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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 mechanism of action of plant leaves on atmospheric particulate matter can be divided into the process of adsorption, resuspension, rainwater leaching and absorption. However, there are few studies on the resuspension process after the atmospheric particles settle on the surface of the leaves. And the content of leaf elements were discussed.This study selected two kinds of common green tree species, Platycladus orientalis and Magnolia grandiflora, and analyzed the contents and content of airborne particulate matter and leaf elements in leaf leaves and the proportion of resuspension.The results showed that: The amount of dust per unit area (4.98 g · m -2) of A. tabaci leaves was significantly higher than that of Magnolia biondii (2.65 g · m -2) Induced coupling plasma emission spectroscopy (ICP) analysis showed that all 15 different elements could be detected in the leaves and leaves of Platanus and Magnolia leaves, However, only Cr, Fe, V and other three kinds of elements in Platycladus orientalis leaf table and leaf inter-leaf there is a significant correlation, and the Magnolia only K, Mn, Si, Ti and Zn, etc. The five elements have no significant phase The results showed that the leaves of the two species had a strong selectivity for the absorption of different elements.The resuspension analysis showed that with the increase of the wind speed or the extension of the time of the wind, the resuspension proportion of the atmospheric particulates was significant Increase.When studying the effect of plant on atmospheric particulate retention, the resuspension of particulate matter must be taken into account to accurately evaluate the relationship between vegetation and atmospheric particulate matter sedimentation.