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? ( )
People gain age when a year passes, so are the trees grow an age after 365 days. But do you know whether flowers have ages? No! But why?
Because no flower could keep blooming over a year. In this way, flowers’ age could not be counted by year, it could only counted by day or hour.
Orchid is a tropical flower, it could keep blooming for 80 days, which could be called the star of longevity in the flowers.The famous royal water lily could just keep blooming for 2 days.
There are some flowers with even shorter blooming days which could only be counted by hours, such as morning gloryetc. The shortest blooming flower is Cornflower, only blooms for 5 minutes to half an hour.
On the other hand, plants, especially forest or tropical plants, blocking, and absorbing the ashes in the air, refreshing the air.
In order to maintain life, human being have to take in oxygen and expire carbon dioxide.If the carbon dioxide in the air is too high, people would hardly breath and be toxicated. Plants are the only creature in the world to photosynthesis, besides, it is the absorber of carbon dioxide and producer of oxygen.
There are other plants which can take in toxic gas like sulfur dioxide and carbon monoxide. Besides, some plants could even take in some harmful radiation to human body, such as the cactus put in front of the computer could take in large amount of radiation sent out by the screen.
Have a Think
Plants are the air cleaner in the nature and they take in ( ) in air.
Flowers have a kind of cell called eleocyte filled with fragrant oil. Different flowers produce different fragrant oil, so they smell different. This oil would volatilize into the air with water, especially when the sunlight is strong, the fragrant oil could volatilize fast and the fragrance would be denser.
We don’t have to worry that the fragrant oil would be fully volatilized, because it could be produced constantly. It could not only reduce the water lost, but also attracts insects to gather honey and pollinate。
Flowers with bright color usually smell not dense. They always attract insects by their bright colors during their evolution, so they don’t have to send out fragrance.
As for those small flowers without bright color, they have strong fragrance, because they have to attract the insects by their fragrance.
The biggest flower in the world is Rafflesia，which is also called Rafflesia arnoldii。It grows in the tropical forest on Java and Sumatra islands in Indonesia.
– Wikimedia Commons
The longest diameter of the petal is 1.4 meters. 5 blood red petals is spotted with faint yellow plaque，looking like luxurious topaz sprinkling on the red velvet.
There is a big disk in the middle of the flower with diameter reaching to 0.3 meter. It seems like a big basin. Although the flower is large, its seeds is very small, which would broadcast themselves by attaching to animals’ feet.
Rafflesia has neither obvious root nor any stems and leaves. It inhabit on the rhizome of the wild rattan in the tropical forest, absorbing nutrients to raise themselves.
It need only few days from grow to bloom. We can smell slight fragrance when it just bloom, but after 4 days when it began to wither，it has a smell of odour, attracting flies and insects to transmit flower powder for them. In few weeks, the flowers began to curl，becoming sticky mash.
Rafflesiawas found by English people in 1818 on the Sumatra. Now this flower is near extinction.
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? ( )