A Study On Relationships Between Landscape Structures And Functions Of Riparian Zone

The aim of environmental design related (landscape design, garden design or ecological design etc.) is to give some functions which will be benefited to human. However, we can’t design these functions directly, while we can design landscape structures which carry landscape functions. The difference between design aim and design process puts forward the questions:What is the relationship between landscape structure and function? Which kind of structure does control a special function? For a specific function, which structures are more important for it? At present, these questions are not answered well by designers. This article tries to explore the relationships between landscape structures and functions by conducting a case study of the riparian zone in Xuzhou, China.Landscape structures are related closely to scales. With studying the characteristics of riparian zones in Xuzhou, they belong to the small scale. Riparian zone is a special ecosystem which possesses some exclusive landscape structures. In this paper, based on the actual situation of riparian zones in Xuzhou, the author constructed a landscape structure indicator system which contained12specific landscape structure indicators. Meanwhile, the landscape function indicator system was constructed, which contained Level One indicators (ecological function, using function and beautifying function), eight Level Two indicators and14Level Three indicators.23sample areas of riparian zones were selected to survey or evaluate these indicators, and the data of these indicators were gathered. The relationships between three Level One function indicators were checked by regression analysis. The result showed that, for urban riparian zone, its ecological function and using function took a significantly linear relationship, beautifying function and using function took a significantly linear relationship, too, but beautifying function and ecological function took no statistically significant relationship; for rural riparian zone, its use function and beautifying function took a significantly linear relationship, with except the outlier, ecological function and use function, ecological function shared a linear relationship, but ecological function and use function were no statistically significant relationship.Multiple stepwise regression analysis took the interactions between independent variables into account, and this method could remove the multi-collinearity of independent variables. This analysis was beneficial to understand the influence on landscape functions by landscape structures, comprehensively. And its results were meaningful to guide landscape design involved multi-structures. Thus, this paper used the method to explore the relationships between landscape structures and functions of riparian zones.The results from multiple stepwise regression analysis showed that, for the urban riparian zone, the important landscape structures, to ecological function, were "vertical layers of vegetation","tree diameter at breast height" and "relative coverage of ever-green trees or shrubs", the important landscape structures, to using function, were "artificial elements density" and "relative coverage of dominant species"; and to beautifying function, it was "relative coverage of dominant species"; for the rural riparian zone, to ecological function, the important landscape structure were "vertical layers of vegetation","herbaceous plant coverage" and "woody plants coverage", no landscape structure was important to using function, to beautifying function, they were "variation coefficient of tree diameter at breast height","relative coverage of dominant species" and "vertical layers of vegetation".The conclusions of the relationships between landscape structure and function were practical meaning to guide the design of riparian zone. To the design for a special function (ecological function, using function or beautifying function), it can be guided by the results of multiple stepwise regression analysis. To the design for comprehensive functions of riparian zone on urban area, the following structures should be manipulated:increasing the vertical layers of vegetation, selecting the bigger trees, increasing the quantities of artificial elements, multiplying the number of tree species and enhancing the ratio of deciduous trees. To the design for comprehensive functions (ecological function and beautifying function, not include using function) of riparian zone on rural area, the following structures should be manipulated:widening the riparian zone, enhancing the coverage of woody plants and grass, planting the trees with similar size, multiplying the number of tree species and increasing the vertical layers of vegetation.The conclusions of this paper can evaluate landscape design schemes quickly, objectively and quantitatively, and can choose the good scheme with high-efficiency.The creative findings in the paper are as follows:(1)The theory of relationships between landscape function and landscape structure, applied in landscape ecology, was transferred to solve the problems of riparian ecological landscape design;(2)This paper constructed the indicator systems of landscape function and landscape structure, respectively, and studied the relationships between them, which provide a scientific base for ecological landscape design of riparian zone;(3)Based on the relationships between landscape functions and landscape structures, this paper gave some practical methods for riparian ecological landscape design.