Natural Resources, School of

 

Authors

Eva Falge, Pflanzenökologie, Universität Bayreuth, 95440 Bayreuth, Germany
Dennis Baldocchi, ESPM, University of California at Berkeley, Berkeley, CA 94720, USA
John Tenhunen, Pflanzenökologie, Universität Bayreuth, 95440 Bayreuth, Germany
Marc Aubinet, Unité de Physique, Faculté des Sciences, Agronomiques de Gembloux, B-50 30 Gembloux, Belgium
Peter Bakwin, NOAA/OAR, Climate Monitoring and Diagnostics Laboratory, 325 Broadway, Boulder, CO 80303, USA
Paul Berbigier, INRA, Bioclimatologie, Bordeaux, France
Christian Bernhofer, Technische Universität Dresden, IHM Meteorologie, Pienner Str. 9, 01737 Tharandt, Germany
George Burba, University of Nebraska - Lincoln
Robert Clement, Institute of Ecology and Resource Management, University of Edinburgh, Edinburgh EH9 3JU, UK
Kenneth J. Davis, Department of Meteorology, Pennsylvania State University, University Park, PA 16802, USA
Jan A. Elbers, Alterra, Postbus 47, 6700 AA Wageningen, The Netherlands
Allen H. Goldstein, ESPM, University of California at Berkeley, Berkeley, CA 94720, USA
Achim Grelle, Department of Ecology and Environmental Research, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden
Andre Granier, INRA, Unité d’Ecophysiologie Forestière, F-54280 Champenoux, France
Jon Gundmundsson, Department of Environmental Research, Agricultural Research Institute, Keldnaholti, IS-112 Reykjavik, Iceland
David Hollinger, USDA Forest Service, 271 Mast Road, Durham, NH 03824, USA
Andrew S. Kowalski, Research Group of Plant and Vegetation Ecology, Department of Biology, University of Antwerpen, Universiteitsplein 1, B-2610 Wilrijk, Antwerp, Belgium
Gabriel Katul, School of the Environment, Duke University, Box 90328, Durham, NC 27708-0328, USA
Beverly E. Law, Richardson Hall, Oregon State University, Corvallis, OR 97331-2209, USA
Yadvinder Malhi, Institute of Ecology and Resource Management, University of Edinburgh, 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
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, USA
Kyaw Tha 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, University of Helsinki, P.O. Box 9, FIN-00014 Helsinki, Finland
Corinna Rebmann, Max-Planck-Institut für Biogeochemie, Tatzendpromenade 1a, 07701 Jena, Germany
Andrew E. Suyker, University of Nebraska - LincolnFollow
Riccardo Valentini, Department of Forest Environment and Resources, University of Tuscia, I-01100 Viterbo, Italy
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

October 2002

Comments

Published in Agricultural and Forest Meteorology 113 (2002) 53–74.

Abstract

Differences in the seasonal pattern of assimilatory and respiratory processes are responsible for divergences in seasonal net carbon exchange among ecosystems. Using FLUXNET data (http://www.eosdis.ornl.gov/FLUXNET) we have analyzed seasonal patterns of gross primary productivity (FGPP), and ecosystem respiration (FRE) of boreal and temperate, deciduous and coniferous forests, Mediterranean evergreen systems, a rainforest, temperate grasslands, and C3 and C4 crops. Based on generalized seasonal patterns classifications of ecosystems into vegetation functional types can be evaluated for use in global productivity and climate change models. The results of this study contribute to our understanding of respiratory costs of assimilated carbon in various ecosystems.

Seasonal variability of FGPP and FRE of the investigated sites increased in the order tropical < Mediterranean < temperate coniferous < temperate deciduous < boreal forests. Together with the boreal forest sites, the managed grasslands and crops show the largest seasonal variability. In the temperate coniferous forests, seasonal patterns of FGPP and FRE are in phase, in the temperate deciduous and boreal coniferous forests FRE was delayed compared to FGPP, resulting in the greatest imbalance between respiratory and assimilatory fluxes early in the growing season.

FGPP adjusted for the length of the carbon uptake period decreased at the sampling sites across functional types in the order C4 crops, temperate and boreal deciduous forests (7.5–8.3 g Cm−2 per day) > temperate conifers, C3 grassland and crops (5.7–6.9g Cm−2 per day) > boreal conifers (4.6 g Cm−2 per day). Annual FGPP and net ecosystem productivity (FNEP) decreased across climate zones in the order tropical > temperate > boreal. However, the decrease in FNEP with latitude was greater than the decrease in FGPP, indicating a larger contribution of respiratory (especially heterotrophic) processes in boreal systems.