长沙市9种绿化植物叶片微结构与吸附PM_(2.5)能力的研究

Study on leaf microstructure and PM25 adsorption capacity of nine greening plants in Changsha

为了探究植物叶片微观特征差异对PM_(2.5)吸附量的影响,本研究以长沙市9种常见阔叶、针叶、灌木绿化植物为研究对象,通过气溶胶再发生器对不同植物叶表面PM_(2.5)的含量进行测定,并采用方差分析和多重比较分析了叶片的面积大小、表面气孔密度和表面绒毛长度等叶面微观特征对PM_(2.5)吸附量的影响。结果显示:方差分析显著性P<0.01,说明9种植物间PM_(2.5)吸附能力具有极显著差异;多重比较发现广玉兰和香樟差异不显著(P>0.05),其他植物间差异极显著(P<0.01),经比较发现不同植物单位叶面积PM_(2.5)吸附量大小表现为月季花>杜鹃>红叶石楠>金钱松>马尾松>池杉>桂花>广玉兰>香樟;月季花、杜鹃吸附PM_(2.5)的能力较强,原因可能是其叶表面气孔密度大和凹凸起伏沟壑多即叶表面粗糙;香樟和广玉兰因其叶片表面光滑、气孔密度小和气孔周围分布有大量浅线性条纹,吸附PM_(2.5)的能力较弱;不同植物叶表面气孔密度与吸附PM_(2.5)的能力成较强的正相关关系,气孔密度越大,越容易吸附PM_(2.5)。

In order to explore the impact of differences in the microscopic characteristics of plant leaves on the adsorption capacity of PM_(2.5),this study took nine kinds of common broad-leaved coniferous and shrubs greening plants as the research objects,and measured the adsorption behavior of PM_(2.5)on different plant leaves through aerosol regenerator.The effects of differences in leaf surface micro characteristics such as leaf area size,leaf surface stomatal density,and leaf surface villus length on PM_(2.5)adsorption capacity were analyzed by using analysis of variance and multiple comparisons.The significance of ANOVA was P<0.01,indicating a significant difference in PM_(2.5)adsorption capacity among the nine plants.In the results of multiple comparisons,it was found that there was no significant difference between Magnolia grandiflora and Cinnamomum camphora(P>0.05),while the differences between other plants were extremely significant(P<0.01).After comparison,the adsorption capacity of PM_(2.5)per unit leaf area of different plants was shown as following:Rosa chinensis>Rhododendron simsii>Photinia fraseri>Pseudolarix amabilis>Pinus massoniana>TaxoOium ascendns>Osmanthus fragrans>Magnolia grandifora>Cinnamomum camphor.Rosa chinensis and Rhododendon simsii had strong abilities to uptake PM_(2.5)due to their high stomatal density on the leaf surface,as well as numerous undulating and undulating grooves,resulting in rough leaf surfaces.Cinnamomum camphorr and Magnolii grand/orr had weaker abilities to absorb PM_(2.5)due to their smooth leaf surface,low stomatal density,and a large number of shallow linear stripes distributed around the stomata.There was a strong positive correlation between the stomatal density on the surface of different plant leaves and their ability to uptake PM_(2.5).The higher the stomatal density,the easier it was to adsorb PM_(2.5).