How to treat alien species

The self-introduction of alien species was originally intended to enrich species and economic uses, but the existence and harm of alien invasive species is still a very serious problem both in China and around the world. Alien invasive animals and plants will bring direct economic harm to farmland, horticulture, lawn, forest, animal husbandry and aquaculture. Invasive species can cause 1 to directly reduce the number of species, indirectly reduce the number of species dependent on local species, change the local ecosystem and landscape, reduce the ability to control and resist fires and pests, reduce the ability to improve soil conservation and nutrition, reduce the ability to maintain water and improve water quality, and reduce the ability to protect biodiversity. Alien species have actually come into our lives, but we don't know it yet. For example, crayfish, named Procambarus clarkii, which is very popular in Beijing, originated in Mexico and then spread to North America, posing a great threat to the fishery production and dams of five major lakes in 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 the dam facilities. 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, it has been abandoned or escaped in large quantities, and has now invaded farmland and natural systems, becoming pests of crops, vegetables and ecosystems in southwest Shenzhen. Mikania micrantha, a "plant killer", is spreading rapidly and has become an irresistible trend. In the past, this shady and leafy island was covered with Mikania micrantha. They are like huge nets, shrouded in the darkness of beautiful litchi trees, banana trees and acacia trees. Trees die silently because they can't get sunshine, flowers and green grass wither because they can't get fresh air, and the land on the island is becoming a wasteland. Neilingding Island, known as the "plant paradise", may be destroyed by Mikania micrantha. This horrible "plant killer" originated in Central and South America. In 1980s, Mikania micrantha spread to Southeast Asia, causing immeasurable losses to farmers who planted cash crops such as bananas, tea, cocoa and rice. In the early 1990s, Mikania micrantha's magic feet set foot on Hainan Island in China. A few years later, I arrived in Shenzhen. In a 4000-mu plantation in Baoan, Shenzhen, almost 80% of the forest was ravaged by Mikania micrantha. Some fir forests have been blocked by Mikania micrantha and some hilltops have been completely covered by Mikania micrantha. In China, a South American aquatic plant water hyacinth greatly reduced the water area of Dianchi Lake in Kunming. The local climate is obviously dry, and 38 of the 68 species of fish in the lake no longer exist. According to conservative estimates, the serious occurrence and damage area of forest invasive pests such as Bursaphelenchus xylophilus, Pinus elliottii, Hemiberlesia pitysophila, and Hemiberlesia pitysophila in China has reached about 654.38 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. 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. February 2, 20021Daily News: The General Administration of Quality Supervision, Inspection and Quarantine, the Ministry of Agriculture and the State Forestry Administration jointly issued an announcement recently, announcing the suspension of the import of pineapple, banana seedlings and other parasitic plants of banana perforation nematodes from the Philippines. Once found, they will all be returned or destroyed. Pomacea canaliculata, also known as Pomacea canaliculata and apple snail, is native to the Amazon River basin in South America. 198 1 was introduced into China as an edible snail, which became a harmful alien invasive species because of its strong adaptability and rapid reproduction. The most recognizable feature of Ampullaria canaliculata is that the female snail can lay "pink eggs" on the surface of solid objects above the waterline. Pomacea canaliculata is a veritable rice killer, because it eats rice and other agricultural plants, which will cause serious yield reduction. In addition, the snail shell is sharp and easy to scratch the hands and feet of farmers, and a large amount of feces will pollute the water body. Because each female snail can produce about 1 10,000 eggs a year, the reproductive amount is amazing, which can cause the extinction of other aquatic species and easily destroy the local wetland ecosystem and agricultural ecosystem. Introduced to China on 198 1. Its meat is tender and delicious, rich in protein, carotene, vitamins and minerals, and it is a delicious food on the table. Because of its low fat content, it is a high-quality tonic for patients with hypertension and coronary heart disease. In addition, it is also the feed for some precious aquatic animals. Pomacea canaliculata is large in size, wide in feeding habits, strong in adaptability, fast in growth and reproduction, and high in yield. It is cultivated all over China. Eating inadequately heated snails may cause human bodies to be infected with parasites such as Angiostrongylus cantonensis. In recent summers, a strange mosquito has appeared in the coastal areas of Shandong Province. It is very different from the local mosquitoes. It has a big body, white spots on its wings and long legs. The locals call it "flower mosquito". It is very toxic to sting people when they come out during the day. The bitten area is itchy and uncomfortable, and it will take many days to reduce the swelling. These uninvited guests are said to have invaded our country with wood imported from the United States. In fact, some creatures in our country 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. The problem of alien species invasion in the world is also very serious. In western Europe, a North American shrimp disease is attacking local shrimp, causing local shrimp to disappear in many rivers. In the Mediterranean Sea and Adriatic Sea, a Pacific seaweed covers 3000 hectares of the sea floor. ④ From East Africa to the Indo-Pacific region, a A Lang grass from South Asia invaded millions of hectares of tropical forests, seriously affecting the natural regeneration of local trees. ⑤ A pathogenic fungus from Australia, possibly from Papua New Guinea, invaded from 1920, resulting in the destruction of thousands of hectares of forests. This fungus is harmful to three quarters of plants, including tall trees and short shrubs. In New Zealand, a nocturnal kangaroo from Australia is estimated to eat 265,438+0 tons of local forest every night. ⑦ The palm tree snake from Papua New Guinea made the wild 1 1 species of birds and some lizards and bats extinct in Guam in the Pacific Ocean. Invasive species will also directly threaten human health. Measles, smallpox, bubonic plague and AIDS may all become invasive diseases. Ebola virus that attacked Congo and other places many years ago. The pollen of Ambrosia trifoliata is the main pathogen causing human pollen allergy, which can cause 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." From this perspective, biological intruders are very frightening and discolored, but there are still successful examples of biological intruders in China. Bullfrog is the natural enemy of amphibians and one of the first foreign invaders in China. Bullfrog is rich in nutritional value and delicious. Every 100g frog meat contains protein 19.9g and fat 0.3g .. It is a nutritious food with high protein, low fat and low cholesterol, which is deeply loved by people. Bullfrog has the effect of nourishing and detoxifying, and people with poor digestive function or hyperacidity and weak constitution can be used to nourish the body. Bullfrog can promote human vitality and energy, nourish yin and strengthen yang, and has the effects of nourishing heart, calming nerves and invigorating qi, which is beneficial to the rehabilitation of patients. Bullfrog also has good economic value, so far there are many bullfrog farmers around us. Bullfrog originated in the Rocky Mountains of North America. 1959 was domesticated in China, and 1986 was reared in large quantities in south-central China. Breeding value of bullfrog: Bullfrog is a world-famous meat frog, especially its legs are very popular in the international market. The skin of bullfrog can be tanned into high-grade gloves and elastic bands, which are very popular with consumers. Its skin can also be refined into leather glue, which can be used as viscose in jewelry, diamonds, jadeite and other decorations. Its bones, head, internal organs, limbs and feet can also be processed into feed for fish and livestock. However, human beings have the obligation and must control alien harmful species instead of simply destroying them. They should change their thinking, turn harm into treasure, and find ways to break through the dilemma of prevention and control. Poisonous weeds are innocent, and the key lies in how people treat the species itself, whether it is' harmful' or' beneficial'. Water hyacinth was originally introduced as a beneficial species, but now it has become a water killer. Advantages and disadvantages cannot be generalized, and we cannot go from one extreme to the other. Invasive species are "misplaced resources", and the cause of this error is often the irresponsible behavior of human beings to the safety of ecological environment. The key to species invasion is how people treat it. Things often have duality. Water hyacinth is rich in protein, amino acids, carotene and trace elements. It has always been a classic feed and an expert in water purification. Experts found that "Solidago" is a treasure all over the body, and its flowers are rich in plant essential oil, which is 10 times higher than that of jasmine. Plant essential oil can be mixed with other raw materials to make cosmetics, which has a good therapeutic effect on "acne" on young people's faces. Due to people's short-sighted behavior and utilitarianism in the utilization of exotic biological resources, some exotic species have frequently become disasters, and the prevention and control have fallen into the dilemma of wasting people and money. When these species are submerged, they will try their best to kill them all. This is an immature attitude towards foreign creatures, and it is also against the laws of science. The key to turning an enemy into a friend and using it scientifically lies in rational development and utilization. Last year, Haining city began to produce biogas from water hyacinth, and then mixed biogas with diesel to generate electricity. Biogas slurry and biogas residue can be used as organic fertilizer. Technical officials at FAO headquarters said that this technology will be vigorously promoted in developing countries. Associate Professor Lu Jianbo, one of the project leaders, from the College of Life Sciences, Zhejiang University, said that in terms of cost, only salvage and processing costs are needed, and the price of the produced ecological organic fertilizer can reach about 400 yuan per ton, with considerable profits. In Shanghai, some people weave furniture with water hyacinths in an ingenious way, with an annual income of 400,000. There are also enterprises that extract nutrients from water hyacinth and process and refine food, health care products, medicines and feed additives. In the reality of some alien species flooding, as a country with a shortage of resources, if biological resources can be used, its economic and ecological benefits will be immeasurable. Nevertheless, this work is still facing a very difficult stage, and the high production cost is the main problem. Therefore, there is still a long way to go to turn waste into treasure and use exotic species.