caa a22 4500 52878756X 20190104030322.0 cr unu---uuuuu 180924s2010 xx s 000 0 eng 10.3929/ethz-b-000025657 doi 10.5194/bg-7-683-2010 doi (ETHRESEARCH)oai:www.research-collection.ethz.ch:20.500.11850/25657 Estimating carbon dioxide fluxes from temperate mountain grasslands using broad-band vegetation indices [Elektronische Daten] [Georg Wohlfahrt, Sebastian Pilloni, Lukas; id_orcid 0000-0002-5569-0761 Hörtnagl, Albin Hammerle] Open access ethresearch 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. There was no significant statistical difference between the relationships of midday mean NEE with narrow- and broad-band NDVI and SR, measured during and calculated for that same time window, respectively. The skill of broad-band NDVI and SR in predicting CO2 fluxes was higher for metrics dominated by gross photosynthesis and lowest for ecosystem respiration, with NEE in between. A method based on a simple light response model whose parameters were parameterised based on broad-band NDVI allowed to improve predictions of daily NEE and is suggested to hold promise for filling gaps in the NEE time series. Relationships of CO2 flux metrics with broad-band NDVI and SR however generally differed between the two studied grassland sites indicting an influence of additional factors not yet accounted for. Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0 ethresearch Wohlfahrt Georg joint author Pilloni Sebastian joint author Hörtnagl Lukas; id_orcid 0000-0002-5569-0761 joint author Hammerle Albin joint author Biogeosciences Göttingen : Copernicus 7 (2), pp. 683-694 http://hdl.handle.net/20.500.11850/25657 text/html WWW-Backlink auf das Repository (Open access) 1 Journal Article ethresearch ETHRESEARCH 856 40 http://hdl.handle.net/20.500.11850/25657 text/html WWW-Backlink auf das Repository (Open access) ETHRESEARCH 700 1- Wohlfahrt Georg joint author ETHRESEARCH 700 1- Pilloni Sebastian joint author ETHRESEARCH 700 1- Hörtnagl Lukas; id_orcid 0000-0002-5569-0761 joint author ETHRESEARCH 700 1- Hammerle Albin joint author ETHRESEARCH 773 0- Biogeosciences Göttingen : Copernicus 7 (2), pp. 683-694 BK010053 XK010053 XK010000 ETHRESEARCH ETHRESEARCH ETHRESEARCH Journal Article Open access