摘要
植物叶片对大气颗粒物的作用机制可分为吸附、再悬浮、雨水淋洗、吸收等过程,但却少有研究探讨大气颗粒物沉降于叶片表面后的再悬浮过程,并对叶片表面吸附的颗粒物含量与叶片内部元素含量之间的相关性进行探讨.本研究选择二球悬铃木和广玉兰两种常见绿化树种,分析其叶表大气颗粒物和叶内元素成分与含量及再悬浮比例.结果表明:二球悬铃木叶片的单位面积滞尘量(4.98 g·m^(-2))明显高于广玉兰(2.65 g·m^(-2)),这可能与二球悬铃木叶片上下表面均粗糙、有绒毛有关.电感耦合等离子体发射光谱(ICP)分析表明,15种不同的元素均可在二球悬铃木和广玉兰叶表和叶内监测出来,在整体上两树种叶表与叶内元素含量间存在明显的相关性.但仅有Cr、Fe、V等3种元素在二球悬铃木叶表与叶内间存在显著的相关性,而广玉兰中仅有K、Mn、Si、Ti和Zn等5种元素没有显著的相关性,说明两树种叶片对不同元素的吸收具有较强的选择性.再悬浮分析表明,无论是随着风速的增加还是随着风力作用时间的延长,大气颗粒物的再悬浮比例均随之显著增加.在研究植物对大气颗粒物滞留效果时,必须考虑到颗粒物的再悬浮,才能准确评估植被与大气颗粒物的沉降关系.
The purification mechanisms of plant leaves with atmospheric particles include adsorption, resuspension, rainwater leaching and absorption. However, few studies focused on the resuspension process of atmospheric particles suspending on the surface of leaves, and the correlation between content of adsorbed particles and content of elements in the leaves. Therefore, two common greening tree species, Platanus acerifolia and Magnolia grandiflora, were selected to analyze the atmospheric particles contents on the leaf surface, the leaf mineral element content, and the resuspension ratios. The results showed that the adsorption capacity of P. acerifolia （4.98 g· m-2 ） was higher than that of M. grandiflora （2.65 g · m-2）, which might be connected with rough leaves and dense hairs. The selected 15 elements were all detected by ICP on the leaf surface and in the leaves of two species. In general, the elemental values of the leaf surface were positively related with those in the leaves. However, the two plants showed different selective absorption capacities because positive relation between element adsorption and absorption was only found for Cr, Fe and V for P. ace- rifolia, while such relation was only not found for K, Mn, Si, Ti and Zn for M. sults implied that the absorption was of high selectivity to different elements. Moreover, both increase in wind speed and exposure duration in the wind significantly enhanced resuspension ratios of atmospheric particles. We suggested that resuspension should be taken into account of assessing the relationship between the atmospheric particles deposition and associated plants＇ function in the future.
出处
《应用生态学报》
CAS
CSCD
北大核心
2017年第1期266-272,共7页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(41571472)资助~~
