The significance of Arbor Day

March 12 is our own Arbor Day and the anniversary of Sun Yat-sen's death. So what is the significance of Arbor Day? Let me share the significance of Arbor Day with you, hoping to help you!

Significance of Arbor Day 1

Afforestation can not only green and beautify homes, but also play a role in expanding forest resources, preventing soil erosion, protecting farmland, regulating climate and promoting economic development. This is a grand project for the benefit of present and future generations. In order to protect forestry resources, beautify the environment and maintain ecological balance, many countries in the world have set up Arbor Day according to their own actual conditions. With the enhancement of people's awareness of environmental protection and their active participation in afforestation activities, our living environment will be continuously improved.

The meaning of Arbor Day II

Afforestation can not only green and beautify homes, but also play a role in expanding forest resources, preventing soil erosion, protecting farmland, regulating climate and promoting economic development. This is a grand project for the benefit of present and future generations. In order to protect forestry resources, beautify the environment and maintain ecological balance, many countries in the world have set up Arbor Day according to their own actual conditions. With the enhancement of people's awareness of environmental protection and their active participation in afforestation activities, our living environment will be continuously improved.

Some foreign scholars have calculated the ecological value of trees: a 50-year-old tree produces about 365,438+0,200 dollars worth of oxygen; Absorbing toxic gases to prevent air pollution, worth about $62,500; Increase the value of soil fertility by about $365,438+$0,200; The water saving value is $37,500; Providing breeding grounds for birds and other animals is worth $365,438+$0,250; Resulting in a protein worth $2,500. Excluding the value of flowers, fruits and wood, the total value is about $ 196000.

Whether this calculation is accurate or not is obvious from the practical value of trees.

A tree can produce 200 kilograms of pulp. If these pulps are to produce toilet paper, there must be at least 750 rolls100g of toilet paper.

In the city, a tree can store the pollutants emitted by a car driving for one year 16 km. Many trees can absorb harmful gases, such as 1 hectare Cryptomeria fortunei forest, and can absorb 60 kilograms of sulfur dioxide every day. Others, such as Ailanthus altissima, oleander, Ginkgo biloba, Sycamore, etc., all have the function of absorbing sulfur dioxide. When the urban green area reaches more than 50%, the pollutants in the atmosphere can be effectively controlled.

Urban forests can increase air humidity, and an adult tree can evaporate 400 kilograms of water a day, so the air humidity in forests is obviously increased. According to calculation, the local summer temperature can be reduced by 0. 1% for every increase in urban green area.

Urban forest belts and hedges can reduce noise. A forest belt 30 meters wide can reduce noise by 6? 8 decibels

There are 3.5 bacteria per cubic meter of air in forest areas, while there are 34,000 densely populated cities lacking greening. Urban streets with trees contain about 80% less bacteria than urban streets without trees.

Urban shelterbelt can slow down the wind speed, and its effective range is less than 40 times of the tree height, of which 10? The best effect is within 20 times, which can reduce the wind speed by 50%.

In the farmland forest network, the wind speed can usually be slowed down by 30%? 40%, relative humidity increased by 5%? 15%, increase soil water content 10%? 20%. According to the measurement, the canopy can intercept about 20% of the precipitation, which greatly weakens the influence of raindrops; As long as there is litter with a thickness of 1 cm on the surface, the surface runoff can be reduced to less than 1/4 of the bare land, and the sediment can be reduced to less than 7% of the bare land.

Compared with bare land, a hectare of woodland can store at least 3000 cubic meters more water. The storage capacity of 1 10,000 mu of forest is equivalent to a reservoir with storage capacity of 1 10,000 cubic meters, and the construction of such a reservoir requires an investment of more than10,000 million yuan.

Some experts predict that if forests are lost on the earth, about 4.5 million biological species will cease to exist, 90% of fresh water on land will flow into the sea in vain, and human beings will face serious water shortage. The disappearance of forests has increased the wind speed in many areas by 60%? 80%, hundreds of millions of people will die because of typhoons?

The significance of Arbor Day 3

Everything revives in spring, which is the golden season for afforestation. Afforestation can not only beautify the environment, improve air quality, but also improve climate conditions, which can be described as killing two birds with one stone. Dense canopy can block sunlight and reflect about 20% of heat back to the sky, 60%? 70% of the heat is absorbed by the canopy. In addition, the maintenance of plant transpiration also needs to absorb a lot of heat. Because of the high air humidity, large heat capacity and small wind force in the forest, the temperature changes slowly.

It is observed that the temperature in the forest area is 8? Summer is lower than that in non-forest areas. 9℃, but 2℃ higher in winter? 3℃, really? Warm in winter and cool in summer? . In addition, forests can also regulate air humidity. The regulation of air by forest is accomplished through the constant transpiration of tree crown. In the dry season, the huge roots of trees absorb a lot of water in the soil and transport it to the atmosphere through leaves, which increases the humidity of the air, thus alleviating the degree of drought. According to the measurement, the relative humidity in summer in forest areas is 30% higher than that in non-forest areas? 40%, which is about 10% higher in winter.

Forest is not only an air conditioner of nature, but also a humidifier, which contributes a lot to improving air quality. When the forest coverage rate reaches more than 35%, a climate suitable for human life can be produced. According to scientists' estimation, in summer, every hectare of poplar transpiration 57 tons of water every day, consuming 654.38+0.8 megajoules of heat; Each hectare of broad-leaved forest absorbs 575 tons of groundwater from the soil a year, and consumes heat 1.25 mj. Its transpiration is 50% more than that of the ocean at the same latitude and 20 times that of the forest-free area. Besides, the forest is a paradise for nature. After the wind meets the forest, part of the airflow crosses the sky, part of the airflow is blocked by trees, and the wind drops sharply. When it reaches the forest area 200 meters, the wind speed is generally only about 5% of the original, thus greatly reducing the wind disaster.

The nationwide voluntary tree planting campaign is a great cause for the benefit of the people. Over the years, the national voluntary tree planting movement has flourished, which has played an important role in raising the awareness of greening, speeding up the construction of green space and ecological environment, and promoting economic development and social civilization and progress.

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