Directly estimating diurnal changes in GPP for C3 and C4 crops using far-red sun-induced chlorophyll fluorescence
Directly estimating diurnal changes in GPP for C3 and C4 crops using far-red sun-induced chlorophyll fluorescence
复制标题
DOI：
10.1016/j.agrformet.2016.06.014
复制
发表时间：
2017-01-15
影响因子：
6.2
通讯作者：
Liu, Xinjie
中科院分区：
文献类型：
--
作者：
Liu, Liangyun;Guan, Linlin;Liu, Xinjie
准确估算初级生产总值（GPP）对全球变化研究以及粮食和燃料安全具有重要意义。以往的研究表明，太阳诱导叶绿素荧光（SIF）从高光谱数据检索的值提供了一个直接的措施生态系统GPP。然而，卫星SIF和基于模型的GPP之间的关系的全球分析表明，这两个参数之间的关系是高度依赖于植物功能类型（PFT）。本研究的首要目标是检查在760 nm（SIF 760）检索的远红SIF跟踪C3和C4作物GPP的日变化的潜力，并调查GPP SIF关系是否依赖于光合作用的类型。GPP值是根据通量塔记录估算的，每日SIF 760数据来自地面光谱测量。结果表明，C3和C4作物的GPP和SIF 760具有相似的日变化规律，且两者之间存在线性相关。然而，C3小麦的GPP（P）与GPP（F）之比（基于SIF的线性GPP模型的斜率，GPP= GPP（P）/GPP（F）x SIF）约为C4玉米的46%。从日变化实验的结果表明，eF是弱敏感的光合途径类型（PsP型）和C3和C4作物之间的sp的巨大差异导致的差异的斜率。我们的研究证实了遥感SIF信号作为GPP的直接代理的能力，并建议PsP类型时，应考虑试图准确地量化生态系统生产力使用简单的经验方法。(C)2016爱思唯尔B. V.保留所有权利。
Accurate estimation of gross primary production (GPP) is of great importance to global change research and also food and fuel security. Previous studies have demonstrated that values of sun-induced chlorophyll fluorescence (SIF) retrieved from hyperspectral data provide a direct measure of ecosystem GPP. However, global analysis of the relationship between satellite SIF and model-based GPP indicates that the relationship between the two parameters is highly dependent on the plant functional type (PFT). The overarching goal of this study is to examine the potential of far-red SIF retrieved at 760nm (SIF760) to track the diurnal variations in GPP for C3 and C4 crops, and to investigate whether the GPP SIF relationship is dependent on the type of photosynthesis. GPP values are estimated from flux tower records and daily SIF760 data are derived from ground-based spectral measurements. The results show that GPP and SIF760 have similar diurnal patterns and are linearly correlated for C3 and C4 crops. However, the ratio of epsilon(P) to epsilon(F) (the slope of the linear SIF-based GPP model, GPP= epsilon(P)/epsilon(F) x SIF) for C3 wheat is about 46% of that for C4 maize. The findings from the diurnal variation experiments imply that theeF is weakly sensitive to the photosynthetic pathway type (PsP type) and that the large difference in sp between C3 and C4 crops leads to the difference in the slopes. Our studies confirm the capability of the remotely sensed SIF signals to act as a direct proxy for GPP and suggest that the PsP type should be considered when trying to accurately quantify the ecosystem productivity using the straightforward empirical approach. (C) 2016 Elsevier B.V. All rights reserved.