Using reflectance to explain vegetation biochemical and structural effects on sun-induced chlorophyll fluorescence

REMOTE SENSING OF ENVIRONMENT

卷:231

Article

Yang, Peiqi¹  van der Tol, Christiaan¹  Verhoef, Wout¹  Damm, Alexander^2,3  Schickling, Anke⁴  Kraska, Thorsten⁵  Muller, Onno⁴  Rascher, Uwe⁴ 

[1] Univ Twente, Fac Geoinformat Sci & Earth Observat ITC, NL-7500 AE Enschede, Netherlands

[2] Univ Zurich, Remote Sensing Labs, Winterthurerstr 190, CH-8057 Zurich, Switzerland

[3] Eawag, Swiss Fed Inst Aquat Sci & Technol, Uberlandstr 133, Dubendorf, Switzerland

[4] Forschungszentrum Julich GmbH, Inst Bio & Geosci, IBG 2 Plant Sci, Leo Brandt Str, D-52425 Julich, Germany

[5] Univ Bonn, Fac Agr, Field Lab, Campus Klein Altendorf,Klein Altendorf 2, D-53359 Rheinbach, Germany

关键词: Chlorophyll fluorescence;    Reflectance;    Radiative transfer models;    Canopy structure;    HyPlant;    Airborne;   

DOI  :  10.1016/j.rse.2018.11.039

来源: Elsevier

【 摘 要 】

The growing availability of global measurements of sun-induced chlorophyll fluorescence (SIF) can help in improving crop monitoring, especially the monitoring of photosynthetic activity. However, variations in top-of-canopy (TOC) SIF cannot be directly interpreted as physiological changes because of the confounding effects of vegetation biochemistry (i.e. pigments, dry matter and water) and structure. In this study, we propose an approach of using radiative transfer models (RTMs) and TOC reflectance to estimate the biochemical and structural effects on TOC SIF, as a necessary step in retrieving physiological information from TOC SIF. The approach was assessed by using airborne (HyPlant) reflectance and SIF data acquired over an agricultural experimental farm in Germany on two days, before and during a heat event in summer 2015 with maximum temperatures of 27 degrees C and 34 degrees C, respectively. The results show that over 76% variation among different crops in SIF observations was explained by variation in vegetation biochemistry and structure. In addition, the changes of vegetation biochemistry and structure explained as much as 73% variation between the two days in far-red SIF, and 40% variation in red SIF. The remaining unexplained variation was mostly attributed to the variability in physiological status. We conclude that reflectance provides valuable information to account for biochemical and structural effects on SIF and to advance analysis of SIF observations. The combination of RTMs, reflectance and SIF opens new pathways to detect vegetation biochemical, structural and physiological changes.

【 授权许可】

Free