Information on alien pests

Biological invasions are now a global concern. There are many concepts involved here, including alien species. Scientifically speaking, an alien species refers to an ecosystem, and if it does not belong to this ecosystem, it is introduced and called an alien organism.

There is an invasive alien species, the so-called invasion refers specifically to those harmful, that is, beneficial species, we need it, not called invasion. Because invasion and invasion are not beneficial, species that are harmful to human health, agriculture, and biodiversity are called invasive species. The process by which invasive species spread from their place of origin, spread to the point of causing harm in new ecosystems, is called biological invasion.

Now there are several figures that the Ministry of Agriculture investigates the impact of major alien pests on agriculture, and this figure is the annual loss of more than 50 billion such figures. The State Environmental Protection Administration, now the Ministry of Environmental Protection, has also assessed that the annual losses caused by foreign pests are about 100 billion yuan, equivalent to more than 1% of the gross national product, which is similar to the situation in other countries. Like the United States, which is one of the hardest hit by the loss of more than GDP caused by alien organisms.

There are many methods, first of all, consider from the source, because the incoming route is mainly human. National ministries and commissions, such as the customs and the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, are in charge of this part to prevent alien organisms from being brought into the country through artificial means. There is a domestic quarantine in this area, which is mainly done by the Ministry of Agriculture and the State Forestry Administration.

There is a line of defense at the national gate, and there is a line of defense at home.

Once a pest occurs, each local protection department will conduct quarantine, and they will have jurisdiction over the invasion of these alien pests, and there is such a system. From the perspective of nature conservation, it is our Ministry of Environmental Protection that does this, from the perspective of protected areas, the needs of ecology in various places, what kind of regulations do they have. Something to be introduced, something to be evaluated, and what kind of harm will be caused in the future, some such preparations have been made.

Refers to alien species that are harmful to the local ecology, such as some algae shellfish attached to the bottom of the ocean-going ship to another place to cause damage, Australia's eucalyptus, eucalyptus oil is useful, and our country has introduced seeds, resulting in a lack of soil water, the surrounding vegetation is dead, eucalyptus absorbs water and is known as an underground pumping machine, as well as American snapping turtles, piranhas (fierce but bright colors can be seen), etc., national policy will not be said, I don't understand.

1. Artificial prevention and control.

Rely on manpower to catch exotic pests or pull out exotic plants. Artificial control is suitable for those invasive species that have just been introduced and settled, and have not yet spread in a large area. China has abundant human resources, and manual control can quickly remove pests in a short time, but it is powerless for plant seeds and some harmful animals that have sunk into water and soil; Harmful plants with high fecundity are easy to grow and spread again, and need to be controlled every year; If animal and plant residues (bodies, such as eggs) are not properly disposed of after artificial control of harmful animals and plants, they may become a new source of transmission, which objectively accelerates the spread of alien organisms.

2. Mechanical or physical removal.

Specially designed and manufactured machinery and equipment are used to control pest plants. Mechanical prevention of harmful plants is safe for the environment, and it can also quickly kill alien plants within a certain range in a short time. The use of mechanical salvage vessels to control aquatic weeds such as water hyacinth in Lake Victoria and other places in Africa has achieved certain results.

Kunming City, Yunnan Province, China, has also designed and manufactured a mechanical salvage ship to remove water hyacinth in Dianchi Lake, and Fujian Agricultural University has also helped Fujian Ningde District to design and manufacture a "lawn mower" to control rice grass, but they were ultimately unsuccessful due to technical and other reasons. In addition to technical problems, if harmful plant residues are not properly disposed of after mechanical removal, these residues may become a new source of transmission by relying on vegetative propagation. Alien pests can also be controlled through various ways of physics, such as controlling harmful plants by fire, trapping harmful insects by black lights, and so on.

3. Alternative control.

Substitution control is mainly aimed at alien plants, which is an ecological control method, the core of which is to replace invasive alien plants with native plants with economic or ecological value according to the law of plant community succession. Its advantages are: (1) once the alternative control plant is planted, the invasive plant will be controlled for a long time, and there is no need to control it for many years; (2) Alternative plants can maintain water and soil, improve soil, conserve water and improve environmental quality; (3) Alternative plants have direct economic value, which can recover the planting cost in the short term and benefit in the long term; (4) Alternative plants can turn barren land into economic land and improve land utilization.

The deficiency of substitution control lies in the high requirements for the environment, many habitats are not suitable for artificial planting of plants, such as steep mountains, waters, etc., and there are many ecological factors involved in the restoration of the natural ecological environment of artificial planting of native plants, and there is a certain difficulty in practical operation. To study the use of alternative plants to control alien harmful plants, we should fully study the biological and ecological characteristics of native plants, such as their competitiveness and allelopathic effects with invasive plants, master the technical points of propagation and cultivation of these plants, and develop the economic characteristics and market potential of native plants, so as to obtain economic and ecological benefits at the same time.

The invasion of alien organisms is intensifying around the world, which has brought great harm to biodiversity and people's production and life, and has become a global problem. The invasion of alien plants not only has an astonishing direct loss to our country economically, but also in the environment, due to the destruction of the ecosystem balance caused by them, the loss of biodiversity, and the indirect loss caused by the damage to the agricultural environment is immeasurable, and some alien species are invasive, causing different degrees of threat to ecosystems, habitats or species, which can cause the destruction of ecosystems, the decline of biodiversity, and even the extinction of species, often leading to major environmental, economic, Health and social problems have caused huge losses and seriously affected human lives. Globally, invasive alien species are the second most important threat to biodiversity after habitat destruction, and for islands, invasive alien species are the most important factor in island biodiversity loss.

At the same time, the degradation of natural habitats, ecosystems and land increases the vulnerability of ecosystems and provides better opportunities for the invasion of alien species.

In addition, alien organisms contribute to the extinction of native species, the reduction of biodiversity, and the loss of aesthetic value due to alteration of the environmental landscape.