Study On Vegetation Characteristics And Conservation Strategy In The Conservation Area Of Chenshan Botanical Garden, Shanghai

As one of the sole hilly-forest in Sheshan mountain area,Shanghai,the representative modified vegetation in further urbanized area,and the important part of Shanghai's vegetation,Chenshan has been inflected by the temporal and spatial human disturbance as the urbanization expanding.Furthermore,the Chenshan hilly forest will be proposed as the conversation area of Chenshan Botanical Garden(CBG) in building.It is also the one of the only remnant nature vegetation in Shanghai,which plays a very important part of Shanghai's vegetation.The functions of modern botanical garden contain plant research,education, recreation,conservation and the produccing activities relative to plant resource.Wherein the conservation is including both of migration preservation and the local preservation. For example,the Hendrie Valley Sanctuary,belonging to Royal Botanical Garden, Canada,as the biological refuge is protecting the natural mountain vegetaion and wetland vegetaion.What is the vegetation pattern of the conservation area of CBG illustrating? What the succession rule it processes? How to confirm the conservating target and formulate an eco-efficient in premise of its ecological service function in used? The answers of those questions will play an important role on the execution of the implementation of conservation strategy of CBG,and the researches on zonal vegetation restoration in urbanized area.Such principles were applied in understanding of the vegetation characteristics, predition of the community succession,and the rehabilition of Shanghai's local representative community by utilizing the mountain environment and current artificial communities.The induction to evergreen and deciduous mixed forest should be refered to the relevance of vegetaion and habitat which is based on the monitoring and analysis on the current vegetation.Applying of the plant social investigation and the enumeration survey,the following factors,respectively in 7 classical communities in conservation area of CBG,were analyzed:species constitute,flora and living forms composition,flora distribution,dominant species composition,community structure and age structure; Through diversity indexes calculation,the species diversity,richness and evenness in different communities were also analyzed;futhermore,the following 4 habitat factors: soil physical and chemical characteristics,the recycling features of litter-falls, micro-climate of ecological interphase and the photosynthesis resource utilization,for guaranteeing of the confirmation and inplementation of conservating strategy can be highly reflected to the information of this ecosystem.Finanlly,a close-to-nature ecological restoration conservation strategy and its additional measures for the conservation area of CBG are summarized.The conferences of this study as follows:1.The results show that only 94 vascular plant species belong to 49 families and 69 genera in the total sample area of 1 400m².The flora composition reflects the mid-subtropical zone and north-subtropical zone transitional vegetaion feature,which also is the classic natural recovery form in local vegetation.2.The dominant deciduous species of 7 communities are Liquidambar formosana, Robinia pseudoacacia,Ailanthus altissima and Acer buergerianum.These species are predominant in the respective communities,and improving the local surroudings and facilitating the extra-planted trees such as Cinnamomum camphora and Ligustrum lucidum in plantation.3.The diversity,richness and evenness analysis of 7 classical communities illustrated that the highest Shannon-Wiener index is located in the Plot-3:Robinia pseudoacacia+ Cinnamomum camphora+ Liquidambar formosana+ Celtis sinensis community(Dsw=1.757),then the Plot-4:Liquidambar formosana+ Robinia pseudoacacia+ Celtis sinensis community(Dsw=1.477).However,the population is still not filling in all the layers of these two plots,by the evident of the low simpson index(E_1/D=0.027 and E_1/D=0.05).The pielou evenness indexes of plot1-plot4 deciduous communities are between 0.732-0.918,generally higher than that of evergreen and deciduous mixed community and Phyllostachys heterocycla community,specially the mixed community is the lowest 0.533.4.The vertical structure illustrated a "Canopy-Post-aggregate" system than the full understory hierarchical system in most of communities,which means there is a large light utilization space for the plantation. 5.Accourding to the analysis of the age structure,except for the Acer buergerianum, the post-growing trees of the current dominant species such as Liquidambar formosana, Robinia pseudoacacia and Ailanthus altissima,are not enough for the seedling recruitment.All of these communities belong to unstable pre-middle succession phase.6.Applying the Lion 6400 and the HOBOware Climate Staion in the ecological monitoring of the habitat of classical communities in the conservation area of CBG,the relationship of vegetation and habitat show that in a constant radiation quantity,the difference of landform leads to the difference of the photosynthesis resource utilization among various trees;the air temperature and humidity,and the constant soil temperature and moisture of understory provide a proper condition for the zonal vegetation;the soil is weakly acidic and range from the prophase deciduous forest to the late mixed forest,the differences of varied layers of the soil physical and hydro characteristics are not significant;but the differences of varied layers on the indexes such as TN,TP and C/N are significant,due to the return of N and P element through litter-falls.7.Based on the vegetation characteristics,succession rule and the dynamic habitat change,the close-to-nature ecological restoration management strategy is proposed,and added by the following measures:forest phase rehabiliting,recovery of zonal vegetation fastening,reasonable managing for the protection of flora and faund,multi-layers mixed forest building with the local trees,for a better ecological profit and landscape effect,and protecting the potential vegetation in the special habitat.