As is proved by scientists, 1 tons of leaves could take in 10-30 kilogram carbon dioxide and chlorine. Each leave is a small factory, continually providing energy for plants, as well as providing oxygen essential for human life. It could be said that there would be no life on earth if there is no photosynthesis by leaves. Besides, leaves also conduct transpiration。
The major functions of green leaves are as following:
Trees fall ill when lacking water. Their temperature would also rise when lacking water.Besides, temperature in different part of the tree is different.
The change of temperature of leaves is the most obvious.
During the daytime, the leaves mainly adjust temperature by transpiration. When there is enough water in the earth, the effect of transpiration is prominent. When there is not enough water, the leaves would close their pores under the sunlight. In this way, the transpiration is decreased and the temperature of the leaves rises.
The temperature of the sick trees would rise like that of men.When people get ill, their temperature rise at night and the fever is reduced in the morning.
However, this is quite contrary to the trees, whose temperature is highest in the morning.
According to the situation of the trees’ fever, the forest rangers could judge out which area of the forest is sick and take effective measures to cure them.
2. When do trees usually have most badly fever? ( )
A Indian botanist whose name is Bose has carried out an experiment: he waved a rake before a plant. As a result, the tentacles of the plant wave together with the rake, as if the plant is forbidding any harm from rake by waving its tentacles. Based on the experiment, Bose made an assumption that a plant has a heart. Besides, Bose invent a Cardiac curvometer and found out that the plants not only have hearts, but also have impulse. And the activity circle of the hearts is 1 minutes.
Assumed that the plants have hearts, they would have emotions.
In 1996, a scientist called Baxter has connected the Lie detector’s electrode to one of the leaves of dragon tree. He watered the dragon tree first and a smooth sawtooth-like curve has appeared on the detector. It seems that the dragon tree was feeling comfortable.
Then, he dipped one of the leaves into hot coffee, the reaction on the detector sent out a response of slight fear, which is not too terrible.
However, when he decided to burn this leave and held burning match near the dragon tree，the needle on the detector showed a strong wave. And apparently, this is the reaction of fear. When Baxter take back the match，the detector showed that the dragon tree has resumed normal state.
Now you may understand that trees have emotions like people. So we must take care of them!
Have a Think
When you hold a fire near a sapling，will it feels fearful? ( )