Downscaling of far-red solar-induced chlorophyll fluorescence of different crops from canopy to leaf level using a diurnal data set acquired by the airborne imaging spectrometer HyPlant

Abstract

Remote sensing-based measurements of solar-induced chlorophyll fluorescence (SIF) are useful for assessing plant functioning at different spatial and temporal scales. SIF is the most direct measure of photosynthesis and is therefore considered important to advance capacity for the monitoring of gross primary production (GPP) while it has also been suggested that its yield facilitates the early detection of vegetation stress. However, due to the influence of different confounding effects, the apparent SIF signal measured at canopy level differs from the fluorescence emitted at leaf level, which makes its physiological interpretation challenging. One of these effects is the scattering of SIF emitted from leaves on its way through the canopy. The escape fraction ( ) describes the scattering of SIF within the canopy and corresponds to the ratio of apparent SIF at canopy level to SIF at leaf level. In the present study, the fluorescence correction vegetation index (FCVI) was used to determine of far-red SIF for three structurally different crops (sugar beet, winter wheat, and fruit trees) from a diurnal data set recorded by the airborne imaging spectrometer HyPlant. This unique data set, for the first time, allowed a joint analysis of spatial and temporal dynamics of structural effects and thus the downscaling of far-red SIF from canopy ( ) to leaf level ( ). For a homogeneous crop such as winter wheat, it seems to be sufficient to determine once a day to reliably scale SIF 760 from canopy to leaf level. In contrast, for more complex canopies such as fruit trees, calculating for each observation time throughout the day is strongly recommended. The compensation for structural effects, in combination with normalizing SIF 760 to remove the effect of incoming radiation, further allowed the estimation of SIF emission efficiency ( ) at leaf level, a parameter directly related to the diurnal variations of plant photosynthetic efficiency.

Regional detection and assessment of chilling damage on maize considering land surface temperature, crop growth status and solar radiation changes

“…It is directly related to the photosynthetic apparatus of vegetation (Siegmann et al, 2021) and is sensitive to environmental stressors (Lee et al, 2013;Mohammed et al, 2019;Zeng et al, 2022;Zhang et al, 2014). With decreasing temperature, an increase in the fluorescence yield at both 685 nm and 735 nm is observed, and a marked change occurs at the longer emission, resulting in a decrease in the chlorophyll fluorescence ratio (Agati et al, 2000).…”

“…Solar‐induced chlorophyll fluorescence ( SIF ), a promising indicator, represents weak radiation at far‐red wavelengths (650–800 nm), which is reemitted by vegetation during the light reactions of photosynthesis (Wang, Clevers, et al., 2022; Zhang et al., 2018). It is directly related to the photosynthetic apparatus of vegetation (Siegmann et al., 2021) and is sensitive to environmental stressors (Lee et al., 2013; Mohammed et al., 2019; Zeng et al., 2022; Zhang et al., 2014). With decreasing temperature, an increase in the fluorescence yield at both 685 nm and 735 nm is observed, and a marked change occurs at the longer emission, resulting in a decrease in the chlorophyll fluorescence ratio (Agati et al., 2000).…”

High-Precision Ultra-Long Air Slit Fabrication Based on MEMS Technology for Imaging Spectrometers

“…The advancement of hyperspectral remote sensing has enabled the detection of many objects previously undetectable using broadband technology. The utilization of imaging spectrometers mounted on satellites enables various applications, such as ocean exploration [9,10], environmental monitoring, surface exploration [11], natural resources exploration [12], and biological activity monitoring [13][14][15].…”

Performance of Singular Spectrum Analysis in Separating Seasonal and Fast Physiological Dynamics of Solar‐Induced Chlorophyll Fluorescence and PRI Optical Signals

“…Numerous studies have shown that F and PRI measured from a variety of tower‐based (e.g., Cogliati et al., 2015; Kim et al., 2021; Wieneke et al., 2018; Xu et al., 2021), airborne (e.g., Middleton et al., 2017; Rascher et al., 2015; Rossini et al., 2015; Siegmann et al., 2021; Tagliabue et al., 2019), and spaceborne platforms (e.g., Middleton et al., 2016; Sun et al., 2018; Wang et al., 2020; Zhang et al., 2020) can successfully track variations in GPP and/or LUE . However, canopy‐scale F and PRI are not exclusively driven by plant physiology.…”