摘要
绿化树种的滞尘能力差异与叶面微结构特征密切相关。以宁东能源化工基地火电厂周边5种典型阔叶绿化树种为研究对象,采用洗脱法测定叶片滞尘量,并用扫描电镜-能谱分析仪(SEM-EDX)研究植物叶表面微结构与滞尘能力的相关性。结果表明:各树种间滞尘量差异明显,5个树种单位面积滞尘能力从大到小依次为火炬树(Rhus typhina)>臭椿(Ailanthus altissima)>榆树(Ulmus pumila)>山槐(Maackia amurensis)>白蜡(Fraxinus chinensis);叶表面兼有表皮毛、气孔和沟壑、粗糙等微结构特征的树种如火炬树、臭椿等其滞尘能力较强;对叶表面滞尘颗粒物粒径及其组成分析发现,部分树种存在对不同粒径颗粒物选择性滞留和吸附现象,如白蜡以气孔吸附型为主导,对PM2.5的吸附能力相对较强;而兼具表皮毛、气孔和沟壑等微结构的火炬树和臭椿则吸附粒径范围较广;通过能谱分析发现,源自土壤扬尘的颗粒物在5种绿化树种上广泛存在,而源自人为源的有机污染物则更易于被具有表皮毛的树种所滞留。因此,在进行能源工业区绿化树种选择时,应依据当地大气污染类型和对滞尘有利的叶面微结构选择并推广相应树种。
The dust retention capacity of greening tree species is closely related to leaf surface micro-structure.We measured the dust retention quantities of the leaves from five broad-leaved greening tree species around a thermal power plant in Ningdong Energy Industrial Base,using the method of washing and filtering.The leaf surface micro-structure was observed by scanning electron microscopy.The relationship between leaf surface micro-structure and dust retention capability was analyzed.Results showed that there were significant differences in dust retention capability of leaves among the five species,with a rank of Rhus typhina>Ailanthus altissima>Ulmus pumila>Maackia amurensis>Fraxinus chinensis.Rhus typhina and Ailanthus altissima,with combined characteristics of epidermis trichome,stomata,gap and roughness,had higher dust retention capability.According to the analysis of particle size and composition of dust detained on the leaves,some tree species showed selective retention and adsorption.For example,Fraxinus chinensis as a stomatal adsorption type tree species had stronger capability of PM2.5 adsorption,while Rhus typhina and Ailanthus altissima,due to the combined characteristics of epidermis tomentum,stomata,gap and roughness,had a wider particle size adsorption range.Based on the results of energy dispersive spectrometer analysis,dust derived from soil was identified on leaves broadly,while organic pollutants derived from anthropogenic sources were also found on the tree species with epidermis tomentum.Therefore,according to the local air pollution type,tree species with leaf surface micro-structures being beneficial to dust retention should be chosen for greening in the energy industrial zone.
作者
李诗瑶
牛玉斌
樊瑾
余海龙
黄菊莹
LI Shi-yao;NIU-bin;FAN Jin;YU Hailong;HUANG Ju-ying(College of Resources and Environment,Ningxia University,Yinchuan 750021,China;Institute of Environmental Engineering,Ningxia University,Yinchuan 750021,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第2期604-614,共11页
Chinese Journal of Ecology
基金
中国科学院“西部青年学者”(XAB2019AW03)
宁夏自然科学基金项目(2020AAC03050)
国家自然科学基金项目(41961001,41561060)资助。
关键词
绿化树种
大气颗粒物
叶表面滞尘
微结构
greening tree species
atmospheric particulate matter
leaf surface dust retention
micro-structure