What is the current environmental situation and the role of trees in China?

Between heaven and earth, between man and stars, there is a strange kingdom of trees.

In the tree kingdom on earth, there are thousands of different kinds of trees. As far as its height is concerned, there are giant fir trees (122m) higher than Freiburg Cathedral (15m) in Germany, and Australian eucalyptus trees (146m) higher than the Egyptian pyramids (137m). There are also recumbent rhododendrons, the plant height is only 5 ~ 10 cm. As far as annual growth is concerned, some trees, such as kapok trees, can grow more than 2 meters a year in suitable places; Bamboo shoots are buds on the underground stems (bamboo whips) of bamboo, which usually grow on the ground in spring. Some bamboo shoots can grow 2 ~ 3 meters high in one night, and "like mushrooms after rain" is a vivid portrayal. As far as the trunk diameter is concerned, the trunk diameter of baobab in tropical Africa can reach more than 12 m, which is 2 m more than that of giant sequoia. Giant sequoia, also known as the "master of the world", originated in the United States, with fast growth and long life. The height of the giant fir tree can reach more than 100 m, and the trunk diameter can reach more than 10 m; The bark alone is 60 cm thick, and the total weight of a tree exceeds 6000 tons. It is said that there is a road passing through the center of the trunk of giant sequoia, and cars shuttle back and forth, which is very spectacular. But some trees won't get thicker in their lifetime. For example, bamboo, the maximum thickness of the grown bamboo pole is the thickness of the bamboo shoots, and it will not become thicker.

The oldest tree in the world is Ginkgo biloba, which originated in China. Ginkgo trees in Ding Lin Temple in Juxian County, Shandong Province are said to have grown for more than 3700 years. There is an ancient ginkgo tree in Fuquan City, Guizhou Province. According to expert research, it is 4440 years old, the longest in the world. Trees older than 1000 years include Sabina vulgaris, Platycladus orientalis, Taxus chinensis, Cinnamomum camphora, Mulberry, Dracaena draconis, redwood, Lebanese cedar, etc.

The leaf shape of trees is even more strange and ubiquitous. As far as the size of its leaves is concerned, a leaf length of 1 m to several meters includes cycads, palms, mallows, coconuts, oil palms and so on. The longest leaf length of Brazilian brown can reach more than 20 meters; There is also a kind of small leaves only a few millimeters, such as Platycladus orientalis, Tamarix chinensis, Casuarina equisetifolia and other trees with scales.

The flowering period of trees is full of four seasons: spring, summer, autumn and winter. The colors and flowers of trees are really colorful; The size of flowers and the length of flowering period are even more colorful.

The fruits of the tree are coconut, grapefruit and durian as big as basketball, and even pineapple (jackfruit) with a length of more than 60 cm, a width of 40 cm and a weight of more than 20 kg, and some are as small as rice grains; Its size and shape are different, and it is really varied and varied. The fruits of some trees are human food and delicacies; There are also some trees whose fruits contain toxins that can kill people.

In the propagation of trees, in addition to asexual propagation and seed propagation such as cutting, layering, rameting and grafting, some trees also have viviparous phenomena. For example, before the fruits of mangroves growing on tropical beaches leave their mother's body, the seeds inside the fruits begin to germinate and grow like rod roots, sticking out the fruits. Once the fruit leaves the mother, it is inserted into the soil by its own weight. After a few hours, the lateral roots can grow and form new plant individuals.

It is worth mentioning that there is a tree in the tree kingdom: banyan. There are many air roots on the trunk, which grow downward and go deep into the soil, making a banyan tree form a forest year after year. The spectacular scene of "a single tree into a forest" refers to banyan trees. Some trees also have the function of prospecting. For example, there is a kind of wild rose with red flowers under normal circumstances, which absorbs a lot of copper ions and produces blue flowers. This led geologists to discover a copper mine in the Urals.

In ancient times, there was a legend that trees were used to treat people's diseases. Now there is a tree therapy in Russia. A Russian scientist revealed the wonderful performance of wood ring (cutting a trunk and digging a hole in the middle) in treating diseases through experiments, and thus invented a "biological corrector" for rehabilitation (similar to wood ring). Biological orthotics made of different trees can treat different people's diseases. For example, birch can treat arteriosclerosis, hepatitis, gastritis, gastric ulcer, prostatitis and so on. Populus davidiana can treat influenza, pneumonia and so on.

Early humans thought that the trees in this strange tree kingdom were incredible objects beyond nature. Trees gradually "die" in autumn, stand solemnly in winter and recover in spring. All this makes people feel how mysterious trees are, just like Almighty God and Holy Spirit. In the west, people in ancient times knew the kingdom of trees with simple feelings, thinking that roots can reach hell, green crowns extend to heaven, trees, and only trees can closely connect heaven, earth and hell; Only through trees can we realize God's long-cherished wish. There was a similar legend in ancient China. In many legends, people think that human life is produced by the germination and growth of trees. So now people plant trees in cemeteries to show that life will not end with death. Trees have become the trees of fate and life. Because the tree is "a symbol of life, it represents the universe that gives life, and the universe is reborn because of it." In the west, Christmas is colorful and full of vitality because of the Christmas tree. As the representative of trees all over the world, the Christmas tree symbolizes the inexhaustible source of life. Indeed, without the tree kingdom and green plants, the world would be unimaginable.

From the perspective of modern science, what has the tree kingdom brought to people?

The tree kingdom can improve the quality of the environment on which human beings depend. The tree kingdom and green plants continue to carry out photosynthesis, consuming carbon dioxide and producing fresh oxygen; More than 60% of the oxygen in the air comes from trees and green plants on land, so people compare trees and green plants to "oxygen factories" and "fresh air treatment factories". There are many trees in the tree kingdom that can secrete fungicides to kill all kinds of germs in the air; It can also absorb toxic gases discharged in industrial production, intercept dust that pollutes the atmosphere, and eliminate noise pollution harmful to human beings.

In summer, people feel very different under the shade of trees and direct sunlight. People will feel cool in the shade of trees in summer. This is because the green leaves in the dense tree crown can block the sun and absorb the radiant heat of the sun, thus reducing the temperature in the small ring. Trees are like giant water pumps, constantly absorbing water from the soil into trees, and then diffusing most of the water absorbed by roots into the atmosphere in the form of water vapor through transpiration of leaves, thus improving and regulating the relative humidity in the air.

In addition, the tree kingdom can also play an important role in protecting the environment on which human beings depend. We know that strong wind will increase soil evaporation, reduce soil moisture and cause soil wind erosion. In severe cases, sandstorms can bury towns and farmland. According to the statistics of UN 1984, 6 million hectares of land are buried by sand every year, and 2 1 10,000 hectares of land are lost due to desertification. At present, 1/3 of the world's land is in danger of desertification, calling on the international community to fight to stop desertification in some parts of the world. "If you want to live in a sandstorm, you must plant more trees." The effective ways to prevent wind and fix sand are to plant trees, set up shelterbelts, reduce the wind speed and stop the erosion and migration of sandstorms.

In mountainous areas with few trees, it is easy to form a miserable scene of "drought makes rain come, rain rushes in, takes away fertilizer and soil, and leaves stones and eggs". The uneven crown and branches of trees can intercept and block rainwater, slow down the intensity of showers, and effectively prevent soil erosion to conserve water. People often say that "beautiful scenery" and "green mountains and green waters" are the truth. However, if human beings violate the laws of nature, they will be punished by nature. Six thousand years ago, the Shaanxi-Gansu region of China was a beautiful and vibrant place, full of beautiful scenery, towering trees, green grass and flowers. However, in the Tang Dynasty, the green hills here had disappeared and the clear water had dried up, leaving only an endless desert in front of people. The reason why the green mountains and clear waters here are turned into deserts is because we humans have cut down forests excessively, reclaimed grasslands indefinitely, destroyed vegetation for a long time, and unreasonably developed and utilized natural resources. 1983 In July and August, Sichuan Province was hit by a rare flood, which flooded more than 250,000 mu of crops in 53 counties/kloc-0, reduced grain production by 3 billion Jin, and1600,000 houses collapsed, resulting in direct economic losses of more than 2 billion yuan. An important reason is that the forest resources in the upper reaches of the Yangtze River were destroyed in the Cultural Revolution, and the flood control ability was greatly weakened, resulting in serious soil erosion.

It can be seen that the tree kingdom and green plants are indeed of great value to human life, and they are indeed important events related to our human life and death. How important the existence of the tree kingdom is to us human beings! We must upgrade to a higher level to look at the benefits brought by the tree kingdom. The tree kingdom not only brings us food, wood, housing and work, but more importantly, it has great ecological benefits to the environment on which human beings depend. This is something that nothing else can do; Nothing can replace it. If humans destroy trees, it is destroying their homes.

What is the actual value of a tree? A professor at the University of Calcutta, India, made a scientific calculation. If a medium-sized tree grows for 50 years, its direct and indirect values are:

The value of producing oxygen is $365,438+0,250.

The value of preventing air pollution is $62,500.

The value of soil and water conservation is $37,500.

The value of preventing brain drain and increasing fertility is $3 1250.

The value of providing a shelter for livestock is $365,438+0,250.

The value of manufacturing protein is $2,500.

The total amount is $ 196250.

Although, due to different national conditions and different calculation methods, it may be difficult for people in China to truly understand the full value of the tree kingdom, we should clearly realize that many values of the tree kingdom are intangible through the above calculation, and its ecological and environmental values far exceed the value of its wood. It is enough to see how close and important the relationship between the tree kingdom and human beings is. Especially in today's industrialization and serious pollution, it is more important. This view has been gradually accepted in China. In Beijing, China, people who destroyed trees were fined 9900 yuan, and cadres of relevant departments were punished. In Hefei and Tianjin, they spent 50,000 yuan and 80,000 yuan respectively to move trees. These are concrete manifestations of our love for the tree kingdom.

For the sake of our human survival, let's love trees, tree kingdom and nature!

Climate and trees: There are many kinds and shapes of trees in the world. There are many "craftsmen" who shape them, and one of them is an important craftsman called climate.