Every year, the global production and consumption of paper has reached 320 million tons. If four trees with an average age of 20 years are cut down from each ton of paper, nearly 1 300 million such trees will disappear from the earth after1year.
Historically, forests once covered 2/3 of the earth's land area. After entering the 20th century, the rate of forest reduction has further accelerated. If this development continues, tropical forest resources all over the world may be destroyed in a few years.
The forest coverage rate in China is only 1/4 of the world average. According to statistics, during the period of 10, the forest in China decreased by 23% and the logging volume decreased by 50%. Since 1950s, the natural forests in Xishuangbanna, Yunnan Province are disappearing at a rate of about10.6 million hectares per year. At that time, 55% of the original forest coverage area has now been reduced by half. so much/so many
The natural forest coverage rate of an island in China is 25.7% in 1965, 8.7% in 1964, and only 8.53% in 198 1 year, which greatly reduces the shielding degree to the ground, resulting in rare tree species and some precious medicinal plants on hillsides. Case 2: 1967 The area of wild licorice in a county in northwest China is more than 40,000 hectares. Half of them were dug up after 30 years, and wild horses and camels in China became extinct. Case 3: In 1980s, a forest pest originated in Japan invaded the western coastal areas of China and spread rapidly due to the lack of natural enemies. According to statistics from 65438 to 0990, this pest harmed more than130,000 hectares of Pinus massoniana forest in this area.