On the basis of analyzing the connotation and characteristics of conservation-oriented landscape greening, and drawing lessons from successful practices and advanced theories at home and abroad, this paper puts forward ecological strategies for the construction of conservation-oriented landscape greening from the planning and design level, mainly including technical measures for saving land resources, fresh water resources, energy, materials and management. [Keywords:] conservation-oriented gardens; Greening; Scientific planning; At present, the shortage of resources has become one of the main factors restricting the sustainable development of the world economy and society. All countries are committed to researching energy-saving and environmental protection technologies to alleviate the increasingly serious resource and environmental problems, and China will also take "accelerating the construction of an economical society and promoting comprehensive, coordinated and sustainable economic and social development" as the focus of future work [1]. The construction of conservation-oriented garden green space is an important part of building a conservation-oriented society and an important carrier for landscaping industry to implement Scientific Outlook on Development and create a resource-saving and environment-friendly society. To truly realize the conservation-oriented landscaping, we need to start with planning, design, construction, maintenance and management, change traditional concepts, and build a technical support system for conservation-oriented landscaping by relying on scientific and technological progress and innovation. Among them, planning and design is the earliest and most critical technical link in the construction process. Based on the connotation and characteristics of conservation-oriented gardens, the ecological strategies and methods of planning and design of conservation-oriented garden green space were discussed on the basis of drawing lessons from successful practices and advanced theories at home and abroad. Second, the proposal of conservation-oriented landscape greening. As the only system with self-purification ability in the city, urban landscape green space plays a very important role in improving environmental quality, maintaining urban ecological balance and beautifying urban landscape. In 2006, Chou Baoxing, Vice Minister of the Ministry of Construction, put forward "conservation-oriented" landscaping for the first time at the national on-site meeting on conservation-oriented landscaping: urban landscaping should take the road of resource-saving and environment-friendly, and must use the least land, the least water and the least capital investment, choose the greening mode with the least interference to the surrounding ecological environment, and take local conditions as the basic criterion to provide the most efficient ecological security system for urban residents. This is a new requirement put forward by China in view of the current situation of resource shortage, which has important strategic significance. Three. Connotation and characteristics of conservation-oriented landscaping The conservation-oriented urban landscaping refers to "choosing the greening mode with the least land use, the least water consumption, the least financial allocation and the least interference to the surrounding ecological environment". It contains three meanings: first, to save natural resources and all kinds of energy to the maximum extent and improve the utilization rate of resources and energy; The second is to maximize the ecological and environmental benefits of urban garden green space; The third is to get the maximum ecological, environmental and social benefits with the minimum investment. Economical garden should be the most reasonable, economical and efficient garden form. At the same time, according to the connotation of conservation-oriented landscaping, conservation-oriented garden green space should be an ecological garden, which should conform to the basic laws of natural ecosystem and have the basic characteristics of sustainability, self-maintenance, high efficiency and low cost. The idea of vigorously advocating conservation in the construction of garden green space is put forward in order to conform to the construction of a conservation-oriented society and oppose many extravagance and waste in the current greening construction, but the requirements for the quality, standard and grade of urban garden green space construction cannot be relaxed because of conservation. 4. Ecological strategy for planning and design of conservation-oriented garden green space (1) Scientific planning and rational utilization of urban land resources 1. Scientific planning to improve the ecological efficiency of urban green space system A good ecological pattern of urban garden green space can improve the ecological efficiency of urban green space system, which is the basic condition to meet the functional requirements of urban green space such as ecological environment, landscape, culture, recreation and protection. The ideal urban green space system structure should conform to the laws of urban physical driving forces such as urban aerodynamics, urban hydrology, urban heat dissipation and human activities, and should have basic characteristics such as uniform layout, flow of elements, functional accessibility, system stability and spatial openness, so as to play a great role in improving the quality of urban ecological environment. These are all based on scientific and reasonable planning. Forward-looking planning can prolong the service life of green space, avoid frequent reconstruction of urban garden green space, save urban construction funds, and thus achieve economic savings. 2. Reasonable design, improve the utilization rate of garden green space The premise of improving the utilization rate of garden green space is that the site selection of garden green space should be correct and the design should be reasonable. The survey shows that the large space in urban garden green space, such as large lawn or paving site, is grand and spectacular in spatial scale, but there are few users and the utilization rate of the site is very low; On the contrary, those small-scale spaces, such as rest and fitness equipment areas that meet people's needs, are often overcrowded. In addition to the landscape function, urban garden green space also shoulders multiple functional requirements such as ecology, fitness, leisure, culture and protection. These requirements should be considered in the design, focusing on creating diversified small-scale spaces and reducing the design of indifferent and empty large-scale spaces, so as to improve the utilization rate of green space and indirectly save land resources. 3. Three-dimensional greening to improve the ecological benefits of urban garden green space. Vertical landscape greening includes vertical greening, roof greening, viaduct greening and overpass greening. Through three-dimensional greening, the ecological efficiency of green space can be improved, the urban landscape can be beautified, the urban greening rate can be improved, urban land resources can be saved, and great social and ecological benefits can be brought into play. Without increasing the green area, the technical measures of three-dimensional greening and multi-layer vegetation construction can obviously improve the three-dimensional green quantity and leaf area index of urban landscaping, enrich the coverage level of urban greening and improve the quality of human settlements. At present, the three-dimensional greening technology is basically mature, which urgently needs policy guidance and project support from relevant government departments and industries. (2) Rational selection of plant resources and optimization of plant allocation 1. According to local conditions, the plant planting design of giving priority to native plants is an important part of modern garden green space ecological design, which mainly includes the selection of plant varieties and the establishment of plant landscape ecological community, among which the selection and utilization of a large number of native plants is a basic principle of plant variety selection. In the "Provisional Standard for the Construction of Ecological Garden City" promulgated by the state, there are also clear requirements for the basic indicators of the application of native tree species. However, due to the psychology of some builders blindly following the trend and comparing with others, and driven by the economic interests of designers and builders, there are still many phenomena of neglecting native tree species and introducing a large number of exotic tree species, especially exotic ornamental varieties, which directly leads to a large increase in construction and maintenance costs. For the planning and design of conservation-oriented garden green space, native plants not only have unique natural advantages such as low cost, strong adaptability and obvious local characteristics, but also have strong adaptability to the environment and soil, few pests and diseases, ecological safety and reliability, and save water resources. Some plants can survive well only by rainfall, thus reducing maintenance costs such as irrigation and fertilization. 2. Planting design simulates the dominant community structure of native plants. After long-term succession competition, the general local vegetation community gradually formed the community structure of local dominant population formed by local dominant plant varieties and combinations of dominant plant varieties. These dominant plant populations and community structures are the result of long-term competition in nature, the product of survival of the fittest, and have strong adaptability to the local environment and climate. Based on this, American ecologist and landscape planner Macharge put forward the design concept of "combining design with nature". This artificial plant community landscape design, which follows the law of natural succession and simulates the dominant community structure of native plants, has stronger landscape diversity and ecological stability than the traditional plant configuration that only pays attention to landscape. At present, this design concept has been widely recognized and applied in many ecological garden constructions at home and abroad. 3. Greening mode The greening mode is mainly a layered community. The multi-layer mixed community greening model composed of tree layer, shrub layer, herb ground cover layer and interlayer plants is an important form to realize the landscape and ecological function of garden green space. The traditional greening model pays more attention to the ornamental effect, but lacks sufficient attention to the biological characteristics, niche and community structure and configuration of plants, which leads to the simplification of most interspecific configuration and community hierarchy of urban green artificial communities. At the same time, in order to emphasize the ornamental effect, lawns, artificially trimmed patterned altars and a large number of annual grass flowers are widely used. The overuse of this regular allocation technology leads to the decrease of plant species per unit area and the simplification of community structure level, which leads to the poor stress resistance of some community structures, and eventually the plants will grow poorly until they die. Experiments show that the water consumption of trees and shrubs is much lower than that of lawns, but the ecological benefits are much higher than that of lawns. The ecological benefit of 10m2 trees is equivalent to that of a well-growing 50m2 lawn. In addition, a large amount of money is invested in the centralized placement of annual grass flowers in the garden green space. Although a strong "display" effect can be obtained in a short time, faults and gaps will appear in the landscape when the flowering period is short. These practices are uneconomical and should be corrected in future greening construction. Emphasis is placed on the use of perennial perennial flowers to build a multi-layer plant ecological community of trees, shrubs and flowers (grass). (3) Using the recycling theory to save natural resources. The so-called recycling theory refers to the construction of a complete biological chain of landscaping from producers to consumers to decomposers based on the theory of material circulation and energy conversion of ecosystems. What it advocates is an application model based on the continuous recycling of materials, which requires human activities to be organized into a material recycling process of "resources-products-renewable resources" according to the model of natural ecosystem, and no or only a little waste is produced in the whole production and consumption process of landscaping. In the theory of ecological design, the "3R" principle is usually followed, that is, reduction and reuse. These design principles are also applicable to the planning and design of economical garden green space. The design of conservation-oriented garden green space is to reduce the use of non-renewable resources, reduce pollution emissions and reduce the interference of human factors on natural ecosystems. For example, in the landscape design of garden green space, we should make full use of topographic features and vegetation conditions, reserve all available landscape resources in the original site, and carry out organic transformation, which not only highlights the local characteristics of the landscape, but also saves a lot of construction funds. At the same time, the vertical design of the site follows the principle of reducing large terrain transformation and balancing earthwork on the spot, which is an effective means to reduce human interference, reduce economic investment and save resources. In addition, "recycling" is another resource-saving measure of conservation-oriented landscaping, which mainly includes the reuse of abandoned landscapes, the substrate treatment of garbage, and the collection and reuse of rainwater. 1. Landscape reuse of wastes includes buildings, structures, facilities and equipment left over from various abandoned lands. In the planning of landscape reconstruction, the landscape value of these wastes should be fully excavated and utilized for landscape reconstruction and reuse. Taking the park reconstruction of industrial wasteland as an example, the successful development models of famous industrial heritage parks at home and abroad, such as Duisburg Park in Germany, Gas Factory Park and Zhongshan Park in Qijiang, Guangdong, provide valuable experience for waste reuse. For example, transforming abandoned railway tracks into unique flower diameters, transforming abandoned machine tools into industrial sculptures, transforming water towers into watchtowers, retaining the steel frames of old factories, and transforming them into places for rest and leisure, which not only continues the characteristics of places, creates unique landscapes, but also saves construction funds. It is a material saving means that conservation-oriented gardens should learn from. 2. Substrate treatment and reuse of garden waste, such as litter in garden green space, sludge dredged from ponds and rivers, etc. If they are treated harmlessly and turned into nutrient-rich plant growth substrates, it can not only eliminate the pressure of garden garbage treatment, but also provide efficient fertilizers for agricultural production and urban greening, and realize the sustainable material cycle of garden greening ecosystem. At present, there are many garden waste treatment plants at home and abroad to treat urban garden waste and garbage, which have played significant ecological and economic benefits in realizing the harmlessness and recycling of garden waste, saving capital investment and saving the use of inorganic fertilizer materials. 3. Recycling of rainwater and reclaimed water The water quality of rainwater can meet the needs of conservation water and landscape water in urban green space, so rainwater can be collected by buildings, roads and lakes in garden green space for green space irrigation and landscape water. For the hard pavement part, the permeable pavement is established and paved with permeable materials, which directly increases the permeability. At the same time, combined with the design of rainwater collection pipeline system, rainwater is collected and finally collected in the water body or underground reservoir in the garden green space for irrigation and maintenance of the garden green space. Germany is one of the most advanced countries in rainwater collection and utilization in the world, and its urban greening has solved most of the landscape water and conservation water by collecting and utilizing a large amount of rainwater, and some even achieved zero consumption of urban clean water resources. Semi-circular gutters and rain gutters are designed under the eaves of ecological buildings to collect rainwater from the roof. Part of the collected rainwater is used to irrigate green land and part of it is used to supplement groundwater. In addition to rainwater resources, urban reclaimed water can also be used for irrigation and conservation of garden green space through recycling, which can not only effectively use and save limited fresh water resources, but also reduce the discharge of sewage and wastewater and reduce water environmental pollution. In the "Provisional Standard of Ecological Garden City" promulgated by the state, there are also clear requirements for the utilization rate of reclaimed water. Using reclaimed water to irrigate urban gardens has a history of several decades in Israel, the United States, Japan and other countries, especially in Israel, where more than 80% of urban garden maintenance water is simply treated with domestic sewage and industrial wastewater, combined with modern irrigation technology [3]. In China, the use of sewage for green space irrigation is still in its infancy, and the city's water quantity is large and relatively concentrated, and the water quantity and quality are relatively stable, which is a water source that can provide continuous water supply. A large part of them can meet the requirements of garden water after simple primary or secondary treatment. (4) Application of new water-saving and energy-saving technologies. The traditional irrigation method of garden green space not only wastes a lot of water resources, but also causes untimely and uneven irrigation, which is prone to surface runoff and deep leakage, thus affecting the irrigation effect. Automatic spray and drip irrigation technology is based on automatic monitoring of plant ecological habits and soil and climate conditions, and irrigation is carried out in a timely and appropriate manner by using automatic control system. Compared with traditional irrigation technology, it can save about 30% ~ 50% water, save labor and be efficient. Universal automatic sprinkler irrigation technology is especially suitable for the irrigation of densely planted or low plants, such as lawns, shrubs and flowers. In addition to the main advantages of sprinkler irrigation, drip irrigation can save about 40% water and 50% ~ 70% energy compared with sprinkler irrigation, but the pipeline system is widely distributed, which increases the investment cost and the workload of operation management. At present, drip irrigation is mainly used to irrigate flowers, shrubs and street trees, but it is seldom used in lawns and other close-planted plants. Its technical principle is to supply water directly to the roots of plants, reduce the evaporation loss of water, and inhibit the growth of weeds without affecting the ground landscape. It is an irrigation technology with great development potential in the future garden green space. (5) Design and manage a wide range of landscapes to save maintenance costs. Garden management is an important link in garden construction. Compared with the engineering construction stage, maintenance management is a long-term and periodic process. At present, many exquisite landscape projects are accompanied by a lot of manpower and material resources for a long time, especially the large-scale application of lawns, fountains and pools, artificial shaping and patterned plant pruning. Because of the need for regular pruning, weeding and other fine maintenance work, or the landscape that needs a lot of water resources and power resources as a price like a large fountain, once it loses careful care and high operating cost support, the original dazzling landscape will soon lose its glamorous appearance, become messy and be abandoned beyond recognition. Therefore, management saving is also an important part of conservation-oriented garden green space, which should be clearly defined in the early stage of project construction and fully controlled through planning and design. V. Conclusion The planning and design concept of conservation-oriented landscaping is put forward in order to adapt to the increasingly serious energy shortage and conform to the construction of conservation-oriented society in China. Its construction theory and thought embody the essence and connotation of ecological garden, namely, economy, sustainability, self-maintenance, circulation, high efficiency and low cost. Therefore, building a conservation-oriented garden is also an important way to realize an ecological garden city. Only through scientific conservation-oriented planning and design can we adjust measures to local conditions, maximize the ecological and environmental benefits of conservation-oriented garden green space and save all kinds of funds to the maximum extent. [References] [0] Published papers. Liu Chunqing. Building Economical Landscaping —— Chou Baoxing, Vice Minister of the Ministry of Construction, asked the whole country to carry out economical landscaping [J]. Landscape Science and Technology, 2006, (4). [2] Nie Lei. Talking about the building-saving landscaping technology.