Study On Microclimate Effects Of Urban Green Space Plant Communities In Hot And Humid Regions

The hot and humid climate zone with hot summer and warm winter has the characteristics of high temperature,high humidity and rainy weather.The urban buildings in the hot and humid area are dense,and the construction of urban green space can effectively improve the characteristics of hot and humid climate and contribute to the physical and mental health of the citizens.Plant communities are the basic building blocks of urban green space and have a critical impact on the formation of local microclimate environments.Studying the microclimate effects of plant communities in urban green space can provide a basis for optimizing the design of urban green space plant communities in hot and humid climate regions.Guangzhou is located in Lingnan area and has a typical hot and humid climate characteristics.The campus green space carries a wealth of social functions,and the types of green spaces are diverse.Therefore,this study selected Guangzhou campus green space as the representative of urban green space in hot and humid areas,and launched the following research:The plant communities in campus green space of five universities in Guangzhou were investigated.The species composition,quantity specifications and layout characteristics of 96 plant community samples were analyzed.The plant species,family type,tree color characteristics commonly used in the campus green space of Guangzhou,the height,crown width,canopy characteristics of the arbor layer,the density distribution characteristics of the shrub layer,the distribution characteristics of the cover layer,and common layout patterns of the plant community are accounted.In order to explore the microclimate effects of plant communities with different structures,representative samples of Joe Shark,Johor,Joe and Arbor type,as well as a hard paving sample,were selected to carry out the microclimate effect observation.The observation results show that the microclimate effect of the plant community regulating the site is significant,and that the plant community of the Johor-type structure has a significant cooling and ventilation effect inside and around the community.The ENVI-met software was used to simulate the plant communities of different layout patterns with the same structure type,exploring the influence on microclimate effect between plant communities of different layout patterns.The simulation results show that the difference of plant communities layout patterns has a significant influence on the wind speed and wind direction,but an inconspicuous influence on temperature and humidity inside and around the community.The plant community with uniform arbor and block shrub layout patterns has an obvious cooling and ventilation effects on microclimate.Observations and simulation experiments results show that the plant communities with Johor-type structure and uniform layout patterns has an significant effect on mitigating high temperature and high humidity climate.The actual plant community case is optimized to verify the scientificity and feasibility of the conclusion.This paper investigates and analyzes the plant communities of campus green space in Guangzhou,combining the actual measurement and simulation methods to explore the effects on microclimate of plant communities in hot and humid regions,providing decision-making basis and optimization strategies for scientific and rational construction of urban green space plant communities in hot and humid regions,which is of an application value to improve the microclimate of urban green space in hot and humid areas.