八种乔木滞尘效益及其与叶表面特征关系

以青岛市城阳区道路绿地8种乔木为试验材料,采用洗脱法和质量差值法研究8种乔木的滞尘能力,采用扫描电子显微镜(JEOL7500F)、扫描探针显微镜(SPI3800-SPA-400,Seiko Instruments Inc.)和Image J观察叶表面结构并测定叶表面粗糙度、叶毛数量、气孔大小和气孔密度,分析了8种乔木的滞尘能力与叶表面特征的关系。结果表明:8种乔木的季节滞尘量总体上表现为秋季>春季>夏季。紫叶李、悬铃木和毛白杨单位叶面积滞尘量较大,洋白蜡、绦柳单位叶面积滞尘量较小,紫叶李的单位叶面积滞尘量最大,平均达到2.044 7 g·m^-2,最小的绦柳为0.574 7 g·m^-2,前者是后者的3.6倍左右。通过分析叶表面结构与滞尘量的关系得出,具明显网状结构、叶表面粗糙且具明显褶皱、叶表面具沟槽或绒毛,气孔较多且开口大等特征的植物滞尘能力较强。8种乔木叶片粗糙度、叶毛数量、气孔大小和气孔密度与单位叶面积滞尘量之间具有显著正相关关系,表明叶片粗糙度、气孔大小和气孔密度越大,叶毛数量越多,叶片滞尘量越大。

Relationship Between the Surface Characteristics of Eight Tree Leaves and Dust Retention

The dust retention ability of 8 tree species in Chengyang district of Qingdao city was studied by washing method and weight difference method.Scanning electron microscope(JEOL7500 F),scanning probe microscope(SPI3800-SPA-400,Seiko Instruments Inc.)and Image J were used to study the surface roughness,leaf hair quantity,stomatal size and stomatal density.The relationship between dust retention ability and leaf surface characteristics of 8 tree species was analyzed.The results showed that the seasonal dedust of the 8 tree species was shown to be in the autumn>spring>summer.The dust retention per unit leaf area of Prunus cerasifera,Platanus orientalis and Populus tomentosa was larger than that of Fraxinux pennsylvanica and Salix matsudana,and the dust retention per unit leaf area of Prunus cerasifera was the largest,averaging 2.044 7 g·m-2.The smallest Salix matsudana was 0.574 7 g·m-2,while the former was 3.6 times larger than the latter.By analyzing the relationship between leaf surface structure and dust retention,it is concluded that plants with waxy layer or obvious reticulate structure,rough leaf surface with obvious folds,groove or villi on leaf surface,more stomata and large opening have stronger dust retention capacity.There was a significant positive correlation between leaf roughness,leaf hair quantity,stomatal size,stomatal density and dust retention per unit leaf area,indicating that the greater the leaf roughness,stomatal size and stomatal density,the greater the number of leaf hairs and the greater the dust retention in leaves.