The purpose of urban greening is to improve the ecological environment, beautify the living environment and enhance people's physical and mental health. To really improve the greening level of a city and create a pleasant living environment, we must adhere to the three principles of ecology, landscape and economy in the process of greening construction.
First, adhere to the ecological principle.
Urban ecosystem is a special ecosystem, and the biggest difference from natural ecosystem lies in the different proportion of its components. In the natural ecosystem, plants (producers) account for the largest proportion, while in the urban ecosystem, human beings occupy the most important position, accounting for the largest proportion, which makes the ecological structure change from the positive pyramid to the inverted pyramid, and the urban ecosystem becomes artificial, incomplete, open, complex, fragile and high-quality (in physical sense). In the process of urban greening construction, we should use the basic principles of ecology to make the urban ecosystem close to the natural ecosystem. Green plants fix the primary production process of solar energy and organic matter through photosynthesis, which is the original source of energy and material needed for all activities in our world. Although the purpose of urban greening is not to provide residents with the materials they need by planting plants, the improvement of the environment and the promotion of urban landscape by green plants are what contemporary urban people need most. There is no doubt that human ancestors who have lived in the primitive jungle for a long time have embedded their instinctive love for green plants in their genes. The function of urban greening should be to meet this demand as much as possible, which requires us to set up as many green spaces as possible, build more green spaces and increase the number of green spaces in the limited human living space in the city, so as to maximize the ecological benefits and create a pleasant living environment.
Increasing the amount of urban green space is the primary guarantee to increase the amount of urban green space. To increase the number of green spaces, we must first rely on the government's attention. The government should rely on the overall urban planning and green space system planning to ensure that the city reaches a certain green space rate and park green space area. This should not be a problem under the current social and economic development level and the national policy implementation and environment of promoting sustainable development, building an ecological province and creating a garden city. But we should pay attention to the uniformity of green space distribution. According to national standards, there should be leisure green space for residents to enjoy within 500 meters. We still have a gap in this respect and need to continue our efforts.
Secondly, relying on the lever of market economy, we will vigorously guide farmers to develop seedling production and increase the production green space for supplying urban seedlings. Furthermore, through our publicity, we will raise the greening awareness of all citizens, so that all units, communities, residents, streets, etc. Can "see the cracks and insert green" and strive for garden standard units and garden-style units. The garden department should make full use of the existing laws and regulations to check the greening rate and really improve the greening area of the city.
Increasing the amount of green space in green space construction has not received enough attention in all aspects. To really improve the ecological environment of the city, it is very important to increase the amount of green space. A piece of green space lacking green space is bound to have poor ecological benefits. We still have to vigorously advocate the combination of trees, shrubs, vines, grass and land, and the loess is not open in the air, and a variety of seedlings are full of crowns. All walks of life have different opinions on the issue of planting big trees. The author believes that if a city does not have a big tree, it will appear that the city has no history and no cultural precipitation, just like an upstart. Liang Shiqiu described the nouveau riche with the phrase "a small tree and a new painting are not ancient". It is necessary to plant some big trees properly in the construction of green space, but we must take appropriate measures and move them properly when planting big trees. Old city reconstruction, village relocation, reservoir inundation area, land consolidation and other trees that need to be relocated should be fully utilized. Illegal felling of ancient and famous trees and predatory transplanting of ecological public welfare forest trees are strictly prohibited. In the process of transplanting big trees, we must pay great attention to maintaining the basic crown of big trees. In the construction of the Civic Square, we basically used full crown trees in an area of 6.5438+0.5 million square meters, and the effect was very good.
In addition, the competent department of landscape architecture should strictly examine and approve all greening projects to ensure sufficient green quantity. Fully embodies the purpose of improving the ecological environment.
On the other hand, the problem of green quantity is the diversity of plant varieties, and efforts should be made to arrange as many compatible plants as possible in the built green space to increase the complexity and stability of the ecosystem.
Second, adhere to the landscape principle.
Adhering to the principle of landscape means having a sense of quality products. On the premise of green quantity, green space should have aesthetic feeling and pleasing feeling. Only in this way can people feel comfortable and achieve the purpose of promoting people's mental health. This requires us to plant green space with not only green quantity, but also quality, give full play to the artistic techniques of landscaping, and create artistic garden scenery through plant configuration.
China is the mother of world gardens. As early as 3000 years ago, the Yin and Zhou Dynasties had built platforms and dug pools. When the palace gardens were built in Qin and Han Dynasties, gardening began. By the Wei, Jin, Southern and Northern Dynasties, it had developed into an artificial landscape garden with the theme of landscape, and the technology of installing mountains and managing water was quite clever. The culture and art of Tang and Song Dynasties flourished unprecedentedly, and famous landscape painters came forth in large numbers. Influenced by landscape painting, the gardening art developed into a poetic stage, which enhanced the expression of artistic conception, and was called the freehand brushwork landscape garden in Tang and Song Dynasties. Some bureaucrats, landlords and literati live in a bustling city, longing for rural life and looking for a secluded place, so they opened a velvet garden next to their houses. The pond was dug very low, the mountains were built very high, pavilions and pavilions were connected, buildings were numerous, bamboo forests were shaded, vines hung, and the gardening level was quite good. The existing classical gardens in China are represented by the royal gardens in the north and the private gardens in the south, with small bridges and flowing water, winding paths, changeable scenery, twists and turns, pavilions and picturesque scenery. , echoing the classical architecture in China, or the Forbidden City or mansion compound. But today, China's urban architectural style has long been in line with the world, and the city has been composed of high-rise buildings, skyscrapers, worry-free roads, city squares, residential quarters and so on. Using the gardening techniques of China classical gardens to build green space will be very incongruous with modern architecture. However, the current landscape construction imitates a lot of foreign gardening techniques, and sparse forests, grasslands, large lawns and other landscapes appear from time to time, resulting in the greening situation of a thousand cities, regardless of regions and vague styles, and losing the historical tradition and cultural essence of China gardens, which is not a good greening technique.
China's gardening art has paid attention to artistic conception since ancient times. The true essence of China's gardens should be from nature, higher than nature, imitating nature and surpassing nature. The word artistic conception gives people endless aftertaste. However, it is precisely this artistic conception that is difficult to express in words and pictures. The Ming Dynasty's calculation of "Gardening and Metallurgy" said: The skills of the ancients were handed down from books, and none of them were handed down to gardening. It means' there are differences in the garden, and there is no way'. If you can't get it, you can spread it ....., which just shows the profoundness of gardening art. Bonsai art is a unique art in China, which can condense nature, simulate nature and create ideal nature. You can create many associations on a tree without feet, so bonsai art is called silent poetry and three-dimensional painting, and it is called shrinking thousands of miles and shrinking dragons into inches. In terms of landscaping, we can learn from the production methods of combined bonsai and landscape bonsai, and create a variety of artistic landscapes through plant planting and plant configuration, such as grassland landscape, forest landscape, shrub landscape, swamp landscape and water landscape. To enrich the urban environment with diverse ecological landscapes and create landscapes with China characteristics is also the goal that contemporary landscape workers should pursue.
Third, adhere to economic principles.
Economic principle can also be said to be the principle of sustainable development. Sustainable development strategy is a global concern in the 2 1 century, including the sustainable development of economy, environment, population and resources. In our garden construction, there is also the problem of sustainable development, especially in our garden management department. In the future, most of the built green spaces will be managed by us. In addition to construction costs, maintenance and management costs must also be taken seriously. On the one hand, it is the direct management cost, on the other hand, it is the development and utilization of the planted trees in the future. These are the sustainable development problems of landscape architecture. However, there are many unreasonable practices in the current garden construction work, and the author talks about some views on this.
(1) block planting
To increase the green amount, patch planting is undoubtedly a good way to increase the green amount. This is the favorite of construction companies. The construction technology is simple, the amount of work is large, and it is the easiest to make a profit. However, as a construction owner, it should be carefully considered. What are the advantages and disadvantages of film planting? There is no doubt that it increases the amount of green, is easy to construct and has beautiful scenery. What are the disadvantages? It seriously violates the natural growth law of plants, limits the overground and underground growth space of plants, has high maintenance cost and needs frequent pruning, and the key is short life. As a rule, the growth of patched plants in a decade is bound to decline seriously. The plants dug up at this time are useless, ugly and painful, but this is contrary to our sustainable development policy. Therefore, the author believes that it is necessary to use slice planting as little as possible unless it is necessary, such as road isolation belt. In order to increase the green amount, bulbous shrubs can be used instead. With good configuration, many good sketches of plant configuration can be made. When the bulbous shrub grows up, it can be dug out for use, which will not waste resources but also obtain economic benefits.
(2) Grass flowers
Cities need green and colors, and they need vivid colors. Decorating urban green space with grass flowers is undoubtedly the most effective means. However, in cities, a large number of grass flowers are used to decorate the landscape, and its operating expenses are quite high. According to Hangzhou's greening maintenance standard, the annual cost of grass flowers per square meter is 270 yuan, which is about 50 times that of general green space. Such high maintenance costs are obviously not conducive to the sustainable development of greening, and will aggravate the pressure of insufficient funds for greening maintenance. The solution is to use perennial flowers or local self-sown flowers in general plots, such as chrysanthemum, impatiens, safflower, cockscomb, mirabilis jalapa, hollyhock, iris, day lily, morning glory and so on.
(3) Tree species
It is necessary to correct the prejudice that exotic tree species are better than local tree species. As long as it is a living plant, it has ecological benefits. As for whether it looks good or not, it depends on how we plant and maintain it. We should vigorously promote the use of local tree species and plants, and do not use or use less exotic plants.
(4) Soil (fertilization)
In urban green space construction, the source of planting soil is a big problem. Soil is the foundation of plant growth. Without good soil, no good plants can grow. However, in the construction of green space, a large amount of construction waste and construction waste soil are used, which is extremely unfavorable for the future growth of trees in Yu Jiancheng green space. However, due to various reasons, it is difficult to treat the basic soil of green space according to the technical regulations of garden tree planting. In view of this situation, when we build green space, on the one hand, we should try our best to use good planting soil that meets the requirements, on the other hand, we should improve the green space soil through maintenance and management to supplement various nutrients that trees lack, that is, fertilize plants in time to meet the nutritional needs of normal growth of plants. It is best to use organic fertilizer to fertilize, and to crush the trimmed plant residues and put them back into the green space, which is worth advocating. American scientists believe that most of the problems in the aboveground parts of plants, such as pests and diseases, are because the nutrients in the soil can't meet the needs of plants.
(5) Ground cover plants (lawn)
Lawn fever was once popular in China. Practice has proved that the extensive use of lawns in urban greening is not suitable for China's national conditions, and there are many disadvantages such as high maintenance cost, consuming a lot of water resources and relatively poor ecological benefits, which has been recognized by many people of insight. However, in practical work, the application of lawn is still too great, and we still need to vigorously advocate and promote the replacement of lawn with plants. We have made a lot of efforts in this regard. In the greening construction of public squares, we use a large number of ground cover plants, such as vine, herb, Ardisia japonica, day lily, mugwort, honeysuckle, saxifrage, sorrel, iris, ivy, Hosta, etc. The effect is very good.
Even if we plant lawns, we also pay attention to the choice of grass species. In Taizhou, we have been troubled by the choice of grass seeds. Taizhou is located in the middle of subtropical zone. It is cold in winter, and the lowest temperature can reach -3-5℃. In summer, it is hot and dry, and the highest temperature can reach 38-39℃. Especially in June, the mildew and rain season often lasts for one month, and then it enters dry and hot days, which is extremely unfavorable to the growth of various lawns. We have tried to plant too many kinds of grass, but due to their respective shortcomings, it is difficult to meet the dual needs of ecological benefits and landscape benefits of urban greening. After years of exploration, our conclusion is that Manila grass or paradise grass should be planted if it is not required to be evergreen all year round, and ryegrass can be planted on Manila grass if it is to be green in winter. The maintenance cost of this lawn is relatively low.
(6) Close planting and thinning
Because it is emphasized that greening construction should be formed at one time, the initial planting density of plants on the newly-built green space is very high, which leads to fierce competition among plants, and some plants are bound to be gradually eliminated under pressure. For these plants, they can be liberated in the initial stage of stress. Through thinning, on the one hand, the problem of plant competition is solved, which is beneficial to the growth of group plants, on the other hand, plant resources can be fully utilized.