Individual effects of trichomes and leaf morphology on PM2.5 dry deposition velocity: A variable-control approach using species from the same family or genus.
Individual effects of trichomes and leaf morphology on PM2.5 dry deposition velocity: A variable-control approach using species from the same family or genus.
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DOI：
10.1016/j.envpol.2020.116385
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发表时间：
2020-12
影响因子：
8.9
通讯作者：
Xuyi Zhang;Junyao Lyu;Yuxiao Zeng;Ningxiao Sun;Chunjiang Liu;Shan Yin
中科院分区：
文献类型：
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作者：
Xuyi Zhang;Junyao Lyu;Yuxiao Zeng;Ningxiao Sun;Chunjiang Liu;Shan Yin
城市绿色基础设施与减轻大气颗粒物污染密切相关。虽然颗粒沉积已被证明取决于叶片特征，但由于缺乏控制变量，早期研究的结果有时是模糊的。在本研究中，我们采用控制变量方法研究了叶片形态特征对pm2.5干沉降速度的影响。我们重点研究了4个指标：毛密度、叶柄长度、纵横比（宽长比）和分形偏差。每个指标选用同一科或属的树种，尽量减少其他因素的影响，对单个指标进行一组处理。采用间接法测定了pm2.5的干沉降速度。结果表明，叶片毛状体的存在对pm2.5干沉降速度有正向影响，毛状体密度越大，颗粒沉降速度越大。叶片长径比越小、叶柄越短、叶片分形偏差越大，pm2.5干沉降速度越大。控制变量方法允许独立研究沉积速度和某些叶片特性之间的相关性，同时最大限度地减少其他特性的影响。因此，我们的研究可以比已发表的研究更科学地阐明单个叶片特征如何影响颗粒沉积速度，并阐明其潜在机制。我们的研究指出了控制变量的重要性，也为未来相关因素的研究提供了思路。同时，研究结果将有助于为设计改进或缓解空气污染的适应性管理提供见解。
Urban green infrastructure is closely linked to the alleviation of pollution from atmospheric particulate matter. Although particle deposition has been shown to depend on leaf characteristics, the findings from earlier studies are sometimes ambiguous due to the lack of controlling variables. In this study, we investigated the impact of leaf morphological characteristics on PM2.5dry deposition velocity by employing a control-variable approach. We focused on four indices: trichome density, petiole length, aspect ratio (width-to-length ratio), and fractal deviation. For each index, tree species were chosen from the same family or genus to minimize the influence of other factors and make a group of treatments for an individual index. The dry deposition velocities of PM2.5were determined through application of an indirect method. The results revealed that the presence of leaf trichomes had a positive effect on PM2.5dry deposition velocity, and a higher trichome density also led to a greater particle deposition velocity. Lower leaf aspect ratio, shorter petioles, and higher leaf fractal deviation were associated with greater PM2.5dry deposition velocity. The control-variable approach allows to investigate the correlation between deposition velocity and a certain leaf characteristic independently while minimizing the effects of others. Thus, our study can clarify how a single leaf characteristic affects particle deposition velocity, and expound its potential mechanism more scientifically than the published studies. Our research points out the importance of controlling variables, and also provides ideas for future researches on related factors to be found. Meanwhile the results would help provide insight into design improvements or adaptive management for the alleviation of air pollution.