What are the four major biological protection projects in the world?

Roosevelt Grassland Project in the United States, Stalin's plan to transform nature in the Soviet Union, Green Dam Construction in five North African countries (Morocco, Algeria, Tunisia, Libya and Egypt) and Shelterbelt Project in China are four famous biological projects in the world.

"Roosevelt afforestation project"

After World War I, the United States began to immigrate to the southern prairie on a large scale. In order to maximize profits, immigrants immediately abandoned the cultivated soil and turned to new land after the soil fertility was exhausted. With the large-scale development, serious disturbance to grassland induced large-scale sandstorms: 1932 14 times; Up to 38 times in 1933; 1934 The spring sandstorm swept across the great plains of the central and western regions, reducing the wheat yield in the United States by one third: 1935 In May, the "black storm" originated in Kansas, Accra, Homer and Colorado, and was wrapped in a large amount of black soil on the surface of cultivated land. A "black storm" was formed, which was 2400 kilometers long from east to west, 1440 kilometers wide from north to south, and 1000 kilometers wide from north to south. Later, according to the statistics of the Bureau of Soil and Water Conservation of the United States Department of Agriculture, the area destroyed by sandstorms in grassland areas was as high as 40 years from 1935 to 1975.

In order to control land desertification and "black storm", the United States fought a protracted ecological defense war. President Roosevelt initiated the "Grassland State Forestry Plan". The planting scale of this project was second to none at that time. In eight years, six southern states planted 2170,000 trees, with a total length of 28,962 kilometers, protecting 654,380+0.62 million hectares of farmland of more than 30,000 farms. The "black storm" that has been noisy for many years has also completely disappeared in the United States. The above achievements are naturally attributed to afforestation. The project has also had a great impact in the world, and afforestation and sand control seems to be an irrefutable truth.

However, people ignore the facts behind afforestation. The radical cure of the "black storm" is ultimately attributed to the government's efforts in agriculture and grassland protection, because it is difficult for the planted trees to exert their ecological benefits in a short time (less than 10 years). In order to cooperate with forestry projects, the US government promoted the "Farm Act" to encourage people to give up farming, and the government adopted a compensation system for those who gave up farming. At the same time, nature reserves have been built, returning grazing to forests and grasslands and restoring natural grasslands as much as possible.

Results In less than five years, the area of returning farmland to forest and grassland reached 1.5 million square kilometers, accounting for 1% of the total cultivated land area in China, and on this basis, 1.44 nature reserves were established.

It can be seen that the United States has successfully curbed the "black storm" that has plagued the country for decades mainly through the way of "people retreating".

Stalin's Reform Attempt

Let's look at Stalin's attempt to transform nature in the former Soviet Union.

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 square kilometers. 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 the south, affecting more than 40,000 square kilometers of crops in spring. 1963, the area affected by sandstorms in China was as high as 200,000 square kilometers, and the farming system in the new reclamation area was almost paralyzed. Dust storms hit Romania, Hungary and the former Yugoslavia at the same time.

What's more, there was a "white storm" in the former Soviet Union, which was more harmful than the "black storm" and lasted longer, and it has been harmful to this day. The reason is that the former Soviet Union built the Karakum Canal in the Karakum Desert of Turkmenistan, which draws water from the Amu Darya, the main water source of the Aral Sea, the third largest lake in Asia, every year. Irrigate about 1000 square kilometers of farmland and grassland. The ecological disaster caused by "creatively recreating nature" is extremely serious: the cut-off of the Amu Darya River led to a sharp drop in the water level of the Aral Sea downstream, and the shoreline of the lake retreated 10 ~ 20k m in 30 years, and the saline-alkali at the bottom of the Aral Sea was exposed, followed by a "white storm" (a storm containing salt dust), which destroyed about 60% of the new reclamation area and made it 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. During the period of 1949 ~ 1953, the shelterbelt of this project was nearly 30,000 square kilometers, but by the end of 1960s, the area of the preserved shelterbelt was only 2% of the original afforestation area.

"paper shelter forest"

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 a world-class afforestation project (Green Dam Project). The project has been extended to neighboring Morocco and Tunisia, with a total length of 65,438+0,500 kilometers. According to theoretical calculation, the project can expand the forestland area of Algeria 10% every year. However, because they don't know the local water resources and environmental carrying capacity, they blindly use exotic species to engage in intensive so-called ecological construction. As a result, ecological construction turned into an ecological disaster, and the desert continued to expand northward. At present, the area of forest land lost in this country exceeds the area of afforestation every year.

From June 5438 to February 2004, the author went to northern Tunisia for investigation. After driving along the coast for a day, there was no sign of the "Green Dam". When the author asked Dr. Hussein Khatri, director of the National Institute of Arid Areas in Tunisia, about the progress of the Green Dam project in five countries in North Africa, Director Ka said humorously, "That is a shelter forest on paper".

"Three North Shelterbelts"

Besides the three afforestation projects mentioned above, China's "Three-North Shelterbelt" is also world-famous.

The scope of the "Three-North Shelterbelt" project starts from Binxian County, Heilongjiang Province in the east, reaches the Uzbek Pass in Xinjiang in the west, reaches the national border in the north, and runs along Tianjin, Fenhe River, Weihe River, the lower reaches of Taohe River, Burkhanbuda Mountain and Karakorum Mountain in the south, with a length of 4,480 kilometers from east to west and a width of 560 ~ 1460 kilometers from north to south. Including Shaanxi, Gansu, Ningxia, Qinghai, Xinjiang, Shanxi, Hebei, Beijing, Tianjin, Inner Mongolia, Liaoning, Jilin and Heilongjiang provinces (autonomous regions and municipalities directly under the Central Government) 55 1 county (flag, city and district). The total construction area of the project is 4.069 million square kilometers, accounting for 42.4% of the total land area of China. The project plans to afforest 350,800 square kilometers, including 263,700 square kilometers of artificial afforestation, accounting for 75% of the total task; Aerial seeding afforestation 1. 1 1 10,000 square kilometers, accounting for 3%; 75,900 square kilometers is mountainous and sandy, accounting for 22%. * * * 5.24 billion trees need to be planted.

If the blueprint can be realized, it will surpass the above-mentioned three world-class afforestation projects abroad in scale and benefit and become the largest "artificial ecological project" in the world. At the end of 2003, Guinness World Records Headquarters recognized the "Three North Shelterbelt" system construction project as the "largest afforestation project" in the world.

This grand project started at 1978 and is expected to end in 2050. It takes 73 years and is planned to be built in three phases and eight phases. 1978 ~ 2000 is the first phase, which is divided into three phases: 1978 ~ 1985 is the first phase, 1986 ~ 1995 is the second phase, 1996 ~ 2000. 200 1 ~ 20 10 is the fourth phase project, and 201~ 2020 is the fifth phase project; The third stage is from 202/kloc-0 to 2050, and there are three stages in the middle: the sixth stage is from 202/kloc-0 to 2030, the seventh stage is from 203/kloc-0 to 2040, and the eighth stage is from 2004/kloc-0 to 2050. At present, the fourth phase of the second phase of the "Three North Shelterbelts" project is being implemented.

Since the project was implemented for 30 years, it has played a certain role in preventing wind and fixing sand, conserving water and soil, conserving water, improving the environment and promoting the all-round development of agriculture, forestry, animal husbandry and sideline. However, the "Three-North Shelterbelt System" was planned and constructed in the "Three-North Shelterbelt System", a specific area with harsh natural conditions, frequent disasters, serious ecological environment damage and poor people's lives. There has never been a large area of forest in these areas in history, and it is difficult to achieve the established goal of "afforestation" by manual efforts.

Take Inner Mongolia, one of the sources of sandstorms, as an example. The "Three North" project spans the whole territory of Inner Mongolia, and the forest coverage rate of the whole Inner Mongolia is only about 5%, and it is mainly distributed in the eastern forest area of Inner Mongolia, where there are forests and no afforestation. The vast grassland is basically treeless except for sporadic forests in some areas (sandy land, shady slopes of high-altitude mountains, river banks) (the national competent department lists "shrubs" as forests). If we want to "cover" 15% of the forests on the grassland, the contribution rate of artificially planted forests is 10%, which means that the proportion of artificially planted forests is quite large and it is difficult to achieve.

The climate in the "Three North" area is harsh, and there are naturally distributed herbs and shrubs that are resistant to sandstorms and droughts. Grass grows for three or four months in the same rainy, hot and windless summer, and will not be affected by the harsh climate (cold, cool wind and drought) in late autumn and early winter. Local shrubs also have the ability to adapt to this environment. On the other hand, tall trees must pass the "cold, drought and wind" to survive in the local area. So in terms of woody plants, nature chooses shrubs instead of trees. Artificial tree planting in grassland, loess plateau and alpine plateau. The result observed by the researchers is that only a few tree species such as poplar can adapt relatively (although some have grown into "small old trees"), so in order to achieve the afforestation goal, people have to choose to plant pure forests dominated by poplar. However, pure forests are prone to pests, and when pests occur, large areas lodging. Only a small longicorn beetle destroyed the achievements of Ningxia's 20-year construction-billions of poplar trees, which led to the collapse of thousands of miles of shelterbelts as the "Green Great Wall".

Judging from the effect of ecological protection, the effect of afforestation is also worth discussing. In the spring of 2003, the author and other researchers carried out field observation in the worst season of sandstorm, and found that the sand on the ground of shelter forest (poplar) was still flowing when sandstorm came. The yellow sand inside and outside the forest blocks the sun, and the visibility is below 5 meters; However, in areas covered by natural vegetation, shrubs and herbs, the visibility is more than 200 meters. The role of forests in blocking sandstorms can be seen. Even though 1% forest land on grassland fixes soil like nails, 99% soil is loose. What can this 1% do? What's more, the sand-fixing function of these trees is far less than that of grass and shrubs, but the money spent by human beings far exceeds the price paid for restoring grasslands.

The success or failure of the above-mentioned transformation of nature is enough to show that large-scale tree planting, especially tree planting that violates the laws of nature, is not worth the candle.