Reduction of structural impacts and distinction of photosynthetic pathways in a global estimation of GPP from space-borne solar-induced chlorophyll fluorescence

REMOTE SENSING OF ENVIRONMENT

卷:240

Article

Zhang, Zhaoying^1,2  Zhang, Yongguang^1,2,3  Porcar-Castell, Albert⁴  Joiner, Joanna⁵  Guanter, Luis⁶  Yang, Xi⁷  Migliavacca, Mirco⁸  Ju, Weimin^1,2,3  Sun, Zhigang^9,10  Chen, Shiping¹¹  Martini, David⁸  Zhang, Qian^1,2  Li, Zhaohui^1,2  Cleverly, James¹²  Wang, Hezhou¹³  Goulas, Yves¹⁴ 

[1] Nanjing Univ, Int Inst Earth Syst Sci, Jiangsu Prov Key Lab Geog Informat Sci & Technol, Nanjing, Peoples R China

[2] Nanjing Univ, Sch Geog & Ocean Sci, Jiangsu Prov Key Lab Geog Informat Sci & Technol, Key Lab Land Satellite Remote Sensing Applicat,Mi, Nanjing 210023, Jiangsu, Peoples R China

[3] Collaborat Innovat Ctr Novel Software Technol & I, Nanjing 210023, Peoples R China

[4] Univ Helsinki, Inst Atmospher & Earth Syst Res Forest Sci, Opt Photosynth Lab, Helsinki, Finland

[5] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA

[6] Univ Politecn Valencia, Ctr Tecnol Fis, Cami Vera S-N, E-46022 Valencia, Spain

[7] Univ Virginia, Dept Environm Sci, Charlottesville, VA 22904 USA

[8] Max Planck Inst Biogeochem, Hans Knoell Str 10, D-07745 Jena, Germany

[9] Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China

[10] Univ Chinese Acad Sci, Coll Resources & Environm, Beijing 100190, Peoples R China

[11] Chinese Acad Sci, Inst Bot, State Key Lab Vegetat & Environm Change, Beijing 100093, Peoples R China

[12] Univ Technol Sydney, Sch Life Sci, Terr Ecosyst Res Network, Broadway, NSW 2007, Australia

[13] Chinese Acad Agr Sci, Farmland Irrigat Res Inst, Xinxiang, Henan, Peoples R China

[14] UPMC Univ Paris 06, Univ Paris Saclay, Sorbonne Univ, LMD IPSL,CNRS,ENS,PSL Res Univ,Ecole Polytech, F-91128 Palaiseau, France

关键词: Photosynthesis;    Photosynthetic pathway;    Chlorophyll fluorescence;    Canopy structure;    Spectral invariant theory;   

DOI  :  10.1016/j.rse.2020.111722

来源: Elsevier

【 摘 要 】

Quantifying global photosynthesis remains a challenge due to a lack of accurate remote sensing proxies. Solar-induced chlorophyll fluorescence (SIF) has been shown to be a good indicator of photosynthetic activity across various spatial scales. However, a global and spatially challenging estimate of terrestrial gross primary production (GPP) based on satellite SIF remains unresolved due to the confounding effects of species-specific physical and physiological traits and external factors, such as canopy structure or photosynthetic pathway (C-3 or C-4). Here we analyze an ensemble of far-red SIF data from OCO-2 satellite and ground observations at multiple sites, using the spectral invariant theory to reduce the effects of canopy structure and to retrieve a structure-corrected total canopy SIF emission (SIFtotal). We find that the relationships between observed canopy-leaving SIF and ecosystem GPP vary significantly among biomes. In contrast, the relationships between SIFtotal and GPP converge around two unique models, one for C-3 and one for C-4 plants. We show that the two single empirical models can be used to globally scale satellite SIF observations to terrestrial GPP. We obtain an independent estimate of global terrestrial GPP of 129.56 +/- 6.54 PgC/year for the 2015-2017 period, which is consistent with the state-of-the-art data- and process-oriented models. The new GPP product shows improved sensitivity to previously undetected 'hotspots' of productivity, being able to resolve the double-peak in GPP due to rotational cropping systems. We suggest that the direct scheme to estimate GPP presented here, which is based on satellite SIF, may open up new possibilities to resolve the dynamics of global terrestrial GPP across space and time.

【 授权许可】

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