Analysis Of The Influence Of Tree Species Selection And Planting Spacing On Microclimate Of Tree-shaded Plaza

With the rapid development of urban construction,people's demands for living standards have been continuously enhanced,and more emphasis has been placed on the healthy and comfortable environment of urban public spaces.The tree-shaded plaza is an important open space in the urban green space.It not only provides entertainment and leisure for urban residents,but also serves as an indispensable part of the urban ecosystem,and it plays a crucial role in the urban ecological stability and the improvement of the microclimate environment.At present,the research on the microclimate of urban green space is mostly focused on the ratio of green space and the layout of green space,but lacks the research on the microcosmic impacts of planting distance and tree species selection.In this paper,taking the tree-shaded plaza of shenyang science park as an example,comparing the simulation results of Envi-met 4.0 software with the meteorological data obtained from actual measurements,on the premise of verifying the validity of envi-met4.0 software simulation method,the effects of different tree species and planting space on microclimate of forest shade square such as air temperature,relative humidity and wind speed were investigated.The findings are as follows:When the tree species are the same,the planting distance increases from 4m to 7m,and the lowering of the understory temperature and the increase of relative humidity of the tree-shaded plaza will be enhanced,and the range of influence will increase.The impact of planting spacing on wind speed changes was not obvious.The impact of planting spacing on the wind speed under the forest was mainly to reduce the scope of wind speed change,and did not change the wind speed significantly because of the increase in planting spacing.When the tree planting spacing is the same,different tree species have different effects on the lowering of the understory temperature and the relative humidity of the tree-shaded plaza.When the planting distance is 4m,the cooling and humidification effects of fraxinus excelsior and platanus acerifolia are greater than that of abies alba.The effect of abies alba on the change of wind speed is slightly smaller than that of fraxinus excelsior and platanus acerifolia.In the 7m planting interval,platanus acerifolia had the greatest effect on lowering temperature and increasing humidity,followed by fraxinus excelsior,and abies alba had little effect on the change of wind speed in the tree-shaded plazaa.Leaf area density is an important factor affecting the air temperature,relative humidity,and wind speed in the tree-shaded plaza.