Central China Loess Plateau mixed forests
The Central China Loess Plateau mixed forests are located in a region that spans approximately 250,000 square miles (650,000 square kilometers) in north-central China, a historically significant area that has been the cradle of Chinese civilization. Characterized by its yellowish loess soil, this biome has faced severe degradation due to over a millennium of deforestation, agricultural practices, and erosion. Currently, only about 5 percent of the original forest cover remains, primarily in the southeastern part of the plateau, where mixed forests containing species such as aspen, oak, and pine still exist. The area is also known for its unique geographical features, including dry gullies and fragmented landscapes.
Human activities, including unsustainable farming and overgrazing, have led to significant ecological challenges, such as desertification and increased vulnerability to dust storms. Efforts to rehabilitate this critical ecosystem have been underway since 1978, with initiatives like the Loess Plateau Watershed Rehabilitation Project, which aims to restore forests and grasslands while transforming local agricultural practices. These conservation projects not only focus on ecological restoration but also strive to enhance the livelihoods of local communities. As restoration efforts continue, there is hope for a more sustainable future that balances human needs with environmental health in the Central China Loess Plateau mixed forests.
Central China Loess Plateau mixed forests
- Category: Forest Biomes.
- Geographic Location: Asia.
- Summary: This plateau, also known as the Plateau of Yellow Earth, is the cradle of the Chinese civilization. After more than 1,000 years of deforestation and soil erosion, it is sparsely vegetated but parts of it are being rehabilitated to its natural state.
The Central China Loess Plateau, extending across 250,000 square miles (650,000 square kilometers) of north central China along the Yellow River, is the largest loess deposit region in the world and home to some 100 million people. Tilted upward from southeast to northwest, its elevation ranges from 1,600 to 10,000 feet (488 to 3,048 meters) above sea level. The lush Qinling Mountains to the south and the Mongolia Plateau to the north set up its geographic limits, stretching across broad climatic gradients.
The yellowish silt deposits called loess were formed here up to 2.5 million years ago during repeated waves of glaciation and wind from northern desert regions. Loess tends to make fertile farm lands, but because of its vertical cleavage, loose structure, and high porosity, it is one of the most erosion-prone soils of the planet. Affected by centuries of deforestation and overgrazing, and exacerbated by summer monsoon rainfall and subsequent flash floods, the China Loess Plateau biome has become one of the most eroded areas of the world. The Yellow River, its name given by the silt that colors it, picks up roughly 1.8 billion tons (1.6 billion metric tons) of runoff deposits every year. Periodic dust storms also move large quantities of the yellow silt, while causing visibility problems in urban areas.
Flora and Fauna
Natural vegetation of the loess plateau has experienced degradation during the history of human habitation (a period spanning several thousand years), leaving only about 5 percent of forest cover in the entire region. The existing forest patches are more commonly found in the southeast part of the plateau, where climate is more favorable and where agricultural activities are limited only by rocky soils and more mountainous topography. These mixed forests are comprised of trees like aspen, oak, willow, birch, arborvitae, and pine.
The majority of the current plateau is characterized by a sparsely vegetated landscape of numerous dry gullies and fragmented flat-top ridges and table lands, with slopes encircled by terrace farms. Shrubs and grass are now more common natural vegetation. Despite the loss of an abundance of habitats that forests may have supported earlier in human history, some animals that still may be found in the region are: the rhesus macaque, musk deer, giant salamander, pheasants, black stork, and the golden eagle.
Human Impact and Conservation Efforts
The Central China Loess Plateau mixed forests have gradually been lost to centuries of traditional, yet unsustainable, agricultural practices, such as planting on hillsides and free-range of livestock. Increasing population and farmland expansion, overexploitation of timber for buildings and fuels, and quite often damages incurred by wars and famines have also contributed to the decline of this vast ecoregion. Toward the drier part of the plateau, overgrazing has caused disruption of grassland soil structure, leading to severe desertification and frequent dust storms. The absence of a stable vegetation cover has caused fast erosion of life-supporting soil layers and may have modified the regional climate toward an even drier and more inclement one. Further, sediment loads carried by the Yellow River are quickly deposited in the plains east of the plateau, creating perched river channels 20 feet (6 meters) higher than surrounding areas, constantly posing flood hazards to inhabitants along the river.
Recovering a deeply deteriorated ecosystem is by no means an easy task. However, starting in 1978, national reforestation projects have made steady progress in many areas of northern China, including the Loess Plateau. In 1994, the Chinese government, with help from the World Bank, launched the Loess Plateau Watershed Rehabilitation Project, one of the largest ecological restoration projects in the world in terms of the level of governmental support and public participation.
Farmers in the region were educated about, and subsidized to implement new agricultural practices. Livestock grazing is now restricted, and seeding grasses are encouraged. Herders are subsidized by the government for constructing sheepfolds and nurturing high-productivity grasslands to compensate for the reduced access to natural forage. Farmers are subsidized to plant trees among their own crops. These projects are not only aimed at restoring ecosystems, but also used as opportunities to transform the economic structure of rural regions, and to improve the quality of people's lives.
Already, there has been a noticeable improvement in land quality. According to the government conservation plan, 30,000 square miles (78,000 square kilometers) of forests and 33,000 square miles (85,000 square kilometers) of grasslands will be restored to the plateau before 2030. Subsequent benefits will include increased ecosystem capacity to clean up air, retain water, and resist dust storms.
It is hoped that if desertification trends here are reversed, there will be some protection provided against future global warming pressures. The Central China Loess Plateau mixed forests biome, forming part of the heartland of China, has for centuries constantly experienced intensive interactions between human and nature. A sustainable future requires incessant efforts toward both recovery and protection of vegetation, soil, and water.
Bibliography
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Tianjiao, Feng, et al. “Long-Term Effects of Vegetation Restoration on Hydrological Regulation Functions and the Implications to Afforestation on the Loess Plateau.” Agricultural and Forest Meteorology, vol. 330, 2023, doi.org/10.1016/j.agrformet.2023.109313. Accessed 23 Dec. 2024.
The World Bank. “Restoring China's Loess Plateau.” March 15, 2007, www.worldbank.org/en/news/feature/2007/03/15/restoring-chinas-loess-plateau#:~:text=World%20Bank%20Contribution,counterpart%20funding%20US%2490%20million. Accessed 23 Dec. 2024.
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