Tropospheric ozone alters solar-induced chlorophyll fluorescence and its relationship with gross primary production in a subtropical evergreen forest

作者：Jinghua Chen, Shaoqiang Wang, Kai Zhu, Bin Chen, Qinyi Wang, Leiming Zhang, Yuelin Li, Zheng Chen · 发表于：Agricultural and Forest Meteorology · 年份：2025 · DOI：10.1016/j.agrformet.2025.110695 · 被引用次数：8 · 研究领域：Plant responses to elevated CO2、Plant Water Relations and Carbon Dynamics、Atmospheric chemistry and aerosols

Tropospheric ozone (O 3 ), as a harmful air pollutant and greenhouse gas, is globally increasing in concentration, raising concerns about its detrimental effects on ecosystems. To develop scientific strategies for protecting vegetation from O 3 damage, a comprehensive understanding of vegetation responses to O 3 is essential. Solar-induced chlorophyll fluorescence (SIF) offers a novel approach to studying how plants respond to stress, yet the extent and mechanism by which SIF reflects vegetation changes under varying ambient O 3 remain unclear. Using continuous and simultaneous observations of O 3 , SIF, and carbon fluxes in a subtropical evergreen forest, we investigated the response of canopy SIF to ambient O 3 exposure and explored the underlying mechanisms of vegetation’s response to O 3 . Our findings reveal that high ambient O 3 alters both the canopy SIF and its relationship with GPP in the subtropical evergreen forest. Specifically, canopy SIF decreases when O 3 concentrations exceed 60 ppb, but the threshold for a decrease in canopy SIF differs between the dry season (75 ppb) and the wet season (45 ppb), probably due to reduced stomatal conductance in the dry season, which limits O 3 uptake by leaf. Furthermore, extremely high O 3 concentrations decouple the linear SIF-GPP relationship (especially in wet season), indicating that high O 3 exposure more strongly affects SIF and thus weakens the ability of SIF to track GPP dynamics. Our analysis of the decomposed radiat...