Beside me was a tree, one lone tree. That tree was locally famous because it was the only tree anywhere in that vicinity; yet its presence proved that once there had been a forest over most of that land-now treeless and waste. The farmers of a past generation had cleared the forest. They had plowed the sloping land and dotted it with hamlets. Many workers had been busy with flocks and teams, going to and fro among the shocks of grain. Year by year the rain has washed away the loosened soil. The hamlets in my valley below the Great Wall are shriveled or gone. Only gullies remain -a wide and sickening expanse of gullies, more sickening to look upon than the ruins of fire. You can rebuild after a fire. Can anything be done about it? Yes, something can be done. Therefore, this book is written to persons of imagination who love trees and love their country, and to those who are interested in the problem of saving natural resources-an absolute necessity... (From Chapter 1)