Study On The Spatial And Temporal Characteristics Of Health Care Effects Of Different Vegetation Types On Campus

With the continuous advancement of urbanization,environmental pollution problems have also increased,threatening people’s physical and mental health.As the’’second nature’’of artificial construction,urban vegetation plays an important role in regulating urban heat island effect and purifying air,and its health care effect has been paid more and more attention.As a relatively independent unit in the city,it is particularly important to create an environment suitable for learning and living.The ecological function demand of vegetation in campus is to create a learning and living environment as the leading function.However,at present,the research on campus vegetation environment at home and abroad mostly focuses on planning and visual aesthetics,and the research on the health effect of campus vegetation types has not attracted enough attention.In this study,11 different vegetation types were selected from Daizong Campus and Panhe Campus of Shandong Agricultural University.Combined with geostatistical technology,the spatial and temporal variation of the main health factors（air negative oxygen ions,air particulates and microclimate）of different vegetation types on campus and the difference of landscape effect influencing factors（scenic beauty）were analyzed by using grid uniform distribution method.Based on the evaluation system of single influencing factors,a combination of multiple influencing factors was used to comprehensively evaluate the overall health effects of different vegetation types on campus.The purpose of this study is to provide a scientific basis for teachers and students to choose the best places for learning and leisure activities in different vegetation types on campus,and to provide theoretical support for the construction of campus vegetation environment in the same type of climatic conditions.The main results are as follows:1.The concentration of air negative oxygen ions in different vegetation types on campus has obvious temporal and spatial variation.The seasonal variation of negative oxygen ion concentration in different vegetation types on campus was summer>autumn>spring>winter.The concentration was the highest in summer,with an average of 853/cm³ and a winter average of 502/cm³.The diurnal variation of negative oxygen ion concentration was generally high in the morning and afternoon,and the concentration was low at noon.The maximum value appears at 10:00-12:00,and the minimum value appears at 12:00-16:00.According to the relationship between air negative oxygen ion concentration grading evaluation criteria and health,it can maintain the basic needs of human health under spring conditions.In summer and autumn,the concentration of negative oxygen ions in arbor,shrub and grass vegetation types has reached a’’favorable’’level for human health,which can enhance human immunity and antibacterial ability,and promote human health.The spatial distribution of air negative oxygen ions has the characteristics of spatial heterogeneity,and the overall performance was an increasing trend from the forest edge to the forest.The spatial distribution of air negative oxygen ions between different vegetation types was quite different.The concentration of negative oxygen ions was accumulated in the vicinity of vegetation types with higher vegetation coverage or tree species with larger crown width.2.The concentration of air particulate matter in different vegetation types on campus has obvious temporal and spatial variation.The seasonal variation of air particulate matter concentration in different vegetation types on campus was winter（94.7μg/m³）>autumn（79.6μg/m³）>spring（57.6μg/m³）>summer（37.9μg/m³）,and the seasonal trend of particulate matter concentration with different particle sizes was consistent.The diurnal variation of air particulate matter concentration showed a trend of high in the morning and low in the afternoon.According to the evaluation standard of air particulate matter concentration,the cleanliness of TSP,PM₁₀ and PM_2.5 in spring and summer reaches’’medium’’and above level,which was suitable for teachers and students to study and leisure activities in vegetation environment.In autumn and winter,TSP cleanliness was mostly at’’medium’’level,PM₁₀ and PM_2.5 concentrations are relatively high,reaching’’pollution’’level,which was not suitable for outdoor recreation activities.The spatial variation of air particulate matter concentration in different vegetation types shows that the arbor-shrub-grass vegetation type can exert its dust retention ability to a greater extent than the arbor-grass vegetation type.3.The microclimate of different vegetation types in campus has obvious temporal and spatial variation.The seasonal variation of temperature was significantly different（p<0.05）,summer>spring>autumn>winter;the seasonal variation of humidity was significant（p<0.05）,summer>autumn>spring>winter,the seasonal variation of wind speed was not obvious;the diurnal variation of temperature in different vegetation types showed a single peak,with a peak at 12:00-14:00.The diurnal variation of air relative humidity was low,and the lowest value appeared at 12:00-14:00.The seasonal variation of the overall comfort index of climate comfort in the two campuses was winter>autumn>summer>spring.According to the comfort evaluation standard,the winter comfort index was greater than 6.95 for the’’extremely uncomfortable’’level;the diurnal variation of comfort index showed a single peak trend in summer,and reached the’’uncomfortable’’standard at 12:00-14:00,which was not suitable for outdoor recreation.The diurnal variation in spring,autumn and winter showed a single valley trend.Vegetation type will affect the spatial distribution of comfort index.In the dense distribution of plants,the comfort index was patchy,and the local index increases.4.Changes of scenic beauty of different vegetation types in two campuses.The seasonal variation of scenic beauty was:spring>summer>autumn>winter,and the scenic beauty in spring was the highest.In Daizong Campus,the scenic beauty evaluation value of Cedar and Eucommia mixed type,Pinus tabulaeformis and Liquidambar mixed type and Koelreuteria paniculata and Ginkgo mixed type was high.In the Panhe campus,the scenic beauty evaluation value of the mixed type of cedar and maple,the mixed type of Huangshan Luan tree and ginkgo,and the mixed type of ginkgo and maple was high.The vegetation type was that the beauty evaluation of the vertical structure of arbor,shrub and grass was higher than that of the vertical structure of arbor and grass.5.Comprehensive evaluation and suggestions on campus vegetation health effect.Among the six vegetation types in Daizong campus,the comprehensive evaluation of the health and wellness effect of the mixed type of cedar and Eucommia ulmoides,the mixed type of Pinus tabulaeformis and Sapium sebiferum,and the mixed type of Huangshan Koelreuteria paniculata and Ginkgo biloba was good,which was suitable for teachers and students to carry out learning and recreation activities.In the Panhe campus,the health and wellness effect of the mixed type of cedar and Liquidambar formosana,the mixed type of Ginkgo biloba,and the mixed type of Huangshan Koelreuteria paniculata and Ginkgo biloba was better.It was recommended that teachers and students carry out learning and leisure activities in this vegetation type.Therefore,under the same climatic conditions,the construction of campus vegetation environment gives priority to the vegetation type of multi-layer vertical structure of arbor,shrub and grass.The comprehensive evaluation of its health effect was good.Teachers and students learn and relax in this vegetation type,which was conducive to physical and mental health.In summary,by studying the spatial and temporal variation of health factors of different vegetation types on campus,taking the health of teachers and students as the starting point,this paper explores the best place for teachers and students to carry out outdoor learning and leisure activities,and provides a basis for the transformation and development of campus vegetation types.