Lee Jongkyu, Kwak Myeong Ja, Woo Su Young
Department of Environmental Horticulture, University of Seoul, Seoul, Republic of Korea.
Department of Environmental Horticulture, University of Seoul, Seoul, Republic of Korea.
Sci Total Environ. 2024 Dec 20;957:177744. doi: 10.1016/j.scitotenv.2024.177744. Epub 2024 Dec 4.
Urban trees effectively reduce air pollution, including particulate matter (PM), which is a major concern in East Asia. While acting as biofilters, urban trees can be affected by PM exposure, which hinders their growth and physiological functions, thereby reducing their pollution mitigation ability. Trees absorb pollutants but also emit biogenic volatile organic compounds (BVOCs), which can act as precursors to other forms of air pollution. To better understand the effects of PM on urban trees, this study examined how two tree species, Pinus densiflora and Quercus acutissima, respond to elevated PM levels under controlled conditions at a concentration of 300 μg m. The aim was to investigate how increased PM levels affect BVOCs emissions and physiological responses in seedlings, and how these physiological changes influence BVOCs emission pattern. The results revealed species-specific responses in BVOCs emissions under PM stress with being especially oxygenated monoterpenes more than non‑oxygenated monoterpenes. Increased PM adsorption was found to reduce photosynthetic abilities, including photosynthesis (A), carboxylation capacity (V), and electron transport rate (J). This reduction in photosynthetic efficiency was further evidenced by decreased chlorophyll content and light absorption, which were assessed through chlorophyll fluorescence measurements. Additionally, the study evaluated oxidative stress indicators, such as lipid peroxidation and the accumulation of reactive oxygen species (ROS), to provide a comprehensive understanding of the species' responses to elevated PM conditions. The study found that elevated PM conditions were closely linked to an increase in oxygenated monoterpenes, which was associated with both oxidative stress and impaired physiological function. These observations emphasize the need for strategic urban tree selection to enhance air quality and suggest that understanding species-specific BVOCs emissions in response to PM is crucial for optimizing urban green spaces for health and environmental benefits.
城市树木能有效减少空气污染，包括颗粒物（PM），而颗粒物是东亚地区的一个主要问题。作为生物过滤器，城市树木可能会受到PM暴露的影响，这会阻碍它们的生长和生理功能，从而降低其污染缓解能力。树木吸收污染物，但也会排放生物源挥发性有机化合物（BVOCs），这些化合物可能会成为其他形式空气污染的前体。为了更好地理解PM对城市树木的影响，本研究考察了赤松和麻栎这两种树种在浓度为300 μg/m的受控条件下对升高的PM水平的反应。目的是研究PM水平升高如何影响幼苗中BVOCs的排放和生理反应，以及这些生理变化如何影响BVOCs的排放模式。结果显示，在PM胁迫下，BVOCs排放存在物种特异性反应，尤其是氧化单萜类物质比非氧化单萜类物质更多。发现增加的PM吸附会降低光合能力，包括光合作用（A）、羧化能力（V）和电子传递速率（J）。叶绿素含量和光吸收的降低进一步证明了光合效率的降低，这是通过叶绿素荧光测量评估的。此外，该研究评估了氧化应激指标，如脂质过氧化和活性氧（ROS）的积累，以全面了解这些物种对升高的PM条件的反应。研究发现，升高的PM条件与氧化单萜类物质的增加密切相关，这与氧化应激和生理功能受损都有关。这些观察结果强调了战略性选择城市树木以提高空气质量的必要性，并表明了解物种对PM的特异性BVOCs排放对于优化城市绿地以实现健康和环境效益至关重要。
