The Importance of Green Infrastructure

1 urban greening can improve health conditions in the city
Various types of urban green space, with its large leaf area, dense branches, blocking, filtering, adsorption air of dust, particulates, while also serving as retention, dispersion, absorption of air, the role of toxic gases, which Air can be purified. Forest is a special air purification "filter." For example, in a cement plant two rows of large poplars tied, the amount of dust in the air can reduce 33% ~ 52%. Shows a variety of green plants planted in town, on the regulation of air flow, clean the air has a very important role [1].

1.2 The climate regulation

First of all, garden plants can adjust the temperature. Landscaping can adjust the temperature, plays the role of cool. In the hot summer months, trees can shade a large leaf area, reflects solar radiation effectively, greatly reducing the direct sunlight on the ground. Evaporation of water through the leaves of trees, can reduce its own temperature, increase air humidity around. Thus summer temperatures than non-green space green space within the low temperature 3 ~ 5 ℃, lower than the temperature in the building area is about 10 ℃. Therefore, the urban green area, with high coverage, can improve the microclimate of the living area. Good place in the green, the summer people will feel fresh air, enjoy the cool air can be refreshing, summer cooling. Winter, trees can reduce wind speed, reduced the intrusion of cold air, woods and the back side, the temperature can increase 1 ~ 2 ℃. Second, the garden plants can regulate air flow. The green areas and non-green areas there are differences between the temperature, the temperature of green space adjacent to the non-green than the lower temperature. Law of diffusion with temperature down, and the air flow to the hot air areas, and sometimes flow rate of up to 1m / s, which can form a slight wind, makes people feel cool. Finally, garden plants can adjust the humidity, the temperature of the "regulator." Plants through leaf transpiration and water, large amounts of water to the land to be released into the air, the air humidity increased. According to the research, because the roots absorb almost all the water evaporates, so the air humidity of the forest is 30% higher than in cities around [2]. As a strong tree transpiration, so that more water vapor, the air moist, and therefore, green areas than non-green areas humidity is 10% to 20%, so as to people in the production, life and create a cool, comfortable climate and environment.

Reduced noise 1.3

More serious noise pollution of modern cities, the noise not only affects the people's normal life, serious harm people's health can also affect the central nervous system and spirit of people's reactions, lead to there lack of energy, fatigue, blood pressure and other symptoms [ 3]. Use of large canopy trees and branches, you can absorb and isolate noise. It has been determined, in the absence of trees lined the streets of tall buildings, the noise intensity ratio of both sides of the street trees planted more than 5 times a large, visible, urban greening is important to reduce noise pollution.

1.4 landscape

Garden plants are an important part of the urban landscape. Plant mix, beautiful shape, rich spatial variation of the environment. The level of scattered trees, tree of the variety, the size difference between the crown, breaking the flat monotony of the building become a lively, vibrant, urban environment and thus deepened the sense of space and layering. Various types of plant changes with the seasons, showing a different seasonal colors, such as Acer mono, triangle Maple, autumn leaves of red Swiss wood species such as red, gold and silver honeysuckle, chicken and other tree species Viburnum Article persistent ear branches in winter, as cold winter's unique landscape. Flower color is vivid and, therefore, reasonable for the city green, can make the city become colorful, lively, beautiful and pleasant living environment of people [4].

1.5 Disaster Prevention and Mitigation

Many landscape trees with a strong fire resistance, with outstanding fire safety features. For example: dense and homogeneous pine and cypress leaves can block 95% of radiant heat through, coral trees can block 83% ~ 93% of the heat through its effect can be comparable to avoid firewall. Shore plant trees and grass in the rivers and lakes, you can conserve water, water purification, due to soil embankment, reduce soil erosion, reducing pollution, silt deposition.

1.6 Environmental Monitoring

The response of plants to air pollution, many sensitive than humans, pollution, toxic substances on the plant will be in various forms. This reaction is shown plant pollution "signal." People can plant has issued a "signal" to analyze the identification of environmental pollution. Using plants for environmental monitoring, a wide range of simple, low cost, favorable environment for police to carry out mass work increasingly relevant departments.

2 has a good economic urban greening

2.1 The production value of landscape plants

Many garden plants have multiple uses, both economic plants, have a high ornamental value, but also integrated a lot of products. Therefore, the development of organic gardening and production together, both the considerable economic income, but also play a greening and beautifying effect, so as to realize the value of landscaping industry.

2.2 landscape plants can provide industrial raw materials

Reed garden plants, bamboo, poplar can be used for papermaking raw materials; Rose can provide natural spices, prepared flavors; Saw Palmetto leaves can be used for fan; garden plants in the walnut, forsythia, honeysuckle, peony, chrysanthemum Dengjun important medicinal plants. Metasequoia garden plants, pine, tulip tree, are both excellent materials and ornamental garden plants. Garden plants can provide industrial raw materials, can also provide a variety of business sources; can also use the root of garden plants processed into bonsai trees and root carving, etc., development of the arts industry.

3 urban greening the health and well

3.1 The plant has a bactericidal

Green can reduce the bacterial content of air, many garden plants can inhibit the spread in the air to kill bacteria in a variety of functions. The roots, stems, leaves, flowers and other organs, can secrete a variety of microorganisms or germs to kill or inhibit the development of volatile substances, it is this substance called "phytoncide." Such as pine, cypress, poplar, honeysuckle, may all contain some of spinosad. The secretion of Prunus trees on the deadly mosquitoes have a strong role. Residential areas and non-green environment green environment control, sterilization of green areas in the summer can reach 20% to 59%. Visible, urban greening multiple benefits for humanity, for the promotion of human physical and mental health have a good effect.

3.2 The plant can purify water

Green plants can purify the air, protect water quality, prevent soil and water pollution downstream. If the sewage contains E. coli, from the 30 ~ 40m wide flow through the pine forests, the number of bacteria can be reduced to the original 1 / 8; from oak, ash and acacia mixed forest in the outflow of water, only the control E. coli value of 1 / 23; water if the three decades from a 50m wide poplar and birch mixed forest after the passage of bacteria can reduce the 9 / 10 or more. Sewage into the soil, absorbed by green plants, soil degradation and soil adsorption, precipitation, ion exchange, fixed and other clay minerals, can largely be purified.

3.3 plants help to carry out horticulture therapy

Horticultural therapy is through the "green" to regulate their own natural environment pressure, and promote normal circulation of the endocrine system, increase their immunity as a therapy. Of particular note is the "forest bath", "aroma therapy" has been widely recognized by the industry, such behavior is indeed verified by medical health benefits. Today, forest gardening method therapy quietly rising, many countries in the world, the establishment of the forest horticultural therapy hospital, can be effective in treating people suffering from certain diseases. In these hospitals, no medicine, no injections, do not need medical treatment, with the environment, through the cultivation of fruit trees, flowers, vegetables and other horticultural activities, so that people in the green environment in the treatment of disease and restore health. Horticultural plants using a variety of colors treatment of disease, is an important part of horticultural therapy. Studies have shown that patients with light blue flowers on the fever has a good sedative effect, the red flowers can increase the patient's appetite, purple flowers can make women feel quiet, red with red flowers on blood pressure in patients with blood pressure of great benefit. Living green environment, their pulse, breathing frequency was significantly reduced, blood flow will slow down, become soothing frayed nerves, hearing and thinking activities, sensitivity is enhanced. China's Hubei Province, Su Temple National Forest Park has become an economic, ecological and social benefits of forest bathing win.

3.4 plants can reduce soil pollution

With pesticides and pollutants will eventually wind down most of the dust on the ground, the soil will produce pollution. Garden plants due to soil and slope protection, reduce surface runoff, soil and water, regulating climate, reducing wind erosion dust, can effectively reduce the further pollution of the soil.