Why is the wetland called "kidney of the earth"
Wetland is a special natural complex of land-water interaction, and it is one of the most productive and important living environments for human beings in the world, which is closely related to human survival, reproduction and development.
It not only provides a variety of resources for human production and life, but also has great environmental functions and benefits. It plays an irreplaceable role in resisting floods, regulating runoff, storing flood and resisting drought, degrading pollution, regulating climate, controlling soil erosion, promoting land reclamation and beautifying the environment. It is called kidney of the earth.
China's wetland area accounts for 10% of the world's wetland area, with 66 million hectares, ranking first in Asia and fourth in the world. In China, wetlands are distributed from temperate to tropical, from coastal to inland, from plain to plateau and mountainous areas. There are often multiple wetland types in one area, and a wetland type is often distributed in multiple areas. ?
Extended data:
I. Ecosystem:
There are three major ecosystems on the earth, namely, forests, oceans and wetlands. Wetland, known as "kidney of the earth"; The forest is called "the lung of the earth"; The ocean is called "the heart of the earth".
"Wetland" generally refers to lowlands with a temporary or long-term water depth of less than 2 meters, meadows with more water-filled soil and coastal areas with a water depth of less than 6 meters at low tide, including all kinds of salty and fresh water swamps, wet meadows, lakes, rivers, flood plains, estuarine deltas, peatlands, lakes and beaches, river depressions or flood plains, wet grasslands, etc.
According to the definition of the International Convention on Wetlands, a wetland is a natural or man-made, permanent or temporary swamp, wetland, peatland or water body, which is still or flowing, or a body of fresh water, brackish water or salt water, including water with a depth of less than 6 meters at low tide.
Wet or shallow water areas develop into a geographical complex of aquatic biota and aquatic soil. It is the general name of all kinds of swamps and wetlands in land, flowing water, still water, estuaries and marine systems.
Wetland is an ecosystem with many unique functions on the earth. It not only provides a lot of food, raw materials and water resources for human beings, but also plays an important role in maintaining ecological balance, maintaining biodiversity and rare species resources, conserving water resources, storing flood and preventing drought, degrading pollution, regulating climate, replenishing groundwater and controlling soil erosion.
Wetland is a transitional zone between terrestrial ecosystem and aquatic ecosystem. Many wetland plants grow in a specific environment where the soil is soaked in water. Wetlands are widely distributed all over the world, and there are many wildlife resources, which are important ecosystems.
The breeding and migration of many rare waterfowl are inseparable from wetlands, so wetlands are called "birds' paradise". Wetland has a strong ecological purification function, so it has the reputation of "kidney of the earth".
Under the dual pressure of population explosion and economic development, a large number of wetlands were transformed into farmland in the middle and late 20th century. Coupled with excessive resource development and pollution, the wetland area has been greatly reduced and wetland species have been seriously damaged.
Wetland is a multifunctional and biodiversity-rich ecosystem on the earth and one of the most important living environments for human beings.
There are many types of wetlands, which are usually divided into natural and artificial categories. Natural wetlands include swamps, peatlands, lakes, rivers, beaches and salt marshes, while constructed wetlands mainly include paddy fields, reservoirs and ponds. According to statistics, there are 8.558 million square kilometers of natural wetlands in the world, accounting for 6.4% of the land area.
Second, the wetland function:
Wetlands have many functions. They can be used as direct water source or groundwater supplement, and can effectively control floods and prevent soil desertification. They can also retain sediments, toxic substances and nutrients, thus improving environmental pollution.
It can store carbon in the form of organic matter, reduce the greenhouse effect, protect the coast from wind and waves, and provide a clean and convenient mode of transportation. It is called "kidney of the earth" because it has many beneficial functions.
Wetland is also a paradise for many plants, animals, especially waterfowl. At the same time, providing food (aquatic products, livestock products, grains), energy (hydropower, peat, firewood), raw materials (reeds, wood, medicinal plants) and tourist sites for human beings is an important foundation for human survival and sustainable development.
References:
Baidu encyclopedia-wetland