Application And Evaluation Of Local Medicinal Plant Resources In Urban Green Space In Harbin

Medicinal ornamental plants have been widely used in landscaping and have attracted more and more attention because of their ornamental and medicinal functions and beneficial effects on the human body.The purposeful application of medicinal plants in urban green space can effectively improve the diversity,stability and health of urban garden plants and meet the health experience of a wider population.In this paper,the types of medicinal plants in Harbin green space were analyzed through field investigation,taking Harbin Sun Island Park and Heilongjiang Forest Botanical Garden as the research objects.Combined with the ecological benefits of medicinal plants（carbon fixation and oxygen release,cooling and humidification,air anion concentration,air microbial concentration）,the application of medicinal plants in Heilongjiang Forest Botanical Garden was evaluated by using the constructed medicinal ornamental plant landscape evaluation system.The results are as follows:（1）Field research on medicinal plants in typical green spaces in Harbin（Sun Island Park,Heilongjiang Forest Botanical Garden）was conducted to obtain the application status of medicinal and ornamental plants in Harbin.There are 31 species of arborous medicinal ornamental plants belonging to 22 genera and 17 families in Harbin urban green space.The most species are 11 species of Rosaceae and 3 species of Pinaceae.Among them,evergreen medicinal trees Pinus koraiensis Sieb.et Zucc.Juniperus rigida S.et Z.,Picea koraiensis Nakai,Pinus tabulaeformis Carr.and Taxus cuspidate S.et Z.are widely used.（2）Put forward the construction of Harbin urban green space medicinal ornamental plant landscape evaluation system.Using Bartlett’s sphericity test statistics,the landscape index of medicinal ornamental plants was proposed.The eigenvalue and variance contribution table of each stage of factor analysis are used to verify the selection of index hierarchy factors.According to the factor load matrix,the factors with large load and strong correlation are classified.Finally,the evaluation system of medicinal plant ornamental landscape was constructed with three levels:target layer（medicinal ornamental plant landscape）,index layer（aesthetic value,ecological benefit and social benefit）,factor layer（health status,ornamental richness,landscape diversity,coordination with the environment,carbon sequestration benefit,cooling and humidification,air negative ion concentration,air microbial concentration,healing feeling,social cognition and popular science value）.The analytic hierarchy process is used to determine the weight coefficient of each level.（3）Experimental observation showed that there were significant differences in daily carbon fixation and oxygen release per unit leaf area among 18 medicinal tree species.Among them,Albizzia kalkora（Roxb.）Prain and Fraxinus chinensis subsp.rhynchophylla（Hance）E.Murray capacity,and are significantly higher than the other 16 species.（4）In terms of cooling and humidifying benefits,there were significant differences between different medicinal plants.The daily cooling and humidifying benefits per unit leaf area of 18medicinal ornamental plants were Betula platyphylla Suk.,Syringa reticulata subsp.amurensis（Rupr.）P.S.Green et M.C.Chang,Syringa oblata Lindl.,Quercus mongolica Fischer ex Ledebour var.mongolica,Sorbaria sorbifolia（L.）A.Braun,Sabina vulgaris Ant.and Pinus sylvestris var.mongolica Litv.（5）Through the determination of negative oxygen ions,it can be seen that the main factor affecting the negative oxygen ions in the community is canopy density,and the two are significantly or extremely significantly correlated.The air quality in Pinus tabulaeformis and Betula platyphylla communities reached grade A on average.The concentrations of fungi and bacteria in the community showed obvious diurnal and seasonal dynamics.The average daily concentration of fungi was 176 cfu·m^-3,and the average daily concentration of bacteria was 97 cfu·m^-3.The seasonal dynamics showed that the fungal concentration was the highest in summer(139 cfu·m^-3)and the lowest in spring.The average concentration of bacteria was 113 cfu·m^-3,and the concentration was close between the three seasons.（6）The landscape benefit of medicinal ornamental plants in Heilongjiang Forest Botanical Garden was evaluated by comprehensive evaluation method.The evaluation results show that the aesthetic value,ecological benefit index and social benefit index are 0.864,0.798 and 0.718respectively.The public has a high recognition of the aesthetic characteristics of the landscape value of medicinal ornamental plants.The performance of ecological value is generally close to a good degree,and the preference for its social value is the lowest.（7）Four kinds of plant configuration models of medicinal ornamental plants in Harbin green space were proposed:ecological type,aesthetic type,healing experience type,popular science education type（biodiversity type）.