Wang Xiaoshuang, Xiang Yang, Peng Chucai, Teng Mingjun, Ma Bojun, Zhou Zhixiang, Peng Changhui
School of Environmental Art, Hubei Institute of Fine Arts, Wuhan, 430202 China.
Institute of Environment Sciences, University of Quebec at Montreal, Montreal, QC H3C 3P8 Canada.
Landsc Ecol. 2025;40(1):5. doi: 10.1007/s10980-024-02023-7. Epub 2024 Dec 19.
Trees play a vital role in reducing street-level particulate matter (PM) pollution in metropolitan areas. However, the optimal tree growth type for maximizing the retention of various sizes of PM remains uncertain.
This study assessed the PM reduction capabilities of evergreen and deciduous broadleaf street trees, focusing on how leaf phenology influences the dispersion of pollutants across particle sizes.
We collected data on six PM size fractions from 72 sites along streets lined with either evergreen or deciduous broadleaf trees in Wuhan, China, during the summer and winter of 2017-2018.
Evergreen trees demonstrated superior PM reduction capabilities compared to deciduous trees, with evergreen street canyons showing 27.2% and 12.6% lower PM and PM concentrations in summer, and 13% and 5.5% lower concentrations in winter. During summer, evergreen streets predominantly contained fine particles (PM, PM), posing potential health risk due to their ability to infiltrate the human respiratory system. In contrast, deciduous streets primarily harbored coarser particles (PM, PM, PM, and total suspended particulate [TSP]). During winter, larger particles were dominant, regardless of the tree growth form.
Evergreen trees showed superior PM reduction capabilities compared to deciduous trees due to their year-round leaf retention, enhanced surface properties, and denser canopies that maximize PM capture. We recommend prioritizing evergreen broadleaf trees as the primary street trees while interspersing deciduous trees at appropriate intervals. This approach will ensure that urban greenery provides maximum ecological benefits while reducing the PM concentration.
树木在减少大都市地区街道层面的颗粒物（PM）污染方面发挥着至关重要的作用。然而，关于何种最佳树木生长类型能最大程度保留各种粒径的PM仍不明确。
本研究评估了常绿和落叶阔叶行道树减少PM的能力，重点关注叶物候如何影响不同粒径污染物的扩散。
在2017 - 2018年夏季和冬季，我们在中国武汉沿着种有常绿或落叶阔叶树的街道的72个地点收集了六种PM粒径级别的数据。
与落叶树相比，常绿树表现出更强的PM减少能力，常绿街道峡谷在夏季的PM和PM浓度分别低27.2%和12.6%，在冬季浓度分别低13%和5.5%。在夏季，常绿街道主要含有细颗粒物（PM、PM），因其能够渗透进入人体呼吸系统而带来潜在健康风险。相比之下，落叶街道主要含有较粗的颗粒物（PM、PM、PM和总悬浮颗粒物[TSP]）。在冬季，无论树木生长形式如何，较大颗粒占主导。
由于常绿树全年保持叶片、表面特性增强且树冠更密集从而能最大程度捕获PM，与落叶树相比，常绿树表现出更强的PM减少能力。我们建议优先选择常绿阔叶树作为主要行道树，同时适当间隔穿插种植落叶树。这种方法将确保城市绿化在降低PM浓度的同时提供最大的生态效益。
