植物群落调节微气候舒适度能力及其影响因子——以湖南省怀化市公园绿地为例

The ability of plant communities to regulate microclimate comfort and influence factors:take the green space of Huaihua parks in Hunan province as an example

【目的】通过对比研究怀化城市公园与郊野公园植物群落夏季调节微气候舒适度能力差异,查找城市公园植物配置存在的不足,提出植物群落优化措施,旨在为怀化市创建国家园林城市提供理论指导,为园林设计师科学配置植物提供技术支撑。【方法】于2021年夏季对怀化4个公园26个植物群落进行实地调查。采用“平面量模拟立体量”法计算乔木层、灌木层植物三维绿量值,采用覆盖面积乘以高度计算地被层植物三维绿量。实测植物群落内空气温度、相对湿度值,根据国家人居环境气候舒适度评价标准,采用温湿指数评价微气候舒适度。分析温湿指数降低率与植物群落高度、群落分层数量、三维绿量密度相关性。【结果】1)郊野公园植物群落高度平均为16.69 m、分层数量3.55层、三维绿量密度7.59 m^(3)·m^(-2)、降温率20.50%、增湿率62.87%、温湿指数降低率10.49%;城市公园各指数分别为13.05 m、2.33层、3.60 m^(3)·m^(-2)、20.50%、52.84%、8.57%。2)群落高度、分层数量、三维绿量密度与温湿指数降低率呈极显著正相关关系;当植物群落高度为19.00 m时,温湿指数降低率达10.11%;分层数量为4层时,温湿指数降低率达10.59%;三维绿量密度为7.22 m^(3)·m^(-2)时,温湿指数降低率达10.74%。【结论】与郊野公园相比较,城市公园植物群落层次结构简单、三维绿量密度小、调节微气候舒适度能力弱。植物群落调节微气候舒适度能力强弱受群落高度、分层数量、三维绿量密度影响;其中,三维绿量密度大小对植物群落调节微气候舒适度能力影响最大。基于此,提出增加植物群落三维绿量密度、丰富层次结构、提升群落高度、保护自然林地等优化建议。

【Objective】By comparing the adjustment abilities of plant communities to microclimate comfort in summer in the urban parks and suburban parks in Huaihua,the research aimed to propose the optimization measures for plant communities based on the deficiencies found in plant allocations of urban parks by comparing the function in regulating the microclimate comfort in summer of plant communities in urban parks and that in suburban parks in Huaihua,so as to provide technical support for garden designers to scientifically allocate plants and theoretical guidance for Huaihua to create a national garden city.【Method】A field investigation of26 plant communities in 4 parks in Huaihua was conducted in the summer of 2021.The three-dimensional green biomass of the trees and shrubs was simulated by plane biomass and that of the ground cover was calculated by multiplying the covered area by the height.The air temperature and relative humidity in the plant communities were measured,and the temperature-humidity index was used to evaluate microclimate comfort according to the standard of“Climatic Suitability Evaluating on Human Settlement”.The research also analyzed the correlation between the reduction rate of temperature-humidity indexes and the height of plant communities,the number of layers and the three-dimensional green biomass density.【Results】1)For the plant communities in the suburban parks,the average height was 16.69 m,the number of layers was 3.55,the three-dimensional green biomass density was 7.59 m^(3)/m^(2),the cooling rate was 20.50%,the humidification rate was 62.87%,and the reduction rate of temperature-humidity indexes was 10.49%,while in urban parks,they were 13.05 m,2.33,3.60 m^(3)/m^(2),20.50%,52.84%,and 8.57%,respectively.2)The reduction rate of temperature-humidity indexes was significantly positively correlated with the height,number of layers,and three-dimensional green biomass density of the plant community.When the plant community height was 19.00 m,the temperature-humidity index reduction rate reached 10.11%,while when the number of layers was 4,it reached 10.59%,and when the three-dimensional green biomass density was 7.22 m^(3)/m^(2),it reached10.74%.【Conclusion】Compared with suburban parks,urban parks have a simpler plant community structure and a lower threedimensional green biomass density,which is less capable of regulating microclimate comfort.The function of plant communities in regulating microclimate comfort is influenced by their height,layer number and three-dimensional green biomass density.Among them,the last is the leading factor.Based on that,suggestions are proposed to advance the three-dimensional green biomass density of plant communities,enrich the layers and structure,increase their height and protect the natural woodland.