The global distribution of leaf chlorophyll content

REMOTE SENSING OF ENVIRONMENT

卷:236

Article

Croft, H.^1,2  Chen, J. M.¹  Wang, R.¹  Mo, G.¹  Luo, S.³  Luo, X.⁴  He, L.¹  Gonsamo, A.⁵  Arabian, J.^1,6  Zhang, Y.⁷  Simic-Milas, A.⁸  Noland, T. L.⁹  He, Y.¹⁰  Homolova, L.¹¹  Malenovsky, Z.¹²  Yi, Q.¹³  Beringer, J.¹⁴  Amiri, R.¹⁵  Hutley, L.¹⁶  Arellano, P.¹⁷  Stahl, C.¹⁸  Bonal, D.¹⁹ 

[1] Univ Toronto, Dept Geog, Toronto, ON M5S 3G3, Canada

[2] Univ Sheffield, Dept Anim & Plant Sci, Sheffield S10 2TN, S Yorkshire, England

[3] Chinese Acad Sci, Inst Remote Sensing & Digital Earth, Key Lab Digital Earth Sci, Beijing 100094, Peoples R China

[4] Lawrence Berkeley Natl Lab, Climate & Ecosyst Sci Div, Berkeley, CA 94720 USA

[5] McMaster Univ, Sch Geog & Earth Sci, 1280 Main St W Hamilton, Hamilton, ON L8S 4L8, Canada

[6] WWF Canada, 410 Adelaide St, Toronto, ON M5V 1S8, Canada

[7] Delta State Univ, Div Biol & Phys Sci, Cleveland, MS 38733 USA

[8] Bowling Green State Univ, Dept Geol, Bowling Green, OH 43403 USA

[9] Ontario Minist Nat Resources, Ontario Forest Res Inst, 1235 Queen St E, Marie, ON P6A 2E5, Canada

[10] Univ Toronto Mississauga, Dept Geog, 3359 Mississauga Rd, Mississauga, ON L5L 1C6, Canada

[11] Global Change Res Inst CAS, Belidla 986 4a, Brno 60300, Czech Republic

[12] Univ Tasmania, Sch Technol Environm & Design, Dept Geog & Spatial Sci, Coll Sci & Engn, Hobart, Tas 7001, Australia

[13] Chinese Acad Sci, Xinjiang Inst Ecol & Geog, 818 Beijing South Rd, Urumqi 830011, Xinjiang, Peoples R China

[14] Univ Western Australia, Sch Earth & Environm SEE, Crawley, WA 6009, Australia

[15] Monash Univ, Sch Earth Atmosphere & Environm, Clayton, Vic 3800, Australia

[16] Charles Darwin Univ, Sch Environm, Res Inst Environm & Livelihoods, Livelihoods, NT 0909, Australia

[17] Yachay Tech Univ, Sch Geol Sci & Engn, CEO, Urcuqui, Ecuador

[18] INRA, UMR Ecol Forets Guyane, Campus Agron,BP 709, Kourou 97387, French Guiana

[19] INRA Univ Lorraine, UMR EEF, F-54280 Champenoux, France

关键词: Radiative transfer;    4-Scale;    SAIL;    PROSPECT;    Leaf biochemistry;    MERIS;    Satellite;    Remote sensing;    Leaf physiology;    Carbon cycle;    Ecosystem modelling;    Phenology;   

DOI  :  10.1016/j.rse.2019.111479

来源: Elsevier

【 摘 要 】

Leaf chlorophyll is central to the exchange of carbon, water and energy between the biosphere and the atmosphere, and to the functioning of terrestrial ecosystems. This paper presents the first spatially-continuous view of terrestrial leaf chlorophyll content (Chl(Leaf)) at the global scale. Weekly maps of Chl(Leaf) were produced from ENVISAT MERIS full resolution (300 m) satellite data using a two-stage physically-based radiative transfer modelling approach. Firstly, leaf-level reflectance was derived from top-of-canopy satellite reflectance observations using 4-Scale and SAIL canopy radiative transfer models for woody and non-woody vegetation, respectively. Secondly, the modelled leaf-level reflectance was input into the PROSPECT leaf-level radiative transfer model to derive Chl(Leaf). The Chl(Leaf) retrieval algorithm was validated using measured Chi(Leaf) data from 248 sample measurements at 28 field locations, and covering six plant functional types (PFTs). Modelled results show strong relationships with field measurements, particularly for deciduous broadleaf forests (R-2 = 0.67; RMSE = 9.25 mu g cm(-2); p < 0.001), croplands (R-2 = 0.41; RMSE = 13.18 mu g cm(-2); p < 0.001) and evergreen needleleaf forests (R-2 = 0.47; RMSE = 10.63 mu g cm(-2); p < 0.001). When the modelled results from all PFTs were considered together, the overall relationship with measured Chl(Leaf )remained good (R-2 = 0.47, RMSE = 10.79 mu g cm(-2); p < 0.001). This result is an improvement on the relationship between measured Chl(Leaf) and a commonly used chlorophyll-sensitive spectral vegetation index; the MERIS Terrestrial Chlorophyll Index (MTCI; R-2 = 0.27, p < 0.001). The global maps show large temporal and spatial variability in Chl(Leaf), with evergreen broadleaf forests presenting the highest leaf chlorophyll values, with global annual median values of 54.4 mu g cm(-2). Distinct seasonal Chl(Leaf) phenologies are also visible, particularly in deciduous plant forms, associated with budburst and crop growth, and leaf senescence. It is anticipated that this global Chl(Leaf) product will make an important step towards the explicit consideration of leaf-level biochemistry in terrestrial water, energy and carbon cycle modelling.

【 授权许可】

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