Study On Riparian Forest Landscape And Soil Ecological Function In Central Urban Area Of Chengdu Under Different Vegetation Allocation Modes

Forest is the cradle of human beings and the most important representative of biological resources.With the intensification of urbanization,forest fragmentation becomes more and more serious,and urban ecological problems become more and more prominent.As an indispensable and important factor to improve urban ecological environment,urban forest construction and management has been paid more and more attention.How to give full play to the various functions of urban forest in urban construction is a problem worthy of further discussion.Urban riparian forest not only plays an aesthetic role,but also an ecological role.On the one hand,aesthetic quality evaluation is the most intuitive feeling of visitors to urban forest,and is one of the external manifestations of urban forest quality.Chengdu,on the other hand,many rivers,ditches,city park many rely on urban water system building,urban forest are widely distributed along the water system,the impact on the soil ecological risk of heavy metals and soil improvement effect is one of the forms of urban forest ecological function,are unique function of urban forest ecological protection function,the function is the building elements not possessed by other cities.Center of Chengdu urban riparian forest vegetation configuration mode mainly includes halosols deserts,Joe stand of grass,bringing stand and stand of single-layer Lin,five kinds of patterns such as single lawn,in the central city of Chengdu as the study area,this study aesthetic evaluation theory and the scientific test method of the combination of central city riparian forest were studied.The aesthetic quality of riverside landscape recreation forest in the central urban area of Chengdu was evaluated by using the method of SBE.Through the investigation and detection of the soil condition of riparian forest in the central urban area of Chengdu city,the paper analyzes the pollution situation of heavy metals in soil by stands under different vegetation allocation modes,evaluates the ecological risk of heavy metals in soil,and analyzes the improvement effect of different stands on soil.Based on the analysis and discussion of the research results from the two aspects,a better vegetation allocation model with comprehensive evaluation was obtained,and some Suggestions on the construction,transformation and operation and management of riparian forest in the central urban area of Chengdu were put forward to serve the overall tourism strategy of Chengdu and improve the quality of leisure,health and tourism experience of Chengdu.This study draws the following conclusions:(1)Seven factors,including color richness,natural pruning,undergrowth coverage,tree density,average tree height,trunk morphology and broad-leaved tree species,have a great impact on the beauty.(2)The ecological harm of the planting mode was significantly lower than the threshold value of 150(the threshold value of ecological harm is slight),and all were at the level of slight pollution(E<40,RI<150).(3)The physical and chemical properties of the soil are significantly affected by the stand,and the effect of the multi-layer forest vegetation allocation model on soil improvement is the most significant.The well-evaluated ripari forest vegetation allocation model in Chengdu city is the multi-layer forest vegetation allocation model with trees,shrubs and grasses.