Recent patterns and mechanisms of carbon exchange by terrestrial ecosystems

David S. Schimel (1) , Joanna I. House (1) , A. Hibbard (2) , Philippe Bousquet (3, 4) , Philippe Ciais (3, 5) , P. Peylin (3, 6) , B. Braswell (2) , M. Apps (7) , D. Baker (8) , Alberte Bondeau (9) , J. Canadell (10) , G. Churkina (11) , Wolfgang Cramer (9) , S. Denning (12) , C. Field (13) , P. Friedlingstein (14) , C. Goodale (13) , M. Heimann (1) , R. Houghton (15) , M. Melillo (16) , B. Moore (2) , D. Murdiyarso (17) , I. Noble (18) , W. Pacala (19) , C. Prentice (1) , R. Raupach (20) , P. Rayner (8) , R. Scholes (8) , W. Steffen (8) , C. Wirth (21)

1 MPI-BGC - Max Planck Institute for Biogeochemistry
2 UNH - University of New Hampshire
3 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
4 SATINV - Modélisation INVerse pour les mesures atmosphériques et SATellitaires
5 ICOS-ATC - ICOS-ATC
6 MOSAIC - MOSAIC
7 Canadian Forest Service Northern Forestry Center
8 AUTRES
9 PIK - Potsdam Institute for Climate Impact Research
10 GCTE International Project Office
11 ZALF - Leibniz-Zentrum für Agrarlandschaftsforschung = Leibniz Centre for Agricultural Landscape Research
12 CSU - Colorado State University [Fort Collins]
13 Carnegie Institution of Washington
14 University of Exeter
15 Woods Hole Research Center
16 Marine Biological Laboratory Massachussetts USA
17 GCTE Impacts Center for Southeast Asia
18 ANU - Australian National University
19 Princeton University
20 CSIRO Division of Land and Water
21 Max-Planck-Gesellschaft

Knowledge of carbon exchange between the atmosphere, land and the oceans is important, given that the terrestrial and marine environments are currently absorbing about half of the carbon dioxide that is emitted by fossil-fuel combustion. This carbon uptake is therefore limiting the extent of atmospheric and climatic change, but its long-term nature remains uncertain. Here we provide an overview of the current state of knowledge of global and regional patterns of carbon exchange by terrestrial ecosystems. Atmospheric carbon dioxide and oxygen data confirm that the terrestrial biosphere was largely neutral with respect to net carbon exchange during the 1980s, but became a net carbon sink in the 1990s. This recent sink can be largely attributed to northern extratropical areas, and is roughly split between North America and Eurasia. Tropical land areas, however, were approximately in balance with respect to carbon exchange, implying a carbon sink that offset emissions due to tropical deforestation. The evolution of the terrestrial carbon sink is largely the result of changes in land use over time, such as regrowth on abandoned agricultural land and fire prevention, in addition to responses to environmental changes, such as longer growing seasons, and fertilization by carbon dioxide and nitrogen. Nevertheless, there remain considerable uncertainties as to the magnitude of the sink in different regions and the contribution of different processes.

Domaines: Sciences de l'environnement

David S. Schimel, Joanna I. House, A. Hibbard, Philippe Bousquet, Philippe Ciais, et al.. Recent patterns and mechanisms of carbon exchange by terrestrial ecosystems. Nature, 2001, 414 (6860), pp.169-172. ⟨10.1038/35102500⟩. ⟨hal-01757652⟩