长沙市道路绿化带滞留PM_(2.5)的能力

PM_(2.5) retention capacity of the road green belt in changsha

【目的】研究道路绿化带不同植物PM_(2.5)滞留量并比较不同配置模式PM_(2.5)的滞留能力,为城市绿化树种的筛选和城市生态规划提供科学依据。【方法】选取长沙市韶山路道路绿化带13种常见道路绿化植物,通过微孔滤膜称重法等研究长沙市道路绿化带单位叶面积、单株、单位绿地面积滞留PM_(2.5)能力,比较乔灌、灌木纯林、乔灌草、灌草、乔乔灌、乔木纯林配置模式下的滞尘能力,并在R 4.0.2软件中使用Ward.D方法按欧式距离对13种植物在单位叶面积滞留PM_(2.5)能力、单株滞留PM_(2.5)能力、单位绿地面积滞留PM_(2.5)能力3个尺度综合进行层次聚类分析。【结果】不同植物单位叶面积PM_(2.5)滞留量的变化范围为10.39~427.12 mg·m^(-2),沿阶草对PM_(2.5)的滞留能力最强,罗汉松次之;在单株尺度上,滞留能力的变化范围较大为0.03~16000 mg·株^(-1),石楠和罗汉松对PM_(2.5)的滞留能力最强,酢浆草PM_(2.5)滞留量最低;从单位绿地面积植物对PM_(2.5)的滞留能力来看,PM_(2.5)滞留量的变化范围为10.00~500.00 mg·m^(-2),罗汉松对PM_(2.5)的滞留能力最强,酢浆草和荷花玉兰滞留PM_(2.5)能力较差(10~40 mg·m^(-2));不同配置模式下,植物滞留PM_(2.5)能力依次为:乔灌>灌木纯林>乔灌草>灌草>乔乔灌>乔木纯林;聚类分析发现石楠、罗汉松滞留PM_(2.5)能力较强,其中罗汉松滞留PM_(2.5)的综合能力最强。【结论】道路绿化带同一植物不同尺度、不同植物、不同配置模式滞留PM_(2.5)能力存在差异,优化植物配置可以增强城市道路绿化带的滞尘效应。

【Objective】The PM_(2.5) retention capacity of plants under different configuration modes in the road green belt was studied in order to provide a scientific basis for the selection of urban greening tree species and urban ecological planning.【Method】Thirteen kinds of common road greening plants were selected to study the PM_(2.5) retention capacity of unit leaf area,single plant and unit green area of the road green belt in Changsha City through the microporous membrane weighing method,and the dust retention capacities of tree shrub pure forest,tree shrub grass,shrub grass,arbor shrub and pure tree forest were compared.The Ward.D method was used to conduct hierarchical cluster analysis on PM_(2.5) retention capacity per unit leaf area,PM_(2.5) retention capacity per plant and PM_(2.5) retention capacity per unit green space of 13 plants in R 4.0.2.【Result】The PM_(2.5) retention capacity per unit leaf area of different plants ranged from 10.39 mg·m^(-2) to 427.12 mg·m^(-2),and the retention capacity of Ophiopogon bodinieri to PM_(2.5) was the strongest,followed by Podocarpus macrophyllus.On the single plant scale,the retention capacity varied widely:0.03-16000 mg·plant^(-1).Among them,Photinia serrulata and Podocarpus macrophyllus had the strongest retention abilities,and the PM_(2.5) retention of Oxalis corniculata was the lowest.In terms of the retention capacity of PM_(2.5) particles on plant leaves per unit of green space area,the variation range was 10.00-500.00 mg·m^(-2).Podocarpus macrophyllus had the strongest retention capacity,while Oxalis corniculata and Magnolia grandiflora had poor retention capacities(10-40 mg·m^(-2)).The PM_(2.5) retention capacity of plants under different configuration patterns was in the following order:Arbor-Shrub>Shrub>Arbor-Shrub-Herb>Shrub-Herb>Arbor-Arbor-Shrub>Arbor.The cluster analysis found that Photinia serrulata and Podocarpus macrophyllus had great PM_(2.5) retention capacities,and Podocarpus macrophyllus had the strongest comprehensive ability to retain PM_(2.5).【Conclusion】PM_(2.5) retention capacities of the road green belt vary according to plant types,configuration patterns and study scales.Optimizing plant configuration can enhance the dust retention effect of the road green belt.