A physiological signal derived from sun-induced chlorophyll fluorescence quantifies crop physiological response to environmental stresses in the U.S. Corn Belt

Abstract Sun-induced chlorophyll fluorescence (SIF) measurements have shown unique potential for quantifying plant physiological stress. However, recent investigations found canopy structure and radiation largely control SIF, relevance of SIF remains yet to be fully understood. This study aims evaluate whether the SIF-derived signal improves quantification crop responses environmental stresses, by analyzing data at three different spatial scales within U.S. Corn Belt, i.e. experiment plot, field, regional scales, where ground-based portable, stationary space-borne hyperspectral sensing systems are used, respectively. We that, when controlling variations in incoming structure, signals can decomposed into non-physiological (i.e. radiation, 60% ∼ 82%) information yield, Φ F , 17% 31%), which confirms contribution variation SIF. further evaluated indicated under high-temperature high vapor pressure deficit (VPD) stresses. The plot-scale showed that responded proxy stress (partial correlation coefficient, r p = 0.40, < 0.001) while did not respond ( > 0.1). field-scale water from comparison between irrigated rainfed fields, was positively correlated with canopy-scale stomatal conductance, a reliable indicator condition (correlation coefficient 0.60 0.56 an sites, respectively). regional-scale more strongly spatially air temperature VPD 0.23 0.39) than 0.11 0.34) Belt. lines evidence suggested reflects stresses greater sensitivity factors capability is scalable. Utilizing will contribute improve our understanding vegetation high-VPD