Journal article
Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance : DISSOLVED CARBON LEACHING
University College Dublin1
Risø National Laboratory for Sustainable Energy, Technical University of Denmark2
Centre for Ecology and Hydrology3
Trinity College Dublin4
Grassland Ecosystem Research5
Johann Heinrich von Thunen Institute6
University of Manchester7
Alterra8
Biosystems Division. Management, Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark9
Helmholtz Centre for Environmental Research10
Technische Universität Berlin11
Dresden University of Technology12
Martin Luther University Halle-Wittenberg13
Swiss Federal Institute of Technology Zurich14
INRAE15
Max Planck Institute16
University of Zurich17
Ecosystems, Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark18
Biosystems Division, Risø National Laboratory for Sustainable Energy, Technical University of Denmark19
...and 9 moreEstimates of carbon leaching losses from different land use systems are few and their contribution to the net ecosystem carbon balance is uncertain. We investigated leaching of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved methane (CH4), at forests, grasslands, and croplands across Europe.
Biogenic contributions to DIC were estimated by means of its d13C signature. Leaching of biogenic DIC was 8.34.9 gm2 yr1 for forests, 24.17.2 gm2 yr1 for grasslands, and 14.64.8 gm2 yr1 for croplands. DOC leaching equalled 3.51.3 gm2 yr1 for forests, 5.32.0 gm2 yr1 for grasslands, and 4.11.3 gm2 yr1 for croplands.
The average flux of total biogenic carbon across land use systems was 19.44.0 gCm2 yr1. Production of DOC in topsoils was positively related to their C/N ratio and DOC retention in subsoils was inversely related to the ratio of organic carbon to iron plus aluminium (hydr)oxides. Partial pressures of CO2 in soil air and soil pH determined DIC concentrations and fluxes, but soil solutions were often supersaturated with DIC relative to soil air CO2.
Leaching losses of biogenic carbon (DOC plus biogenic DIC) from grasslands equalled 5–98% (median: 22%) of net ecosystem exchange (NEE) plus carbon inputs with fertilization minus carbon removal with harvest. Carbon leaching increased the net losses from cropland soils by 24–105% (median: 25%). For the majority of forest sites, leaching hardly affected actual net ecosystem carbon balances because of the small solubility of CO2 in acidic forest soil solutions and large NEE.
Leaching of CH4 proved to be insignificant compared with other fluxes of carbon. Overall, our results show that leaching losses are particularly important for the carbon balance of agricultural systems.
Language: | English |
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Publisher: | Wiley |
Year: | 2011 |
Pages: | 1167-1185 |
ISSN: | 13652486 and 13541013 |
Types: | Journal article |
DOI: | 10.1111/j.1365-2486.2010.02282.x |
ORCIDs: | Ibrom, Andreas and Pilegaard, Kim |