With the development of society, people increasingly realize that forests have the functions of absorbing carbon dioxide and releasing oxygen, taking medicine, removing dust, sterilizing, purifying sewage, reducing noise, preventing sandstorms, regulating climate, indicating and monitoring toxic substances and so on. So many people began to feel the joy of the big forest in nature and realize the various benefits of the big forest to the human body.
When you step into the green forest, you will suddenly feel comfortable and fatigue will disappear. Green in the forest not only brings beautiful scenery to the earth, but also acts on people's central nervous system through various senses, regulating and improving the body's function, giving people a feeling of tranquility, comfort, vitality and spirit, thus improving health.
According to the investigation, the green environment can reduce the secretion of human adrenaline and the excitability of human sympathetic nerve to a certain extent. It can not only make people calm and comfortable, but also reduce the skin temperature of human body by 1℃-2℃, reduce the pulse by 4 -8 times per minute, and enhance the sensitivity of hearing and thinking activities. Scientists have proved through experiments that when the reflectivity of green to light reaches 30%-40%, it can stimulate people's retinal tissue properly, absorb ultraviolet rays harmful to human eyes in the sun, make eye fatigue disappear quickly, and have a bright spirit.
According to the research, the plants in the forest, such as Chinese fir, pine, eucalyptus, poplar, juniper and oak, can secrete a monoterpene, sesquiterpene and diterpene gas "bactericide", which has an aromatic smell and can kill diphtheria, typhoid, tuberculosis, dysentery, cholera and other germs in the air. According to the survey, there are 4 million germs in the air per cubic meter in dry and forestless places, while there are only 600,000 germs on the boulevard and dozens in the forest.
Photosynthesis of green plants can absorb carbon dioxide, release oxygen and absorb harmful gases. It is reported that 0.4 hectares of forest belt can absorb and assimilate 100000 kg of pollutants a year. 1 ha Cryptomeria fortunei forest can absorb 720 kilograms of sulfur dioxide every year. So the air in the forest is fresh and clean. According to Japanese scientists, there is a substance in forests and Yuan Ye-negative ions, which is extremely beneficial to human health. It can promote human metabolism, make breathing stable, lower blood pressure, be energetic and improve human immunity. It has been measured that there are only forty or fifty negative ions per cubic centimeter in urban houses, one or two hundred in tree-lined places, and more than ten thousand in forests, valleys and grasslands.
In addition, forests also have the function of regulating microclimate. According to the measurement, the temperature of forest land is 3℃-5℃ lower than that of non-forest land in high temperature summer. In the cold and windy winter, the forest can reduce the wind speed and increase the temperature, thus playing the role of warm in winter and cool in summer. In addition, the leaves of plants in the forest have transpiration, which can increase the humidity of the surrounding air.
In a word, forest is the main body of terrestrial ecological environment and the regulator of nature. Protecting the forest is to protect the environment where human beings live, that is, to protect themselves. Let's try our best to protect the big forest and let it benefit mankind!
If there is no forest
Cinnamomum camphora, oleander, clove, maple, locust, Ailanthus altissima, Sabina vulgaris, Ligustrum lucidum, oak, willow, hibiscus, elm, Pinus massoniana, Platanus acerifolia, etc. They all have strong ability to absorb toxic and harmful gases such as sulfur dioxide, chlorine gas and hydrogen fluoride. These gases pass through the green belt and can usually be purified 1/4.
Leaves have a strong adsorption and filtration effect on dust particles through their fluff, secreted mucus and oil. Each hectare of forest can absorb 50 ~ 80 tons of dust every year, and the dust content in the air of urban green space is generally less than half of that of non-green space.
Many trees can secrete fungicides, for example, the fungicides secreted by pine trees can kill pathogenic microorganisms of diphtheria, dysentery and tuberculosis. The content of bacteria in the air in downtown area is 85% higher than that in green area.
Trees can also absorb noise. A 40-meter-wide forest belt can reduce noise 10 ~ 15 decibels.
You see, forests can not only provide food, medicinal materials, fuel and raw materials, but also prevent wind and fix sand, maintain water and soil, promote the revival of degraded land and improve agricultural production capacity, which is the guarantee for the sustainable development of human beings and nature.
You see, trees can not only beautify the environment and improve the microclimate, but also have the functions of vacuuming, silencing, decontamination, epidemic prevention and creating fresh air. Urban residents are really lucky if they can live in a green environment with trees and flowers.
Forests are so important that FAO has chosen "Forests and Life" as the theme of World Food Day in 199 1 year: not to plant trees, but to show how forests can help mankind achieve the goal of sustainable development; What needs to be emphasized is that forests have the function of lasting productivity, that is, while preserving the resource base for future generations, they can also meet the needs of the continuous development of current production; It is necessary to remind people that forests can not only provide food and fuel, but also have the most fundamental value of protecting the environment.
If there is no forest, most of the life on land will be extinct, and most of the water will flow into the ocean; Oxygen in the atmosphere will decrease and carbon dioxide will increase; The temperature will rise significantly, and floods and droughts will occur frequently. ...