Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 7 2 2010 10.5194/bg-7-683-2010 http://www.biogeosciences.net/7/683/2010/ http://www.biogeosciences.net/7/683/2010/bg-7-683-2010.html http://www.biogeosciences.net/7/683/2010/bg-7-683-2010.pdf 683 694 2010-02-17 Estimating carbon dioxide fluxes from temperate mountain grasslands using broad-band vegetation indices G. Wohlfahrt georg.wohlfahrt@uibk.ac.at S. Pilloni L. Hörtnagl A. Hammerle Institute of Ecology, University of Innsbruck, Innsbruck, Austria now at: ETH Zürich, Institute of Plant, Animal and Agroecosystem Sciences, Zürich, Switzerland The broad-band normalised difference vegetation index (NDVI) and the simple ratio (SR) were calculated from measurements of reflectance of photosynthetically active and short-wave radiation at two temperate mountain grasslands in Austria and related to the net ecosystem CO₂ exchange (NEE) measured concurrently by means of the eddy covariance method. 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