Using spectral chlorophyll fluorescence and the photochemical reflectance index to predict physiological dynamics
Using spectral chlorophyll fluorescence and the photochemical reflectance index to predict physiological dynamics
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DOI：
10.1016/j.rse.2015.12.036
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发表时间：
2016-04-01
影响因子：
13.5
通讯作者：
Porcar-Castell, A.
中科院分区：
文献类型：
--
作者：
Atherton, J.;Nichol, C. J.;Porcar-Castell, A.
从空间观测陆地叶绿素荧光和光化学反射指数有可能改进对全球碳交换的估计。然而，光合速率和这些测量之间的关系是复杂的几个因素，涉及通过光化学（光合作用）和非光化学途径吸收的光能耗散。生理遥感信号的数值模拟需要将基于物理的辐射传输模型与生理动力学模型相结合。这些计划提供了定量的框架，从中可以提取生理信息的植被遥感观测，有助于解决上述复杂性。我们提出了这样一个框架，将生理荧光理论与光谱遥感类型的测量在叶尺度。我们展示了如何一个简单的表达式可以用来预测光化学的量子产率（Phi（PSII）），光合效率的代理，从光谱测量和建模的非光化学猝灭（NPQ）。我们测试了两种替代模型的NPQ;一个过程为基础的（PHOTOII）和其他经验，基于可见光区反射率的变化（PRI）。我们用蒙特卡罗辐射传输（MCRT）模型反演了光系统II和I的叶绿素荧光分离产额。测量动态光谱荧光，PRI，半球反射率和透射率，饱和脉冲积分荧光和色素含量收集枫叶，并用于校准和验证建模框架。这两个NPQ模型再现所观察到的光化学和非光化学动力学。未来的工作建议跨空间，时间和物种的规模的框架。(C)2016 Elsevier Inc. All rights reserved.
Observations of terrestrial chlorophyll fluorescence and the Photochemical Reflectance Index (PRI) from space have the potential to improve estimates of global carbon exchange. However the relationship between photosynthetic rate and these measurements is complicated by several factors that relate to the dissipation of absorbed light energy via both photochemical (photosynthesis) and non-photochemical pathways. Numerical simulations of physiological remote sensing signals require the coupling of physically-based radiative transfer models with models of physiological dynamics. These schemes provide the quantitative frameworks from which physiological information can be extracted from remote sensing observations of vegetation, helping to resolve the aforementioned complexities. We present such a framework that links physiological fluorescence theory with spectral remote sensing type measurements at the leaf scale. We show how a simple expression can be used to predict the quantum yield of photochemistry (Phi(PSII)), a proxy for photosynthetic efficiency, from spectral measurements and modelled non-photochemical quenching (NPQ). We tested two alternate models of NPQ; one process-based (PHOTOII) and the other empirical, based on visible region reflectance changes (the PRI). We used a Monte Carlo Radiative Transfer (MCRT) model to retrieve the separated yields of chlorophyll fluorescence from photo systems II and I. Measurements of dynamic spectral fluorescence, the PRI, hemispherical reflectance and transmittance, saturation pulse integrated fluorescence and pigment contents were collected from maple leaves and used to calibrate and validate the modelling framework. Both NPQ models reproduced the observed photochemical and non-photochemical dynamics. Future work is recommended to scale the framework across space, time and species. (C) 2016 Elsevier Inc. All rights reserved.