Matsuura Takumi, Okamoto Yousuke, Matsumoto Mayu, Kiyomizu Takashi, Kumpitsch Luisa, Kume Atsushi, Hanba Yuko T
Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, 606-8585, Japan.
Department of Marine Sciences, University of Gothenburg, 45296 , Strömstad, Sweden.
Sci Rep. 2025 Jan 9;15(1):1453. doi: 10.1038/s41598-024-85080-x.
Phytotoxic air pollutants such as atmospheric nitrogen dioxide (NO) are among the major stresses affecting tree photosynthesis in urban areas. We clarified the relationship between NO concentrations and photosynthetic function for three major urban trees, Prunus × yedoensis, Rhododendron pulchrum, and Ginkgo biloba, planted in Kyoto and surrounding cities, combining our published data and new data collected from 2020 to 2023. High NO increased long-term water use efficiency for all species. High NO decreased photosynthesis in P. yedoensis and R. pulchrum, while for G. biloba, NO imposed little effect on photosynthesis. We then focused on the decrease in NO due to (1) air pollution control measures from 2005 to 2023 and (2) the economic recession caused by the COVID-19 pandemic, and examined whether these factors improved photosynthesis in urban trees. The historic decrease in NO improved leaf photosynthesis for P. yedoensis and R. pulchrum, while the COVID-19 pandemic reduced NO by only 0.3 ppb and did not further improve photosynthesis in these tree species. This report shows that air pollution control measures improved photosynthesis in urban trees over several years in Japan, and is valuable because it demonstrates that air pollution control measures can increase CO uptake by urban trees.
植物毒性空气污染物，如大气中的二氧化氮（NO），是影响城市树木光合作用的主要胁迫因素之一。我们结合已发表的数据和2020年至2023年收集的新数据，阐明了种植于京都及周边城市的三种主要城市树木——东京樱花、锦绣杜鹃和银杏——的NO浓度与光合功能之间的关系。高浓度NO提高了所有物种的长期水分利用效率。高浓度NO降低了东京樱花和锦绣杜鹃的光合作用，而对于银杏来说，NO对光合作用影响不大。然后，我们关注了由于（1）2005年至2023年空气污染控制措施以及（2）新冠疫情导致的经济衰退所引起的NO浓度下降，并研究了这些因素是否改善了城市树木的光合作用。NO浓度历史性的下降改善了东京樱花和锦绣杜鹃的叶片光合作用，而新冠疫情仅使NO浓度降低了0.3 ppb，并未进一步改善这些树种的光合作用。本报告表明，空气污染控制措施在日本数年内改善了城市树木光合作用，其价值在于证明了空气污染控制措施可增加城市树木对CO2的吸收。
