Study On The Ecological Benefits Of Green Space In Fuzhou City

With the development of society and the accelerated process of industrialization and urbanization, human survival environment has been seriously damaged. So the environmental issues occurred frequently, such as urban floods, air pollution, urban heat island and so on. Environmental problems will hinder the further development of social undertakings, have serious impact on physical and mental health of humans, even cause huge urban disaster, and have a threat to people’s lives and property safety. Urban green space, the lungs of the city, is an important part of the urban ecosystem, which has plenty of functions in ecological regulation:flood control and disaster mitigation, temperature decreasing and humidity increasing, carbon fixation and oxygen release, dust detaining, sterilization, noise reduction, health care, pollutant gases absorbtion and many other aspects of ecological regulation. The ecological benefits of urban green space can be a good solution to a variety of environmental problems which caused by urbanization, enhance the quality of the urban environment, improve the living environment, conserve biological diversity, and promote the sustainable development of society. Fuzhou is facing a variety of environmental issues in the development of urbanization currently. Researching the green ecological benefits in Fuzhou has important theoretical value and practical significance.In this paper, taking Fuzhou urban green space as test objects and using theoretical knowledge and experimental methods of Landscape Architecture, Botany, Landscape Ecology and so on. This paper quantitatively analyzed the regulation of rainfall effect and dust-retention effect of Fuzhou green plants, as well as the temperature-decreasing effect, humidity-increasing effect, light intensity reduction effect of the green patch. Probe the relationship between urban green space and ecological benefits, reveal the main factors which can affect the green ecological benefits, which provide theoretical support to both the selection of Fuzhou green plants and the planning construction of green patch. But also provide scientific basis for the conservation and management of follow-up urban green space and the ecological function enhancement. Though the research on ecological benefits of urban green space in Fuzhou city, the results are summarized as following:(1) The regulation of rainfall effect on garden plants in Fuzhou city showed that:The throughfall, stemflow and canopy interception all increased with the increasing rainfall. There was a highly significant linear relationship between the rainfall and throughfall. The relationship between canopy interception and the rainfall, fitting with a parabolic equation. A power function relationship existed in the rainfall and the canopy interception. The garden plants of throughfall ratio, stemflow ratio and canopy interception ratio were influenced by species characteristics. The throughfall ratio, stemflow ratio and canopy interception ratio of different garden plants had great differences. Tree-shrub-herb had the good regulate ability to rainfall. We should choose the plants which had a high canopy interception ratio in greening, adopt the ecological planting form, for example the combined form of tree-shrub-herb to regulate urban floods effectively.(2) The research on dust-retention effect of garden plants in Fuzhou city indicated that:Different garden plants had great differences on dust-retention ability. About urban greening in Fuzhou, we can choose the plants which had high dust-retention ability, such as Grevillea robusta, Psidium guajava, Tibouchina semidecandra, Lantana camara, Rhododendron pulchrum，Eremochloa ophiuroides. The plants, which have high dust-retention ability, have the hard foliage, but not sag. The leaves are much smaller, which have rough surface, multi-hairs, more wrinkled, more oil and other characteristics. The comparasion study of tree, shrub, herb on dust-retention ability showed that:shrub> tree> herb. The dust-retention ability can grow with time increasing, has the accumulation effect. The dust-retention ability of plant affected by the growth environment, which can also reflect the quality of the environment whether is good or bad.(3) The effect on temperature decreasing of green patch in Fuzhou demonstrated that:Green patch area and the patch perimeter had great influences to the effect on temperature decreasing. The temperature decreasing grown with the increasing green patch area and perimeter, that can be reflected by the logarithmic function. The time showed a single peak polyline on temperature decreasing, the highest temperature difference was at noon, in the morning and evening, the temperature difference was less than noon. Green patch of different planting structure affected the temperature decreasing,ranked as: Tree-shurb-herb>Tree-shurb>Tree-herb>Shurb-herb>Brush>Lawn. Different shapes of green patch affected the temperature decreasing, ranked as:Irregular graphics> Square>Trapezoid>Rectangle> Round> Fan> Triangle. Different types of green patch affected the temperature decreasing, ranked as: Green patch of Campus (Fujian Agriculture and Forestry University)> Green patch of Parks (Xihe Park)> Green patch of residential area (Rongqiao Jinjiang residential area)> Green patch of road (Riverside West Boulevard)> Green patch of square (Rongcheng Square). The temperature decreasing of green patch ranged from0.18℃to1.13℃.(4) The effect on humidity increasing of green patch in Fuzhou demonstrated that:Green patch area and patch perimeter had great influences to the effect on humidity increasing, that can be reflected by exponential function. With the area and circumference increased, the humidification overall showed increasing trend. The time showed a single peak polyline on humidity increasing, the highest humidity difference was at noon, in the morning and evening,the humidity difference was the lowest. Green patch of different planting structure affected the humidity increasing, rankedas:Tree-shurb-herb>Tree-shurb>Tree-herb>Shurb-herb>Brush>Lawn.Different shapes of green patch affected the humidity increasing, ranked as: Irregular graphics> Square>Trapezoid>Rectangle> Round> Fan> Triangle. Different types of green patch affected the humidity increasing, ranked as:Green patch of Campus (Fujian Agriculture and Forestry University)> Green patch of Parks (Xihe Park)> Green patch of residential area (Rongqiao Jinjiang residential area)> Green patch of road (Riverside West Boulevard)> Green patch of square (Rongcheng Square). The humidity increasing of green patch ranged from0.30%to1.29%.(5) The effect on light intensity reduction of green patch in Fuzhou demonstrated;that:Plant planting density had great effective on light intensity reduction of green patch, which increased with planting density increases, that can be fitted with a linear function. The patch area, patch perimeter, patch shape index had a light influence on the light intensity reduction of green patch. The time showed a single peak polyline on light intensity reduction, the highest light difference was at noon, in the morning and evening,the light difference was lower than noon. Green patch of different planting structure affected the light intensity reduction, ranked as:Tree-shurb-herb>Tree-shurb>Tree-herb>Shurb-herb>Brush>Lawn. Different shapes of green patch affected the light intensity reduction,ranked as:Irregular graphics> Square> Trapezoid>Rectangle> Round> Fan> Triangle. Different types of green patch affected the light intensity reduction, ranked as:Green patch of Campus (Fujian Agriculture and Forestry University)> Green patch of Parks (Xihe Park)> Green patch of residential area (Rongqiao Jinjiang residential area)> Green patch of road (Riverside West Boulevard)> Green patch of square (Rongcheng Square).The light intensity reduction of green patch ranged from2328Lux to12096Lux.(6) After analyzing the existing problems in the construction and management of the green patch in Fuzhou, according to the principles of urban green space ecological planning and construction that proposed scientific and reasonable recommendations to the future construction and management of green space in Fuzhou city. It should join the plaque and plaque, plaque and corridors together by corridor, which can form a green network system. In urban construction, we should control population and urban development, protect the existing green patch and increase the green area. When designing the urban green patch, we shall use more irregular shapes, or use a variety of geometric shapes puzzle into irregular shapes, combined with local specialties to create urban natural landscape. We can apply more native tree species to rich plant species, increase the number of plants, imitate the natural plant communities configuration, adopt meticulous conservation and management, improve the ecological benefits of green patch to improve the quality of the urban environment. To govern the ecological problems from the source, we should develop good habits, change the way of economic development. increase the publicity efforts, formulate protection laws so that the thought of taking care of green and preserving green ideas understood by the public.