气候变化领域集成服务门户(CCPortal): Assessing the contribution of understory sun-induced chlorophyll fluorescence through 3-D radiative transfer modelling and field data

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DOI	10.1016/j.rse.2020.112195
	Assessing the contribution of understory sun-induced chlorophyll fluorescence through 3-D radiative transfer modelling and field data
	Hornero A.; North P.R.J.; Zarco-Tejada P.J.; Rascher U.; Martín M.P.; Migliavacca M.; Hernandez-Clemente R.
发表日期	2021
ISSN	00344257
卷号	253
英文摘要	A major international effort has been made to monitor sun-induced chlorophyll fluorescence (SIF) from space as a proxy for the photosynthetic activity of terrestrial vegetation. However, the effect of spatial heterogeneity on the SIF retrievals from canopy radiance derived from images with medium and low spatial resolution remains uncharacterised. In images from forest and agricultural landscapes, the background comprises a mixture of soil and understory and can generate confounding effects that limit the interpretation of the SIF at the canopy level. This paper aims to improve the understanding of SIF from coarse spatial resolutions in heterogeneous canopies by considering the separated contribution of tree crowns, understory and background components, using a modified version of the FluorFLIGHT radiative transfer model (RTM). The new model is compared with others through the RAMI model intercomparison framework and is validated with airborne data. The airborne campaign includes high-resolution data collected over a tree-grass ecosystem with the HyPlant imaging spectrometer within the FLuorescence EXplorer (FLEX) preparatory missions. Field data measurements were collected from plots with a varying fraction of tree and understory vegetation cover. The relationship between airborne SIF calculated from pure tree crowns and aggregated pixels shows the effect of the understory at different resolutions. For a pixel size smaller than the mean crown size, the impact of the background was low (R2 > 0.99; NRMSE < 0.01). By contrast, for a pixel size larger than the crown size, the goodness of fit decreased (R2 < 0.6; NRMSE > 0.2). This study demonstrates that using a 3D RTM model improves the calculation of SIF significantly (R2 = 0.83, RMSE = 0.03 mW m−2 sr−1 nm−1) when the specific contribution of the soil and understory layers are accounted for, in comparison with the SIF calculated from mixed pixels that considers only one layer as background (R2 = 0.4, RMSE = 0.28 mW m−2 sr−1 nm−1). These results demonstrate the need to account for the contribution of SIF emitted by the understory in the quantification of SIF within tree crowns and within the canopy from aggregated pixels in heterogeneous forest canopies. © 2020 Elsevier Inc.
英文关键词	Chlorophyll fluorescence; Heterogeneous canopies; Hyperspectral; HyPlant; Radiative transfer modelling; SIF; Understory
语种	英语
scopus关键词	3D modeling; Aggregates; Agricultural robots; Chlorophyll; Fluorescence; Forestry; Radiative transfer; Vegetation; Agricultural landscapes; Chlorophyll fluorescence; Field data measurements; Model inter comparisons; Photosynthetic activity; Radiative transfer model; Radiative transfer modelling; Terrestrial vegetation; Pixels; assessment method; chlorophyll; field method; fluorescence; heterogeneity; image analysis; induced response; numerical model; pixel; radiative transfer; spatial resolution; three-dimensional modeling; Varanidae
来源期刊	Remote Sensing of Environment
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/179020
作者单位	Department of Geography, Swansea University, Swansea, SA2 8PP, United Kingdom; School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences (FVAS), Department of Infrastructure Engineering, Melbourne School of Engineering (MSE), University of Melbourne, Melbourne, Victoria, Australia; Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Científicas (CSIC), Alameda del Obispo s/n, Córdoba, 14004, Spain; Institute of Bio- and Geosciences, IBG-2: Plant Sciences, Forschungszentrum Jülich, Leo-Brandt-Str, Jülich, 52425, Germany; Environmental Remote Sensing and Spectroscopy Laboratory (SpecLab), Spanish National Research Council (CSIC), Albasanz 26-28, Madrid, 28037, Spain; Max Planck Institute for Biogeochemistry, Hanks Knöll Straße 10, Jena, D-07745, Germany
推荐引用方式 GB/T 7714	Hornero A.,North P.R.J.,Zarco-Tejada P.J.,et al. Assessing the contribution of understory sun-induced chlorophyll fluorescence through 3-D radiative transfer modelling and field data[J],2021,253.
APA	Hornero A..,North P.R.J..,Zarco-Tejada P.J..,Rascher U..,Martín M.P..,...&Hernandez-Clemente R..(2021).Assessing the contribution of understory sun-induced chlorophyll fluorescence through 3-D radiative transfer modelling and field data.Remote Sensing of Environment,253.
MLA	Hornero A.,et al."Assessing the contribution of understory sun-induced chlorophyll fluorescence through 3-D radiative transfer modelling and field data".Remote Sensing of Environment 253(2021).