Quantifying the relative importance of lake emissions in the carbon budget of a subarctic catchment

TY - JOUR

T1 - Quantifying the relative importance of lake emissions in the carbon budget of a subarctic catchment

AU - Karlsson, Jan

AU - Christensen, Torben Røjle

AU - Crill, P

AU - Förster, J

AU - Hammarlund, Dan

AU - Jackowicz-Korzynski, M

AU - Kokfelt, Ulla

AU - Roehm, C

AU - Rosen, P

PY - 2010/9/1

Y1 - 2010/9/1

N2 - Climate change and thawing of permafrost will likely result in increased decomposition of terrestrial organic carbon and subsequent carbon emissions to the atmosphere from terrestrial and aquatic systems. The quantitative importance of mineralization of terrestrial organic carbon in lakes in relation to terrestrial carbon fluxes is poorly understood and a serious drawback for the understanding of carbon budgets. We studied a subarctic lake in an area of discontinuous permafrost to assess the quantitative importance of lake carbon emission for the catchment carbon balance. Estimates of net ecosystem production and stable carbon-isotope composition of dissolved organic carbon in the lake water suggest substantial input and respiration of terrestrial organic carbon in the lake. The lake was a net source of CO2 and CH4 to the atmosphere at ice breakup in spring and during the whole ice-free period. The carbon emission from the lake was similar in magnitude to the terrestrial net release of carbon to the atmosphere. The results indicate that lakes are important sources of catchment carbon emission, potentially increasing the positive feedback from permafrost thawing on global warming.

AB - Climate change and thawing of permafrost will likely result in increased decomposition of terrestrial organic carbon and subsequent carbon emissions to the atmosphere from terrestrial and aquatic systems. The quantitative importance of mineralization of terrestrial organic carbon in lakes in relation to terrestrial carbon fluxes is poorly understood and a serious drawback for the understanding of carbon budgets. We studied a subarctic lake in an area of discontinuous permafrost to assess the quantitative importance of lake carbon emission for the catchment carbon balance. Estimates of net ecosystem production and stable carbon-isotope composition of dissolved organic carbon in the lake water suggest substantial input and respiration of terrestrial organic carbon in the lake. The lake was a net source of CO2 and CH4 to the atmosphere at ice breakup in spring and during the whole ice-free period. The carbon emission from the lake was similar in magnitude to the terrestrial net release of carbon to the atmosphere. The results indicate that lakes are important sources of catchment carbon emission, potentially increasing the positive feedback from permafrost thawing on global warming.

U2 - 10.1029/2010jg001305

DO - 10.1029/2010jg001305

M3 - Journal article

SN - 0148-0227

VL - 115

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

IS - 3

ER -