caa a22 4500 606218882 CHVBK 20210128101115.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s11104-014-2371-7 doi (NATIONALLICENCE)springer-10.1007/s11104-014-2371-7 Partitioning NEE for absolute C input into various ecosystem pools by combining results from eddy-covariance, atmospheric flux partitioning and 13CO2 pulse labeling [Elektronische Daten] [M. Riederer, J. Pausch, Y. Kuzyakov, T. Foken] Background and aims: The complexity of ecosystem processes, especially under continuously changing environmental conditions, requires high-resolution insight into ecosystem carbon (C) fluxes. It is essential to gain not only information about relative C balance and fluxes (common for partitioning studies), but also to obtain these in absolute mass units. Methods: To evaluate absolute fluxes in belowground C pools, the results of 21-day eddy-covariance and stable isotope labeling experiment in summer 2010, were combined. Eddy-covariance based net ecosystem exchange was measured on extensively managed grassland and separated into underlying assimilation and ecosystem respiration through the use of a C flux partitioning model. Resultant CO2 assimilation served as absolute C input into the ecosystem and was further partitioned by applying the relative C distribution in subsidiary pools, gained by 13C pulse labeling and tracing. Results: The results form eddy-covariance measurements showed that the extensively managed grassland was a significant net C sink of −91g C m−2 a−1 in 2010. The mean daily assimilation of −7.1g C m−2 d−1 was partitioned into fluxes of 2.5, 0.8, 0.5, 2.3 and 1.0g C m−2 d−1 into shoots, roots, soil, shoot respiration and CO2 efflux from soil, respectively. Conclusions: We conclude that the combination of EC measurements with isotope labeling techniques allowed determining the absolute C input into several ecosystem pools. Hence, the study demonstrates an approach to expand atmospheric flux measurements and to gain insight into the importance of individual ecosystem pools for soil C cycling. Springer International Publishing Switzerland, 2015 Stable isotope pulse labeling nationallicence Net ecosystem exchange nationallicence Carbon flux nationallicence Extensively managed grassland nationallicence Riederer M. Department of Micrometeorology, University of Bayreuth, 95440, Bayreuth, Germany aut Pausch J. Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077, Göttingen, Germany aut Kuzyakov Y. Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077, Göttingen, Germany aut Foken T. Department of Micrometeorology, University of Bayreuth, 95440, Bayreuth, Germany aut Plant and Soil Springer International Publishing 390/1-2(2015-05-01), 61-76 0032-079X 390:1-2<61 2015 390 11104 https://doi.org/10.1007/s11104-014-2371-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-014-2371-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Riederer M. Department of Micrometeorology, University of Bayreuth, 95440, Bayreuth, Germany aut NATIONALLICENCE 700 1- Pausch J. Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077, Göttingen, Germany aut NATIONALLICENCE 700 1- Kuzyakov Y. Department of Soil Science of Temperate Ecosystems, University of Göttingen, 37077, Göttingen, Germany aut NATIONALLICENCE 700 1- Foken T. Department of Micrometeorology, University of Bayreuth, 95440, Bayreuth, Germany aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 390/1-2(2015-05-01), 61-76 0032-079X 390:1-2<61 2015 390 11104