Plant adaxial (upper) and abaxial (lower) leaf sides have different reflectances and transmittances, and this has been explored and modeled in several studies. The emitted chlorophyll fluorescence is also not identical when different leaf sides are illuminated; although this has already been discovered, its effects on canopy-level fluorescence have not been explored, and there is a lack of models for explaining this phenomenon. This study develops two radiative transfer models, LFD (Leaf chlorophyll Fluorescence with Dorsiventrality) and CFD (Canopy chlorophyll Fluorescence with leaf Dorsiventrality), to model leaf dorsiventrality (including and ) at the leaf and canopy scales, respectively, and to explore its influence on canopy fluorescence. Evaluation of LFD against the measured spectra revealed that the proposed model accurately simulated leaf fluorescence with an RMSE of 0.056 W/m/µm/sr, an NRMSE of 3.3%, and an of 0.963. Evaluation of CFD under various conditions via comparison with the ray-tracing discrete anisotropic radiative transfer (DART) model revealed that CFD is consistent with DART, with an RMSE of 0.031 W/m/µm/sr, an NRMSE of 1.0%, and an of 0.998. The influences of leaf dorsiventrality are then analyzed based on the developed models and measured spectra. The results show that neglecting both and induces a maximum relative error above 30% and a maximum NRMSE of 15.7%. In contrast, neglecting only the induces a maximum relative error of more than 30% and a maximum NRMSE of 9.3%. It is concluded that leaf dorsiventrality is an important influencing factor in canopy chlorophyll fluorescence, and the proposed models can accurately and efficiently simulate this dorsiventrality.

中文翻译：

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利用叶背侧探索植物叶绿素荧光


植物近轴（上）和远轴（下）叶面具有不同的反射率和透射率，这已在多项研究中进行了探索和建模。当光照不同的叶面时，发射的叶绿素荧光也不相同；尽管这一点已经被发现，但其对冠层荧光的影响尚未被探索，并且缺乏解释这种现象的模型。本研究开发了两种辐射传输模型：LFD（叶背侧叶绿素荧光）和 CFD（叶背侧叶绿素荧光），分别在叶片和冠层尺度上模拟叶背侧（包括 和 ），并探讨其对冠层荧光。根据测量光谱对 LFD 进行评估表明，所提出的模型准确模拟了叶片荧光，RMSE 为 0.056 W/m/μm/sr，NRMSE 为 3.3%，an 为 0.963。通过与射线追踪离散各向异性辐射传输 (DART) 模型进行比较，对不同条件下的 CFD 进行评估，结果表明 CFD 与 DART 一致，RMSE 为 0.031 W/m/μm/sr，NRMSE 为 1.0%， 0.998。然后根据开发的模型和测量的光谱分析叶片背心的影响。结果表明，忽略 和 会导致最大相对误差超过 30%，最大 NRMSE 为 15.7%。相比之下，仅忽略 会导致超过 30% 的最大相对误差和 9.3% 的最大 NRMSE。结果表明，叶片背心是冠层叶绿素荧光的重要影响因素，所提出的模型可以准确、有效地模拟这种背心。