The first list of alien invasive species is 1. Eupatorium adenophorum II. Mikania micrantha 3. Alternanthera philoxeroides 4. Qiongjiang yuye 5. Poisonous wheat 6. Spartina alterniflora 7 Flying grass 8. Eichhornia crassipes False sorghum 10. Perrin sugarcane 1 1. Slash pine mealybug 38+03. Hyphantria cunea 14. African snail 15. Amphibian snail 16. Bullfrog China National Geographic: Investigation of Alien Invasion in China Click here to see all the scientific and technological pictures. For thousands of years, oceans, mountains, rivers and deserts have provided natural isolation barriers for the evolution of species and ecosystems. However, in recent hundreds of years, with the process of global integration, these barriers have gradually lost their due role. Alien species, with the help of human beings, cross the ocean, reach new habitats and thrive. Are they friends or enemies? In early 2003, on a winter afternoon, we walked into the Beijing Aquarium and visited the processed piranha. Not long ago, piranha was once a popular pet that people rushed to visit. The sight of them tearing live fish makes many people tremble with fear, and they are called "the wolf clan in the water". But at the moment, they just lay motionless in the freezer, with hopeless eyes open. Reports about piranhas gradually decreased with their silence. However, although the initiator of the sensational event has remained silent, the thinking about alien invasive species will not stop. Why are people so afraid of them that they are not even allowed to live in small aquariums? Just because they are cruel by nature? "Because there is no such fish in China," said the head of the aquarium, "piranha is native to the Amazon River basin in South America and has no natural enemies in China. Man-eating pomfret, with strong constitution and not strict requirements on water quality, can easily find water suitable for reproduction and growth in vast areas of southern China. Once it flows into natural waters, it will definitely break the existing biological chain and threaten the survival of indigenous fish. Just like the invasion of intruders, the damage to the ecology is unimaginable. " I have read some reports about the invasion of alien species, but I always feel that the weaker names such as Mikania micrantha, Eupatorium adenophorum, Alternanthera philoxeroides and Maisui are related to "invasion". Man-eating pomfret has sharp teeth, but how can whitebait in Taihu Lake "cause a devastating blow to the ecosystem" without extra fingers? How far are alien invasive species from us? Crayfish is an invasive species. "Alien species have actually entered our lives, but we don't know it yet." Dr Wu Min from the Institute of Zoology, Chinese Academy of Sciences is an expert in shellfish research in China. He talked about invasive shellfish species. "For example, the crayfish that Beijingers love to eat, the scientific name is Procambarus clarkii, which originated in Mexico and later spread to North America, posing a great threat to fishery production and dams in the Great Lakes of the United States. In the 1920s and 1930s, it entered Nanjing area of China via Japan, and then spread rapidly in Jiangsu and Zhejiang provinces, posing a great threat to local fish, crustaceans and aquatic plants. They will dig holes in the dams of rice fields, and now the crayfish in Dongting Lake multiply in large numbers, threatening dam facilities. " Dr. Wu Min also pointed out that Ampullaria gigantea and White Jade Snail, which were once active on people's dining tables, were introduced to China as high-protein foods in the early days and vigorously promoted. However, due to market reasons, they have been abandoned or escaped in large quantities, and now they have invaded farmland and natural systems and become pests of crops, vegetables and ecosystems. It turns out that alien invasive species have reached our lips. The next interview became more and more scary. In addition to liriomyza sativae, Bursaphelenchus xylophilus and Hyphantria cunea, which have been treated as pests in agriculture, forestry and fishery, even in many bustling urban communities, roadsides, ditches, wasteland, gardens, playgrounds, lawns and other places that are easily overlooked by people, it has long been a paradise for invasive weeds. Veronica, abutilon, Datura stramonium, Amaranth retroflexus, and even ragweed, which makes Americans pale, can be seen everywhere. Mr. Yang Chaofei from the State Environmental Protection Administration provided us with some figures: According to incomplete statistics, there are 0/07 species of exotic weeds and more than 40 species of exotic animals in China, ranging from vertebrates (mammals, birds, amphibians, reptiles and fish) to invertebrates (insects, crustaceans and mollusks), as well as bacteria, microorganisms and viruses. Dr. Xie Yan from the Institute of Zoology, Chinese Academy of Sciences, who was the first to conduct research on alien invasive organisms in China, told us: "At present, there are alien species in 34 provinces, municipalities, autonomous regions and special administrative regions in China, and almost all exotic weeds can be found except a few protected areas on the Qinghai-Tibet Plateau." There are also preliminary statistical reports of direct economic losses caused by exotic species in China. It's boring to list the figures, but we should carefully read the following statistical reports: According to conservative estimates, the serious occurrence and damage area of forest invasive pests such as pine wood nematode, slash pine mealybug, pine cone scale, American white moth and pine cone scale in China has reached about 6.5438+0.5 million hectares every year. In recent years, serious agricultural invasive pests such as rice weevil, liriomyza sativae, potato beetle and African snail have reached 6.5438+0.4 million ~ 6.5438+0.6 million hectares every year. The economic loss of agriculture and forestry caused by alien species reaches 57.4 billion yuan every year, the cost of controlling Liriomyza sativae only needs 450 million yuan, and the cost of salvaging water hyacinth needs more than 565.438+0 billion yuan every year. Biological invasion is a world problem. According to statistics, the losses caused by alien invasion in the United States, India and South Africa are as high as 654.38+05 billion US dollars, 654.38+03 billion US dollars and 80 billion US dollars respectively. Dr. Xie Yan believes that these are only conservative estimates, which are not enough to include those immeasurable hidden losses, such as the extinction of local biological species caused by exotic organisms, the reduction of biodiversity and the loss of aesthetic value caused by changing the environmental landscape. Biological invasion leads to species endangerment and extinction. Bai Chengshou, an expert from the Biosafety Office of the State Environmental Protection Agency, reminded me: "The concept of' aliens' is not only defined by national boundaries." . People once had such a question, why the "four big fish" (green, grass, silver carp and bighead carp) have also become exotic species, but they are not native to China? The reason is that the "four big fish" are local indigenous species in many areas of China, but if they are introduced into the waters of high-altitude areas such as Yunnan, Qinghai and Xinjiang, they will become exotic species because these areas belong to completely different ecosystems. So is the whitebait in Taihu Lake. Yunnan is the province with the richest fish species in China. However, since the 1960s, people have transplanted and introduced exotic fish twice for the purpose of industrial economy. For the first time, during the period of 1963- 1970, economic fish such as "four big fish" were introduced, and non-economic fish such as wheat ear fish and [[summer] tiger fish were introduced. The second large-scale introduction was in 1982- 1983, and the new whitebait and [[real] fish in Taihu Lake were introduced to Dianchi Lake, Xingyun Lake and other lakes. Among the original 432 indigenous fish species in Yunnan, about 130 species have not been collected in recent 5 years, accounting for about 30% of the total species; In addition, about 150 species of fish were common species in the 1960s, but now they are rare species, accounting for about 34.7% of the total species. The population of the remaining 152 species of fish is also significantly lower than that in the 1960s. Overfishing, water conservancy projects, reclamation around lakes and exotic fish are the four major factors that lead to the endangered fish in Yunnan, and exotic fish is the biggest factor that leads to the sharp decline of indigenous fish population. The extinction of salamanders in Dianchi Lake is also closely related to the introduction of exotic species in Dianchi Lake. Spartina alterniflora, a terrible invasive organism ravaging Chongming Island in Shanghai, was introduced from the United States 20 years ago, which has the function of fixing sand and promoting siltation. Due to the lack of natural enemies, Spartina alterniflora has become the absolute overlord of Chongming beach, resulting in a large number of deaths of fish and shellfish due to lack of food, and fatal injuries to aquaculture. The break of the biological chain directly affects the survival of birds that feed on small fish on the island. "If it is not controlled, the biological chain of Chongming Island will be seriously broken." Spartina alterniflora is now spreading in Fujian coastal areas and other places, and the large-scale mangrove death in coastal beaches is the evil result caused by Spartina alterniflora. At the end of Ming Dynasty, cactus was introduced to China, and now it can be seen all over the country. In the coastal areas of South China and the southwest dry-hot valley, cactus has defeated the local native plants and become the dominant community, where the original natural vegetation landscape may never be seen again. In fact, some creatures in China have entered other areas and become invasive species in other places. Pueraria lobata, for example, was introduced into the United States as a medicinal material, but it multiplied in large numbers in the United States, which had a great impact on the local ecological environment. Another example is herring, which is just an ordinary carnivorous fish in China. However, when it accidentally spread to the United States, it has become a major fishery disaster in the United States. The local government even offered a reward of $65,438+000 for catching herring. About 35% to 46% of the plants on the world endangered species list are caused by foreign invasion. The latest research shows that biological invasion has become the second largest factor leading to species endangerment and extinction, second only to habitat loss. Invasive species will also directly threaten human health. Measles, smallpox, bubonic plague and AIDS may all become invasive diseases. The cultivation of tropical rain forests by human beings has provided new opportunities for more viruses to invade, including viruses previously carried only in wild animals, such as Ebola virus that attacked Congo and other places many years ago. As mentioned above, the pollen of Ambrosia trifoliata is the main pathogen causing human pollen allergy, which can lead to hay fever. About 20% people in the United States are affected by pollen allergy. Although there are not many reports in China, many overseas Chinese will have hay fever symptoms within one or two years after coming to the United States. At present, ragweed has been distributed in Northeast China, North China, East China and Central China 15 provinces and cities. If a large-scale outbreak occurs, the consequences will be unimaginable. All these are caused by "biological invasion", whether it is a formidable malignant infectious disease such as mad cow disease, foot-and-mouth disease, plague, or the notorious red ants in the United States, forest pests such as American white moth and pine wood nematode that ravage the northeast and north China, and water hyacinth that blocks the river course in Shanghai and covers the water surface of Dianchi Lake. Their harm has gone far beyond people's imagination, so that some people call it "the cancer of the whole ecosystem."