Detecting the critical periods that underpin interannual fluctuations in the carbon balance of European forests

Le Maire, G.; Delpierre, N.; Jung, M.; Ciais, P.; Reichstein, M.; Viovy, N.; Granier, A.; Ibrom, A.; Kolari, P.; Longdoz, Bernard; Moors, E. J.; Pilegaard, K.; Rambal, S.; Richardson, A. D.; Vesala, T.

doi:10.1029/2009JG001244

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Detecting the critical periods that underpin interannual fluctuations in the carbon balance of European forests

Le Maire, G.; Delpierre, N.; Jung, M. et al.

2010 • In Journal of Geophysical Research. Biogeosciences, 115 (4)

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10.1029/2009JG001244

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[en] The interannual variability of CO<inf>2</inf> exchange by forest ecosystems in Europe was analyzed at site and regional scales by identifying critical periods that contributed to interannual flux anomalies. Critical periods were defined as periods in which monthly and annual flux anomalies were correlated. The analysis was first conducted at seven European forest flux tower sites with contrasting species and climatic conditions. Organizing Carbon and Hydrology in Dynamic Ecosystems (ORCHIDEE), a generic process-based model, represented fairly well most features of the critical period patterns and their climate drivers at the site scale. Simulations at the scale of European forests were performed with ORCHIDEE integrated at a 0.25° spatial resolution. The spatial and temporal distributions of critical periods for canopy photosynthesis, ecosystem respiration, and net ecosystem exchange (NEE) as well as their underlying climate drivers were analyzed. The interannual variability in gross primary productivity (GPP) was explained by critical periods during spring and summer months. In contrast, the interannual variability in total ecosystem respiration (TER) was explained by critical periods occurring throughout the year. A latitudinal contrast between southern and northern Europe was observed in the distributions of critical periods for GPP and TER. The critical periods were positively controlled by temperature in northern Europe and by soil water availability in southern Europe. More importantly, the latitudinal transition between temperature-driven and water-driven critical periods for GPP varied from early spring to late summer. Such a distinct seasonal regime of critical periods was less clearly defined for TER and NEE. Overall, the critical periods associated with NEE variations and their meteorological drivers followed those associated with GPP. Copyright © 2010 by the American Geophysical Union.

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Earth sciences & physical geography

Author, co-author :

Le Maire, G.; Laboratoire des Sciences de Climat et de l'Environnement, CEA CNRS UVSQ, Orme des Merisiers, F-91191 Gif-sur-Yvette, France, UMR Eco and Sols, Cirad, UPR 80 Ecosystmes de Plantations, Montpellier, France

Delpierre, N.; Laboratoire Ecologie, Systématique et Evolution, UMR 8079, Université Paris-Sud, Orsay F-91405, France

Jung, M.; Max-Planck-Institute for Biogeochemistry, Hans Knöll Str. 10, D-07745 Jena, Germany

Ciais, P.; Laboratoire des Sciences de Climat et de l'Environnement, CEA CNRS UVSQ, Orme des Merisiers, F-91191 Gif-sur-Yvette, France

Reichstein, M.; Max-Planck-Institute for Biogeochemistry, Hans Knöll Str. 10, D-07745 Jena, Germany

Viovy, N.; Laboratoire des Sciences de Climat et de l'Environnement, CEA CNRS UVSQ, Orme des Merisiers, F-91191 Gif-sur-Yvette, France

Granier, A.; UMR INRA-UHP Écologie et Écophysiologie Forestiéres, INRA Centre de Nancy, Champenoux F-54280, France

Ibrom, A.; Biosystems Department, Risø National Laboratory for Sustainable Energy, Technical University of Denmark, PO Box 49, DK-4000, Roskilde, Denmark

Kolari, P.; Department of Physics, University of Helsinki, PO Box 64, FIN-00014 Helsinki, Finland

Longdoz, Bernard ; INRA‐UHP Écologie et Écophysiologie Forestières, INRA Centre de Nancy, Champenoux, France

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Language :

English

Title :

Detecting the critical periods that underpin interannual fluctuations in the carbon balance of European forests

Publication date :

2010

Journal title :

Journal of Geophysical Research. Biogeosciences

ISSN :

2169-8953

eISSN :

2169-8961

Publisher :

Blackwell Publishing

Volume :

115

Issue :

Peer reviewed :

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