caa a22 4500 467885583 CHVBK 20180406152733.0 cr unu---uuuuu 170328e20060401xx s 000 0 eng 10.1007/s10021-005-0013-x doi (NATIONALLICENCE)springer-10.1007/s10021-005-0013-x Seasonal Variation in Aboveground Production and Radiation-use Efficiency of Temperate rangelands Estimated through Remote Sensing [Elektronische Daten] [Gervasio Piñeiro, Martín Oesterheld, José Paruelo] Aboveground net primary production (ANPP) of grasslands varies spatially and temporally. Spectral information provided by remote sensors is a promising new tool that may be able to estimate ANPP in real time and at low cost. The objectives of this study were (a) to evaluate at a seasonal scale the relationship between ANPP and the normalized difference vegetation index (NDVI), (b) to estimate seasonal variations in the coefficient of conversion of absorbed radiation into aboveground biomass (εa), and (c) to identify the environmental controls on such temporal changes. We used biomass-based field determinations of ANPP for two grassland sites in the Flooding Pampa, Argentina, and related them with NDVI data derived from the NOAA Advanced Very High Resolution Radiometer (AVHRR) satellites using three different models. Results were compared with data obtained from the new Moderate Resolution Imaging Spectroradiometer (MODIS) sensor at an additional site. The first model was based solely on NDVI; the second was based on the amount of photosynthetically active radiation absorbed by the green vegetation (APARg), which was derived from NDVI and incoming photosynthetically active radiation (PAR); the third was based on APARg and εa, which was in turn estimated from climatic variables. NDVI explained between 63 and 93% of ANPP variation, depending on the site considered. Estimates of ANPP were not improved by considering the variation in incoming PAR. At both sites, εa varied seasonally (from 0.2 to 1.2 g DM/MJ) and was significantly associated with combinations of precipitation and temperature. Combining εa variations with APARg increased our ability to account for seasonal ANPP variations at both sites. Our results indicate that NDVI produces good, direct estimates of ANPP only if NDVI, PAR, and εa are correlated throughout the seasons. Thus, in most cases, seasonal variations of εa associated with temperature and precipitation must be taken into account to generate seasonal ANPP estimates with acceptable accuracy. Springer Science+Business Media, Inc., 2006 grasslands nationallicence radiation-use efficiency nationallicence aboveground net primary production nationallicence normalized difference vegetation index (NDVI) nationallicence NOAA Advanced Very High Resolution Radiometer (AVHRR) nationallicence Moderate Resolution Imaging Spectroradiometer (MODIS) nationallicence remote sensing nationallicence Argentina nationallicence Piñeiro Gervasio Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Laboratorio de Análisis Regional y Teledetección (LART), Universidad de Buenos Aires, IFEVA/CONICET, Buenos Aires, Argentina aut Oesterheld Martín Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Laboratorio de Análisis Regional y Teledetección (LART), Universidad de Buenos Aires, IFEVA/CONICET, Buenos Aires, Argentina aut Paruelo José Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Laboratorio de Análisis Regional y Teledetección (LART), Universidad de Buenos Aires, IFEVA/CONICET, Buenos Aires, Argentina aut Ecosystems Springer-Verlag; www.springer-ny.com 9/3(2006-04-01), 357-373 1432-9840 9:3<357 2006 9 10021 https://doi.org/10.1007/s10021-005-0013-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10021-005-0013-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Piñeiro Gervasio Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Laboratorio de Análisis Regional y Teledetección (LART), Universidad de Buenos Aires, IFEVA/CONICET, Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Oesterheld Martín Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Laboratorio de Análisis Regional y Teledetección (LART), Universidad de Buenos Aires, IFEVA/CONICET, Buenos Aires, Argentina aut NATIONALLICENCE 700 1- Paruelo José Facultad de Agronomía, Departamento de Recursos Naturales y Ambiente, Laboratorio de Análisis Regional y Teledetección (LART), Universidad de Buenos Aires, IFEVA/CONICET, Buenos Aires, Argentina aut NATIONALLICENCE 773 0- Ecosystems Springer-Verlag; www.springer-ny.com 9/3(2006-04-01), 357-373 1432-9840 9:3<357 2006 9 10021 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer