Articles | Volume 8, issue 7
Biogeosciences, 8, 2009–2025, 2011
Biogeosciences, 8, 2009–2025, 2011

Research article 25 Jul 2011

Research article | 25 Jul 2011

Controls on winter ecosystem respiration in temperate and boreal ecosystems

T. Wang1, P. Ciais1, S. L. Piao2, C. Ottlé1, P. Brender1, F. Maignan1, A. Arain3, A. Cescatti4, D. Gianelle5, C. Gough6, L. Gu7, P. Lafleur8, T. Laurila9, B. Marcolla10, H. Margolis11, L. Montagnani12,13, E. Moors14, N. Saigusa15, T. Vesala16, G. Wohlfahrt17, C. Koven18, A. Black19, E. Dellwik20, A. Don21, D. Hollinger22, A. Knohl23, R. Monson24, J. Munger25, A. Suyker26, A. Varlagin27, and S. Verma26 T. Wang et al.
  • 1LSCE/IPSL, UMR8212, CEA-CNRS-UVSQ – Unité Mixte de Recherche, CE L'Orme des Merisiers, Gif-sur-Yvette 91191, France
  • 2Department of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871, China
  • 3School of Geography and Earth Sciences, McMaster University, Hamilton, ON, L8S 4K1, Canada
  • 4Climate Change Unit, Inst. for Environment and Sustainability, European Commission, DG joint Research Centre, Ispra, Italy
  • 5IASMA, Research and Innovation Centre, Fondazione Edmund Mach, Viote del Monte Bondone, Trento, 38040, Italy
  • 6Deparment of Biology, Virginia Commonwealth University, P.O. Box 842012, 1000 West Cary St. Richmond, VA 23284-2012, USA
  • 7Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
  • 8Department of Geography, Trent University, Peterborough, Ontario K9J 7B8, Canada
  • 9Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
  • 10Edmund Mach Foundation, Research and Innovation Center, 38010 S. Michele all' Adige, Trento, Italy
  • 11Centre d'Étude de la Foret, Faculté de Foresterie, de Géographie et de Géomatique, Université Laval, Québec, QC, G1V 0A6, Canada
  • 12Autonomous Province of Bolzano, Forest Services and Agency for the Environment, Bolzano, Italy
  • 13Free University of Bolzano, Faculty of Science and Technology, Bolzano, Italy
  • 14Alterra Wageningen UR, Wageningen, 6700 AA, The Netherlands
  • 15Center for Global Environmental Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
  • 16Department of Physics, University of Helsinki, P.O. Box 48, 00014, Finland
  • 17University of Innsbruck, Institute of Ecology Sternwartestrasse 15, Innsbruck 6020, Austria
  • 18Lawrence Berkeley National Lab, Berkeley 94720, CA, USA
  • 19Faculty of Land and Food systems, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
  • 20Wind Energy Division, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, 4000 Roskilde, Denmark
  • 21Johann Heinrich von Thünen Inst., Inst. of Agricultural Climate Research, Bundesallee 50, 38116 Braunschweig, Germany
  • 22Northern Research Station, USDA Forest Service, 271 Mast Rd, Durham, NH 03824, USA
  • 23Chair of Bioclimatology, Büsgen Institute, Georg-August University of Göttingen, Germany
  • 24Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
  • 25Division of Engineering and Applied Science, Deptment of Earth and Planetary Science, Harvard University, Cambridge, MA 02138, USA
  • 26School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583, USA
  • 27A. N. Severtsov Institute of Ecology and Evolution, Russia Academy of Sciences, Leninsky Prospect 33, Moscow, 117071, Russia

Abstract. Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco) of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m−2 d−1), when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m−2 d−1). Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m−2 d−1) of 0.70(±0.33), 0.60(±0.38), 0.62(±0.43), 0.49(±0.22) and 0.27(±0.08), respectively. Our cross site analysis showed that winter air (Tair) and soil (Tsoil) temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands). Besides temperature, the seasonal amplitude of the leaf area index (LAI), inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (QS) was higher than the one over time (interannual, QT). This can be expected because QS not only accounts for climate gradients across sites but also for (positively correlated) the spatial variability of substrate quantity. Thus, if the models estimate future warming impacts on Reco based on QS rather than QT, this could overestimate the impact of temperature changes.

Final-revised paper