Authors
Eva Falge, Pflanzenökologie, Universität Bayreuth
John Tenhunen, Pflanzenökologie, Universität Bayreuth
Dennis D. Baldocchi, University of California, BerkeleyFollow
Marc Aubinet, Faculté des Sciences Agronomiques de Gembloux, Unité de Physique, B-5030 Gembloux, Belgium
Peter Bakwin, NOAA/OAR, Climate Monitoring and Diagnostics Laboratory
Paul Berbigier, INRA, Bioclimatologie, Bordeaux, France
Christian Bernhofer, Technische Universität Dresden, IHM Meteorologie, Pienner Str. 9, 01737 Tharandt, Germany
Jean-Marc Bonnefond, INRA, Bioclimatologie, Bordeaux, France
George Burba, University of Nebraska-LincolnFollow
Robert Clement, Institute of Ecology and Resource Management, University of Edinburgh, Darwin Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JU, UK
Kenneth J. Davis, Pennsylvania State UniversityFollow
Jan A. Elbers, Alterra, Postbus 47, 6700 AA Wageningen, The Netherlands
Matthias Falk, Atmospheric Science Group, LAWR, UC Davis, 122 Hoagland Hall, Davis, CA 95616, USA
Allen H. Goldstein, ESPM, University of California, Berkeley, CA 94720, USA
Achim Grelle, Department of Ecology and Environmental Research, Swedish University of Agricultural Sciences, S-75007 Uppsala, Sweden
Andre Granier, INRA, Unité d’Ecophysiologie Forestière, F-54280 Champenoux, France
Thomas Grunwald, Technische Universität Dresden, IHM Meteorologie, Pienner Str. 9, 01737 Tharandt, Germany
Jon Gundmondsson, Department of Environmental Research, Agricultural Research Institute, Keldnaholti, IS-112 Reykjavik, Iceland
David Hollinger, USDA Forest Service, 271 Mast Rd, Durham, NH 03824, USA
Ivan A. Janssens, Department of Biology, Research Group of Plant and Vegetation Ecology, University of Antwerpen, Universiteitsplein 1, B-2610, Wilrijk, Antwerp, Belgium
Petri Keronen, Department of Physics, P.O. Box 9, University of Helsinki, FIN-00014 Helsinki, Finland
Andrew S. Kowalski, Department of Biology, Research Group of Plant and Vegetation Ecology, University of Antwerpen, Universiteitsplein 1, B-2610, Wilrijk, Antwerp, Belgium
Gabriel Katul, Duke University
Beverly E. Law, Oregon State UniversityFollow
Yadvinder Malhi, Institute of Ecology and Resource Management, University of Edinburgh, Darwin Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JU, UK
Tilden Meyers, NOAA/ATDD, 456 S. Illinois Avenue, Oak Ridge, TN 37831-2456, USA
Russell K. Monson, Department of Environmental, Population, and Organismic Biology, University of Colorado, Campus Box 334, Boulder, CO 80309, USA
Eddy Moors, Alterra, Postbus 47, 6700 AA Wageningen, The Netherlands
J. William Munger, Department of Earth and Planetary Sciences, Harvard University, 20 Oxford St., Cambridge, MA 02138, USA
Walt Oechel, Department of Biology, San Diego State University, San Diego, CA 92182, USA
KyawTha Paw U, Atmospheric Science Group, LAWR, UC Davis, 122 Hoagland Hall, Davis, CA 95616, USA
Kim Pilegaard, Plant Biology and Biogeochemistry Department, Risoe National Laboratory, P.O. Box 49, DK-4000 Roskilde, Denmark
Ullar Rannik, Department of Physics, P.O. Box 9, University of Helsinki, FIN-00014 Helsinki, Finland
Corinna Rebmann, Max-Planck-Institut für Biogeochemie, Tatzendpromenade 1a, 07701 Jena, Germany
Andrew E. Suyker, University of Nebraska - LincolnFollow
Halldor Thorgeirsson, Department of Environmental Research, Agricultural Research Institute, Keldnaholti, IS-112 Reykjavik, Iceland
Giampiero Tirone, Department of Forest Environment and Resources, University of Tuscia, I-01100 Viterbo, Italy
Andrew Turnipseed, Department of Environmental, Population, and Organismic Biology, University of Colorado, Campus Box 334, Boulder, CO 80309, USA
Kell Wilson, NOAA/ATDD, 456 S. Illinois Avenue, Oak Ridge, TN 37831-2456, USA
Steve Wofsy, Department of Earth and Planetary Sciences, Harvard University, 20 Oxford St., Cambridge, MA 02138, USA
Date of this Version
10-21-2002
Abstract
As length and timing of the growing season are major factors explaining differences in carbon exchange of ecosystems, we analyzed seasonal patterns of net ecosystem carbon exchange (FNEE) using eddy covariance data of the FLUXNET data base (http://www-eosdis.ornl.gov/FLUXNET). The study included boreal and temperate, deciduous and coniferous forests, Mediterranean evergreen systems, rainforest, native and managed temperate grasslands, tundra, and C3 and C4 crops. Generalization of seasonal patterns are useful for identifying functional vegetation types for global dynamic vegetation models, as well as for global inversion studies, and can help improve phenological modules in SVAT or biogeochemical models. The results of this study have important validation potential for global carbon cycle modeling.
The phasing of respiratory and assimilatory capacity differed within forest types: for temperate coniferous forests seasonal uptake and release capacities are in phase, for temperate deciduous and boreal coniferous forests, releasewas delayed compared to uptake. According to seasonal pattern of maximum nighttime release (evaluated over 15-day periods, Fmax) the study sites can be grouped in four classes: (1) boreal and high altitude conifers and grasslands; (2) temperate deciduous and temperate conifers; (3) tundra and crops; (4) evergreen Mediterranean and tropical forests. Similar results are found for maximum daytime uptake (Fmin) and the integral net carbon flux, but temperate deciduous forests fall into class 1.
For forests, seasonal amplitudes of Fmax and Fmin increased in the order tropical < Mediterranean and temperate coniferous < temperate deciduous and boreal forests, and the pattern seems relatively stable for these groups. The seasonal amplitudes of Fmax and Fmin are largest for managed grasslands and crops. Largest observed values of Fmin varied between −48 and −2μmolm-2 s-1, decreasing in the order C4-crops > C3-crops > temperate deciduous forests > temperate conifers > boreal conifers > tundra ecosystems.
Due to data restrictions, our analysis centered mainly on Northern Hemisphere temperate and boreal forest ecosystems. Grasslands, crops, Mediterranean ecosystems, and rainforests are under-represented, as are savanna systems, wooded grassland, shrubland, or year-round measurements in tundra systems. For regional or global estimates of carbon sequestration potentials, future investigations of eddy covariance should expand in these systems.
Comments
Published in Agricultural and Forest Meteorology 113 (2002) 75–95.