Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil
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Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil. / Siemens, Jan; Pacholski, A.; Heiduk, Katia et al.
In: Biogeochemistry, Vol. 108, No. 1-3, 01.04.2012, p. 135-148.Research output: Journal contributions › Journal articles › Research › peer-review
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TY - JOUR
T1 - Elevated air carbon dioxide concentrations increase dissolved carbon leaching from a cropland soil
AU - Siemens, Jan
AU - Pacholski, A.
AU - Heiduk, Katia
AU - Giesemann, Anette
AU - Schulte, Ulrike
AU - Dechow, Rene
AU - Kaupenjohann, Martin
AU - Weigel, Hans-Joachim
PY - 2012/4/1
Y1 - 2012/4/1
N2 - Increasing leaching losses of carbon from soils due to accelerated weathering and increasing concentrations of dissolved carbon as a result of intensified soil respiration are suspected to provide a negative feedback on rising atmospheric CO 2 concentrations. We tested this hypothesis by studying concentrations of dissolved carbon and groundwater recharge at the Braunschweig free air carbon dioxide enrichment (FACE) experiment under winter wheat and winter barley. Dissolved carbon concentrations under elevated atmospheric CO 2 and ambient conditions were rather similar and not consistently higher under FACE. An analysis of δ 13C signatures suggested that dissolved organic and inorganic carbon contained 9-29% (DOC) and 26-49% (DIC) of "new" carbon originating from CO 2 added to the FACE rings. Dissolved inorganic carbon additionally contained 15-42% of carbonate-derived C. A 15% reduction in evapotranspiration under elevated CO 2 increased groundwater recharge by 60 mm or 55%, which was the main driver for an observed 81% increase in dissolved carbon leaching from 2.7 to 4.9 g C m -2 year -1 at 90 cm depth. Our results suggest that future changes of dissolved carbon leaching losses will be mainly governed by changes in climate and groundwater recharge and to a lesser extent by increasing dissolved carbon concentrations.
AB - Increasing leaching losses of carbon from soils due to accelerated weathering and increasing concentrations of dissolved carbon as a result of intensified soil respiration are suspected to provide a negative feedback on rising atmospheric CO 2 concentrations. We tested this hypothesis by studying concentrations of dissolved carbon and groundwater recharge at the Braunschweig free air carbon dioxide enrichment (FACE) experiment under winter wheat and winter barley. Dissolved carbon concentrations under elevated atmospheric CO 2 and ambient conditions were rather similar and not consistently higher under FACE. An analysis of δ 13C signatures suggested that dissolved organic and inorganic carbon contained 9-29% (DOC) and 26-49% (DIC) of "new" carbon originating from CO 2 added to the FACE rings. Dissolved inorganic carbon additionally contained 15-42% of carbonate-derived C. A 15% reduction in evapotranspiration under elevated CO 2 increased groundwater recharge by 60 mm or 55%, which was the main driver for an observed 81% increase in dissolved carbon leaching from 2.7 to 4.9 g C m -2 year -1 at 90 cm depth. Our results suggest that future changes of dissolved carbon leaching losses will be mainly governed by changes in climate and groundwater recharge and to a lesser extent by increasing dissolved carbon concentrations.
KW - Sustainability Science
KW - Ecosystems Research
KW - Carbon sequestration
KW - Dissolved inorganic carbon
KW - Dissolved organic carbon
KW - Free air carbon dioxide enrichment
KW - Net biome productivity
KW - Net ecosystem carbon balance
UR - http://www.scopus.com/inward/record.url?scp=84857638261&partnerID=8YFLogxK
U2 - 10.1007/s10533-011-9584-0
DO - 10.1007/s10533-011-9584-0
M3 - Journal articles
AN - SCOPUS:84857638261
VL - 108
SP - 135
EP - 148
JO - Bioenergy Research
JF - Bioenergy Research
SN - 1939-1234
IS - 1-3
ER -