造纸术是我国四大发明之一。东汉的蔡伦改进了造纸术。现代造纸术的原料经过演化已经由原来的树皮、麻布、敝布、渔网等变成了木材。我们现在的用纸量不断增大。随之而来的问题就是森林急速消失。节纸成为刻不容缓的任务。据专家计算,每制造一吨纸张需要3.5吨的树木,等于砍伐17棵树直径16厘米和高8米(约三层楼高)的原生树木。每棵原生树木要生长到如此高度,平均需要20年至40年。 Papermaking is one of the four major inventions in our country. Cai Lun Eastern Han improved papermaking. The raw material of modern papermaking has evolved from the original bark, linen, cloth, fishing nets into wood. Our paper consumption is increasing. The ensuing problem is the rapid disappearance of the forest. Paper festival has become an urgent task. According to experts, 3.5 tons of trees are required for each ton of paper produced, equating to cutting down 17 native trees of 16 cm in diameter and 8 m in height (about three stories high). Every native tree needs to grow to such an altitude that it takes on average 20 to 40 years.