柏木叶片滞尘量及叶面微形态解释初步研究

Preliminary Study on Dust-retention and Leaf Micromorphology of Cypress Leaves

以柏木叶片为研究对象,定量测量叶片单位叶表面滞尘能力,采用扫描电镜分析叶表面微观结构。结果表明:(1)同一生境下的柏木叶片单位叶面积的TSP、PM_(10)、PM_(2.5)的累积滞尘量均以春季最高,秋季最低;叶片单位叶面积的TSP、PM_(10)、PM_(2.5)的滞尘速率均以春季最高,秋季最低;整体表现为春夏季高于秋冬季。(2)同一季节不同生境的叶片TSP、PM_(10)累计滞尘量表现为春季、夏季、冬季林中木>孤立木,而在秋季则表现为孤立木>林中木;而叶片PM_(2.5)累计滞尘量则表现为春季、秋季、冬季均林中木>孤立木,而在夏季则表现为孤立木与林中木大小相等。为此,初步认为通过群植、丛植营造的森林环境,其优势树种植物叶片对大气的滞尘效应更为明显;(3)以冬季孤立木为例,随着雨后间隔时间增加,叶片的TSP、PM_(10)累计滞尘量逐渐增加,滞尘速率则表现出先减小后增大趋势;而叶片PM_(2.5)累计滞尘量、滞尘速率则均表现出逐渐增大趋势。

Taking the leaves of cypress as the study object,the dust retention ability of the leaves on the unit leaf was quantitatively measured,and the microstructure of the leaf surface was analyzed by scanning electron microscope. The results showed that：（ 1） The accumulative adsorbing dust quantity of TSP,PM10 and PM2.5 of unit cypress leaves in the same habitat was the highest in spring and the lowest in autumn,and the dust rate of TSP,PM10 and PM2.5 of the area of unit leaf was the highest in spring and the lowest in autumn,and the overall performance was higher in spring and summer than in autumn and winter.（ 2） The accumulative adsorbing dust quantity of TSP and PM10 in leaves of different habitats in the same season was shown forest wood 〉isolated wood in spring,summer,winter,but in autumn,it was isolated wood forest 〉wood. However,the accumulative adsorbing dust quantity of of PM2.5 in leaves was shown forest wood 〉isolated wood in the spring,autumn and winter,while in summer the total amount of dust absorption from isolated trees is equal to that of forest trees. So it was preliminarily considered that the dust retention effect of dominant tree species leaves on the atmosphere was more obvious through the forest environment constructed by group planting and cluster planting.（ 3） Taking the isolated wood in winter as an example,with the increase of the interval time after the rain,the accumulative adsorbing dust quantity of TSP and PM10 in the leaves gradually increased,the dust rate of the leaves increased first and then increased,while the accumulated dust and dust rate of PM2.5 in the leaves increased gradually.