One mu of forest land stores 20 tons more water than no forest land;
One mu of windbreak forest can protect 100 mu of farmland from wind disaster;
One square kilometer of green space can reduce noise 16 decibels;
One hectare of green trees can consume 1000 kg of carbon dioxide a day and produce 730 kg of oxygen, which can be used by thousands of people to breathe;
One mu of forest land can absorb 22 ~ 60 tons of dust every year and 4 kilograms of toxic gas every month;
A tree is a small reservoir;
A tree is a miniature air purifier;
A tree is an invisible air conditioner.
People living in cities are often disturbed by noise and various harmful gases, but it is different in forests. Everywhere is full of quiet, harmonious green and pleasant scenery. The air in the forest is also fresh and abnormal, and some trees also secrete disinfectant juice, such as pine trees. It can be seen that regular "forest bath" can really play a role in strengthening the body. No wonder the Japanese are vigorously promoting this unique "forest bath".
A recent study by scientists in the United States and Brazil shows that the so-called "selective logging" of sporadic logging has caused great damage to the tropical rain forest in the Amazon basin of Brazil, and the speed at which the tropical rain forest in the Amazon basin is destroyed is twice as fast as previously estimated.
The so-called "selective logging" refers to sporadic and selective logging of economically valuable timber in the forest, rather than cutting down the whole forest. This secret logging activity is not easy to attract official attention, and it is difficult to find it even with satellite photos. It has been going on in the local area for decades.
Previously, scientists used satellite photos to study the destruction speed of Amazon rainforest, but it was only the result of the whole forest being cut down. Gregory Aznar of Carnegie Institution and others found that the tropical rain forest is thinning after being "selectively cut down" by using a new satellite image analysis technology.
In traditional satellite photos, a pixel represents a piece of land, and researchers can only judge whether there is a forest on this land as a whole. Aznar and others used photos taken by three different satellites to study the same land, and built a computer model with reference to the results of field investigation, so that they could not only see whether the land represented by the photo pixels was covered by forest, but also judge the density of forest.
Using this model, scientists studied the forest conditions in five states of the Brazilian Amazon basin. They found that from 1999 to 2002, the damage caused by "selective logging" to forests was equivalent to 600 ~ 128% of the total deforestation in the above areas in the same period, with an area of about1.2 ~ 20,000 square kilometers per year. If the damage caused by "selective logging" is also taken into account, the actual damage degree of tropical rain forest is twice as high as that of the whole logging.
Scientists warn that this "selective logging" will cause serious environmental damage to the Amazon basin. First of all, it will increase the greenhouse gas emissions of the region by nearly 1/4. The disappearance of some tree species also destroys the ecological balance, and the climbing plants, shrubs and turf attached to the cut tree species also disappear together, making the land drier and more prone to forest fires. Scientists call on countries to stop "selective logging" more forcefully. What is the future of the Amazon rainforest? At present, there are two completely different views.
Pessimists believe that the land development activities in the Amazon rainforest are bringing unprecedented harm to this rainforest. In a recent report, Carlos Nobri, the general coordinator of the climate change research project of the Brazilian Institute of Space Research, pointed out that deforestation, land reclamation for agricultural cultivation and forest fires are the three major enemies of the Amazon rainforest, and biodiversity is being lost at an alarming rate. The decrease of forest will increase the temperature, decrease the rainfall, intensify the desertification process and make the land dry up and even unsuitable for farming in the Amazon basin.
Optimists believe that in the past 10 years, Brazilians' awareness of environmental protection has been significantly improved, and the speed of deforestation has been significantly reduced. David Kaleri, director of Amazon project of Brazil's nature conservation organization, pointed out that in 1990s, the Amazon rainforest decreased by an average of 6.5438+0.8 million hectares per year, equivalent to the area of Rhode Island in the United States. However, compared with the 1980s, the situation has changed a lot, when the rainforest was reduced by an average of 2 million hectares per year. Although people have cut down the Amazon rainforest for many years, 86% of the original forest in the Amazon basin is still well preserved.
Weiss, president of the Brazilian Institute of Economic and Social Development, said that the "Brazilian Rainforest Protection Experimental Project" started in the 1990s has raised the protection of the Amazon forest to a new level. In this project, the governments of the seven most developed industrialized countries, the Netherlands, the European Union and Brazil are working together to protect the Amazon forest. So far, relevant parties have raised $350 million in project funds through various channels. Weiss and others believe that in this case, some people still think that the Amazon forest will disappear from the earth in 50 years, which is too utopian.
Brazil's environmental protection department is under great pressure. A controversial study shows that the Brazilian government's economic development plan of up to $40 billion will seriously damage 42% of the Amazon rainforest. Some environmentalists strongly advocate the establishment of Amazon nature reserve, but the population of this area has soared from 3.5 million in 1970 to 20 million now. Establishing nature reserves is not an easy task.
The Amazon rainforest stretches for thousands of miles and is the largest tropical rainforest in the world. It is called "the lung of the earth". 85% of the total area of Amazon rainforest is in Brazil, which is larger than that of Western Europe. The Amazon rainforest is home to half the plants and animals on the earth.