodan said that today, scientific research has become a strong support for Xizang to build a national ecological security barrier. (New Society)