These animals stay in memory ...

Author:Beijing Science and Technology Time:2022.08.07

Recently, the World Nature Conservation Alliance's endangered red list update report announced the extinction of white sturgeon and the extinction of the Yangtze River.

Source: Members of the World Nature Conservation Alliance Sturgeon Expert Group

IUCN (World Nature Protection Alliance) Global catfish re -evaluation results show that about 2/3 of the catfish population is extremely endangered. Arne Ludwig, chairman of the IUCN catfish expert group, said, "the result is shocking and sad, but it is expected. The evaluation shows that the catfish still cannot remove the" most threatened group in the world in the world. 'This title. "

It is not uncommon for species to extinct. A BBC report said: "Since the first industrial revolution, the phenomenon of extinction of earth species due to human activities has become increasingly prominent. Many animal species have disappeared forever. Mammals, more than thousands of birds, and tens of thousands of plants. "In recent years, over 37,000 species worldwide are endangered, and 8 million tons of plastic garbage will eventually flow into the ocean every year ... The living conditions of the earth are not optimistic.

How many species are there on the earth?

For centuries, human beings have been looking for the diversity of earth creatures, from the depths of the crust to the top of the Himalayas, from tropical rain forests to the deep sea. Plants, animals, and microorganisms have become more and more detailed.

In 2011, Hawaii and Canadian biologists in the United States evaluated reports that the number of species on the earth is expected to be about 8.7 million kinds, the minimum real data is 7.4 million, and the maximum is 10 million kinds. However, some researchers have pointed out that the previous evaluation data were clearly underestimated. All previous survey reports ignored microorganisms and used unreliable speculative technologies. Professor Jay Lennon, the University of Indiana, said: "Evaluating the number of species on the earth is a huge challenge. Our research data combined with the largest database of ecological models will provide a strict new Earth microbial statistical report . Microbial is very small, and it is difficult for humans to watch it, including single -cell creatures, bacteria, pale bacteria, and certain fungi. "

Therefore, although humans spare no effort to explore the diversity of the earth, there is no data on the specific species information on the planet.

Although the technology of human society is constantly improving, the acquisition of water, food, drugs, fuel and other resources still depends on the most basic natural ecosystem. The epidemic in 2020 swept the world. The invasion of the virus re -examined the relationship between man and nature, and once again emphasized the importance of the earth's ecology and species diversity. Data show that the diversity of earth biodiversity has been decreasing in recent years.

In the past forty years, the diversity of the earth has been reduced by 68%

In September 2020, UN Secretary -General Gutres said at the Biological Diversity Summit that more than 60%of coral reefs in the world were endangered due to excessive fishing, destructive practices and climate change. Excessive consumption, population growth and intensive agriculture, the number of wild animals has declined sharply. The speed of species extinction is accelerating, and 1 million species are currently threatened or endangered.

"Earth Ecology Report 2020" was released by the World Nature Foundation. The report was released every two years. The report showed that from 1970 to 2016, mammalized, birds, amphibious, crawling and fish population scale monitored. Average decreased by 68%.

Globally, Latin American biodiversity, which has the world's largest tropical forest, is the most obvious. The richness of species has decreased by 94%in 40 years, which is the worst region in the world. The changes in land and ocean, including the loss and degeneration of habitats, are the biggest threat to biodiversity.

Taking Latin America as an example, Amazon Tropical Forest is one of the most biodiversity ecosystems on the earth. More than 3 million species live in the rain forests, and more than 2,500 tree species (about 1/3 of all tropical trees on the earth) are maintained together. We are full of this dynamic ecosystem.

But in this rainforest, the speed of species extinction has never been seen before. According to the United Nations estimates, 1 million species are in a state of extinction. From August 2018 to July 2019, the Amazon area lost more than 9,842 square kilometers of forests, and the forest cutting rate reached the highest peak of ten years.

Human occupation of land and industrial land expansion, excessive development of grasslands, rain forests, and wetlands is the main reason for the decrease in species in the region.

Compared with the ocean and forests, the loss of biological diversity of freshwater is faster. According to "Earth Vitality Index 2020", since 1700, nearly 90%of the wetlands on the earth have disappeared, which has a profound impact on the diversity of freshwater biological diversity. The number of populations decreased by an average of 84%.

Among these freshwater organisms, larger species are more likely to be threatened. Like some catfish, the Yangtze River porpoise, otter and other creatures with more than 30 kg, the number of populations has decreased sharply due to over -development of humans. From 2000 to 2015, 78%of the species capture in the Mekong River declined, and the decline of medium and large species was even more obvious.

Although humans are working hard to relieve climate change in recent years, global temperatures have risen, sea level rises, and extreme weather has affected species diversity.

Ecological and species evolution is very slow. If the climate change is very severe, biological evolution cannot adapt to this speed, and the risk of species extinction can only be "forced" to accelerate. 03

Nearly 40,000 species in the world are endangered

"Earth Ecology Report 2020" pointed out that at present, global terrestrial biodiversity is already at stake, and the global average biological diversity integrity index is only 79%, which is far lower than the security lower limit of 90%, and it is still declining.

According to the decline of species, the total number of species, the total number of species, and geographical distribution, the red list of the Endangered species of the World Nature Protection Alliance divides the species into "extinction", "field extinction", "extremely dangerous", "endangered", "easy danger" and so on.

The latest red list released by the World Nature Protection Alliance shows that currently there are 38,543 species on the verge of extinction, accounting for about 28%of all evaluated species.

This is some animals that are extinct or endangered in recent years. Let us remember them:

The extinction of each species makes people regret