Since spring has set in, our country vast north area already suffer seven the attacks of the sandstorm this year, sand blown by the wind that cover all the
sky, not only influence traffic seriously ,but also have caused the enormous loss to agriculture, traffic, animal husbandry and even industry too. This is undoubtedly a warning to us of nature: It has already been the very urgent time to protect the environment around us.
The most effective method of preventing sandstorm is no more than planting trees . Trees is best land guard. At first, trees is best air purifier, per mu broad leaf absorb carbon dioxide during one day is up to 66
kilograms, at same time it Will release 50 kilograms of fresh oxygen again ; second , they take" dust collector" without being charged, spruce per mu remove more than 2 tons dust in one year and some tree of having luxuriant branch and leaf , It can be up to more than 4 tons unexpectedly to suck dust ! The wonderful one
is, a lot of plants have the function of disinfecting ,that is the invincible opponent of those harmful germs, If material who pine secrete let diphtheria, dysentery, pulmonary tuberculosis germ unable to survive; And typhoid fever or
other germ fall burnet root, die at once; moreover, large area of trees play function of savings source of water, regulating temperature, dispel noise, attracting birds, beautify the
environment, etc.
It was worth people treasuring extraordinarily even if it is a trivial tree. Famous botanist ,the professor Dais of Indian Calcutta university, on the basis of further investigating, have made an interesting calculation to a value of the big trees of long 50 years. He points out, counts with the price of market of the timber , sell to the timber market after cut down it, is generally worth 50-125 dollars, But its sterling worth is its more than 1500 times at least!
The professor thinks , even disregards those enormous value in environmental
protection, etc., only come to estimate from following three respects, Enough to describe" a tree is worth ten thousand gold" too: 1.Release a ton of oxygen to count every year with , the oxygen emitted in 50 years is worth 31250 dollars, meanwhile, benefit in preventing the atmosphere pollution is 2 times of its
effect ,so the sum of two aspect is 93750 dollars; 2.The big tree prevent soil erosion, increase land in
decades, its value is about 68750 dollars; 3. Its luxuriant branch and leaf hide wind, rain, offer nest place for birds and perch for livestock, promote living beings diversification while eliminating insect pest, And the intangible value which is difficult to estimate is more than 31250 dollars , therefore the albumen of animal increased is 2500 dollars . The total of this three aspects has already been up to 196250 dollars. Its annual output will be above 3925 dollars afterwards, still much better than to regard as the timber.
Moreover, if it is one fruit tree, market income is incredible , adding several trees and become woods the result above-mentioned is even better, Its value is even more very considerable. Therefore, the person who cuts tree is really a confused worm that has" picked up the sesame seeds but overlook the watermelons".
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