Where is the "lung of the earth"?

Through the photosynthesis of green plants, forests can not only convert solar energy into various organic substances (forests provide 2.83 billion tons of organic substances every year, accounting for 53. Land plants produces 5.3 billion tons of organic matter (4% of the total output), but also absorbs a lot of carbon dioxide and releases oxygen through photosynthesis, maintains the balance between carbon dioxide and oxygen in the atmosphere, purifies the environment, and enables human beings to continuously obtain fresh air. So biologists once said that "forests are the lungs of the earth". The development of forest and human beings is closely related to the ecological balance of nature.

The forest has given mankind a clean living environment and a green treasure house, but the destruction of the forest by human beings has made the ecological environment worse and worse, and disasters have occurred frequently. Natural and man-made disasters have reduced the global forest area from about 8 million square kilometers to 2.8 million square kilometers now. Moreover, the forest area is still disappearing at the rate of 200,000 square kilometers per year.

Gandhi once said, "Nature is more than enough to meet people's needs, but it can't satisfy people's greed." In the preface of Man and Nature, Dieter Fult solemnly warned: "For hundreds of years, human beings have always held the most presumptuous and arrogant attitude towards nature. If we do not immediately stop the willful transformation of the earth by human judgment, mankind will bear the brunt of the coming disaster. Due to the loss of the natural protection of the life layer, human beings will eventually fall into a lot of death whirlpools that have already begun. "

For centuries, natural punishment caused by deforestation has occurred all over the world. Two or three hundred years ago, Yulin area in northern China was once a good place with dense forests and grass and abundant soil and water. Later, due to the excessive destruction of forests by the Qing government and sand erosion, Yulin City has now become a desert. /kloc-in the 0 th and 8 th centuries, a large number of immigrants came to the American continent to cut down forests, turning large grasslands into cultivated land and changing the layout of nature. 1934 In May, a "black storm" broke out, which lasted for three days and three nights. It carried a lot of sediment, cracked the fields, buried wells, streams and houses with sand, and made thousands of people homeless. These sad facts tell us how important it is to protect forests to protect the good ecological environment of human beings.

Regrettably, the lessons of history have not made mankind take warning, and the tragedy of self-destruction of homes is still repeated in many places. The bad luck of the Amazon virgin forest in South America, known as the "lung of the earth", is another typical example. The rich Amazon rainforest contains 45% of the world's wood. Since the 1960s, under the conquest of heavy tractors and fires, large areas of forests have been destroyed. Only 1966 ~ 1975 destroyed more than110,000 hectares of forest. Uncontrolled logging has reduced Brazil's national forest coverage from 80% to 40%. The consequences of deforestation are also obvious. In recent years, the precipitation in Brazil has decreased and the climate has become hot and dry. It is conceivable that if left unchecked, who can guarantee that the Amazon region will not become a big desert in decades?

The more direct impact of forest destruction is that it destroys the ecological balance, resulting in soil surface exposure and soil erosion, which leads to soil drying and soil erosion. The change of the Loess Plateau in China is also a good example in this respect. According to records, the former Loess Plateau was once densely forested, lush, humid and clean. During the Western Zhou Dynasty, the forest area reached 560,000 square kilometers and the vegetation coverage rate reached 53%. With the great construction of dynasties and countless wars, the Loess Plateau was destroyed by forests and grass, resulting in today's situation of thousands of valleys, sediment loss and barren land. The Yellow River changed from clear to turbid, which is the witness of nature's punishment for deforestation.

China is a country with poor forest resources. Compared with some countries with high forest coverage, Guyana is 97%, Finland is 6 9%, Japan is 68%, the United States is 33%, and China is only 13%, which is far below the world average of 22%. The per capita forest area is only 1.9 mu (the world average is 16 mu), ranking 1 in the world. Therefore, it is urgent to plant trees vigorously to improve our ecological environment.

Forests are the lungs of the earth. Terrible is that this "lung" has been cut off by 2/3 due to massive logging. Protecting, saving and expanding forests has become the only way for human beings to protect their own survival and sustainable utilization.