一 棵 树 的 价 值森林,是地球的肺;绿树,是我们地球家园的空气净化器。 你知道吗,一棵50年树龄的树,产生的氧气价值约31200美元;在吸收有毒气体、防止大气污染方面价值约62500美 元;在增 加土壤肥力方面价值约31200美元;在涵养水源方面价值约37500美元;为鸟类及其他动物提供繁 The value of a tree The forest is the lungs of the earth; the green tree is the air purifier of our Earth’s homeland. Did you know that a 50-year-old tree produces about 31,200 U.S. dollars worth of oxygen, about 62,500 U.S. dollars in absorbing toxic gases and preventing atmospheric pollution, about 31,000 U.S. dollars in increasing soil fertility and about 31,000 dollars in water conservation 37,500 US dollars; for birds and other animals to provide complex