What harm does the invasion of exotic plants do to China?

Why does the invasion of alien species cause great harm?

1

American scientists studied 473 species of plants that originated in Europe and then spread to the United States, and examined their infection by fungi and viruses. The results showed that, on average, each plant was infected with 84% fewer fungi and 24% fewer viruses in its new habitat. At the same time, after studying 26 species of terrestrial, marine and freshwater animals that invaded the United States from Europe, it was found that in the country of origin, each animal carried an average of 16 species of parasites, of which only 3 species followed the animals to new habitats, and each animal was infected with 4 new parasites in new habitats. Generally speaking, they carry about 50% less parasites than their place of origin.

From the above research, it can be seen that in the new habitat, alien species have got rid of the shackles of the original natural enemies and parasites to a certain extent, thus prospering abnormally. Plants that are originally harmless may become harmful when they arrive in another area, and exotic animals will threaten the survival of local creatures and cause great harm.

2

On the one hand, alien species provide many conditions and opportunities for human development, creating huge economic benefits for countries and regions around the world. On the other hand, alien species have also brought negative impacts on local biodiversity and human health. With the increase of global trade and the prosperity of international tourism, many examples show that alien species directly endanger terrestrial, freshwater and marine ecosystems and hinder the protection and sustainable utilization of biodiversity, and this impact is generally irreversible and uncertain in risk assessment. Therefore, legislation should be adopted to protect the national economy and biodiversity on the basis of in-depth understanding of alien species and according to China's actual situation.

I. Losses and harms caused by the invasion of alien species

(A) the definition of alien species and alien species invasion

1, definition

In biology, alien species refers to species, subspecies or low-level taxonomic groups that indicate their natural distribution range (past or present) and distribution position (that is, naturally colonized outside the original distribution range, or unable to colonize without direct or indirect introduction or human activities), including any part, gamete or propagule that these species can survive and reproduce. Invasion of alien species refers to the process of biological species migrating from the place of origin to a new ecological environment by natural or artificial means, which has two meanings. First, the species must be exotic and non-native; Second, alien species can settle in the local natural or artificial ecosystem, reproduce and spread by themselves, and ultimately obviously affect the local ecological environment and damage the local biodiversity. Alien invasive species will destroy the naturalness and integrity of the landscape, destroy the ecosystem, endanger the diversity of animals and plants and affect the genetic diversity.

2. The channels of alien species invasion

The invasion channels of alien species generally include: intentional introduction, unintentional introduction, natural transmission and other forms, in which intentional introduction is mainly to meet the needs of agricultural, forestry and fishery production activities; Inadvertently introducing alien species mainly through trade, commerce, tourism and other activities; Natural transmission is mainly a phenomenon that species spread to another country with the help of natural laws between countries with adjacent borders.

(2) Loss and harm caused by alien species invasion in some countries in the world.

A recent report published by the International Union for Conservation of Nature and Natural Resources in Nairobi shows that the economic losses caused by alien species invasion to countries around the world exceed 400 billion US dollars every year. The research reports submitted by the United States, India and South Africa to the United Nations show that the economic losses caused by alien species invasion in these three countries are 654.38+05 billion, 654.38+03 billion and more than 80 billion dollars respectively.

Alien species have caused serious damage to another habitat through intentional or unintentional behavior. For example, after 19 10 was introduced to the United States by tourists from Hawaii, the population of the Mediterranean fruit fly expanded rapidly, causing a fatal blow to citrus, the main variety of fruit industry in California and Florida. Even if the United States sent troops to uproot citrus trees, it would still be of no help. The invasion of Mediterranean fruit flies caused the United States to suffer a total loss of $200 billion.

The sclerophyllous shrub community growing in the poor soil of West Cape Town, South Africa has the functions of soil conservation, erosion prevention, water conservation and fire intensity reduction. In order to improve the landscape and fix sand dunes, Huckabee, Pinus and Acacia plants were introduced. Exotic plants have gradually reduced the diversity, density and coverage of native plants, resulting in the extinction of 548 species and the threat of 3435 species, which have been listed in the red list by IUCN.

The atypical pneumonia that occurred in 2003 is a disease that human beings have never seen before. For humans, this pathogen is a typical alien invasive species. The fragile resistance of human body to SARS pathogen fully embodies the invasion danger of exotic organisms to human beings and ecosystems. SARS spread all over the world in just five months by plane, ship and car, which clearly showed the fact that alien invasive species passed through active communication.

(3) The harm and loss caused by the invasion of alien species to China.

China is 5,500 kilometers from north to south and 5,200 kilometers from east to west, spanning 50 latitudes. There are five climatic zones: cold temperate zone, temperate zone, warm temperate zone, subtropical zone and tropical zone. The diverse ecosystems make China vulnerable to invasive organisms, and most exotic species from all over the world may find suitable habitats in China.

About half of the world's worst 100 alien invasive species announced by IUCN have invaded China. Up to now, there are 283 alien invasive species in China, and the direct or indirect economic losses caused to China's agriculture, forestry, animal husbandry and fishery, ecosystems and species resources amount to 65.438+0.65438+0.998 billion yuan. The indirect economic losses caused by ecosystems, species and genetic resources amount to1001164.43 million yuan every year, among which the economic losses caused to ecosystems reach 99.9266 billion yuan every year. Terrestrial plants 170 species, the rest are microorganisms, invertebrates, amphibians and reptiles, mammals, fish, trees and weeds. 54.2% of alien invasive species are from America and 22% are from Europe. According to the survey, 76.3% of alien invasive animals were introduced into China with trade goods or means of transport due to lax inspection. The direct economic losses caused by these alien invasive species to related industries in China are19.859 billion yuan each year, of which the direct economic losses to forestry and animal husbandry are16.005 billion yuan, and the direct economic losses to human health are 294.38+0 billion yuan. In terms of species, the economic losses caused by liriomyza sativae, ragweed, Rattus norvegicus, greenhouse whitefly and Eupatorium adenophorum are all above 654.38+0 billion yuan each year. More seriously, alien invasive species pose a serious threat to the health of China's ecosystem, seriously undermine the structural and functional integrity of the ecosystem, threaten population diversity, and lead to the extinction of local populations.

Taking Chongqing as an example, Chongqing has complex terrain, diverse climate types, abundant rainfall and sufficient heat, which provide superior conditions for biological growth and development, so it is rich in biodiversity. At the same time, however, due to economic development, western development, migration and construction in the Three Gorges reservoir area and other factors, the intensity of human activities in Chongqing has increased, especially driven by economic interests, some exotic creatures have been introduced into Chongqing and camped, which has sounded the alarm for Chongqing's ecological security. It is understood that among the first batch of 16 alien invasive species announced by the State Environmental Protection Administration, among the first batch of 24 key harmful plants (two of which are the same as those announced by the State Environmental Protection Administration) and 36 dangerous organisms-* * * 74 species that may have a great impact on local organisms, 53 species appear in Chongqing, with a frequency of 71. In September, 2002, the trace of Japanese dodder was found in the area of Lianglukou, the main city of Chongqing. On June+10, 5438, the piranha originated from the Amazon River basin in South America appeared in the main city of Chongqing. On June 5438+ 10, 2003, Silurus meridionalis, native to South America, was found in the Four Seasons Aquarium in Jiangjiaxiang, the largest wholesale market for fish appreciation in Chongqing. In July, 2003, experts from Chongqing Forestry Bureau found the harmful plant Eupatorium adenophorum near the city amusement park, the former reagent factory, Changshengqiao and Tieshanping. From 2000 1990 to 10, the annual occurrence area of forest diseases and insect pests was about100000 hectares, and the annual control area was about 66700 hectares. The investment was130000 yuan, and more than 20 kinds of forest diseases and insect pests occurred throughout the year.

It is not difficult to see from the invasion of alien species in Chongqing that due to the lack of complete laws and regulations, effective exchange of scientific knowledge and information, lax law enforcement, and weak ecological awareness, economic benefits were given priority at the beginning of species introduction, without risk assessment or blind introduction regardless of ecological consequences, which eventually led to the invasion of alien species in China.

Second, China's prevention and control of alien species invasion of the legislative status and deficiencies

At present, many developed countries in the world have formulated relatively complete laws and regulations to prevent the invasion of alien species. For example, Australia formulated the National Strategy for Biodiversity Conservation in Australia in 1996, promulgated the National Weed Strategy in 1997 and revised it in 1999; 199 1 issued the ballast water guide, which is the first mandatory regulatory document on ballast water management in the world. The United States has passed many laws to control the invasion of alien organisms, such as the Plant Quarantine Act, the Animal Damage Control Act, the Federal Plant Pest Act, the National Environmental Policy, the Endangered Species Protection Act and the Federal Weed Control Act. 1On February 3, 1999, US President Bill Clinton signed a presidential decree to adjust the federal strategy, involving the threat of invasive animal and plant species in non-federal ecosystems to the environment and economy. The directive aims to establish an invasive species committee. The Committee decided to launch a comprehensive plan to reduce the threat of invasive species to economy, ecology and human health, and further prevent the introduction and spread of unusual invasive species. In fiscal year 2000, President Clinton proposed to allocate an additional $28.8 million to the Alien Species Prevention Fund, including the Alien Pest Prevention Fund and the Strategic Fund for Accelerating Research on Habitat Restoration and Integrated Biological Pest Management.