资源环境科技发展态势分析平台

Recent advances in remote sensing of solar‐induced chlorophyll fluorescence (SIF) have garnered wide interest from the biogeoscience and earth system science communities, due to the observed linearity between SIF and gross primary productivity (GPP) at increasing spatiotemporal scales. Three recent studies, Maguire et al., (2020, https://doi.org/10.1029/2020GL087858), He et al. (2020, https://doi.org/10.1029/2020GL087474) and Marrs et al. (2020, https://doi.org/10.1029/2020GL087956) highlight a non‐linear relationship between fluorescence and photochemical yields, and show empirical evidence for the decoupling of SIF, stomata, and the dark reactions of photosynthesis. Such mechanistic studies help advance our understanding of what SIF is, and what it is not. We argue that these findings are not necessarily contradictory to the linear SIF‐GPP relationship observed at the satellite scale, and provide context for where, when and why fluorescence and photosynthesis diverge at smaller spatiotemporal scales. Understanding scale dependencies of remote sensing data is crucial for interpreting SIF as a proxy for GPP.