What are the extinct and endangered plants, and how many are left in that year?

Davidia involucrata, a pigeon tree in China.

Davidia involucrata, alias water pear, pigeon tree. It belongs to Orchidaceae, a national first-class protected plant, and is a haplotype plant which is a specialty of our country. Distributed in Zhenping, Shaanxi; Shennongjia and Xingshan in Hubei; Hunan Sangzhi; Guizhou Songtao, Fan Jingshan; Wushan, Nanchuan, Pingwu, Wenchuan and guanxian in Sichuan; Altitude of Suijiang and other places in Yunnan 1250-2200m.

Davidia involucrata is about 10 to 20 meters high and has a tall tree shape. It is a beautiful deciduous tree and a famous ornamental tree in the world. Davidia involucrata is in full bloom in April and May every year. There are two white bracts of different sizes under its head, which are oblong or oval in shape, 6-15cm long and 3-8cm wide, such as white silk, beautiful and peculiar in shape, like a dove spreading its wings; Its flower heads are like the heads of pigeons, so Davidia involucrata has the reputation of "China pigeon tree". Davidia involucrata has a fine wood structure and is not easy to deform and cut. It is a good material for wood carving. More importantly, Davidia involucrata is of great scientific value to the study of paleoflora and phylogeny. Davidia involucrata was discovered in China on 1869. Due to the excavation and planting of wild seedlings and the destruction of forests, the number is small and the distribution range is shrinking day by day, which is in danger of being replaced by other broad-leaved trees.

Rhododendron protozoa

Rhododendron macrophylla is a primitive and ancient plant type. It was first discovered in the virgin forest of Gaoligongshan Mountain in Tengchong County, Yunnan Province at an altitude of 19 100-2400 meters. At that time, Rhododendron macrophylla was over 280 years old and the tree was 25 meters high.

Rhododendron grandiflora is an evergreen tree with a height of 20-25 meters and a maximum diameter of 3.3 meters ... The brown bark is peeling off from left to right, which looks mottled and vicissitudes. Branchlets are stout, covered with short hairs, and leaves are thick and large, oval, oblong and inverted. There are hairs under the leaves, which gradually fall off when they grow up. February-March civilization, umbrella-shaped tidbits. The color of the flower is rosy and purplish, and the calyx is a linear disk with small dentate cracks on it. Stamens 16, extremely unequal in length, ovary 16 room, and villi. By June 65438+10, it had produced a long cylindrical wooden capsule with edges and dark brown fluff.

Rhododendron macrophylla belongs to dicotyledonous plants such as Cycas, Ericaceae and Ericaceae. There are more than 1300 species of Ericaceae in the world, which are distributed all over the world, but most of them are in subtropical mountainous areas. There are about 700 species in China, which are distributed all over the country, but most of them are in the southwest mountain forests, so this area is considered as the distribution center of rhododendrons in the world. Rhododendron not only ranks first among the three famous natural wild flowers in China-Rhododendron, Primula and Dracaena, but also is one of the most famous flowers in the world today, with the reputation of "two colors in flowers". Among more than 800 varieties in the world, there are more than 650 in China. Different kinds of rhododendrons have great differences in height and height. The height of small species is less than 1 m, and that of large species such as Rhododendron grandiflora is as high as several tens of meters.

Rhododendron grandiflora is so precious and rare that it is listed as a national sub-group protected plant.

Wild litchi

Litchi is known as the "fruit queen". China is the hometown of litchi, and it is also the first country to cultivate litchi. Wild litchi is mainly distributed in Bawangling, Macaque Ridge, Diaomaoshan, Jianfengling, Xuwen, Fengdao and Leizhou in Guangdong, Yaxian, Lingxiao, Changjiang, Baoting, Dongfang and Qiongzhong in Hainan.

Wild litchi is an evergreen tree with a height of 32 meters and a DBH 1.94 cm. Its branches and leaves are lush and full of vitality. Its bark is brown with yellowish brown spots. Its leaves are pinnately compound, alternate, grasslike, oval, entire, dark green at the top, pink and green at the bottom, and linear brown on the tender leaves. It is a cymose female inflorescence with smaller green and white flowers. The fruit is usually ovoid or ovoid, and the skin is dark red when it matures, with small tumor-like bodies on it. This species is oval, with dark brown seed coat, shiny top and white aril outside.

Litchi trees cultivated in China are generally only 5- 10 meters high, with smooth bark and dark green leaves. The flowers are small, with a little white in light green, which is not bright, but the fruit is particularly eye-catching. Every harvest season, many fruits are covered with branches, one ear and one string, such as jade and agate, which are attractive and coveted. Peel off the shell of the fruit, and what is revealed inside is fat and translucent meat balls, crystal clear as snow, dripping with sweet water. Eating a few will make you feel cool, sweet and sour, and make people feel excited.

Litchi is a kind of high-grade nourishing fruit with rich nutrition, which has the medicinal value of nourishing blood, reducing swelling, stimulating appetite and strengthening spleen. Its wood is also classified as a special commodity material, which is vertically staggered, compact in structure, hard and heavy in material, less in cracking, smooth in section, shiny and strong in corrosion resistance, and can be used as a material for making fine furniture and high-grade buildings.

Wild litchi belongs to dicotyledonous plants, Sapindaceae and Sapindaceae. It is listed as a national first-class protected plant.

dawn redwood

More than 40 years ago, everyone thought that Metasequoia glyptostroboides was extinct on the earth, and its appearance could only be known through fossils excavated in ancient strata.

In the early 1940s, China scholars first discovered several strange trees in Modaoxi, Wanxian County, Sichuan Province. They are more than 30 meters high, 7 meters in diameter at breast height, with huge roots, straight trunks and vitality, and the age of trees is over 400 years. At that time, due to insufficient information, it was impossible to make an appraisal. In the two years after 194 1, people studied and identified the branches, leaves, flowers and seeds of this tree, and named it Metasequoia glyptostroboides. This is a descendant of Metasequoia glyptostroboides endemic to China.

Metasequoia glyptostroboides is a deciduous tree of Taxodiaceae, with a height of 30-40 meters. Its trunk is straight and its lateral branches extend horizontally. The trunk is planted alternately in the north-south direction and the east-west direction, and the lower part is long and the upper part is short, stretching layer by layer, like a steeple. Linear flat leaves, planted on the left and right branchlets. Leaves can change color with the seasons: in spring, leaves are light green; In summer, the leaves are green and lovely; In autumn, the leaves turn yellow and the peaks are covered with gold; Leaves turn red in winter, redder after frost, and then wither.

Metasequoia glyptostroboides blooms in late February. The flowers are unisexual, and the female and male plants are the same. The cones are solitary in biennial branches or leaf axils, with about 20 stamens opposite. Female cones are solitary at the top of biennial poles, and Huaxian County has short stalks. They are composed of 22 -28 bract scales and pearl scales, which are also alternately opposite, each with 5-9 ovules. After pollination, nearly round cones are formed. Seeds flattened into obovate. The cones are dark brown when they are hot, and the maturity period is 1 1 month.

Metasequoia glyptostroboides is not only a precious living fossil, but also a leader among trees. It is an excellent greening tree species with strong vitality, wide adaptability and rapid growth. Its economic value is very high, the wood is purplish red, thin and soft, and it is a good material for shipbuilding, construction, paper making and making furniture and farm tools.

Metasequoia belongs to gymnosperms, conifers and cedars. It is a first-class protected plant in China.

Wangtianshu Huaxia

Wangtianshu is not only the tallest tree in the tropical rain forest, but also the tallest broad-leaved tree in China. China is mainly distributed in Mengla, Xishuangbanna, southern Yunnan, Hekou, Maguan and other counties in the southeast, as well as southwest Guangxi.

Wangtianshu is an evergreen tree, with a height of more than 60 meters, a DBH of about 1.3 meters and a maximum height of 3 meters. The trunk is round and straight, and there is not even a small branch as high as 30 meters. Its bark is brown or dark brown. Evergreen herbs, alternate, elliptic or lanceolate, pointed or acuminate at the front, rounded or broadly cuneate at the base. There are pinnate veins on the leaves, almost parallel. The veins on the back of the leaves are prominent and there are many thin and dense hairs.

Torreya grandis mostly grows in mountain canyons between 350 meters and 1 100 meters above sea level, and on the slopes on both sides, with a distribution area of only 20 square kilometers. Its distribution area is located in the valley area open to the south in the tropical monsoon climate zone, and it is in a state of high temperature, high humidity, calm wind and frost-free all the year round. Wang Tianshu likes to grow on lateritic red soil, sandy soil and calcareous soil. In Yunnan, it is accompanied by Cephalotaxus fortunei, Acer truncatum, Dou Shi and other trees in Guangxi.

Straight trunk, excellent wood, very hard, good processability, not afraid of corrosion, not afraid of pests. It is an excellent timber tree species and an ideal material for manufacturing advanced furniture, musical instruments and bridges. Its wood is also rich in gum, and its flowers contain perfume oil, which are also important industrial raw materials.

Cephalotaxus fortunei belongs to dicotyledonous and borneol spices in taxonomy. Because of its independent community type and natural landscape, this tree species can be regarded as a symbolic tree species of tropical rain forest. Although the tree is tall, it bears little fruit. In addition, the phenomenon of fruit drop caused by pests and diseases is very serious, which leads to seeds falling to the ground, sprouting or rotting quickly, short life and difficult to collect. Therefore, the number of wild plants is very rare and has been listed as a national first-class protected plant.

walnut

Walnut, also known as walnut and peach, is a very old cultivated fruit tree. Walnut kernel is a famous dried fruit, together with hazelnut, cashew nut and almond, it is called the four largest dried fruits in the world. China is not only rich in walnuts, but also the hometown of walnuts.

Walnut is a deciduous tree of Juglandaceae, with a height of 30 meters, a broad crown and lush foliage. Its bark is gray-white, but it is gray-green and smooth when it is young. In old age, it has many shallow longitudinal cracks and thick branches. Odd pinnate compound leaves, 5- 1 1 leaflets, oblong, entire. Flowering in early summer, unisexual, monoecious and catkin drooping. Drupe is oval or spherical, with vertical and horizontal sides and high and low patterns. Seeds are rich in oil.

Walnut is produced in the Yellow River valley and south of China. It likes sunny sparse forests, mild and humid atmosphere and deep loose, fertile and humid soil. Cold-tolerant, cold-tolerant, drought-tolerant, but not hot and humid, salt-tolerant, and shade-tolerant. In the forest with high canopy density, the seedlings are very small and grow poorly. In the natural distribution area, they grow in the lower part of shady slopes or the bottom of canyons in the middle and low mountain areas between 1400 m and 1700 m above sea level.

Walnut has been regarded as a rare tonic since ancient times. Besides containing a lot of fat and protein, it also contains calcium, phosphorus, iron, iodine, carotene, thiamine, nicotinic acid and other vitamins. Seeds, septa, peels and leaves can all be used as medicine. In traditional Chinese medicine, it is used as a medicine for warming lung and tonifying kidney. It is warm and sweet, and is mainly used to treat deficiency cold, asthma and cough, kidney deficiency and low back pain. In addition, the core wood is tough, smooth and beautiful, which is a good hardwood material and can be used as the wood part of high-end furniture, weapons and vehicles. Tannin can be extracted from walnut bark, tannins can be extracted from bark and exocarp, roots can be used as dyes, and even hard and broken shells can show their magical power in industry. Activated carbon made of it can adsorb all kinds of toxic substances and is an indispensable material in gas masks.

Walnut belongs to dicotyledonous plants, Juglans and Juglandaceae. It is listed as a first-class protected plant in China. Due to the destruction of human economic activities such as deforestation, the wild distribution area of walnut is shrinking day by day and is on the verge of extinction.

snow lotus

Tianshan Mountain is located in the northwest frontier of China, with an altitude of more than 4,000 meters. Bogda, the main peak, is 5445 meters high. The top of the mountain is covered with snow all year round, which is particularly spectacular. Saussurea involucrata is a famous plant in Tianshan Mountain. It likes to be born near the snowy mountain with steep mountains, sandy gravel and wet sand, so it is named Xuelian.

Saussurea involucrata is a perennial herb, and the aboveground plants are very short, only 15 cm -24 cm high. During the flowering season in July every year, Saussurea involucrata produces a large and bright disk at the top of the stem, surrounded by yellowish hemispherical bracts. The whole flower looks like an aquatic lotus, which is more beautiful against the white snow. When the clouds and snow covered, it quietly closed again. The scent of Saussurea involucrata is attractive, and it can float to tens of meters when the wind is downwind. Shortly after flowering in August, Saussurea involucrata quickly produced oblong achenes with longitudinal edges. Their roots are very long and can fully absorb nutrients and water; The white fluff on their bodies can protect them from cold and heat, and can also reflect strong ultraviolet rays from the mountains to reduce the harm to them.

Saussurea involucrata grows very slowly in the harsh conditions of high mountains, and it takes at least 4 -5 years to bear fruit. However, due to the short growth period, they can germinate, grow, blossom and bear fruit quickly in a short time, which is also the result of their long-term adaptation to the environment.

Saussurea involucrata is a precious medicinal material, and its whole beads can be used as medicine after drying. Traditional Chinese medicine believes that Saussurea involucrata is flat in nature and slightly bitter in taste, and has the functions of dispelling cold and dampness, promoting blood circulation and removing blood stasis, strengthening tendons and supporting yang, diminishing inflammation and relieving pain. Folk medicine is used to treat cough due to lung cold, lumbago due to kidney deficiency, irregular menstruation, measles discomfort, traumatic injury, rheumatoid arthritis, anemia, impotence, mountain discomfort and other diseases.

Saussurea involucrata can be propagated by seeds, but when the seeds are ripe, it has begun to snow in high temperature and cold areas, which brings trouble to seed collection. Moreover, Saussurea involucrata seeds have low germination rate, difficult reproduction, slow growth and difficult artificial cultivation.

Botany is studying artificial propagation to obtain various useful products.

flower of wintersweet

The distribution area of Chimonanthus praecox is extremely narrow, only distributed in the western part of Lin 'an County, Zhejiang Province.

Chimonanthus praecox is a deciduous shrub with a height of about 1 -3 meters. There are big branches and small branches on the tree. Branches are bifurcated and branchlets are opposite. One-year-old shoots are yellow-green, and turn to grayish brown in the second year. In winter, tree buds are wrapped by the base of petiole. Chimonanthus praecox leaves are oval, opposite, entire, and without stippling. The leaves of Chimonanthus praecox began to fall off in late June of 65438+ 10 every year, and did not grow again until late March to early April of the following year.

Chimonanthus praecox is a special kind of Chimonanthus praecox, which is different from most members of Chimonanthaceae who bloom in late winter and December, and only in the middle and late May and early summer every year. The flowers of Chimonanthus praecox generally bloom first and grow alone at the top of the shoots. The flowers are huge white, solitary, bisexual, petal-shaped calyx, many perianth segments, stamens 18-19, inserted at the top of fleshy receptacle, and filaments are extremely short. Carpels are mostly free, inserted in pot-shaped receptacle, with superior ovary and 1 ~ 2 ovules per room. The flowering period of Chimonanthus praecox is also very long, and it does not fade until the beginning of June. The fruit ripens from late September of 10 to early October of 10. Every aggregate fruit has a fruit receptacle, which shrinks near the top like a string of seeds, and contains a slender oval brown fruit. The fruit is flat or angular, covered with branches and swaying in the wind, making it a precious ornamental tree.

Chimonanthus praecox likes to grow in subtropical local evergreen broad-leaved forest or evergreen deciduous broad-leaved mixed forest on the hillside or valley at an altitude of 600-1 100 meters. Belonging to relatively shade-tolerant tree species, the climate is cool and humid, and it will grow badly or even wither under strong sunlight. It is not drought-tolerant and barren, but it is relatively cold-tolerant, especially for Castanopsis carlesii with more mountains and streams.

Chimonanthus is a dicotyledonous plant, Chimonanthaceae. Its flowers are large and beautiful, with high ornamental value, and are listed as national first-class protected plants. Due to deforestation, the habitat is deteriorating and the distribution area is shrinking, so it is necessary to further strengthen the protection work to avoid making it in an endangered state.

Endangered animals are:

Ancient National Treasure: Giant Panda

The giant panda is a carnivore and mainly eats bamboo. It is not only rare, endangered and special, but also very old, so it is called "living fossil". At the same time, ancient animals such as saber-toothed tiger, mammoth and giant tapir were extinct due to glacier invasion, but the giant panda survived by retreating into the valley. Now it is only distributed in the green hills and bamboo forests of about 40 counties in China, Sichuan, Shaanxi and Gansu, and lives in seclusion.

Snubby nose and blue face: golden monkey

China golden monkey includes Sichuan, Yunnan and Guizhou, among which Sichuan golden monkey is the most familiar. Sichuan golden monkey, distributed in Sichuan, Shaanxi, Hubei and Gansu, lives in mountainous areas and lives in groups. Wearing a golden cloak, climbing trees, jumping and prancing. When the golden monkey was first named, because of its upturned nose and golden hair, Mr. Edward, a zoologist, thought of Roqueana, the wife of the European Crusader Commander, so he named the golden monkey Rhinpitheus Roxellanae based on this beauty.

Yangtze river monster: baiji dolphin

The baiji dolphin is an endemic aquatic animal in the middle and lower reaches of the Yangtze River in China. There are more than 70 species of dolphins in the world, and only 5 species of freshwater whales. China is the only freshwater whale with a narrow distribution, which is older and rarer than the giant panda. Baiji dolphin has a graceful figure, smooth skin, a sword-like kiss and a spindle shape. Eyes as small as beans, ears as small as needles, there are more than 130 small teeth in the upper and lower jaws, and there is a round nostril in the upper left of the head. Although its audio-visual ability is not good, its sonar system can get in touch with its companions more than ten kilometers away through ultrasonic echo positioning.

Soul of China: South China Tiger

South China Tiger, English for "Chinese Tiger", is a subspecies endemic to China. It was originally the most widely distributed tiger species in China, with the largest number, the smallest size and the oldest qualification. There is only one kind of tiger in the world, both of which are produced in Asia. In the last century, there were eight subspecies of Bengal tiger, Northeast tiger, Java tiger, South China tiger, Lihai tiger, Bali tiger and Sumatra tiger, but the last three subspecies became extinct one after another. China's Xinjiang tiger (which subspecies is unknown) became extinct in the early 20th century.

Pearl of the Orient: Zhu

To ask what is the rarest bird in China, crested ibis should be among the best. This beautiful wading bird was praised by zoologists as the "Oriental Pearl" and was once considered extinct. They were originally endemic to East Asia and only distributed in China, Korea, Japan and Russia, but all of them disappeared after 1960s. Did Zhu really disappear? In the late 1970s, ornithologists in China began to look for crested ibis. 198 1 year, two nests of ***7 crested ibis were finally discovered in Yaojiagou, Yangxian County, Shaanxi Province, which caused a sensation in the world.

A national bird: brown eared pheasant

Brown eared pheasant is a rare bird, which is found in Pangquangou, Shanxi, China, Xiaowutai Mountain, Hebei and Mentougou, Beijing. Because its ears are like long horns and have two white ear feathers, some people call it horn chicken or ear chicken. The tail feather hangs down like a ponytail, hence the name horse. There are four species of Equus, all of which are produced in China, namely kurama, White Horse, Blue Horse and Brown Horse. Many zoologists suggest that brown eared pheasant should be regarded as the national bird of China. At present, brown-eared pheasant is an "endangered" species in IUCN Red Book, which is a national first-class protected animal.

Heritage species: alligator sinensis

Chinese alligator is the only crocodile species in China. There are 25 kinds of crocodiles in the world, and China only has bay crocodiles and Chinese alligators. However, as the largest crocodile (10 meter long), the Gulf crocodile became extinct hundreds of years ago. The Chinese alligator is unique to China and the only surviving species distributed in temperate zones from ancient north.

Plateau god bird: black-necked crane

Black-necked crane is the only plateau crane in the world, a god bird in the eyes of Tibetan people, and the latest crane recorded among 15 kinds of cranes in the world. On 1876, it was discovered in Qinghai Lake, China by Russian explorer Puge Varski. Black-necked cranes breed in Tibet in summer, migrate to Yunnan and Guizhou in winter, and a few fly over the Himalayas to Bhutan for the winter.

Snow wyndell dichinson: Tibetan antelope

Tibetan antelope has attracted worldwide attention in recent years. The main reason is that the consumption demand of the western fashion circle "shahtoosh" since 1980 has stimulated poachers to kill for money. In addition, some gold miners are also killing on a large scale, resulting in a decrease of nearly 10,000 Tibetan antelopes living in extremely cold areas, reaching the limit of their lives. In order to crack down on poaching, the forestry police, the anti-poaching force in Qinghai, Xinjiang and Tibet, have been fighting for the protection of wild animals such as Tibetan antelope in recent years, among which the "Wild Yak Team" is the best, and two of them have dedicated their lives to it.

Take it back: four are different.

"Four Elephants" is the common name of elk. As a unique wetland deer in China, it became extinct in China in 1900. Fortunately, there are a few in Europe, and after a century of protection, the population has been restored. Elk is a wetland animal. Due to the adaptation to the wetland habitat, a special form has been formed, that is, the so-called "four unlike", with horns like deer instead of deer, face like horse instead of horse, hoof like cow and tail like donkey. Elk is a national first-class protected animal, and IUCN Red Book of IUCN is extremely dangerous. Tibetan antelope in China

Three species go extinct every hour.

A research team led by Jeremy Thomas of the British Center for Ecology and Hydrology reported in the recently published Science magazine that in the past 40 years, the species of native birds in Britain have decreased by 54%, the species of native wild plants by 28% and the species of native butterflies by 7 1%. Insects, which have always been considered to have a large number of species and strong adaptability, are also facing extinction.

Scientists infer that the earth is facing the sixth mass extinction. Dr. Jiang Zhigang, chief researcher of Institute of Zoology, Chinese Academy of Sciences and executive deputy director of China Endangered Species Science Committee, also believes that from the perspective of nature conservation biology, since the industrial revolution, the earth has entered the sixth extinction period.

According to statistics, 75 species are extinct every day and 3 species are extinct every hour in the world.

If we extend the butterfly survey to other insects in Britain and invertebrates on the whole earth, we are obviously facing a serious biodiversity crisis.

A species refers to a natural group of individuals who can mate with each other and produce fertile offspring. Extinct species are those that have not been clearly found in the wild in the past 50 years. "Mass extinction is not only the extinction of one species, but the extinction of many species in a relatively short geological history, that is, hundreds of thousands or millions of years." Dr Jiang Zhigang said.

Thomas said: "Insect species account for more than 50% of the global species, so their mass extinction is bad news for the biodiversity of the earth."

Since the industrial revolution, many species have appeared on the earth, such as great auk, North American passenger pigeon, South African spotted donkey, Bali Lake in Indonesia, Australian marsupial, Zhili macaque, Alpine antelope, Platts wild horse, Taiwan clouded leopard and so on. According to the Red List of Endangered Species published by IUCN, there are still 1/4 species of mammals, 1.200 species of birds and 30,000 species of plants in the world at present.

The first five extinctions are natural.

Since multicellular organisms were born on the earth 600 million years ago, there have been five mass extinctions.

The first mass extinction on the earth occurred at the end of Ordovician 440 million years ago, and about 85% of the species became extinct.

About 365 million years ago, in the late Devonian, the second extinction occurred, and marine life suffered heavy losses. The third extinction occurred at the end of Permian about 250 million years ago, which was the largest and most serious in the history of the earth. It is estimated that 96% of species on the earth are extinct, including 90% of marine life and 70% of terrestrial vertebrates.

The fourth time happened 65438+85 million years ago, and 80% of reptiles became extinct. The fifth time happened in the Cretaceous period 65 million years ago, which is also a well-known one. The dinosaurs that ruled the earth for 65.438+600 million years became extinct.

The first five mass extinctions were mainly caused by geological disasters and climate change. For example, the first mass extinction was caused by global climate cooling, and the one that happened at the end of Cretaceous was that an asteroid hit the earth and caused the global ecosystem to collapse.

The sixth extinction was the culprit.

At present, the sixth mass extinction is going on, and human beings have become the culprit. Experts believe that it is difficult to say whether humans will be included.

Dr Jiang Zhigang does not deny that species extinction is a natural law from an evolutionary point of view. For example, the giant panda population is currently in decline. However, since the emergence of mankind, especially since the industrial revolution, the population of the earth has been increasing and more and more means of subsistence are needed. The scope of human activities is getting bigger and bigger, and there are more and more disturbances to nature. In this way, a large number of forests, grasslands and rivers disappeared and were replaced by roads, farmland and reservoirs. ...

The natural habitat of living things is fragmented by traces of human activities. "Every road is an insurmountable obstacle for animals. Even the butterfly populations distributed on both sides of the road are isolated and no longer fly around for gene exchange as before. " Dr. Jiang Zhigang said sadly, "Not to mention the large animals such as Tibetan antelope, lion and tiger." Some scientists estimate that in the past 200 million years, 90 species of vertebrates have become extinct every 100 years, and one higher plant has become extinct every 27 years. However, due to human interference, the extinction rate of birds and mammals increased by 1000 times, reaching1000 times.

Stuart Pim, a famous biologist at Duke University in the United States, believes that if species decrease at this rate, by 2050, a quarter to half of the existing species will be extinct or endangered.

It is difficult to produce new species.

Existing species are decreasing, but it is difficult to produce new species.

According to the fossil record, after each extinction, some new advanced groups were replaced. The rapid reproduction of mammals after the extinction of dinosaurs is a typical example.

But Dr. Jiang Zhigang believes that creatures are always evolving, and all the creatures we see now have evolved over a long period of time. So it takes a long time and a lot of space to produce new species. But now, under the management of people everywhere, the natural environment is getting worse and worse, and organisms have lost the environment and conditions for natural evolution. Species are constantly dying out naturally, but it is difficult to produce new species.

Just like a tiger, if it is given enough living space to hunt freely, it may evolve and produce a new species similar to a tiger, but now it is difficult for it to survive, let alone evolve.

The surface of the earth is a huge biosphere composed of all biological species such as animals, plants and microorganisms and their living environment, and human beings are one of them. A large number of creatures disappeared in the sixth extinction, but it is difficult to produce new species like the first five. The earth's ecosystem is far more fragile than we thought. When it is damaged to a certain extent, it will lead to the collapse of the system on which we live.

If the last moment doomed by human actions comes, will human beings become survivors?

The extinction of millions of species on the earth in 2050

Scientists from Europe, Australia, Central and South America and Africa have conducted a two-year study on the six regions with the richest biological species in the world, which account for 20% of the earth's surface area, and reached an amazing preliminary conclusion: due to global warming, in the next 50 years, 1/4 of the animals and plants on the earth's land will be devastated. They predict that there will be 1 10,000 species extinct on the earth in 2050.

According to scientists' research, because climate warming is a fait accompli, one tenth of the species that will be extinct are irreversible. But from now on, countries' efforts to control global harmful gas emissions will be able to save more species from the same fate.

Alpine creatures have a great chance of survival.

According to the research results of scientists, biological species living in high mountains are more likely to survive than those living in other areas, because in the case of global warming, species in this area can migrate to higher and cooler areas.

Those who live in flat areas, such as those in Brazil, Mexico and Australia, will have a very fragile living environment in the future. It is almost impossible for creatures in these areas to adapt to the changed climate and environment and have to move to areas thousands of miles away.

Birds have the greatest hope of survival.

In theory, birds are one of the most promising species to survive with their strong migration ability. In order to find a more suitable area, birds can fly long distances, but due to the deterioration of natural conditions such as forests, they may not be able to find a truly suitable natural environment for survival. As a result, you can only face death.

Professor Thomas, a conservationist from the University of Leeds, one of the members of the above-mentioned research team, said: "Scientists all hope to reach a clear conclusion when conducting scientific research.

However, I really hope that we haven't reached the conclusion we have reached. The fact is far more serious than we thought, and our conclusion may underestimate the cruel living environment faced by biological species. "

12 species of butterflies in Australia will disappear.

Another amazing discovery of scientists is that half of the 24 species of butterflies that have been studied in Australia will disappear forever in the coming years.

In South Africa's major biological reserves, 60% of the protected biological species are in danger of extinction. In the savanna area of central and western Brazil, which accounts for one fifth of Brazil's total area, research shows that more than 70% of the 163 trees in this area will be extinct. Many of these plants are rare species endemic to this area.

Europe is the least affected

Europe is the region where the natural environment is least affected by global climate change. The survival probability of animals and plants in this area is greater than that in other parts of the world. Even so, under the influence of climate warming, a quarter of the birds and 1 1% to 17% plants in Europe will gradually become extinct in the future.

Studies in Mexico show that plants and animals in plain and arid areas are most affected by climate warming. Once the climate changes slightly, these animals and plants need to migrate far away to find a new environment suitable for survival. Of the 65,438+0,870 species of animals and plants studied in this area, one third will face survival crisis in the future.

News link scientists put forward "gender imbalance theory"

Xinhua News Agency, Washington, April 2 1 Sunday. According to the popular view in the scientific community, the extinction of dinosaurs was caused by the impact of alien objects on the earth. However, there are different opinions about the consequences of the impact of alien celestial bodies directly accelerating the extinction of dinosaurs. For example, British and American researchers put forward a new view that the climate cooling caused by the impact of alien celestial bodies may cause more males and fewer females in dinosaur offspring, and dinosaurs will eventually go to a dead end because of "gender imbalance."

Professor david miller of Leeds University and his colleagues pointed out in the new issue of American magazine Fertility and Sterility that the sex of offspring of mammals, birds, snakes, most lizards and some fish is determined by chromosomes or genes. In mammals, for example, the offspring who inherit two X chromosomes are females, and the offspring who inherit one X chromosome and one Y chromosome will be males. However, some reptiles living on the earth at present, such as crocodiles, turtles, etc., the environmental temperature of their eggs will affect the sex of their offspring. Researchers say that the sex of some extinct species, such as dinosaurs, is probably determined by the temperature at which they hatch.