How to understand ecosystem degradation and ecological restoration

I. Experiences and lessons at home and abroad

From several serious conflicts between human beings and nature in 100 years, can we learn some lessons to avoid the painful lessons of "destroying first, then treating", "polluting first, then treating" or "introducing first, then eliminating" (which is often difficult to get rid of)?

After World War I, the United States began to immigrate to the southern prairie on a large scale. In order to maximize profits, we abandoned the soil immediately after the soil fertility of the cultivated land was exhausted and turned to cultivate new land. However, the serious disturbance of grassland induced large-scale sandstorms: 1932 14 times, 1933 as high as 38 times, 1934 spring sandstorms swept the central and western plains, and the national wheat production decreased13. 1935 In May, the black wind broke out in Kansas, Accra, Homer and Colorado, wrapping a large amount of black soil on the surface of cultivated land, forming a "black dragon" with a length of 2400km from east to west, a width of 1440km from north to south and a height of about 3km. It swept two-thirds of the United States in three days, and 300 million tons of fertile topsoil was blown into the Atlantic Ocean. 16. Later, according to the statistics of the American Soil and Water Conservation Bureau, during the 40 years of 1935- 1975, the area of the Great Plains damaged by sandstorms was as high as 4,000-6,000 km2a-1. In order to control land desertification and sandstorms, the United States fought a protracted ecological defense war. The main measures include implementing the "Farm Bill", encouraging the abandonment of farming, adopting compensation system by the government, establishing nature reserves, restoring natural grasslands, and returning grazing to forests and grasslands. In less than five years, the area of returning farmland to forests and grasslands in China has reached150,000 km2, accounting for 10% of the total cultivated land in China. On this basis, 144 nature reserves were established. From this point of view, the United States has successfully curbed the "black storm" that has plagued the country for decades mainly through the way of "people retreating".

Since 1954, the former Soviet Union has cultivated a large number of grasslands in Kazakhstan, Siberia, Urals, along the Volga River and parts of the Caucasus. By 1963, it had cultivated 600,000 km2. Due to the lack of protective measures and the dry climate, the newly reclaimed land is seriously eroded by wind, and the loose topsoil is blown up by strong winds in spring, forming sandstorms. 1960 the sandstorm in March and April swept across the vast plains in southern Russia, causing the affected area of spring-sown crops to reach more than 40000km2. 1963 The area affected by sandstorm was as high as 200000km2, and the farming system in the new reclamation area was almost paralyzed. Dust storms hit Romania, Hungary and Yugoslavia at the same time. What is more harmful and lasting than the black storm is the white storm that happened at the same time and continues to this day: the former Soviet Union built the Karakum Canal in the Karakum Desert of Turkmenistan, which can draw water from the Amu Darya River, the main water source of the Aral Sea, the third largest lake in Asia, to irrigate farmland and grassland 1000 km2 every year. The ecological disaster caused by "creatively recreating nature" is extremely serious: the cut-off of the Amu Darya River has led to a sharp drop in the water level of the Aral Sea downstream, the shoreline of the lake has retreated for 30 years 10-20k m, the saline-alkali at the bottom of the Aral Sea has been exposed, and "white storms" (storms containing salt dust) have followed one after another, destroying 60% of the new reclamation areas and becoming a forbidden area for life. At that time, Stalin put forward a "Stalin's plan to transform nature" bigger than the "Roosevelt plan" of the United States, and advocated planting trees in grassland areas while continuing to develop irrigated agriculture. 1949- 1953, the shelterbelt of this project was nearly 30000km2, but by the end of 1960s, the area of the preserved shelterbelt was only 2%.

In order to prevent the Sahara desert from invading northward, Algeria in North Africa began to plant pine trees on a large scale along the northern edge of the Sahara desert from 1975, which is known as a world-class afforestation project (Green Dam Project). The project extends to neighboring Morocco and Tunisia, with a total length of 1500 km. According to theoretical calculation, the project can expand the forestland area of Algeria 10% every year. However, due to the unclear understanding of local water resources and environmental carrying capacity, the intensive ecological construction with exotic species has caused ecological disasters, and the desert is still expanding northward. At present, the country loses more forest land than afforestation area every year. June 65438+February 20041-65438+June 2004, the author went to northern Tunisia for investigation. We drove all day along the coast, but we didn't see the shadow of the "Green Dam". When asked about the progress of the Green Dam project in five countries in North Africa, the director of the National Institute of Arid Areas in Tunisia said humorously, "That is a shelter forest on paper".

The world-famous land reclamation project in the Netherlands has greatly promoted the agricultural development, urban construction and nature protection in the Netherlands. In recent 20 years, relying on the natural succession law of the ecosystem, the reclamation area has adopted a small number of artificial measures or no human intervention at all, which has revived the barren reclamation area and formed a healthy ecosystem with a total area of 1650km2 (Dong Zheren, 2003). This successful practice has aroused great concern of international ecologists and is often cited as a successful case of ecological reconstruction. In fact, the ecological construction of the reclamation area in this country has gone through several stages, which reflects the deepening understanding of the laws of ecological construction by the Dutch people. The first stage is the reclamation area developed in 1950s, and the landscape design is carried out according to the various leisure needs of residents. In the second stage, after the 1960s, we devoted ourselves to ecological design, creating conditions for the formation of specific biological communities, mainly by artificially planting a variety of plants, creating conditions for the habitat of rare birds and improving the biodiversity of biological communities. In the third stage, from the 1980s, they realized that a healthy wetland ecosystem could be built by relying on the natural succession law of the ecosystem without planting any plants, and the main secret of its success was to use a large number of local species.

Britain, the earliest industrialized country in the world, also tasted the bitter fruit of ecological destruction first. A large number of coal mines have devastated the country's ecological environment. But by the 1990s, they had restored the abandoned land caused by mining (mainly coal mining) in history into a natural ecosystem, and further planned to become a world-famous rural landscape. An important experience of their success is ecological restoration with the help of natural forces (Bradshaw, 2000). They have mastered the initial succession process of destroyed ecosystems, and those ecosystems can become what they are now, largely relying on natural forces. This model was initiated by A.D.Bradshaw, a former chairman of the British Ecological Society, a member of the Royal Society and a professor at Liverpool University. He believes that the benefits of ecological restoration with the help of natural forces are as follows: First, the workload can be greatly reduced; Second, the rest of the recovery process can be self-sustaining because it happens naturally; Third, biodiversity can be increased and maintained. Summing up his experience in restoring ecology all his life, he thinks that there are two important factors in ecological restoration: first, choosing suitable plant species is the key to solving all problems; Second, where nature can be restored, make use of natural forces and never interfere artificially. If these basic laws are not observed, it is impossible to achieve the expected goal of ecological restoration.

Australia, perhaps the most serious ecological disaster caused by blind introduction in the world, tries to take rabbits as an example to illustrate. 1859, an Englishman got five rabbits from England to satisfy his hobby of hunting, and then a terrible ecological disaster broke out. Rabbits breed very fast, and after losing the control of natural enemies in Australia, the number has doubled. In 1880, rabbits arrived in New South Wales and began to affect the sheep industry in South Australia. From 65438 to 0950, the number of rabbits in Australia increased from the initial 5 million to 500 million, and crops or grasslands in most parts of the country suffered huge losses, and some small islands even experienced soil erosion. People had to organize a large-scale rabbit killing operation, but it had little effect. By the 1990s of 19, when the rabbit arrived in Western Australia, people built a 1000-mile fence to try to stop it. However, the fence was soon broken down. In desperation, myxomatosis was introduced from Brazil to deal with the rapidly multiplying rabbits. However, the virus war can only temporarily alleviate the deteriorating situation. A few rabbits have natural immunity to this virus, and they reproduce quickly after escaping. Throughout the mid-20th century, rabbit killing activities in Australia never stopped. This painful example reminds us that when introducing species to prevent ecological degradation, we should not be "hungry for food" and must be alert to biological invasion. In our investigation, we found that a large number of torch trees from North America were planted in the north of the Yangtze River and even on the grassland. Eucalyptus from Australia is planted in a large area south of the Yangtze River, of which Yunnan is the "hardest hit".

The "Three-North Shelterbelt" in China was once called the "Great Green Wall" in China. In more than 20 years, China has spent hundreds of billions of dollars to "build a city", but the effect is not great (Su Yang, 2003; French, 2004). The shelterbelt stretching for thousands of miles is now the collapsed "Great Green Wall". The trees planted are all "Yang Jiajiang" (poplars). Not only have poplars grown into half-dead "little old trees" in many places, but also because pure forests are widely planted, when pests occur, billions of poplars, the fruits of Ningxia's 20-year construction, will be destroyed by a small longicorn. These painful lessons are enough to show that large-scale tree planting, especially against the laws of nature, is not worth the candle. Even if afforestation is successful, its input-output ratio is uneconomical. In 2002, the Beijing-Tianjin sandstorm source control project * * * completed afforestation of 6764km2, with the state investment of 65.438+232 billion yuan, equivalent to 654.38+0.8265.438+0 yuan hm-2; Look at the "Three-North Shelterbelt" again. In 2002, 4538km2 was planted, with an investment of 65.438+39.3 million yuan (State Forestry Administration, 2002) and 3069 yuan hm-2. The sum of the two is 4890 yuan hm-2, so only from the national "afforestation" project (calculated by 5 households in the south and 20hm2 ~ 2 grassland per capita), the income of each household in the southern Inner Mongolia project area is as high as 489,000 yuan. In this case, it is cost-effective for all countries to pay herdsmen's wages-livestock are no longer raised, and degraded grassland is completely restored naturally without afforestation. This is not the case at all. Many herders don't even know that their land has been included in the "Three North Shelterbelt" management area. Those funds can't be guaranteed to be implemented on the unit land area at all, but concentrated on a few project points that are easy to pass the acceptance, far less than 10% of the total area of the governance area! This is the root cause of "degradation while governance" and "governance can't keep up with degradation". A flag county is said to have spent10.50 billion yuan on afforestation, which has managed 6% of degraded land. By analogy, we still need to invest 2 1 100 million yuan to control the remaining 84% of degraded land, because 90% of grassland areas in China are facing different degrees of ecological degradation (Nature Protection Department of State Environmental Protection Bureau, 2000. ). Even regardless of the time, at this rate, the state will spend trillions to control the ecological degradation involving more than 550 counties, and no country can afford such expenses (Jiang Gaoming, 2004).

Second, we must recognize the key issues of ecological governance.

In view of the increasingly serious degradation of the ecosystem, the state has launched many major projects to improve the ecological environment (State Forestry Administration, 2002), but problems still exist, and some governance effects are not ideal compared with huge investment. We believe that the important reason for this problem is that people have long neglected the existence of the following key problems:

First, in the aspect of economic development in the west, the basic facts of fragile ecological environment and weak social foundation in the west are ignored. Mao Zedong (1956) made an incisive exposition on the relationship between ethnic minorities and the Han nationality in his famous "On Ten Major Relationships": "The number of ethnic minorities in China is small, occupying a large area. In terms of population, the Han nationality accounts for 94%, which is an overwhelming advantage "; "Who has more land? There are many ethnic minorities in China, accounting for 50% to 60%. We say that China has a vast territory and a large population. In fact, it is the Han nationality with a large population and the ethnic minorities with a vast territory and rich resources. At least the underground resources are likely to be resource-rich ethnic minorities. To be exact, Heihe-Tengchong Line is a comprehensive differentiation line of China's ecological environment, social economy and industrial types: the eastern part is dominated by Han nationality, accounting for 94.3% of the country, with an area of 42.9%; Ethnic minorities in the west are relatively concentrated. Although the population is only 5.7%, the area is 57. 1% (Zhang, 1999). At present, the eastern part of China is developing rapidly, and the western part is forced to catch up. However, due to the limitations of talents, transportation and basic conditions, it is impossible for the west to catch up with the east. China 1000 famous manufacturing industries, 89% are located in the east, and the west only accounts for11%; Only one Jiangsu province (13.7%) exceeds the sum of more than a dozen western provinces. Therefore, no matter how the western region catches up, the gap of economic imbalance is hard to overcome. However, in the blind pursuit of GDP, the high cost of ecological degradation in the western region has to be "paid" by the state. For example, in 2002, 25.6 billion yuan of the national "six major forestry projects" was mainly used in the western region.

The fragile environment in the west is easy to cause soil erosion, grassland degradation, soil desertification, salinization, climate drought, water shortage and other ecological and environmental problems, which should be the top priority of national ecological protection and construction. At present, the area of soil erosion in China is 3.6 million km2, about 80% of which occurs in the west, and most of the newly-increased desertified land in China is distributed in the west. However, from another perspective, there is a huge biodiversity resource pool in the west. For example, Yunnan is the region with the richest biodiversity in China, where all related species of wild rice, tea and bananas are distributed. There are strong species adapted to special environment (high temperature, drought, cold, strong light, strong ultraviolet) in arid areas of Xinjiang and Qinghai-Tibet Plateau, which contain the sustainable reserve gene pool of agriculture, medicine and industry in China. In the west, the Mongolian, Tibetan, Hui, Uygur, Dai, Yao and Zhuang nationalities live in the most complete place in China. Therefore, we must thank the ethnic minorities for preserving such diverse and beautiful ecosystems for China families. The western development must not blindly pursue GDP, but must advocate green GDP. Protecting the ecology here is a great contribution to the country: first, it can save huge governance costs; Second, it can attract tourists from the east and overseas through the beautiful ecological environment; Third, it can protect the upwind environment and import clean air, moisture and energy for the East. If all these are converted into cash, it is also a huge expense. The internationally popular ecosystem valuation is based on this idea (CostanzaR. 1997). Fourth, a perfect ecosystem can be preserved for future generations. Now the soil in the west is decreasing, the pollution in the east is increasing, the Yellow River will never be clear, and the Yangtze River will become the Yellow River, which is really sad.

Second, in terms of ecological control measures, some basic scientific and theoretical issues have not yet been clarified. For example, the problem of planting trees and flying seeds in sandy grassland has not taken into account the ecological background. Grass or shrubs are naturally distributed on the grassland. We tried to change this ecological foundation by planting trees, but the effect was not great. In the 53 years since the founding of the People's Republic of China, the forest coverage rate of Xilin Gol League in Inner Mongolia is only 0.87% (including the natural elm trees in Hunshandake! ), it just shows that afforestation is actually a failure. In addition, the role of trees in "blocking" sandstorms is much smaller than that of pulling "covering" sandstorms. Aerial seeding only solves a small contradiction in ecological restoration, which is based on the assumption that there are no seeds and seedlings in the soil. There are actually a large number of propagules (spores, seeds, roots, seedlings, etc.). ) in the degraded sandy land and grassland, but people didn't give them a chance to grow, or people didn't control animals. In addition, aerial seeding brings a large number of exotic species, and it is easy to turn a perfect ecosystem into a single species system. For example, the Mu Us sandy land has become a shrub dominated by Leymus chinensis and Artemisia ordosica, and its biodiversity value and ecological service function have been greatly reduced.

Third, there is a serious division of departments in the use of governance fees. The use of funds lacks effectiveness and sustainability. If the funds are allocated for the project of "combating desertification and afforestation" or "returning farmland to forests", the local government will plant trees. No matter what the actual effect is, the superior leaders will supervise it on the grounds of "earmarking", resulting in the situation that "the money for soy sauce can't buy vinegar". Local leaders are concerned about the cost of ecological management, not the benefits of restoration. The current policy emphasizes returning farmland to forests, returning farmland to forests has money, returning farmland to grasslands has no money, or has little money, so that ordinary people will plant trees regardless of their lives. People are most keen on afforestation projects. Obviously, there is oil and water here. The more areas where trees can't survive, the greater the "oil and water", and there is basically no risk-trees will die sooner or later, and they can't be blamed. Afforestation projects in many poor counties are taken by the "number one" personally, and even the "number two" can't stand it. That's the reason. In our investigation, we found that some forestry bureaus on the grassland offered a pine tree less than 1.5m in 300 yuan! Most of these trees died later. Who are we going to get even with? A flag county with an annual revenue of more than RMB100000, the state has invested RMB 654.38+500 million in afforestation in recent three years, and there are 9 such flag counties in the whole league. The benefits of desertification and afforestation to local finance are self-evident. After the sandstorm problem appeared, local leaders' vehicles became more advanced. Imagine that the fiscal revenue of these poor counties (banners) has been greatly reduced because of the reduction and exemption of herdsmen's animal husbandry tax, but the level of public consumption has increased rapidly. Where did the money come from?

Fourth, pay more attention to construction than protection, and even don't want to talk about protection. For a long time, people's attitude towards the ecosystem is only that it is an inexhaustible cheap resource, and less consideration is given to the ability of the ecosystem to withstand a large number of external forces. Driven by interests, people regard the ecosystem as a place where they can make money. Once there is a problem with this system, it is easy for people to push the cause of degradation to the "natural" side, or think that the degradation of other countries has caused our ecological disaster. In terms of policy, it is unreasonable that the cost of local governance with serious degradation will increase, while the protected areas will not be funded; Among the subsidies for herders, whoever has more sheep will get more subsidies. This encourages "ecological destruction" in disguise. The policy of "ecological migration" lacks the consideration of the self-sustaining ability of immigrants, blindly sets tasks and goals, and local governments will also grab tasks in order to get "resettlement fees" from it. This can't understand why the more desertified land is managed, the more grandiose "ecological construction" is actually a deep-seated "ecological destruction". Take the sandstorm as an example. Every time a large amount of soil material experiences a sandstorm, a layer of land is scraped off. These substances are harmful and annoying in different places, but they are precious in the local area and are the key factors supporting the vitality of the land. If the soil formed in hundreds of millions of years is lost, it can't be mended. "If the skin does not exist, the hair will be attached" (Jiang Gaoming, 2002b). However, some scientists did not tell the country this simple truth in time, but were keen to introduce advanced instruments to monitor how much soil we lost. In the long run, what's good for the country? The soil erosion can be slowed down or contained by adopting the method of "let people make way for the soil". The key to ecological protection is soil conservation. Although nature has the ability to cope with environmental fluctuations, human power can surpass this ability and make ecological degradation exceed the "threshold" that can be restored. Therefore, ecological restoration must pay attention to the role of ecological protection and release natural forces while increasing investment in ecological construction projects. Among them, helping communities to develop production and get rid of poverty is the key to solve all ecological and environmental problems (Liutar, 2003). In the restoration of degraded ecosystems, we should clearly advocate the principle of "protection first, construction second", which cannot run counter to each other.

Third, population urbanization and ecological naturalization.

Since the industrial revolution, man and nature have been doomed to be in a state of "fire and water are incompatible", and the fundamental cause of natural degradation is not "natural disasters" but "* * * *". If there were no human beings on the earth, there would be no problem in reviving the natural ecosystem. At present, the most ecologically fragile areas in China are mostly located in the west, where the natural environment is not suitable for the survival of a large number of people. It is generally believed in the world that the suitable population density in arid and semi-arid areas is 1 km-2, but we exceed 2 km-2. The fundamental way to solve the ecological and environmental problems in these areas is that people voluntarily evacuate from these areas and concentrate in cities (towns) (Jiang Gaoming et al., 2003). At present, about 80% of the population in the United States lives in cities, South Korea14 is concentrated in Seoul, and 99% of the population in the Nile Valley in Egypt is in a natural state, and ecological degradation rarely occurs. People-oriented, scattered and pepper-sprinkled funds should be concentrated in cities and towns, and used for ecological compensation, road construction, disaster relief, education, medical and health care, locust control, afforestation and grass planting, airplane seeding, water conservancy projects, hope projects and other expenses. It should be centralized, which greatly improves the effectiveness of the use of funds. Using various favorable conditions of urbanization to improve people's material and cultural living standards can achieve the dual goals of urbanization and controlling ecological degradation. For example, Alashan desert costs 450 yuan hm-2, where each herder has 300hm2 ~ 2. If the expenses are concentrated, he may have more than 1000 yuan a year, which is enough for him to live a well-off life. Without the pressure of population, ecological restoration is only a matter of time. According to the general law, sandy grassland is 1-3 years, grassland is 3-5 years, forest is 5- 10 years, and desert is 10- 15 years. As for wetlands, it is easier to achieve natural ecological restoration. The key point of our future ecological restoration must be to release this natural force. Specifically, there are the following patterns of population migration from severely degraded areas:

First, population migration to big cities. There are 34 big cities in China with a population of 1 10,000. These cities need a lot of cheap labor, mainly from rural areas. "There is a village in Yu Tao in JD. COM Grand Canyon is in Pinggu, Beijing. In recent years, more than 65,438+000 people spontaneously moved to towns outside the ditch, and young people went to work in cities. After the villagers were evacuated, lush forests grew on the surrounding mountains, even the farmers' yards were covered with trees, and the roads and wires built by the government at a cost of millions of dollars were useless. If migrant workers are constantly encouraged to leave the soil, their ecological pressure on the local area can be greatly reduced, which is very conducive to ecological restoration. Economically, their contribution to their hometown is far greater than that in their hometown. Migrant workers who work in the "world factory" will return the money they earned to their hometown, and every little makes a mickle. Together, the money even exceeds the financial income of some provinces where all the machines are started and all the farmers have worked hard. In Sichuan province with a population of 86 million,150,000 migrant workers sent home about 45 billion yuan in 2003, while the province's fiscal revenue in the same year was 29.2 billion yuan! Imagine how many years it will take and how much environment will be sacrificed if the 45 billion yuan is dug up from the local soil. The backward rural areas in the west especially advocate the practice of working in big cities in the east, which can organize immigrants to move and promote urbanization in a planned way.

The second is the transfer of population to local small and medium-sized cities. 587 small and medium-sized cities with a population of less than 500,000 undertake the heavy responsibility of receiving migrants from degraded areas. These cities should be located in existing prefecture-level cities and county-level cities, because in the process of urbanization, many cities still have more space for people, especially in the western region, because the original population is very scattered. Those energy-based cities have more potential, so the economic battlefield in the west is not on the ground, but underground. The energy and mines in the west are superior to those in the east, which can provide power and raw materials for the sustained economic growth in the east, which needs people to do. In the Tarim Basin, the westernmost part of China, the Taklimakan Desert, known as the "Sea of Death", has a bad climate and it is difficult for human beings to survive. Since the discovery and large-scale development of rich oil and gas reservoirs in Tarim Basin, a number of cities such as Korla, Kuqa and Aksu have developed with each passing day. With the development of energy, Korla, located in the northern edge of the desert, was still a primitive town in the early 1990s, and now it has developed into a central city with the highest consumption level and living standard in China. Shenmu county in Shaanxi province was still a desolate scene before 200 1. At present, a large number of mining, processing, service and other labor forces required for energy development have added10.3 million jobs to Shenmu County, Shaanxi Province, and the urban population has grown rapidly. From a "poor county" on the Loess Plateau to a "rich city" with an annual fiscal revenue of 500 million yuan. In addition, it is worth mentioning that in the past, many "resource-based cities" rose in the development of energy, from Datong and Taiyuan in Shanxi to Cocoto Sea in Xinjiang. Nowadays, many of these cities have declined because of the exhaustion of resources, and the new generation of "resource-based cities" that are emerging now are trying their best to avoid repeating the same mistakes. They are not simply exploitation, but exploitation and deep processing. This can maintain the sustainable development of the city and prevent the population from returning to the natural ecosystem.

Third, the transfer of population from scattered to villages and towns In the process of China's transformation from a large agricultural country to industrialization, rural urbanization plays a very important role. Now there are 19692 towns in China. However, 72% of the existing towns are located in the economically developed eastern and relatively developed central regions, while the proportion in the economically backward western regions is only 28%. It is necessary to speed up the urbanization process in the western region in combination with ecological restoration. The urbanization rate of developed countries is over 70%, while ours is only 40%. Therefore, the potential of ecological restoration lies in urbanization. In the future, the general pattern between man and nature must be: man lives in the city, wild animals live in nature and live in peace with each other. Since this trend is inevitable and the ecological degradation in China is so serious, why not combine the money spent on urbanization with the money spent on ecological restoration? Among the existing population of Alashan League in Inner Mongolia, the urban population is 6.5438+0.3 million, the urbanization rate reaches 68%, and the population of agricultural and pastoral areas is only over 60,000. Even so, the existing cultivated land area of the whole league can still be relocated and resettled10.6 million herders. Among the population in agricultural and pastoral areas, there are only more than 30 thousand people engaged in grassland animal husbandry, and there are not many people who need to move. With less investment, the maximum ecological and social benefits can be obtained. At present, the whole league has successfully relocated and transferred herders 1.7, and the herdsmen entering the countryside will mainly engage in secondary and tertiary industries such as service industry and mineral development. These measures have undoubtedly greatly promoted the ecological protection of the 270,000 km2 desert in Alxa League (Wang Fulai, 2000).

Look at Hunshandak again. Without artificial pressure, natural restoration here is easier to achieve. The experiments of China Academy of Sciences for five consecutive years have fully proved that there is no need to plant trees and grass to control the degraded sandy land here, and natural forces are fully capable of restoring the degraded ecology (Jiang Gaoming, 2002a；; Liu Meizhen et al., 2003). On the sandy land of 65438+100000 square kilometers, there are only over 30000 pure herders, and the three towns of Shangdu Gaole, Sangendalai and Habiriga in Zhenglan Banner can be used to concentrate and disperse herders. The land they withdrew from can get a net income of more than 60 million yuan only by developing grass industry with high productivity of 65,438+/kloc-0,000 mu. There is greater potential to build tens of thousands of square kilometers of nature reserves, so that wild animals can roam freely, without fences and human interference (not yet in China), and to develop tourism. At present, the financial income of the flag is less than 20 million yuan, and the national ecological management expenses for the flag are as high as 40-50 million yuan. It can be seen that the land in arid and semi-arid areas can be appreciated, and the key is how to use and protect it.