What are the biological invaders and what are the harmful biological invaders?

In China, a South American aquatic plant, water hyacinth, has greatly reduced the water area of Dianchi Lake in Kunming, and the local climate is obviously dry, and 38 of the 68 species of fish in the lake have ceased to exist.

In Western Europe, a North American shrimp disease is invading local shrimp, causing them to disappear in many rivers. In the Mediterranean and Adriatic Seas, a Pacific seaweed covers 3,000 hectares of seabed.

From East Africa to the Indo-Pacific region, an alang grass found in South Asia has invaded millions of hectares of tropical forests, severely affecting the natural regeneration of local trees.

A pathogenic fungus in Australia, possibly from the Papua New Guinea region, has invaded since 1920, causing thousands of hectares of forest to be destroyed. The fungus is harmful to three-quarters of plants, including tall tree species and dwarf shrubs. In New Zealand, a nocturnal kangaroo in Australia is estimated to eat 21 tonnes of local forests per night.

The brown tree snake in Papua New Guinea has made 11 species of birds and some lizards and bats extinct in the wild.

Coconut leaf beetle. It was first discovered in Haikou City in June 2002 and has caused economic losses of 100 million yuan.

Cane moth larvae. In 1987, it entered Guangzhou with the import of Brazilwood, and has now spread to Beijing.

Fushou snail eggs. This animal, native to South America, has devoured thousands of acres of fertile land in Jiangsu and Zhejiang.

Bulb barley. Lucerne.

Cassia . Native ginseng.

Looking south of the river. American Merchant Land.

Artemisia chrysanthemum. Chicory.

In 1988, the European continent was brought to the North American continent by a cargo ship, and the number of shellfish increased dramatically due to the lack of natural predators, and the canals in the Great Lakes were almost completely "occupied" by them.

The longhorn beetle from Asia and the red ant from South America are two other "invaders" that plague Americans, with the former destroying trees in Chicago and New York, and the latter specializing in biting humans and animals and spreading diseases.

Red fire ants. In the early 20th century, the inconspicuous alien fire ants invaded the southern United States due to negligence in epidemic prevention and control, but caused very important problems and economic losses in agriculture and environmental sanitation in the United States. By forming a large area of monooptimal communities, species diversity is reduced, so that other species that depend on local species diversity do not have a suitable habitat.

The coverage rate of water hyacinth in rivers, lakes and ponds can often reach 100%, which reduces the dissolved oxygen in the water and causes the death of aquatic animals. The dominance of ragweed was 0, and the community diversity was 0. Due to the crowding out of native plants by Mikania, macaques on Neilingding Island in Guangdong Province lack suitable food and can only rely on artificial feeding.

The spread of airgrass in the Xishuangbanna Nature Reserve has brought native plants such as Knotweed to the brink of extinction, and the herbivorous insects that depend on Knotweed for survival are also on the brink of extinction. The cat's claw vine in Gulangyu Island, Xiamen, climbs the greening trees and forms a large single community on the canopy, affecting the photosynthesis of the trees and causing death.

List of the first batch of invasive alien species.

1.Eupatorium purpurea 2Mikania.

3.Hollow lotus seed grass 4Ragweed.

5.Poison Weeds 6Spartina alterniflora.

7.Airplane Grass 8Hyacinth.

9.Fake Sorghum 10Cane moth.

11.Wetland pine mealybug 12Powerful beetle.

13.American White Moth 14African giant snail.

15.Fushou snail 16Bullfrog.

In the mid-19th century, a European explorer came to the Mexican jungle and saw the plant called "Merconia" for the first time. It belongs to the wild peony family, usually more than ten meters tall, without flowers, but with wide and thick leaves - the sunny side is green, while the shaded side is bright purplish-red, very special and beautiful. Intrigued by the Mykonia, the explorers harvested its leaves and fruits, and brought it back to the European continent along with other exotic objects.

In 1961, a European gifted a packet of Mekonian seeds to a botanical garden in Hawaii. The "Merconia" was very vigorous and multiplied quickly, and it was not long before "Merconia" was sold to nurseries and became a popular ornamental plant on the island of Hawaii.

But no one discovered at the time that "Mykonia" was a very destructive plant, and its arrival would bring a lot of changes to the land.

Experts point out that although the growth of plants seems to be peaceful and uncontested, in fact, the world of plants, like the animal kingdom, is full of battles between the jungle and the jungle. Plants with strong viability tend to plunder and destroy the survival resources of other plants.

Merconia is one of them. Another alien creature, the dark green embroidery-eyed bird from Japan, has inadvertently become the "**" of Mykonia. The dark green-eyed bird is very fond of eating the fruit of the Mykonia, although the fruit of this plant is small, with hundreds of seeds in each fruit.

After eating the fruit, the dark green embroidery-eyed bird becomes a volunteer sower, flying freely through the jungle while scattering the undigested seeds in all directions.

Because there are no natural predators in the Hawaiian "Merconia", but there is a suitable temperature for its growth, fertile soil, and plenty of sunlight and water, so that each plant can stretch out to the fullest, absorb water and nutrients, and occupy space. In just over 40 years, the Big Island of Hawaiʻi's "Merconia" has covered an area of 10,000 acres, or about 4,000 hectares. The tall, straight "Merconya" plant is like a large green umbrella, and in its shadow, Hawaii's dwarf native plants gradually wither and die because they do not receive enough sunlight, water and nutrients.

These native plants originally relied on to conserve the island's precious fresh water and feed the many animals that feed on it. What's even more terrifying is that the attenuation of the survival of dwarf plants has also led to the increasing loosening of the soil in the forest, which is facing hidden dangers such as mudslides at any time. Faced with such tenacious vitality and irresistible destructive power of McConia, biologists likened it to a "green cancer".

More than 100 years ago, more than 20 British rabbits were brought to Australia to be raised. The rabbit hutch was destroyed in a fire, and the surviving rabbits wandered into the wilderness. Due to Australia's climate and the lack of natural predators for rabbits, these survivors multiplied at an alarming rate and became hares.

They compete with sheep for food, destroying grassland vegetation and causing great losses to animal husbandry.

List of the first invasive alien species that invaded our country.

1.Eupatorium purpurea.

2.Mikania.

3.Hollow lotus seed grass.

4.Ragweed. 5.Poison weeds.

6.Spartina alterniflora.

7.Airplane grass.

8.Hyacinth.

Water hyacinth) 9.Fake sorghum.

10.Cane moth.

11.Wetland pine mealybug.

12.Powerful beetle.

13.American white moth.

14.African giant snail.

15.Fushou snail.

16.Bullfrog.