如果树叶全被吃光了,树木就会死亡。那么,要保持生存,树木至少需要多少叶子呢?俄罗斯林业工作人员为此进行了试验。试验者研究了被橡树卷叶虫损害的豫树周围进行的气体交换后认为,如果树叶吸收的二氧化碳比施放的要少,树木便不能保证光合作用的进行,继而不可避免地死亡。试验时,将橡树枝放进玻璃纸包一小时,借助化学分析,能够确定包内二氧化碳的含量。结果表明,当90％的树叶 If the leaves are eaten all the time, the trees will die. So how many leaves do trees need to survive to survive? Russian forestry workers have experimented with this. The experimenter studied the gas exchange around Yuma trees damaged by oak leaf winged worms and argues that trees can not guarantee photosynthesis and inevitably die if the leaf absorbs less carbon dioxide than it does. Test, the oak branch into the cellophane bag an hour, with the help of chemical analysis, to determine the content of carbon dioxide in the package. The results showed that when 90% of the leaves