Why does Poyang Lake become a paradise for birds?

"A piece of water flies, and several peaks are in the middle of the lake. The flow is long and the clouds are floating, and there is no way out. " Poyang Lake, the largest freshwater lake in China, has vast smoke waves and boundless inclination, and its spectacular and unique scenery is rare in the world.

"The crane flies a thousand white spots, and the day is not half red." The vast grassland and swamp in Poyang Lake have become a paradise for rare birds and migratory birds such as cranes and swans in winter, adding an intoxicating dynamic beauty to Poyang Lake.

The migratory birds in Poyang Lake are not only famous for their large number and long wintering time, but also for their rare birds. Every year from the end of 10, a large number of migratory birds migrate from Wan Li in the north to Poyang Lake. For a time, the vast lakes and marshes were covered with silver and flowers. As people say, "What do you know about birds in Poyang Lake? Clouds cover the sun when flying, and grass by the lake is not seen when falling. "

Every year, more than 300,000 large waterfowl and migratory birds overwinter in Poyang Lake, with a total of 148 species, among which there are more than 10 species of rare wild birds under first-class protection, such as white crane, white zygomatic, Zhu _, swan, etc., and the number exceeds 1 10,000.

Most of these birds live in the migratory bird paradise-Poyang Lake National Nature Reserve in Jiangxi Province. This holy land in the northwest corner of Poyang Lake is also an important international wetland with rich biodiversity. The nature reserve covers a total area of 22,400 hectares and is home to 3 10 species of birds, with a number of hundreds of thousands. At present, it is the largest wintering crane group in the world, accounting for more than 95% of the global population, and it is also the largest wintering crane group in the world, with more than 30,000 geese. There are also 10 species of national first-class protected animals, 48 species of second-class protected animals, and 13 species of birds listed as endangered birds in the world by the international bird protection organization.

Poyang Lake is worthy of the reputation of "the wonders of migratory birds in the world".

Among the many migratory birds who come here for the winter, the Pohu crane group is particularly amazing. Crane groups almost include most family members of cranes, including white cranes, white-headed cranes, white-naped cranes and gray cranes. , a total of more than four thousand. Every winter, they dance between the lake and the sky, look for food in swampy grass, and play in the beach of the lake, attracting international tourists and experts to watch and conduct scientific investigations.

White crane, also known as Siberian crane and Asian crane, is a rare bird among rare birds and belongs to the world. She is a large wading bird, with a body length of 135 cm, white feathers and only black front wings, so it is also called "black-sleeved crane". It has a long brown knife-shaped mouth and long pink legs. It is monogamous and has a life span of over 70 years. Therefore, it is deified as a "crane" by China people and becomes a symbol of happiness and good luck.

Surprisingly, the largest crane group in the contemporary world was found in Poyang Lake. As early as 1989, there were more than 2,600 cranes, accounting for 95% of the total number of cranes in the world. In recent years, the number of cranes has been increasing steadily. Therefore, Poyang Lake is called "the world of white cranes" and "the kingdom of rare birds".

On June 24th, 1986, Prince Philip, the president of WWF and the husband of Queen Elizabeth, made a special trip to Poyang Lake to watch and inspect migratory birds, and spoke highly of it. Akibo, chairman of the International Crane Foundation, and his party were very excited when they observed 65,438+0,350 cranes in lakes and swamps. He said: The crane forest in Poyang Lake is worth as much as the Great Wall of Wan Li in China, and it is really "the second Great Wall in Wan Li".

It is this "Second Great Wall of Wan Li" that attracts foreign guests such as Danish princes, experts from the Hong Kong World Wildlife Fund and Japanese bird lovers. Since the establishment of the nature reserve in 1983, hundreds of foreign bird watching groups have been received.

Poyang Lake, a paradise for birds, has since become famous at home and abroad, the largest wintering place for migratory birds in Asia, and has since created legends.

Legend of the largest wintering place for migratory birds in Asia: Why is it a paradise for migratory birds?

Why do thousands of white cranes fly from Siberian breeding grounds to Poyang Lake for the winter? Why do thousands of other migratory birds choose Poyang Lake from Mongolia, Japan, North Korea, Northeast China and Northwest China in late autumn and early winter (165438+1October) until March of the following year?

Liu Binsheng, director of Jiangxi Poyang Lake National Nature Reserve Administration, told the reporter that through the joint efforts of scientists from Jiangxi and Shanghai, with the assistance of international scientific research organizations, and through a complete investigation of the wintering ecology of migratory birds in Poyang Lake, these problems that people are interested in and biologists and ecologists are extremely concerned about have been solved.

First of all, there is an ecosystem that is very suitable for waterfowl to overwinter.

The vast Poyang Lake is located in the north of Jiangxi Province, east longitude11550' ~1/645', north latitude 28 20' ~ 29 50'. It is the largest freshwater lake in China. She is like a gourd with a width of 50 ~ 70km from east to west and a length of170km from north to south, hanging upside down on the south bank of the Yangtze River. Five major rivers, Ganjiang, Fuhe, Xinjiang, Poyang and Xiushui, converge at Poyang Lake from the west, south and southeast respectively, and then flow into the Yangtze River from the north. These rivers carry a lot of sediment every year and deposit it at the gentle place where water flows into the lake, thus forming many beaches; At the same time, it also carries a lot of organic matter and aquatic biological resources, enriching this vast lake and swamp.

It belongs to subtropical humid monsoon region, with annual average temperature 17℃, lowest temperature -8℃ in winter, frost-free period of 270 days, and annual average rainfall 1500mm. The water level in the lake area has obvious seasonal changes. The rainy season is from April to September every year, and the water surface is about 3000 square kilometers. The ship sailed into the lake as if it had entered the ocean. As the water level rises, the fish in the Yangtze River swim back to the lake to feed and lay eggs. Here, with abundant sunshine, suitable water temperature, gentle water flow, abundant aquatic plants and rapid plankton reproduction, it is an ideal environment for the growth of fish and other aquatic organisms. Therefore, the aquatic resources here are extremely rich, including natural fish 1 18 species, such as settled Poyang Lake, semi-migratory, migratory Haihe River and mountain stream, among which more than 30 species are of high economic value, such as Chinese sturgeon, shad, whitebait, mandarin fish and perch. In addition, there are turtles, turtles, crabs, clams, snails, clams and a large number of shrimp resources. These have greatly enriched people's economic life and prepared all-round recipes for various waterfowl.

/kloc-October to March is the dry season, and it is also the season for migratory birds to come here for winter. At this time, the water surface is only 500 square kilometers, and most of the lake bottom is exposed, forming a mudflat and grass island as wide as Ye Ping. Beaches and hills divide the water surface into many lakes of different sizes. These seasonal lakes are characterized by shallow dishes with a water depth of only 30 ~ 80 cm, large shoals and open lakes, rich aquatic plants, and rich fish, shrimp and molluscs in the lakes. So it has become a paradise for all kinds of waterfowl. Swan, mandarin duck, grey goose and mallard duck swim on the lake, white crane and white-naped crane set foot in shallow water, bustard and black stork stand on the shore of the lake, seagulls and white-tailed harriers soar in the sky. They can also make short-distance transfers between lakes according to different temperatures, wind directions, water levels and the amount of food.

Migratory birds have spent a life cycle here, gaining weight and strengthening their bones and muscles to prepare for moving back to the north to have children; At the same time, many sick fish, rats and pests were wiped out here, maintaining the ecological balance, leaving behind various feathers and an amazing amount of feces, creating conditions for the growth of aquatic plants and plankton here in the coming year.

Second, the soaring bird population in Poyang Lake is the result of the destruction of surrounding lakes to some extent.

Director Liu opened the map for the reporter, referring to the lower reaches of the Yangtze River in China: If you look carefully, the lower reaches of the Yangtze River are the most concentrated areas of lakes in China. Judging from geography, climate, water quality and fish and grass resources, these lakes should be good places for birds to spend the winter. Therefore, in the past, this area concentrated the largest number of migratory birds, travelers and resident birds in China. A few years ago, according to the survey of bird workers, rare birds such as cranes and storks were distributed in Hongze Lake and gaoyou lake in Jiangsu, Shijiu Lake and Caizi Lake in Anhui, Dongting Lake in Hunan and Poyang Lake in Jiangxi. However, due to the growth of population and the development of economic activities in various places, these birds are increasingly under siege because of water conservancy construction, reclamation, indiscriminate hunting and pollution from industrial wastewater and pesticides and fertilizers.

For example, Hubei Province used remote sensing technology and satellite scanning digital images to measure Jianghan Plain, which is called Thousand Lakes. In the past 30 years, the number of lakes (the water surface is more than 0.5 square kilometers) has decreased from 609 to 309, a decrease of half. The water surface has shrunk by 42%. The water surface area of Dongting Lake 1825 was 6,000 square kilometers, and it was reduced to 4,350 square kilometers in 1949, and then it was reduced even faster. 150 years, Dongting Lake has been reduced by more than half and is still shrinking. It is estimated that if the local government does not take a series of effective protection measures again, the famous Dongting Lake will disappear from the map within 40 years. The whole lake ecosystem has been destroyed, so what about the overwintering of waterfowl?

In contrast, Poyang Lake has a larger area, a smaller population density and a better ecological environment, so when many migratory birds feel that they have no home, it naturally becomes their refuge.

Thirdly, there are many birds in Poyang Lake, which is related to the good situation from natural destruction to natural protection in this place. Director Liu said that in the past, migratory birds were occasionally killed almost every year, but in the past two years, not only did the gunshots not be heard in the protected area, but not even a wild bird was seen in the free market. So, how is this transformation achieved?