Global remote sensing of water–chlorophyll ratio in terrestrial plant leaves

Authors

  • Keiji Kushida

    Corresponding author
    • Center for Far Eastern Studies and Graduate School of Science and Engineering (Science), University of Toyama, Toyama, Japan
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  • This study was supported by the Grant-in-Aid for Scientific Research (C),20510001, 2008, from the Japan Ministry of Education, Science, Sports and Culture (MEXT) and the Arctic Research Projects using the IARC-JAXA Information System of the Japan Aerospace Exploration Agency (JAXA).

Correspondence

Keiji Kushida, Center for Far Eastern Studies and Graduate School of Science and Engineering (Science), University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan. Tel: +81 76 445 6648; Fax: +81 76 445 6549; E-mail: kkushida@sci.u-toyama.ac.jp

Abstract

I evaluated the use of global remote sensing techniques for estimating plant leaf chlorophyll a + b (Cab; μg cm−2) and water (Cw; mg cm−2) concentrations as well as the ratio of Cw/Cab with the PROSAIL model under possible distributions for leaf and soil spectra, leaf area index (LAI), canopy geometric structure, and leaf size. First, I estimated LAI from the normalized difference vegetation index. I found that, at LAI values <2, Cab, Cw, and Cw/Cab could not be reliably estimated. At LAI values >2, Cab and Cw could be estimated for only restricted ranges of the canopy structure; however, the ratio of Cw/Cab could be reliably estimated for a variety of possible canopy structures with coefficients of determination (R2) ranging from 0.56 to 0.90. The remote estimation of the Cw/Cab ratio from satellites offers information on plant condition at a global scale.

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