Green Wall of China
Encyclopedia
The Green Wall of China, also known as the Green Great Wall or Great Green Wall , will be a series of human-planted forest strips
Windbreak
A windbreak or shelterbelt is a plantation usually made up of one or more rows of trees or shrubs planted in such a manner as to provide shelter from the wind and to protect soil from erosion. They are commonly planted around the edges of fields on farms. If designed properly, windbreaks around a...

 in the People's Republic of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

, designed to hold back the expansion
Desertification
Desertification is the degradation of land in drylands. Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.-Definitions:...

 of the Gobi Desert
Gobi Desert
The Gobi is a large desert region in Asia. It covers parts of northern and northwestern China, and of southern Mongolia. The desert basins of the Gobi are bounded by the Altai Mountains and the grasslands and steppes of Mongolia on the north, by the Hexi Corridor and Tibetan Plateau to the...

.BBC News | MEDIA REPORTS | China's Great Green Wall It is planned to be completed around 2050, at which point it is planned to be 2800 miles (4,506.2 km) long.

Effects of the Gobi Desert

China has seen 3,600 km2 (1,390 miles2) of grassland
Grassland
Grasslands are areas where the vegetation is dominated by grasses and other herbaceous plants . However, sedge and rush families can also be found. Grasslands occur naturally on all continents except Antarctica...

 overtaken every year by the Gobi Desert. Each year dust storms blow off as much as 900 square miles (2,331 km²) of topsoil
Topsoil
Topsoil is the upper, outermost layer of soil, usually the top to . It has the highest concentration of organic matter and microorganisms and is where most of the Earth's biological soil activity occurs.-Importance:...

, and the storms are increasing in severity each year. These storms also have serious agricultural effects for other nearby countries, such as Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, North Korea
North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...

, and South Korea
South Korea
The Republic of Korea , , is a sovereign state in East Asia, located on the southern portion of the Korean Peninsula. It is neighbored by the People's Republic of China to the west, Japan to the east, North Korea to the north, and the East China Sea and Republic of China to the south...

. The Green Wall project was begun in 1978 with the proposed end result of raising northern China’s forest cover from 5 to 15 percent and thereby reducing desertification.

Methodology and progress

The 4th and most recent phase of the project, started in 2003, has two parts: the use of aerial seeding to cover wide swaths of land where the soil is less arid, and the offering of cash incentives to farmers to plant trees and shrubs in areas that are more arid. A $1.2 billion oversight system (including mapping and surveillance databases) is also to be implemented. The “wall” will have a belt with sand-tolerant vegetation arranged in checkerboard
Checkerboard
A checkerboard or chequerboard is a board of chequered pattern on which English draughts is played. It is an 8×8 board and the 64 squares are of alternating dark and light color, often red and black....

 patterns in order to stabilize the sand dunes. A gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

 platform will be next to the vegetation to hold down sand and encourage a soil crust to form. The trees should also serve as a wind break from dust-storms.

Measuring success

As of 2009 China’s planted forest covered more than 500,000 square kilometers (increasing tree cover from 12% to 18%) – the largest artificial forest in the world. However, of the 53,000 hectares planted that year, a quarter died and of the remaining many are dwarf trees
Dwarfing
Dwarfing is a characteristic in plants and animals whereby one or more members of a breed or cultivar are significantly smaller than standard members of their species...

, which lack the capacity to protect the soil. In 2008 winter storms destroyed 10% of the new forest stock, causing the World Bank
World Bank
The World Bank is an international financial institution that provides loans to developing countries for capital programmes.The World Bank's official goal is the reduction of poverty...

 to advise China to focus more on quality rather than quantity in its stock species.

Problems

There is still debate on the effectiveness of the project. If the trees succeed in taking root they could soak up large amounts of groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...

, which would be extremely problematic for arid regions like northern China. For example, in Minqin, an area in north-western China, studies showed that groundwater levels dropped by 12-19 metres since the advent of the project.

Land erosion
Erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 and overfarming have halted planting in many areas of the project. China's booming pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

 rate has also weakened the soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

, causing it to be unusable in many areas.

Furthermore, planting blocks of fast-growing trees reduces the biodiversity
Biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

 of forested areas, creating areas that are not suitable to plants and animals normally found in forests. "China plants more trees than the rest of the world combined," says John McKinnon, the head of the EU-China Biodiversity Programme. "But the trouble is they tend to be monoculture
Monoculture
Monoculture is the agricultural practice of producing or growing one single crop over a wide area. It is also known as a way of farming practice of growing large stands of a single species. It is widely used in modern industrial agriculture and its implementation has allowed for large harvests from...

 plantations. They are not places where birds want to live." The lack of diversity also makes the trees more susceptible to disease, as in 2000 where one billion poplar
Poplar
Populus is a genus of 25–35 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar , aspen, and cottonwood....

 trees were lost to disease, setting back 20 years of planting efforts.

Liu Tuo, head of the desertification control office in the state forestry administration, is of the opinion that there are huge gaps in the country's efforts to reclaim the land that has become desert and that it would take around 300 years to do so. At present there are around 1.73 m sq kilometers of land that has become desert in China. Out of which 530,000 sq km is treatable but, at the present rate of treating 1,717 sq km a year, it would take 300 years to reclaim the land that has become desert.

Relations to climate change

Recently the Great Green Wall has been used as defense against critics who accuse China of climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...

 irresponsibility.

China’s forest scientists argue that monoculture tree plantations are more effective at absorbing the greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...

 carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 than slow-growth forests. So while diversity may be lower, the trees purportedly help to offset China’s carbon emissions.

Criticism

There are many who do not believe the Green Wall is an appropriate solution to China’s desertification problems. Gao Yuchuan, the Forest Bureau head of Jingbian County, Shanxi
Shanxi
' is a province in Northern China. Its one-character abbreviation is "晋" , after the state of Jin that existed here during the Spring and Autumn Period....

, stated that “planting for 10 years is not as good as enclosure for one year,” referring to the alternative non-invasive restoration technique that fences off (encloses) a degraded area for two years to allow the land to restore itself. Jiang Gaoming, an ecologist from the Chinese Academy of Sciences and proponent of enclosure, says that “planting trees in arid and semi-arid land violates [ecological] principles”. The worry is that the fragile land cannot support such massive, forced growth. Others worry that China is not doing enough on the social level. In order to succeed many believe the government should encourage farmers financially to reduce livestock numbers or relocate away from arid areas.

See also

  • Buffer strip
    Buffer strip
    A buffer strip is an area of land maintained in permanent vegetation that helps to control air, soil, and water quality, along with other environmental problems, dealing primarily on land that is used in agriculture. Buffer strips trap sediment, and enhance filtration of nutrients and pesticides by...

  • Desertification
    Desertification
    Desertification is the degradation of land in drylands. Caused by a variety of factors, such as climate change and human activities, desertification is one of the most significant global environmental problems.-Definitions:...

  • Energy-efficient landscaping
    Energy-efficient landscaping
    Energy-efficient landscaping is a type of landscaping designed for the purpose of conserving energy. There is a distinction between the embedded energy of materials and constructing the landscape, and the energy consumed by the maintenance and operations of a landscape.Design techniques include:*...

  • Great Plains Shelterbelt
    Great Plains Shelterbelt
    The Great Plains Shelterbelt was a project to create windbreaks in the Great Plains states of the United States, and was launched in 1934. President Franklin D. Roosevelt initiated the project in response to the severe dust storms of the Dust Bowl, which resulted in significant soil erosion and...

  • Macro-engineering
    Macro-engineering
    In engineering, macro-engineering is the implementation of extremely large-scale design projects...

  • Sand fence
    Sand fence
    A sand fence is a structure similar to a snow fence used to force wind blown, drifting sand to accumulate in a desired place. Sand fences are employed to control erosion and to recruit new material in desert areas....

  • Seawater Greenhouse
    Seawater Greenhouse
    The Seawater Greenhouse is a technology that enables the growth of crops in arid regions, using a greenhouse structure, seawater and solar energy...


External links

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