Wetland Ecosystem The term "wetland" first appeared in the U.S. Fish and Wildlife Service's "Notice 39" in 1956, which defined wetlands as "land covered by intermittent or permanent shallow water layers." In 1979, the United States in order to regulate wetlands

To classify the ecological environment of deep water, the bureau redefined the connotation of wetlands, believing that "wetlands are transitional lands between terrestrial ecosystems and aquatic ecosystems. The water level of this land often exists or is close to the surface, or is covered by shallow water..."

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The Convention on Wetlands of International Importance, Especially as Waterfowl Habitat (referred to as the Convention on Wetlands, especially as Waterfowl Habitat) was adopted in Ramsar in 1971. The Convention defines wetlands as: “Regardless of whether they are natural or artificial,

Permanent or temporary swamps, wetlands, peatlands or water areas with static or flowing, fresh, brackish or salt water bodies, including swamps, tidal flats, etc. that are not more than 6m deep at low tide.

Wetland research has a rich accumulation, and in practice a wetland classification system with Chinese characteristics has been formed. It is generally believed that "wetlands refer to areas in the ocean and inland where there is shallow water accumulation or excessive soil moisture all year round."

"Although the concept of wetland is not yet unified, they have the same characteristics: wetland is considered to be a special ecosystem from different perspectives. This system is different from terrestrial ecosystems and aquatic ecosystems. It is

The characteristics of the transitional ecosystem between the two are: (1) The biological diversity of the system. Because the wetland is the transition zone between land and water, it has both rich terrestrial and aquatic animal and plant resources.

It has a natural gene pool and unique habitat that is unmatched by any other single ecosystem. The special hydrology, soil and climate provide complex and complete animal and plant communities. It has irreplaceable ecological value for protecting species and maintaining biodiversity.

(2) Ecological vulnerability of the system. The interaction of wetland hydrology, soil, and climate forms the main environmental factors of the wetland ecosystem. Changes in each factor will lead to changes in the ecosystem, especially hydrology.

When it is disturbed by natural or human activities, the stability of the ecosystem is damaged to a certain extent, which in turn affects the biological community structure and changes the productivity efficiency of the wetland ecosystem. Compared with any other ecosystem, the wetland ecosystem has lower primary productivity.

It is reported that the average annual protein production of wetland ecosystem is 9g/m2, which is 3.5 times that of terrestrial ecosystem. (4) Wetland has comprehensive benefits, including regulating water sources, regulating climate, and purifying water quality.

It has basic ecological benefits such as preserving species and providing wildlife habitats. It also has economic benefits of providing a large amount of raw materials for industry, agriculture, energy, and medical industries. It also has social benefits such as serving as a species research and education base and providing tourism.

(5) The variability of ecosystems. Variability is one of the special forms of vulnerability of wetland ecosystems. When the water volume decreases and even dries up, the wetland ecosystem evolves into a terrestrial ecosystem. When the water volume increases, the system evolves again.

As a wetland ecosystem, hydrology determines the state of the system. Its functions include: The status and role of wetlands in the ecological environment and economic and social development are vast. Wetlands have a variety of ecological functions and contain rich natural resources. They are known as wetlands.

As the "kidneys of the earth", species reservoirs, and climate regulators, wetlands play an irreplaceable and important role in protecting the ecological environment, maintaining biodiversity, and developing the economy and society. First of all, wetlands are huge reservoirs for water storage and flood control.

When floods come every year, many wetlands use their large volumes and deep and loose bottom soil (sediments) to store floods, thereby playing an important role in diverting floods and reducing peaks, regulating water levels, and alleviating the pressure on natural lakes and dams across the country.

The flood control capacity of similar reservoirs is no less than 200 billion cubic meters. Although the area of ??the 22 river-connecting lakes in the Yangtze River has dropped sharply, the current water capacity still reaches more than 60 billion cubic meters. The flood storage capacity of Dongting and Poyang lakes is no less than 20 billion cubic meters.

Flood control and flood reduction still play a key role. At the same time, wetlands store floods during floods and slowly discharge excess water after floods, which can regulate river runoff and help maintain water balance in the basin. In addition to wetland water, wetlands are important water sources.

In addition to the water flow in rivers and ditches, the water storage in lakes, reservoirs, and ponds are also important sources of water for production and domestic use.

It is estimated that the freshwater storage in my country's lakes alone reaches 22.5 billion cubic meters, accounting for 8% of the total freshwater storage.

Some wetlands can also replenish the water source of underground aquifers through infiltration, playing an important role in maintaining the water level of surrounding groundwater and ensuring continuous water supply.

Wetlands are large-area wetlands that optimize the ecological environment. They can produce a large amount of water vapor through transpiration, which can not only increase the air humidity in the surrounding area and reduce soil moisture loss, but also induce rainfall and increase surface and groundwater resources.

According to surveys in some places, the air humidity around wetlands is 5% to 20% higher than the air humidity in areas far away from wetlands, and there is relatively more precipitation.