日韩午夜精品视频,欧美私密网站,国产一区二区三区四区,国产主播一区二区三区四区

The planting of trees and grass on sandy land has been an almost futile effort in China's decades-long battle against expanding deserts, say environmental experts.

Now Chinese experts believe that leaving deserts alone to restore themselves, while resolutely protecting existing forests and grasslands are more effective ecological improvement measures.

An official in charge of afforestation in Jingbian County of northwest China's Shaanxi Province said afforestation campaigns had been of little benefit.

"I led local residents to plant trees on wasteland for 40 years, but finally found neighboring Wuqi county had better forest cover by sealing off and protecting existing forests," he said.

Water shortages and soil erosion are serious concerns in China where 37 percent of the territory is affected by soil erosion to different degrees. During the past half century, people attempted to plant trees on the verges of deserts, believing that manpower could finally defeat nature. But at the same time, the country's numerous forests were felled for the sake of economic development.

Now the experts and officials and farmers have all gradually changed their views.

Shi Yuanchun, academician of both the Chinese Academy of Sciences and the Academy of Engineering of China said alleviating soil erosion and improving the ecological environment should depend on both human afforestation and natural restoration.

However, the latter method has been proved more effective and economical, according to decades-long experience, he added.

Xiong Tie, the country's noted soil erosion control expert, said improving the ecological environment through nature's self-restoration ability was learnt from the valuable experience of the country's water resources departments after decades of afforestation attempts.

At the beginning of 2003, the Ministry of Water Resources organized an investigation into the country's nature restoration work in 10 provinces and autonomous regions, including Shaanxi, Inner Mongolia, Shanxi, Jiangxi, Fujian, Guizhou, Sichuan and Hubei, and compiled a comprehensive report on the country's forest and grassland rehabilitation.

The report shows that about 25 counties in northwest China's Shaanxi Province have sealed off their forests; north China's Inner Mongolia Autonomous Region has imposed a grazing ban on about 10.4 million hectares of grasslands, 16.35 percent of the region's available grasslands.

Meanwhile, north China's other provinces and autonomous regions such as Shanxi, Ningxia and Hebei announced grazing bans on all their grasslands.

Nowadays, the country's 600,000 sq. km. of forests and grasslands have been totally sealed off to allow natural restoration.

Liu Zhen, director of the Water and Soil Conservation Department under the Ministry of Water Resources, said that bans on logging and grazing were insufficient to rehabilitate forests and grasslands. Efforts should also be made to help loggers and herdsmen find new livelihoods.

Na Muhai, a herdsman in Inner Mongolia Autonomous Region, said cattle and sheep were the lifeblood of his ancestors, but today the younger generations believed preserving the ecological environment of the grasslands was more important. Helped by the local government, he now raised his sheep within his farm premises and his livestock were stout and strong.

(Xinhua News Agency June 12, 2003)