You see for yourself:
■2. Destruction and Reconstruction
More than 200 years ago, the French philosopher Chateau Briand said, "The forests and prairies of the barbaric period have become deserts in the period of civilization." Someone else also said, "Humans walk across the earth, leaving deserts in their tracks." This is an overstatement, but it is not without truth. The ecologist Horuwer, faced with the desertification of a large area of fertile land, also said this: "Deserts are caused by man, the climate only provides the right conditions." However, mankind is smart, can learn from failure, the ecological destruction to rebuild, man is ultimately able to win.
There are many examples, both ancient and modern, that tell us that mankind is not completely helpless against the deteriorated ecology. With science and human efforts, nature can be revitalized, and pollution can be cleaned up again.
Soil erosion can be stopped. In the past, it is believed that the ecology of the tropical rainforest is very fragile, after being destroyed, due to the erosion of rainwater, it is very difficult to recover. China's southern tropical and subtropical red soil areas, soil erosion is indeed very serious. According to the 11 southern provinces and regions survey statistics, soil erosion area has reached 690,000 square kilometers, accounting for more than 30% of the land area. The topsoil washed away each year is up to 1 centimeter thick. The surface of the ground has been eroded by typhoons and rainstorms for many years, and some of it has been slabbed and some of it has been sanded, leaving only a layer of red weathered crust. Ground gullies and gullies, gravel everywhere, not an inch of grass, rich tropical rainforest into a barren land. These barren land can grow forests again, must go through the evolutionary process from herbs to shrubs, from shrubs to tall trees, without thousands of years, the ecology is impossible to recover.
People can recognize nature, can heal nature's wounds, can accelerate the pace of natural recovery. The South China Institute of Botany of the Chinese Academy of Sciences and the Shuiliang Soil and Water Conservation Experiment and Extension Station in Guangdong's Dianbai County have successfully rebuilt more than 6,000 mu of artificial forest communities. In order to accelerate the natural succession process of plant communities, they adopted the reconstruction of previous tree communities, configuring multi-level and multi-species broad-leaved mixed forests, to achieve the purpose of shortening the length and accelerating the recovery. Now, in the artificial forest community, trees, shrubs and herbaceous plants grow interlaced. The amount of surface sediment scouring, deserted slopes when more than 1,000 kilograms per mu per year, now only 0.2 kilograms per mu, the soil organic matter content has increased greatly, the temperature variance is reduced, the humidity is increasing, the forest collected more than 400 kinds of insect specimens, more than 100 kinds of vertebrates, soil microbial fungi 38 kinds of soil microbial fungi, due to ecological improvement, the nearby rural rice mu yield by the past 50 ~ 100 kilograms increased to 700 kilograms now. Nature has finally regained its wonderful youth under the careful and loving care of mankind.
Serious pollution can also be eliminated, and the Thames River in Britain is a big river that has been successfully purified of pollution.
A century and a half ago, the Thames River water clean and clear, green water ripples, the water is clear to the bottom, the river in the rich aquatic supply of London's fish market later, the river on both sides of the cover of the factories, factories, sewage flow into the Thames River, soap factories, gas factories, tanneries, paper mills, the colorful dirty water flowed into the river, the Thames River has gradually turned into a seriously polluted river.
The Thames gradually became a heavily polluted river.
Dr. Alvina Wheeler, a biologist at the British Museum, visited the Thames in 1957 and found that in a 20-mile stretch of the Thames, there was no oxygen for nine months of the year, and there was no life from London to Graveside, no insects, no fish, and then even the birds were extinct. The Thames began to emit an unpleasant stench, and sometimes even the windows of the riverside Houses of Parliament had to be hung with sheets permeated with disinfectant water.
Beginning in 1961, Britain began to treat the river in earnest, with sewage treatment plants built in factories along the river, treating 200 million gallons of sewage a day and removing the 5 million tons of sludge left over from sewage treatment every day.
After a long period of treatment, the river became clearer, the oxygen in the river water reached 36%, the river grew water plants, fish groups reappeared, spread a net, a pull up the heavy fish nets, nets are full of river shrimp, lobster, mussels, crabs, perch, red-footed, sandpipers, geese, geese, black geese, magpie ducks, etc. in the winter here birds amounted to more than 10,000, and even swans are also in the river to find food peacefully. The Thames has been resurrected and is once again teeming with fish and tourists.
Deserted land can be turned back into an oasis. Over the years, the desert has launched one attack after another, burying fields, devouring villages and destroying cities. This is the portrayal of the harm caused by wind and sand.
However, the desert can also be managed. China's Yulin people rely on planting grass and trees, so that a large number of deserts into farmland and pasture.
Yulin area is located in the north of the Loess Plateau in the northwest of the southern edge of the Mao Wusu Desert, the ancient Great Wall across it, the north side of about 25.6 million acres of area in the wind and sand area. Historically, it used to be a lush agricultural and pastoral area, with the Tang after the excessive reclamation and successive wars, the vegetation has been a lot of damage to the sand is becoming increasingly serious. 1949 around the time, the desert sand has crossed the Great Wall line of 10 kilometers, and with the speed of 3 ~ 8 kilometers per year continue to the south of the tight. Yulin people in more than 7 million acres of deserted sand, deserted beach planting grass heavy trees, green deserted sand, by the end of 1983, the region's cumulative area of artificial forest and grass preservation of 16.63 million acres, has now made more than 10,000 acres of patches of 62 pieces of forest. In addition, also along the Great Wall to create a total length of more than 850 kilometers of three large-scale protective forest belt, in the Yellow River along the completion of 2.7 million acres of red east forest belt, in the territory of the highway on both sides of the cultivation of 170,000 acres of apple forest belt. The vegetation coverage rate of the whole region has reached 21%, and the average wind speed has been reduced by 49%. 8.62 million mu of quicksand in the whole region have been basically fixed or semi-fixed to more than 5.5 million mu, of which 520,000 mu have been transformed into good land.
Dongshan Island's dramatic change is a vivid example: Dongshan Island is an island in southern Fujian, an area of 192.5 square kilometers, is the second largest island in Fujian Province. 30 years ago, the island of sand dunes rolling, sand rolls, can not plant a place to cook no firewood to burn, there is only a highway, every time the wind will not be able to get through the wind, the wind up sand, the highway is suddenly piled up up as high as 1 ~ 2 meters of small sand dunes. The local folk have this saying: "Dongshan Island bad place, sandy winds and low rainfall, groundnut more rice less." Examination of history can be seen, nearly 100 years, the whole island was swallowed by the wind and sand in 13 villages, more than 1,000 houses, buried more than 30,000 acres of good land, so people left their homes, living in other places.
Dongshan Island is surrounded by the sea, belonging to the southern subtropical maritime monsoon climate. According to statistics, the annual rainfall is also about 1,000 millimeters, and is not a desert climate then dunes all over the landscape and where does it come from? People from the history books to find the reason, it turns out that Dongshan Island has always been a key place of sea defense, Yuan, Ming, Qing three but there are heavily guarded, frequent military activities, making Dongshan's forests constantly being destroyed, to the beginning of the founding of the country, Dongshan Island has not a few shade banyan trees, only a little wind and water forests. So, the wind together, flying sand, dust, sand on the wind, wind to help the sand Wei, Dongshan Island this sand.
Thirty years later, Dongshan Island is simply a different world. The barren slopes of the mountains, rolling sand dunes, dusty sand is gone, replaced by green forests, lush crops, lush mountains, blue Cham reservoir. This is the achievement of the military and civilians of Dongshan Island after 30 years of hard work, planting trees, drilling wells to find water, building reservoirs, and transforming sandy areas. The forest coverage rate has increased from 0.6% in the early days of liberation to 36.5%, and Dongshan Island has been re-dressed in green and full of vitality.
Dongshan Island's present and past changes, once again tell us a truth: deserts are made by people, oasis is also created by people, the climate is only to provide the right conditions.
Some special ecology that has been destroyed can be restored through people's efforts. The Galapagos Islands, once devastated, are now restored to their natural ecology through the efforts of people.
The Galapagos Islands, located in the ocean east of Ecuador, are a research base for the theory of the evolution of species. Darwin, the founder of the theory of evolution, carried out detailed research here, providing rich material for the masterpiece "On the Origin of Species," which is why UNESCO calls it an "international heritage site.
The Galapagos Islands are also the world's largest natural museum. Thanks to the unique natural conditions, the islands are home to penguins from the Antarctic, seals from the Arctic, lizards and giant tortoises endemic to the Equator, as well as a variety of rare birds, and animals from all continents and all corners of the world.
But with the increase of immigrants and the breeding of domestic animals, the natural ecology has been seriously damaged. Goats have eaten the island's shrubs, and giant tortoises, flamingos and seals are in danger of extinction. This international heritage is under serious threat.
In order to save this precious international heritage, the island's scientists first of all on the ecological destruction of the culprits - goats for the siege, a **** annihilated 50,000 head of wild goats, thus protecting the island's vegetation. Artificial insemination and artificial feeding methods were also used to breed giant tortoises and giant eagles, which greatly increased the number of these endangered animals. Today, the island is full of green trees and birdsong, and this "international heritage" has regained vitality.
■3, the local and the whole
Nature is a harmonious whole, everything has a harmonious connection with each other, a system, between organisms and organisms, between organisms and inorganic world, between macro-organisms and micro-organisms; between the environment and human beings are a harmonious whole. Between them, they have a certain structure, relying on the flow of matter and energy to connect with each other, constituting a whole. In dealing with the relationship between man and nature, it is necessary to establish a solid overall concept, to correctly deal with the relationship between the local and the whole.
DDDT is a kind of insecticide invented by human beings, which has made great achievements in the struggle between human beings and pests, and the inventor has won the Nobel Prize. But today, after weighing all its merits and demerits, it has stopped production and use. Such decisions are the result of a holistic approach.
In 1874, a German chemist synthesized DDT, but for a long time, did not know its role. 1940, the Swiss scientist Paul Müller discovered its role, with which it quickly controlled the damage of the potato beetle.
In 1944, the city of Naples, Italy, an epidemic of typhus, doctors were at their wits' end, and then used DDT, two or three days to control the spread of DDT, so DDT has been widely used, and has become the world's best-selling pesticide, which has an annual production of 400,000 tons of organochlorine pesticides of the same kind are also produced in large quantities.
But DDT is a poison, it has stable chemical properties, the residue is 80% after one year, they enter the rivers, lakes and seas, inhibit the growth of algae, and poison fish, shrimp and shellfish. Carp will die within 48 hours when the level of DDT in the water reaches 1.1/1 million, and DDT can kill 100 percent of crabs at concentrations just over 5/10 billion.
Increased levels of DDT in the water jeopardize both aquatic life and the safety of birds that feed on fish. DDT inhibits birds from reproducing, causing them to lay abnormally thin-shelled eggs or even produce offspring at all. An earlier survey of 37 countries found 118 species of wild birds with DDT in their bodies, and some predatory birds, such as bald eagles, falconry eagles, herons and pelicans, have died in large numbers, with some already in danger of extinction.
Pollution from organochlorine pesticides such as DDT will ultimately affect human health, as they enter the human body through various channels such as air, water, and food, and accumulate in human fat and liver tissue. Most of the food we eat today - cereals, fruits, fish, meat, eggs, vegetables, honey, tea, etc. - contains DDT, and even newborn babies are not spared because breast milk contains DDT. DDT damage to the human liver and central nervous system, inhibit the normal physiological activities in the body, DDT will induce cancer is not yet conclusive, but experiments have proved that organochlorine pesticides on mice have carcinogenic effect.
The use of DDT temporarily reduces insect and cold damage, but after a period of time, pests and diseases will still come back, come more fierce. It turns out that in nature, various organisms are interdependent and constrained by each other, and there exists a marvelous relationship of ecological balance. Many pests have their own natural enemies, such as the seven-star ladybug beetle to eat cotton aphids, red-eyed wasp parasites in the pine caterpillar body and so on. DDT and other agents kill pests, but often also kill their natural enemies, and even these natural enemies are more vulnerable to attack, and as a result, some pests lose their original ecological control, multiply rapidly, and explode into a plague.
Now, there is hardly a place on earth where DDT cannot be found. Air, soil, water, living things, everywhere has become their hiding place, even the deserted North and South Poles and the year-round snow Himalayas, there are also its molecules ghost-like wandering. The Eskimos, who live in icy Greenland, have never used or touched DDT, but traces of it have been found in them today.
From a local point of view, DDT has been very effective in preventing and controlling insect pests; from a holistic point of view, it pollutes the environment, kills the natural enemies of insect pests, contributes to the harm of insect pests, and through the chain of life, harms birds, fish, animals, and finally harms human beings. Therefore stopping the production of this pesticide is totally necessary.
■4. Needs and Possibilities
Human beings are both positive factors in regulating the relationship between man and nature and culprits in deteriorating the relationship between man and nature. Forest reduction, soil erosion, biological extinction, atmospheric pollution, etc., in the final analysis are caused by human activities. In the final analysis, they are all related to population growth, which is a contradiction between the material production possibilities of human needs and environmental capacity. Human beings, while acquiring the necessities of life, will more or less have a negative impact on the environment. On the one hand, in order to survive, human beings have to take from nature, cutting down forests in order to heat their homes, build houses, and cook their food; burning and plowing for food; and hunting and killing wild animals for meat. On the other hand, the results of human activities also tend to cause pollution; human automobiles emit exhaust fumes, garbage pollutes the environment, and so on. In short, the size of the population and its rate of growth have a significant impact on the environment. When there are more people, there is more demand and faster consumption of resources. Once the demand of the population exceeds the possibility of material production, even some renewable resources, such as water and the atmosphere, lose their renewability. The more people there are, the more harm is done to the environment, and any remedies can only mitigate, but not eliminate, the impact of population growth on the environment.
Population growth can lead to overcultivation or overgrazing, which can lead to regional land degradation or desertification. The Food and Agriculture Organization of the United Nations (FAO) estimates that the growth of the world's livestock herds has already caused serious damage to many rangelands, and that globally about 6 million hectares fall into desert every year. In order to feed a growing population, 8 million hectares of land are deforested for temporary farming in Asia each year. The recreational period of the land will inevitably be shortened, causing a reduction in the variety of natural plant communities and animal communities and a deterioration of soil structure. Gorillas and chimpanzees in Africa are in danger of extinction because the mountain forests in which they grow are being cleared for farmland; gibbons on Hainan Island in China and orangutans in Indonesia are also declining, also because of the reduction of forests due to excessive population pressure. Soil erosion from its distribution, there is a significant feature; the population density of the place is heavier than the population density of the place is small, easy access to the place is heavier than inconvenient access to the place, near the mountain is heavier than far away from the mountain, the early development of the region is heavier than the late development of the region, which shows that the overpopulation is caused by the ecological deterioration of an important reason. Increased population has also forced people to farm on erosion-prone land on steep mountain slopes and on red soils in the humid tropics, resulting in soil erosion and a reduction in the productive capacity of the land.
The environmental impact of overpopulation growth is manifested in the increasing emission of pollutants. With imperfect control technology, the massive consumption of resources means increasing pollution. Taking solid waste as an example, Japan's garbage discharge in 1977 was 41.26 million tons, equivalent to an average of 1,062 grams per person per day, an increase of more than one fold over the 1960 discharge of 500 grams per person per day.
Industrial countries emit more pollutants than developing countries. It has been argued that one American pollutes the planet more than 100 Asians. The U.S. has about 6 percent of the world's population, while emitting about 40 percent of the pollutants. Modern agriculture has an even greater impact on the environment; for example, the pollutants produced by 3 million farmers in California practicing modern farming methods can be 100 times higher than the pollutants emitted by all farmers' production in India.
This duality of human beings on the ecology requires that we harmonize the growth of population numbers with natural resources. If the rate of population growth exceeds the burden on natural resources, it is bound to cause serious ecological problems and depletion of resources. At the same time, population growth should also be consistent with the natural capacity for environmental evolution. If the pollution caused by population increase exceeds the natural load, it will inevitably cause serious pollution problems, resulting in ecological deterioration and affecting the survival and development of human beings.
■5, big trees and grass
For some reason, people have a prejudice, thinking that to improve the ecology, the important thing is to plant trees, while the planting of grass but do not care about, people tend to be planting trees at the same time, while hoeing grass. Farmers constantly have to hoe grass, school students, organization staff, army soldiers, every year also in schools, organizations, barracks hoeing more than hoeing, hoeing inch grass, grass as if it is the enemy of ecology.
The prejudice against grass has a long history. Shennong's had tasted the grass, then grass is still a bit of a good reputation. But during the Warring States and Qin Dynasties, the reputation of grass deteriorated. Mengzi said: "in the wild said that the minister of grass and mangled", "Lu Shi Chun Qiu" said: "Grass filth also". All the grass as a derogatory term. In the Tang and Song dynasties, people called thatched cottages, the poet Du Fu, Bai Juyi have lived in this kind of ugly room; feudal rulers of the peasant insurgents called "grass bandits". In short, the word "grass" is not good enough. Some people in modern times, and often bad cab things called "poisonous grass", to eliminate thoroughly as "root and branch". In short, people cheap grass, hate grass. In fact, the harmful effects of weeding is very big. In addition to grass, the soil has lost the protection of grass, the soil is easy to lose, the wind is easy to wreak havoc. Grass place, can block the wind and sand, the so-called inch of grass can cover a hundred feet of wind. Many school organs hoe away the grass, the wind suddenly rise, will be mud and sand on the face. In fact, do not weed, green grass, not very beautiful? Some pastoral areas also hoeing farming, "to the grassland to food", the result is that the food is not good, the grassland is not secure. A large number of valuable grass desertification.
Grass is not only harmless, but also beneficial. Grass is fixed solar energy huge factory, according to statistics, the green grass every year, the organic matter made by the accumulation of energy, about the world's annual consumption of energy is comparable. This organic matter greatly improves the fertility of the soil and enriches the living matter of the world. About 2/3 of the organic matter produced by grass is underground and 1/3 is above ground. The underground part improves the soil and the above ground part is good forage. Grass forms an important part of the human food chain. With grass, there are cows, sheep and rabbits for meat and dairy. Grass is also a provider of nitrogen in the ecosystem. Legume forages fix atmospheric nitrogen and turn it into organic matter. An acre of alfalfa can fix 28 to 36 pounds of nitrogen over three years, which is equivalent to 90 to 110 pounds of ammonium nitrate. The protein contained in the above ground part of legume pasture can be up to 20% or more, and these proteins can be directly utilized by animals.
Grass is also a pioneer in improving ecology. It has a short growth cycle and strong vitality. "Grass on the grass away from the original, a year, a year withered and flourished, wildfire can not be eliminated, the spring breeze blowing again." Grass reproduction ability is very strong, many grass can rely on rhizomes, tubers, bulbs, bulbs, tubers, bead buds for asexual reproduction, some grasses, such as dogbane, Matang and other stems can be nourished on the adventitious roots. Grass can produce a large number of seeds, a plant of prickly vetch knot 35000. Grass is an important way to transform the ecology. Although our country planted grass has a long history, the founding of the country for more than 60 years has also been a great development, but compared with some developed countries, the gap is very big. British artificial grass area is about equal to its arable land area; New Zealand artificial grass for arable land of 13 ~ 14 times more. The Soviet Union and the United States grass area for the arable land area of 17.4%, 14.7%. In the greening of good countries, it is almost difficult to see the bare soil, green grass everywhere. And our country so far only but 1%.
Most areas in the north of China, soil reclamation (0 ~ 30 cm) of the soil layer of sandy soil, physical sand are generally more than 80%, if there is no grass and vegetation protection, very easy to cause wind erosion, resulting in sand. However, most of these areas are arid and semi-arid regions, and most of them are distributed in the Gobi sands of the desert. Here is full of sunshine, temperature difference is large, is conducive to the accumulation of plant nutrients and growth, but the wind and sand more drought and less rain is not conducive to crop growth and afforestation, and planting some of the adaptable grasses is completely possible, not only to survive, but also to a certain extent, to change the ecological conditions here, and even for planting forests, the development of arable land, to provide good conditions. In recent years, Xinjiang Yining County in 90,000 acres of land planting grass, transformation of barren slopes, now green grass, coverage rate of 80%, transforming the climate, reduce the wind and sand, increased feed. Xinjiang Turpan's sandy botanical gardens is also in 1970 with sand-fixing herbaceous plants to open the way, 16 years, not only fixed the quicksand to protect the surrounding villages, but also built a set of sandy plants into a large collection of exotic flowers and grasses concentrated in the botanical gardens, Turpan has become a famous tourist attractions, this desert botanical gardens is located in the standard 72 meters below sea level, can also be called the lowest of China's botanical gardens. Therefore, I advise you not to underestimate the grass, of course, planting grass is bound to compete with food for land, but as long as handled properly, planting grass and food can be done to complement each other. In dealing with the relationship between man and nature, must not only see the big trees, do not see grass, and even grass as the enemy, should set up a correct concept of greening, greening not only refers to planting trees, also refers to planting grass.
■6, out of proportion and excessive
Human beings in dealing with the relationship with nature's living creatures, we must pay attention to the degree, out of proportion is not good, excessive and harmful.
The Soviet Union has been y punished for not paying attention to the degree of its attitude toward wolves. At first, the Soviets believed that the wolf was the enemy of the Siberian reindeer, and that it hunted and killed the reindeer, causing their numbers to plummet. It was natural to think that the reindeer would surely grow faster if the vicious wolf was eliminated. Therefore, a large-scale wolf extermination campaign was carried out. The wolves were almost exterminated.
After the wolves were exterminated, the number of reindeer really skyrocketed. However, the increase in the number of reindeer soon exceeded the load of the forest, and the reindeer could not get enough to eat, so they often ran out of the forest to the edge of the city to look for food. One year, there was a continuous snowstorm, and the reindeer died because of the lack of food and the decline in their health. At this time, people realized that wolves play a role in the normal survival of reindeer. First of all, wolf is a control machine, which keeps the number of reindeer population at a certain number, not too much, in order to keep a relative balance with the space and food in the forest. Secondly, the wolf is a seed selection machine, it chases reindeer, the old, weak, sick and disabled reindeer often become the food of the wolf, leaving the strong reproduction of offspring, so that the weak to stay strong, the strong have more business offspring of the opportunity, so that the reindeer herds have always maintained a vigorous vitality. Thirdly, it is a promotion machine for the quality of reindeer. The wolves keep spying on the reindeer, forcing them to keep a sharp sense of sight and hearing, and the wolves keep chasing the reindeer, forcing them to keep running, thus maintaining their vitality. Once the wolves are gone, reproduction is out of control and overpopulation occurs. With the loss of their enemies and little running activity, the caribou's fitness declined greatly, and they finally died mostly from freezing and starvation during the years of the blizzard.
Later, the Soviet Union learned a lesson, and released the wolf, the wolf to reindeer as food, the number of increasing, now up to more than 100,000, the wolf overload, and began to jeopardize the deer herd, and in turn endangered cattle, horses and other livestock. According to statistics, 50,000 cows and horses die from wolves every year, and other poultry are even more numerous. Soviet authorities see the wolves become a disaster, deployed helicopters, falcons, motorcycles to hunt, in 1983 killed 15,000 wolves. Now that there are fewer wolves, what will happen to the reindeer? People are waiting to see. However, this example of the relationship between wolves and reindeer vividly tells us a truth: "Man must pay attention to the degree of nature's biological and inorganic matter, out of proportion and excessive are harmful, it is best to be moderate, so that nature to achieve a better balance, so that all kinds of living things, each in its own place, and each in its own way.
■7, love of nature is love of mankind
Nature is the warehouse of mankind, providing mankind with a variety of food, medicine. Nature is the cradle and courtyard of mankind, providing a suitable environment for mankind. The destruction of nature is bound to destroy the human food storehouse and medicine storehouse, and it is bound to destroy the cradle and courtyard of human beings, so to love nature is to love human beings themselves.
There are millions of plants, animals and microorganisms in nature, which are the treasure trove of life and important resources for human beings. Destroying them deprives mankind of the resources available to it. Human destruction of tropical forests is the greatest destruction of biological resources.
A century ago, tropical forests covered an area twice the size of Europe. But now it has been reduced to half that area, and every year as large an area of rainforest as the size of the United Kingdom is burned or logged out. By the end of the century there will be very little rainforest left, and only a few may remain in Brazil and Zaire. Tropical forests are one of the richest and most diverse regions of the biosphere. There are an estimated 3 million different species of plants, animals and microorganisms in these rainforests, of which scientists have so far named and categorized only about 1/6.
In fact, more than half of all life on Earth inhabits the warm, shady zones of these rainforests, and the tiny country of Panama in Central America, for example, has as many plant species as all of Europe. There are 100,000 insect species in North America, and in the Amazon Basin, sampling in two acres of forest yields 42,000 insect species, of which scientists have identified only 5 percent. At the present rate of deforestation, more than a million species of plants, animals and micro-organisms will become extinct within the next thirty or forty years, which is more than 25% of all the species of the earth, and they will be permanently lost before mankind can recognize them. More than half of what pharmacists now prescribe comes from wild plant and animal sources, many of them from the tropics. According to the National Cancer Institute, tropical plants are the main storehouse of cancer cures, and the loss of these resources is a major setback in the fight against cancer. In the context of genetic engineering, which has been born and is predicted to grow to become a major sector of the world economy, it can be argued that the genetic stores of the rainforests are one of mankind's most valuable natural resources, and that their disappearance would be a loss of incalculable proportions.
Nature has green mountains, green water, red flowers, green trees, waves and clouds, which create a suitable ecological environment for human beings. Deserted mountains and bad water, is not suitable for human survival of the environment, the natural times to care for nature, so that nature will always be green and beautiful water, will provide an excellent environment for human beings, if you do not care, will inevitably lead to the deterioration of the living environment.
On the contrary, caring for nature will enable mankind to have a good ecological environment, so that mankind has a beautiful home. The change of Yulin County in China also fully illustrates this point.
Yulin County is a mountainous area consisting of a mixture of stony mountains and loess hills, five tributaries of the Touzhang River evenly spread throughout the county, the banks of these main and tributary, is a fertile "rice and grain river".
Ancient Yulin, was "forest shade, birds gathered" place, before the War of Resistance against Japan, turbid Zhang River, the birthplace of the Shiyuan area, there are nearly 100,000 acres of forest area, accounting for 4.3% of the county's total area. Later, due to the farmers on the mountain deforestation, the county has 1,700 farmers to the source of the Shi Yuan area to open up land, the upper reclamation of the water source of the turbid Zhang River forest land for farmland. 1945, leaving only 160,000 trees, the remnants of the forest of 20,000 acres of fish. Due to the destruction of forests, the ecosystem is out of balance, mountain soil erosion, river land washed away, turbid Zhang River on both sides of the Mi Liangchuan washed away by the flood 100,000 acres, into a sandy wasteland without grass. After liberation, the local people planted 6.5 million trees, afforestation of more than 220,000 acres, woodland area of 9.2% of the total area. In particular, the turbid Zhang River on both sides of the 75,000 acres of large-scale flood protection forest, like two green belts, firmly bound the turbid Zhang River this dragon, for the people of Yulin Xingli remove harm. 1949 years ago, the village of Shi Yuan, after the rain, the river depth of up to 4 meters or more, the flow of water for three or four days is still muddy and undrinkable, to 1954, the forest land increased, after the rain, the flood is reduced to only more than 1 meter deep, the flow of water to reduce the 1 / 3, 9 hours later, the flood water becomes clear, that can be drunk. the flood water became clear, i.e., drinkable. In the 20-kilometer-long section of the upper reaches of the turbid Zhanghe River, began to flow, really green and Shunshan, green Zhanghe River water, riparian forest belt trees and shrubs and grasses combined to protect the farmland and the riverbed from scouring, wind and sand reduction, harvest increase.