Today it is impossible to imagine a large city without islands of greenery. Flower beds, parks, squares - an integral part of the modern metropolis. Green spaces are, first of all, a natural filter that purifies the air and saturates it with oxygen. Gas contamination is a sore problem in large cities, so more and more measures are being taken for landscaping and landscaping park areas and squares. In this article we will consider the creation, maintenance of green spaces, their role in human settlements.
The main purpose of green spaces and their classification
Based on the functions performed by the stands, they are divided into several classes:
- Common use - recreation parks, boulevards, squares and other landscaping areas with open access for residents. Often these places are used for cultural events. Various holidays, rallies and other events of the city are held here. Public green spaces are a decorative element of the city, making it more comfortable and beautiful. In addition, they are also an excellent natural filter that reduces the concentration of impurities in the air.
- Limited use - these are green spaces that are not accessible to anyone. These include hospitals, universities, sports and cultural institutions, and sanatoriums. In such places, events aimed at treatment and sports events are often held.
- Green spaces for special purposes. These are places located in industrial areas, near roads, nurseries, fields. The content of green spaces of this type is aimed at protecting against fires, cleaning the air from exhaust gases and harmful substances emitted during production.
The types and varieties of plantations directly depend on the role that they will subsequently fulfill. Thanks to special plantings, the risk of spreading fires in the fields is significantly reduced, the risk of dust storms and snow storms is minimized, the consequences of which can be very devastating. In addition, such a landing adorns the roads and becomes an important element of the natural landscape.
Dust reduction
Trees help filter air from exhaust fumes and dust. This is due to the deceleration of the air flow when it enters the green mass encountered on the way. At the same time, its speed decreases significantly, and the dust remains in the form of sediment on the bushes and leaves of trees. When it rains, everything is washed off to the ground. Thanks to green spaces in the city, air is cleared of 70% of harmful impurities. In addition to shrubs and trees, the lawn also takes part in the air cleaning process. It slows the progressive movement of dust carried by the wind. Trees help reduce dust levels even without leaves.
Gas protection
In addition to cleaning air from dust, urban green spaces reduce the concentration of exhaust gases. Plants absorb them, and aerosol particles having a solid structure settle on the crown of trees and shrubs. The green massif that comes across the path of air flow with impurities breaks it up, directing it in different directions. Due to this, polluted air is diluted with clean and the concentration of harmful substances is significantly reduced. Not all plants are suitable for a gas protective role. So, for example, plants with intense photosynthesis are less resistant to gases and therefore do not last long. Experts call the best breeds such as: elm, spruce, willow, aspen, poplar, ash maple, acacia, lilac. These trees can be planted near roads and enterprises where the largest amount of emissions occurs. For the territory of green spaces of common use, birch, mountain ash, Tatar maple and Engelman spruce are perfect.
A key feature of the green massif is its ability to absorb carbon dioxide and release oxygen. Scientists have proven that 1 hectare of green space absorbs 8 liters of carbon dioxide in one hour. Deciduous trees with a large crown emit much more oxygen than conifers.
Reducing the amount of gas in the air depends not only on the number of trees, but also on how tightly planted they are to each other. If a green space is planted close to the emission sources with a tight landing, this can cause stagnation of air, which entails a concentration of gases. Therefore, it is recommended to place well-blown plantings close to enterprises and roads.
Plantations - protection from the winds
As design practice shows, green spaces are not only a decorative element and an air filter in the city, but also an excellent protector from strong winds. In order to solve the problem of dust and snow storms, streaks of green spaces are arranged across the streams.
The protective function of the green massif determines the density and location of plantings. For example, a windproof eight-row strip with trees, whose size does not exceed 17 meters, can reduce the wind flow rate to 70%. If we consider the specific width of forest stands, then enough stripes with a width of 20-30 meters. Such green spaces can significantly reduce wind speed. Trees can reduce it to zero. So, in the depths of the forest at a distance of 200-250 meters comes calm.
Volatile effect
The main part of plants is able to secrete volatile, substances that can kill bacteria harmful to the human body and inhibit their development. So, for example, volatile, contained in oak leaves, kill pathogens of dysentery. The most pronounced ability to form volatile production in poplar, oak, birch and bird cherry. In addition, such substances can produce, but in smaller quantities, about 500 more species.
Effect on wind formation
Green mass plantings have a positive effect on the appearance of air currents. This is due to the fact that the heated air of the city rises up under the influence of hot weather. In turn, in its place comes less warmed air from the area where the trees are planted. Air currents can form only with a temperature difference of at least 5 degrees. In most cases, this occurs on the outskirts of settlements. Streams are formed only in warm weather, in cool it is excluded.
Role in the fight against noise
Scientists have proven that trees located between the housing estate and noise sources significantly reduce its level. The green array is able to reduce noise by up to 10%. At the same time, deciduous trees with a large crown can absorb up to 26% of sound energy, and shrubs planted 40 cm wide can reduce noise to 20-23 decibels. An interesting fact is that the grass on the site also reduces the noise level by 5-7 backgrounds. However, when placing green spaces near noise sources, it is worth considering the location of trees in relation to them, otherwise you can get the opposite effect. For example, if you plant trees along the axis of a street with heavy traffic, the stands will become a screen reflecting sound waves towards the housing estate.
The role of plantings in the garden
I want to live and spend time surrounded by beautiful and useful plants not only to residents of large megacities, but also to people living in small towns. In them, green spaces are the basis of the landscape of any yard. When planting, preference is usually given to fruit trees, which not only decorate the site, but also allow you to enjoy fresh fruit. But besides such trees, species with an exceptional decorative appearance are in demand. These include: pine, fir, oak, linden. By equipping the territory with these plants, you can give a unique appearance to the site for many years.