Tailored to local conditions and continuous exploration (technological perspective: following researchers to control desertification) Researchers | Gurbantunggut Desert | Technology

Researchers at Mosowan Station are monitoring the water and salt changes in the root layer of Haloxylon ammodendron at different depths.

Photo by Song Chunwu

Li Shengyu explains to students how to use a radiation observation instrument.

Photo by Wu Yuehui

Starting from Urumqi, take Wukui Expressway Huke Highway Ganmo Highway, all the way north. After more than three hours' drive, you can reach the hinterland of Gurbantunggut Desert, where Mosuowan Desert Research Station of Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences is located.

For more than 60 years, generations of researchers at Mosuo Bay Station have been steadfast here, continuously exploring scientific desertification control and prevention.

Maintain natural vegetation with good protective effects based on precipitation and soil moisture conditions

Li Shengyu, the head of Mosuowan Station of Xinjiang Institute of Biological Sciences of the Chinese Academy of Sciences, and Song Chunwu, the deputy head of Mosuowan Station, went to Mosuowan Station with the reporter.

On the way, Li Shengyu told reporters about the history of Mosuo Bay Station.

In 1956, the Chinese Academy of Sciences set up a Xinjiang comprehensive investigation team to conduct a comprehensive investigation of Xinjiang's natural conditions and resources, including deserts, and set up Mosuowan Station in 1960.

Mosuowan Station is one of the earliest field observation stations in China, and also the first desert research station of Xinjiang Institute of Biological Sciences, Chinese Academy of Sciences. According to Li Shengyu, in the early stages of construction, Mosowan Station focused on studying the natural evolution trend of the Gurbantunggut Desert and desertification prevention and control. After 1979, the focus was on observing ground processes in desert environments and researching biological sand control measures.

The car drove into the Moso Bay station area, with lush protective forests along the road.

"We maintain the forests around the station area on a daily basis," said Li Shengyu. "Some roads within the station area have been hardened and renovated, making it much easier to walk than before."

Mosowan Station is surrounded by sand on the east, west, and north sides. "Mosuowan Station is located in the largest fixed and semi fixed desert in China, which is ecologically fragile. It is an important section of the ecological barrier of the economic belt on the northern slope of the Tianshan Mountains, and its geographical location is very important," said Li Shengyu.

The Moso Bay station area mainly includes three major areas, namely the living area, watershed afforestation area, and desert conservation area. The latter two areas are located in the northern part of the station area. Li Shengyu told reporters that the station area is located in the desert oasis transition zone, with oasis on one side and desert on the other. The station area itself is a part of the oasis protection barrier, which can block wind and sand from the northwest direction.

The reporter followed Li Shengyu to the desert conservation area. Compared to the lush greenery in the south, this is a natural desert landscape with fixed and semi fixed sand dunes scattered throughout, ranging in height from 10 to 20 meters.

Climbing up a sand dune over 10 meters high, standing at the highest point and looking around, the ground between the dunes is covered with important sand fixing plants in temperate deserts - clusters of Haloxylon ammodendron, including white Haloxylon ammodendron and Haloxylon ammodendron firewood.

"Why not plant trees and build artificial protective forests here?" the reporter asked.

Li Shengyu explained that the annual precipitation in the Gurbantunggut Desert is 70-150 millimeters, and the plants of the Haloxylon genus can maintain their growth by relying on this natural precipitation. If artificial protective forests are built, the water consumption will be many times higher, and relying solely on natural precipitation is far from enough.

"Although these natural vegetation like Haloxylon ammodendron appear sparse, maintaining such growth and vegetation coverage is just right under the existing precipitation and soil moisture conditions, and the protective effect is both good and long-lasting," said Li Shengyu.

Adopt appropriate sand fixation and afforestation techniques for different natural conditions

The precipitation in the Gurbantunggut Desert is concentrated in winter and spring, and better precipitation conditions provide conditions for the growth of desert plants, making it the largest fixed and semi fixed desert in China.

"The fixed and semi fixed nature of the Gurbantunggut Desert also benefits from the widespread presence of suspended wet sand layers in the desert." Song Chunwu said that the wet sand layer of the sand dunes in the Gurbantunggut Desert provides good water conditions for plant roots, allowing plants to survive the hot and dry summer. "The key to artificial afforestation and sand fixation here is to create conditions suitable for plant growth."

In response to the unique conditions of the Gurbantunggut Desert, researchers have continuously explored and developed four types of sand fixation and afforestation technologies: guest sand, water collection, autumn irrigation, and suspended wet sand layer. They have also demonstrated sand prevention and control technologies.

Guest sand afforestation refers to filling the moist sand soil in the vicinity of a sand dune in a very thin area into the seedling planting hole. This can replenish the moisture in the root layer of seedlings, improve their survival rate, and support them through summer.

"In these areas, the 50-60cm place where the roots of seedlings are planted is dry sand. You see, just turn up the dry sand below and fill in the wet sand brought in, and the wet sand will be 'customer oriented'." Li Shengyu said while taking a shovel to demonstrate to reporters.

"If the moisture inside the wet sand filled below evaporates quickly, will it turn back into dry sand?" the reporter asked.

"Don't worry about this issue," Song Chunwu waved his hand as he stood on the side. "The capillary action of the sand layer is very weak, and the dry sand layer formed on the surface can prevent evaporation, so there is no need to worry about water quickly evaporating. After the plant survives, the root system develops downwards and can extend to deeper wet sand layers for continuous growth."

"Due to the soft sand, digging pits to replace sand is relatively labor-saving and very beneficial for the growth of sand fixing plants," said Li Shengyu.

Water harvesting afforestation utilizes the poor permeability of soil and desert to artificially create undulating terrain, forming a surface with alternating slopes. This allows rainfall and melted snow water from the surface to converge to the low-lying bottom of the ditch under gravity, ensuring the good growth of seedlings planted here.

Li Shengyu said, "When planting sand fixing plants, the spacing is usually large. The water collection effect of the surface micro terrain is very obvious, usually only 1-3 millimeters of rainfall can form surface runoff. The catchment slope of a planting ditch is about 20-50 square meters, and the accumulation of surface runoff is equivalent to an increase in rainfall intensity by tens of times."

In autumn, agricultural water usage decreases, and researchers adjust some of the river water for sand control and afforestation, which is called autumn irrigation and afforestation.

Li Shenglin told Li Shengyu that in his view, scientific desertification control includes at least four aspects: technical reliability, tailored measures, disaster prevention, and a combination of construction and management. "Suitable measures for sand prevention and control should be taken according to different natural conditions. Effective governance models should be tailored to local conditions and scientifically promoted. For some desert areas, appropriate measures can be taken to protect them."

Continuously exploring and conducting in-depth research on the mechanism of wind and sand movement and new technologies for sand prevention and control

The wind tunnel laboratory is a major feature of Moso Bay Station. Before heading to Moso Bay Station, the reporter had heard researchers mention it multiple times.

The wind tunnel laboratory is located in the living area in the south of the station area, covering an area of approximately 300 square meters. The entire wind tunnel is 16.2 meters long, with a cross-sectional width of 1.3 meters and a height of 1 meter.

"This is currently the only wind tunnel in Xinjiang for wind and sand environments, which is an important experimental device for simulating wind and sand movement, sand dune formation and evolution, as well as studying plant physiology and ecological changes under wind and sand interference." Li Shengyu said that every year, researchers from all over the country conduct experiments.

At the wind tunnel laboratory, the reporter met Miao Jiamin, a doctoral student from Xinjiang. She has been conducting experiments at the station for almost a month now.

"The experiment I am conducting is about how wind speed affects soil moisture evaporation," said Miao Jiamin.

"Wind tunnels provide researchers with a simulated field environment," Miao Jiamin told reporters. However, many conditions in the field are uncontrollable. "In a wind tunnel environment, we can precisely control the experimental conditions according to our own experimental needs."

The first step before conducting wind tunnel experiments is to make a physical model. For example, in the study of highway sand damage, a scaled model of the highway subgrade needs to be developed.

"Now my sand table model is in the wind tunnel," Miao Jiamin pointed to the reporter and said, "I set it for 10 minutes. After blowing for 10 minutes, I will take out the sand table and weigh it to calculate how much soil moisture has been lost. Then, I will put it in and continue blowing, and then take it out to see how it changes over time."

"Wind tunnel laboratories, these important research equipment, have controllable conditions, can obtain results faster, and are convenient for theoretical research and technical verification," said Li Shengyu.

In recent years, through project cooperation, personnel visits, and other forms, Moso Bay Station has established stable cooperative relationships with scientific research institutions in some countries and shared its experience in sand prevention and control with international peers.

According to Li Shengyu, in the future, Mosowan Station will continue to explore and conduct in-depth research on the mechanism of wind and sand movement and new technologies for sand prevention and control, especially in improving the quality and efficiency of oasis protective forests, to better ensure the ecological security of oases.