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The Scientific World Journal
Volume 2012 (2012), Article ID 705872, 13 pages
http://dx.doi.org/10.1100/2012/705872
Research Article

Relation of Chlorophyll Fluorescence Sensitive Reflectance Ratios to Carbon Flux Measurements of Montanne Grassland and Norway Spruce Forest Ecosystems in the Temperate Zone

1Global Change Research Centre AS CR, Bělidla 4a, 603 00 Brno, Czech Republic
2Remote Sensing Laboratories, Department of Geography, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
3Department of Surveying and Spacial Sciences, School of Geography and Environmental Studies, University of Tasmania, Private Bag 76, Hobart TAS 7001, Australia
4Department of Physics, Faculty of Science, University of Ostrava, 30. dubna 22, 701 03 Ostrava, Czech Republic
5Department of Plant Physiology, Faculty of Science, University of South Bohemia, Branišovská 31, 370 05 České Budějovice, Czech Republic

Received 17 January 2012; Accepted 26 March 2012

Academic Editors: M. Carnol, H. Hasenauer, and B. Tóthmérész

Copyright © 2012 Alexander Ač et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We explored ability of reflectance vegetation indexes (VIs) related to chlorophyll fluorescence emission ( 𝑅 6 8 6 / 𝑅 6 3 0 , 𝑅 7 4 0 / 𝑅 8 0 0 ) and de-epoxidation state of xanthophyll cycle pigments (PRI, calculated as ( 𝑅 5 3 1 − 𝑅 5 7 0 ) / ( 𝑅 5 3 1 − 𝑅 5 7 0 ) ) to track changes in the CO2 assimilation rate and Light Use Efficiency (LUE) in montane grassland and Norway spruce forest ecosystems, both at leaf and also canopy level. VIs were measured at two research plots using a ground-based high spatial/spectral resolution imaging spectroscopy technique. No significant relationship between VIs and leaf light-saturated CO2 assimilation ( 𝐴 M A X ) was detected in instantaneous measurements of grassland under steady-state irradiance conditions. Once the temporal dimension and daily irradiance variation were included into the experimental setup, statistically significant changes in VIs related to tested physiological parameters were revealed. ΔPRI and Δ( 𝑅 6 8 6 / 𝑅 6 3 0 ) of grassland plant leaves under dark-to-full sunlight transition in the scale of minutes were significantly related to 𝐴 M A X ( 𝑅 2 = 0 . 5 1 ). In the daily course, the variation of VIs measured in one-hour intervals correlated well with the variation of Gross Primary Production (GPP), Net Ecosystem Exchange (NEE), and LUE estimated via the eddy-covariance flux tower. Statistical results were weaker in the case of the grassland ecosystem, with the strongest statistical relation of the index 𝑅 6 8 6 / 𝑅 6 3 0 with NEE and GPP.