北京道边银杏叶片大气颗粒物滞纳量冠层变异

为研究树木叶片大气颗粒物滞纳量在冠层内的空间变异性，以城市道路边银杏单木为例，对单木冠层的不同高度、不同方向及不同位置共48个位点进行采样、测定分析其单位面积叶片细颗粒物( PM2.5)、可吸入颗粒物( PM10)和总悬浮颗粒物(TSP)滞纳量。结果显示：在0－2级风且大气污染等级为轻度污染以内的天气下，单位面积叶片PM2.5、 PM10和TSP滞纳量在冠层内的空间分布无明显规律，单位面积叶片PM2.5和PM10滞纳量分布状况较为相似，低处叶片PM2.5、PM10滞纳量更大，高处叶片TSP滞纳量更大；三因素方差分析结果表明，除了高度对单位面积叶片PM2.5滞纳量有显著影响(P<0.05)，其余各因子及交互作用对树冠单位面积叶片PM2.5、 PM10和TSP滞纳量均无显著影响(P>0.05)。针对不同研究目的，对树木冠层大气颗粒物滞纳量研究的采样方法提出建议，为城市植被对大气颗粒物吸滞作用的相关研究提供一定科学依据。

The spatial variability of leaf particulate matter retention amount within tree canopy Ginkgo biloba on the edge of urban road

Ginkgo biloba on the edge of urban road in Beijing was taken as an example to investigate the spatial variability of particulate matter retention amount on leaves within tree canopy in this study. PM2.5 , PM10 and total suspended particle ( TSP ) retention amount by per unit area leaf at different heights, directions and positions ( a total of 48 sampling sites) were analyzed. Results showed wind force and air pollution, there was no obvious canopy spatial distribution pattern of the PM2.5 , PM10 , TSP retention amount by per unit area leaf. The distribution of PM2.5 and PM10 retention amount by per unit area leaf was relatively similar, PM2.5 and PM10 retention amount of lower leaves were greater, and TSP retention amount of higher leaves was greater. Three factor variance analysis indicated that, height had significant effects on PM2.5 retention amount by per unit area leaf (P<0.05), other factors and interactions had no significant influence on PM2.5, PM10, TSP retention amount by per unit area leaf (P>0.05). According to different research purposes, suggestion was put forward on the sampling method of the study on the atmospheric articulates retention amount in tree canopy, and certain scientific basis for the related research on the retention effect of urban vegetation to atmospheric particulate matter was provided.