Remote Sensing of Instantaneous Drought Stress at Canopy Level Using Sun-Induced Chlorophyll Fluorescence and Canopy Reflectance

Climate change amplifies the intensity and occurrence of dry periods leading to drought stress in vegetation. For monitoring vegetation stresses, sun-induced chlorophyll fluorescence (SIF) observations are a potential game-changer, as SIF emission is mechanistically coupled photosynthetic activity. Yet, benefit for not yet understood. This paper analyses impact on canopy-scale surface reflectance over lettuce mustard stand with continuous field spectrometer measurements. Here, measurements linked plant’s efficiency, whereas can be used monitor canopy structure. The showed reduction biochemical component its (the efficiency at 760 nm—ϵ760) reaction stress, structural Fluorescence Correction Vegetation Index—FCVI) barely reaction. both an increase variability sub-daily scale decrease ϵ760 during event. These reactions occurred simultaneously, suggesting that reflectance-based indices sensitive structure provide complementary information. these depend soil water availability atmospheric demand. highlights from upcoming FLuorescence EXplorer (FLEX) satellite unique insight status. At same time, data temporal resolution promising additional indicator certain species.