Biodiversity（biodiversity）It refers to the stable and regular combination of various living organisms (animals, plants, microorganisms) within a certain rangeEcological complex。 This diversity includes animals, plants and microorganismsSpecies diversity, speciesHeredity and variationDiversity andecosystemDiversity.Among them, species diversity is the key to biodiversity, which not only reflects the complex relationship between organisms and the environment, but also reflects theBiological resourcesThe richness of.Humans already know that there are about 2 million kinds of organisms, and these various biological species constitute the diversity of biological species.
Biodiversity is formed by organisms and their environmentEcological complexAnd various relatedEcological processBy genetic diversity,Species diversityandEcosystem diversityAnd other parts.Genetic diversity isRefers to living thingsTrait determiningGenetic factorAnd the diversity of its combination.Species diversity is the manifestation of biodiversity in species, which can be divided into regional species diversity and community species (ecological) diversity.Ecosystem diversity refers to the habitatBiomeAnd the diversity of ecological processes.Genetic (gene) diversity and species diversity are the basis of biodiversity research, and ecosystem diversity is the focus of biodiversity research.
Someone asked, "What are the characteristics of the creator's work that can be inferred from the study of nature?" British scientist John Bolton Sanderson·Haldane(J.B.S. Haldane) replied, "I like beetles too much." Because beetles are the largest on the earthfauna。Terry Owen of the Smithsonian Institution（Terry Erwin）It is inferred that most unknown beetle species may live in the 30 meter hightropical forests treecanopy。Biodiversity will directly affect gene diversity.
Three levels
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It is generally recognized that the three main levels of biodiversity areSpecies diversity、Genetic diversity(or calledGenetic diversity）AndecosystemDiversity.These are the three basic levels for building biodiversity.Commonly used for species diversityspecies richness To represent.The so-called species richness refers to the total number of species in a certain area.By 2022, it has been described and namedBiological speciesThere are about 2 million species, but scientists' estimates of the total number of biological species actually existing on the earth vary greatly, from 5 million to 100 million species.Among theminsectAnd microorganisms account for the largest proportion.Genetic diversity representsgenetic structure Variation of.Each species includes several populations composed of several individuals.Due to mutationnatural selectionOr for other reasons, they are often genetically different.Therefore, some populations have gene mutations that are not found in other populations（Allele）, or a very rare allele in one population may appear many in another population.These genetic differences makeOrganismIt can reproduce and adapt more successfully under specific conditions in local environment.Not only are the genetic characteristics of different populations of the same species different, that is, there areGenetic diversity；There is also genetic diversity within the same population - some individuals in a population often have gene mutations.The genetic diversity within this population is evolutionary material.The population with high genetic diversity may have some individuals who can tolerate adverse changes in the environment andgenetic transmissionTo posterity.The accelerated change of environment makes the protection of genetic diversityBiodiversity protectionChina occupies a very important position.Genetic diversity providesCultivated plantanddomestic animals The breeding materials of the Chinese Academy of Sciences enable people to select individuals and populations with traits that meet people's requirements.Ecosystem diversityIt exists not only between ecosystems, but also within an ecosystem.In the former case, varioushabitat, distributed with differentecosystem；In the latter case, the community of an ecosystem consists of different speciesStructural relationship(including vertical and horizontalspace structure，Trophic structureThe relationships between predators and arresters, herbivores and plants, parasites and hosts, etc.) are diverse and perform different functions, so their roles in the ecosystem are also different.In short,Species diversityIt is the most intuitive embodiment of biodiversity and the center of the concept of biodiversity;Genetic diversityIt is the internal form of biodiversity, and a species is a uniquegeneIt can be said that every species is the carrier of gene diversity;The diversity of ecosystem is the external form of biodiversity. To protect biodiversity, the most effective form is to protect the diversity of ecosystem.
General characteristics
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China is one of the countries with the richest biodiversity on the earth.It occupies a very unique position in the world.In 1990, biodiversity experts ranked China as the eighth richest country in the world in terms of biodiversity.stayNorthern HemisphereAmong countries, China has the richest biodiversity.The characteristics of biodiversity in China are as follows:
1. High abundance of species.China hashigher plantMore than 30000 species, second only to the world's most abundant higher plantsBrazilandColumbia。
2. There are many endemic genera and species.Among the higher plants in China, there are about 17300 endemic species, accounting for more than 57% of the national higher plants.Among 581 mammalian species, there are about 110 endemic species, accounting for about 19%.It is particularly noticeable thatliving fossilSo-calledpanda、Baiji dolphin、metasequoia、ginkgo、Cathaya argyrophyllaandcycas panzhihuaensis , etc.
4. Cultivated plants, domestic animals andWild relative speciesOfgermplasm resource Extremely rich.China has a history of thousands of years of agricultural reclamationRich and colorfulOfgenetic resources As a result, China's cultivated plants and domestic animals are unique and unparalleled in the world.For example, instate-owned economyMore than 1000 species of trees.It is one of the places of origin of riceLocal variety50000;It is the hometown of soybean, with 20000 local varieties;yesmedicinal plantMore than 11000, etc.
Biodiversity is also related to our health and the health of the planet.In fact, the relationship between your health and the health of the planet is inseparable.
When we are sick, we rely onnatural environmentTo help us recover.For many years, people have searched the natural world for treatment of injuries and diseases.Plants provide effective ingredients for modern medicine, such as productionaspirinComponents of.HomeopathyOur medicine also makes great use of plant ingredients.From the perspective of money, it is impossible to calculate the value of medicinal plants.The total value of these plant-based drugs in the world is about 600 billion dollars.
Biodiversityeconomic valueMost people do not understand this, but scientists in pharmaceutical companies are busy looking for specific drug ingredients from plants to treat certain diseases.Not long ago, experts were in the PacificYewAnd Madagascar catharanthus for treatmentcancerThe plant ingredients of.Maybe one day we can find the plant ingredients that kill HIV from a plant.
traditional medicine Our doctors rely on plants andHerb treatmentThe disease has been going on for a long time.In modern times, people also appreciate the efficacy of traditional medicine.For example, the eastAfricaWhen Maasai people make meat, milk or blood products in their traditional way, they will add some bark, which can reducecholesterol。
However, the harvest of medicinal plants and animals is not all good.In fact, the demand for these plants and animals leads to the endangered species.For traditional medicinetortoiseThe use of medicine has led to the extreme decline of this species.
We repeatedly searched the medicine cabinet of the earth for medicine.We need to protect biodiversity, so that the medicine cabinet of nature can store the ingredients of existing medicine and the ingredients needed to manufacture new drugs when we need to resist new diseases in the future.
breathing
In some cities, especially in summer, it is unhealthy to breathe outside air.We know we have to reduceAutomobile exhaust pollution, waste gas pollution from factories and air pollution from power plants to ensure modern life.Yes, we all know that, but do you know what role biodiversity plays in the automatic cleaning of the environment?Do you know that biodiversity helps clean the air?
However, we continue toCutting down trees, cut them up and transport them everywhere.In the world, 492 tree species are in danger of extinction.We have cut down about half of the trees that used to decorate the earth.We cut down trees but do not repair them, which has damaged the lungs of the earth.It's like smoking 10 packs of cigarettes a dayDrug addict, smoking all the time, and the damaged lungs were cut off piece by piece.How big is our lung?
In addition, in many places, we introduce alien invasive species.In the past 200 years, we have transported some tree species from one end of the world to the other.Some of these behaviors have developed to an industrial scale, such aseucalyptusAnd rattan.There are also some retirees or tourists who bring native plants or trees from their hometown to travel with them.
The problem is that these plants are completely adapted to their original growing place, but they are not adapted to the new place.They may need more water than local species, or pesticides to help them avoid being eaten by local insects.
We must respect the arrangement of nature and not force changes in certain characteristics.let nature take its course.In this way, the earth's lungs can breathe more comfortably.
Water
All life is inseparable from water, so biodiversity is also related to water resources.
Because we only have limited water -- not that we can transport a ship from Mars any time in the future -- biodiversity, special differencesecosystemPurify our water: forests, soil and bacteria, streams and clouds work together -- in fact, it is filtering that makes us drink water again.Without biodiversity, the world would become barren and poisoned -- more like Mars -- and then we would not be able to regenerate on Earth.
So the question is, are you ready to move to another planet?
Biodiversity, climate and disasters
Are you aware that we have been experiencing strange weather recently?
The scientific evidence is irrefutable: the earth's climate is changing.Strange things have been happening all over the earth -- coral reef death, large-scaleDebris flowUnusual heavy rain and continuous drought in some areas.Whether due to industrial emissions or natural factors, the world'sCoping mechanismThey are still closely linked fromecosystemIt extends to all kinds of life in the ecosystem.
For example, in many places on the earth, people find that when they cut down forests, their villages and towns are vulnerable to floods.When this kind of flood comes, it is more fierce and faster than previous floods.Why?It is not the thrust of rockets that makes them faster, but because trees can use their roots to conserve water and soil.Roots absorb water in wet season and release water in summer.This is a kind ofNatural regulationmethod.
At present, you have two choices:
1. Help protect biodiversity and the habitat environment of organisms.
2. Do nothing but bear all the consequences.
We want you to choose the first item.That's what we did!
Similarly, people do not consider biodiversity at all, or even the risk that storms may causeCoralmangroveClear All.Mangrove is a good buffer zone for natural rainstorm, and is also rich in biodiversityecosystem。When they are cut down, the buffer zone no longer exists, whether for humans or other species.
When we ignore the lessons we should learn, the practices of people in the world lead to the following results: the slope collapses, the entire community is washed away, resulting in the loss of life.The loss of biodiversity is also hurting our human beings in an extremely sad way.Maybe now is the time for us to pick up the lessons we should have learned long ago.
Value significance
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Biodiversity: the main meaning isThe value of biodiversity。For human beings, biodiversity has directuse value, indirect use value and potential use value.
(1) Direct value: living things provide food, fiber, building and furniture materials and other industrial raw materials for human beings.Biodiversity andaesthetic value It can cultivate people's sentiment and beautify people's life.If there were no colorful plants and animals with different looks in the world, people's travel and rest would be dull.It is the magnificent and beautiful mountains, rivers and colorfulFlowers, birds, fish and insectsTogether, the beautiful scenery is pleasing to the eyes and unforgettable.In addition, biodiversity can also inspire people's literary and artistic creation.
(2) Indirect use value: indirect use value refers to the importance of biodiversityEcological function。Either wayecosystemWildlife is an indispensable component.In the ecosystem, wildlife has a relationship of interdependence and mutual restriction, and they jointly maintain the structure and function of the ecosystem.Once the wildlife is reduced, the stability of the ecosystem will be destroyed, and the living environment of human beings will also be affected.
(3) Potential use value: As far as medicine is concerned,developing country80% of the population depends on traditional medicines provided by plants or animals to ensure basic health;40% of the drugs used in western medicine containWild plantSubstances found in.For example, according to a recent survey, more than 10000 kinds of herbal medicines are used in traditional Chinese medicine.There are many kinds of wildlife, but only a few of them have been fully studied by human beings. The use value of a large number of wildlife will not be known until 2022.But it is certain that these wild creatures have great potential use value.Once any kind of wild life disappears from the earth, it cannot be regenerated, and its various potential use values will disappear.Therefore, wildlife whose potential use value is not clear at present should also be treasured and protected.
-Since the birth of human beings, the population has been growing.When the productivity is backward, the population is affected by natural factors such asdrought、Insect plagueControl of fire, flood and earthquake;In addition, human disasters such as war and poverty also makepopulation sizeCan be controlled. However,Modern science and technologyThe progress of has increased the number and life span of people
-19th centuryindustrial revolutionSince then, population growth has become the mainstream of the world, most obvious in developing countries.The global population was only 1 billion in 1830, 2 billion in 1930 and 6 billion in 2000
-China had a population of about 300 million in 1790, 400 million in 1860, 800 million in 1970 and more than 1.3 billion in 2000
-After the population increases, it must be expandedCultivated land area, meet the needs of eating, so thatNatural ecosystemAnd the living biological species in it
-Due to the rapid population growth and policy mistakes such as the Great Leap Forward, China has formed a large number ofDegraded ecosystem。At present, the area of water and soil loss in China is about 1.8 millionsquare kilometre, accounting for 19% of the land area, of whichThe Loess PlateauAbout 80% of the local water and soil loss
-Northern Desert, GobiDesertified landIt covers an area of 1.49 million square kilometers, accounting for 16% of the land area. In 1987, 200000 square kilometers of desertified land had been desertified,Potentially desertified land130000 square kilometers
-At present, 59 million mu of farmland and 74 million mu of grassland are threatened by desertification.The shrinking area of grassland is 1.3 billion mu, increasing by 20 million mu every year.The pesticide control area is 2.3 billion mu per year, poor qualityChemical fertilizer pollution25 million mu of farmland.
-Daily (1995) ranked human activities that caused ecosystem degradation and biodiversity reduction: over development (including direct damage and environmental pollution) accounted for 35%, deforestation accounted for 30%, agricultural activities accounted for 28%, and over harvestingFuelwoodAccounting for 6%, and biological industry accounting for 1%.The first three human activities account for 93%, and the most intuitive result of these damages is the fragmentation of species habitats and the islanding of habitat environment
-The degree of biodiversity reduction depends onecosystemThe degree to which the structure or process of the plant is disturbed, such as human interference in the process of obtaining resources (such as excessive irrigation affecting the plantWater cycle, effect of excessive fertilizationBiogeochemical cycle）It should be greater than the negative effects caused by direct interference (such as logging or hunting) of producers or consumers
-Generally, if the disturbance is removed before the ecosystem components are completely destroyed, the degradation of the ecosystem will stop and begin to recover (such as the restoration of a small amount of deforestation), and the biodiversity may increase;But in the ecosystemFunctional processIf the disturbance is eliminated after the destruction, the degradation of the ecosystem is difficult to stop, and may intensify (for example, forest land restoration after burning mountains).
Cause 3: Environmental pollution
-With the development of human beings, environmental pollution has also intensified.Environmental pollution will affectecosystemThe structure, function and dynamics of all levels lead to ecosystem degradation.At present, there are two basic views on the impact of environmental pollution on biodiversity: one is that biodiversity will be lost due to the great limitations of organisms in adapting to sudden pollution;Second, pollution will change the original evolution and adaptation mode of organisms, and biodiversity may develop under the conditions dominated by pollution, thus deviating from its natural or conventional trajectory.Environmental pollution will lead to the reduction of biodiversity at three levels of heredity, population and ecosystem
-Influence at the genetic level.Although pollution will lead to resistance adaptation of organisms, it will eventually lead toGenetic diversityDecrease.This is because the population'ssusceptibilityThe individual disappears, and these individuals are characterized bygenetic variationTherefore, it disappears, leading to the reduction of genetic diversity of the whole population;The population size is reduced due to the randomGenetic driftThe increase of may reduce the level of genetic diversity of the population;Pollution causes the population to decrease, so that the population genetics is reachedthreshold Even if the population finally recovers to the original population size, the source of genetic variation will be greatly reduced
-Impact at the population level.Species exist in the form of population. Recent research shows that when the population exists in the form of composite population, the pollution in some place will lead toSubspeciesDisappeared, and due to the pollution of the habitat, the place is obviously no longer suitable for the invasion and settlement of another subspecies.In addition, due to the influence of various species on pollutionResistanceDifferent, some species will disappear, while others will survive, but the final result is localspecies richness Will decrease
-OnecosystemLevel of influence.Pollution will affect the structure, function and dynamics of the ecosystem.Serious pollution may haveConvergence, will be differentEcosystem typeEventually, it becomes a dead zone with almost no living things.General pollution will change the structure of the ecosystem, leading to changes in function.It is worth noting that heavy metal or organic pollution in the ecosystemfood chainFunction, there will beAmplification effectWill eventually affect human health.
-Alien speciesLiterally speaking, the invasion of the "" has increased the biodiversity of a region. In fact, those harmless creatures in history have also expanded their distribution through human efforts. Some domesticated crops or animals have become friends of human beings, such as potato in our foodTomatoes、sesame, pumpkinSweet potato, celery, etc;In treeslocust, SycamoreThe torch tree；animal feedAlfalfa;AnimalRed trout、bay scallop The benefits of these species entering foreign countries outweigh the harm.
-However, forecological equilibriumIn terms of biodiversity, biological invasion is after all a process of disturbing the ecological balance, because the ecological balance and biodiversity in any region are the result of billions of years of evolution. Once this balance is disturbed, it will lose control and cause harm
-When people first introduced species, they only entered the country of originecosystemA component of,Food webThere is no way to introduce some natural enemies or the species it controls, so if it is not well controlled, it is inevitable to cause disasters, and one of the direct consequences of disasters is to the localEcological diversityIt may cause harm or even disaster.
Related protection
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Vigorously developEcological engineeringWe should pay attention to environmental protection while developing the economy. We should not follow the old routine of pollution before treatment, but develop new technologies and improve resourcesUtilization, developing emergingclean energy, reduce dioxideCarbon emissionsAnd make it suitable for the local conditions, combine the geographical characteristics with economic developmentEcological economyEcological development is conducive to maintaining biodiversity.
Before the emergence of mankind, the extinction of speciesspeciationIt is a natural process, and the two are relativeEquilibrium state。It is estimated that the rate of natural extinction of species is only 90 per 100 yearsExtinction of species。Since the emergence of mankind, especially in the past hundred years, with the growth of population andhuman activityThe speed of species extinction has been greatly accelerated.withmammalFor example, in the 17th century, one animal died out every five years, and in the 20th century, one animal died out every two years（Xu Zaifu，1991）。JustbirdsIn the early Pleistocene, one species died out every 83.3 years, while in modern times, one bird died out every 2.6 years（Xu Weishu，1992）。staythe indian ocean、AtlanticThe extinction rate of endemic birds living on some islands was 8 species from 1601-1699, 21 species from 1700-1799, 69 species from 1800-1899, and 63 species from 1900-1978（King,1980）。At present, biodiversity is losing at an unprecedented rate.According to the estimation of foreign scientistsSpeed ratioBefore human intervention, natural extinction was 1000 times faster（Wilson，1988）。Taking birds as an example, among the more than 9000 kinds of birds in the world, only 290 kinds of birds were threatened with extinction to varying degrees before 1978, but now the number has risen to more than 1000 kinds, accounting for about 11% of the total number of birds.according tothe United NationsUNEP estimates that 25 per cent of the Earth's total biodiversity will be in danger of extinction in the next 20-30 years.Between 1990 and 2020, the species lost due to deforestation may account for 5-25% of the total species in the world, that is, 15000 to 50000 species will be lost every year, or 40-140 species will be lost every day.The disappearance of a large number of species from the earth has causedinternational societyExtensive attention.How to take effective measures to save these gradually dying species has become an important research content.
