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- Algesten, Grete, et al.
(författare)
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Role of lakes for organic carbon cycling in the boreal zone
- 2004
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Ingår i: Global Change Biology. - Oxford : Blackwell Scientific. - 1354-1013 .- 1365-2486. ; 10:1, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- We calculated the carbon loss (mineralization plus sedimentation) and net CO2 escape to the atmosphere for 79 536 lakes and total running water in 21 major Scandinavian catchments (size range 437–48 263 km2). Between 30% and 80% of the total organic carbon that entered the freshwater ecosystems was lost in lakes. Mineralization in lakes and subsequent CO2 emission to the atmosphere was by far the most important carbon loss process. The withdrawal capacity of lakes on the catchment scale was closely correlated to the mean residence time of surface water in the catchment, and to some extent to the annual mean temperature represented by latitude. This result implies that variation of the hydrology can be a more important determinant of CO2 emission from lakes than temperature fluctuations. Mineralization of terrestrially derived organic carbon in lakes is an important regulator of organic carbon export to the sea and may affect the net exchange of CO2 between the atmosphere and the boreal landscape.
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| 2. |
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| 3. |
- Wallin, Marcus, et al.
(författare)
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Evasion of CO2 from streams : The dominant component of the carbon export through the aquatic conduit in a boreal landscape
- 2013
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 19:3, s. 785-797
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Tidskriftsartikel (refereegranskat)abstract
- Evasion of gaseous carbon (C) from streams is often poorly quantified in landscape C budgets. Even though the potential importance of the capillary network of streams as C conduits across the land-water-atmosphere interfaces is sometimes mentioned, low-order streams are often left out of budget estimates due to being poorly characterized in terms of gas exchange and even areal surface coverage. We show that evasion of C is greater than all the total dissolved C (both organic and inorganic) exported downstream in the waters of a boreal landscape. In this study evasion of carbon dioxide (CO2) from running waters within a 67 km2 boreal catchment was studied. During a four year period (2006-2009) 13 streams were sampled on 104 different occasions for dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC). From a locally determined model of gas exchange properties, we estimated the daily CO2 evasion with a high-resolution (5×5 m) grid based stream evasion model comprising the entire ~100 km stream network. Despite the low areal coverage of stream surface the evasion of CO2 from the stream network constituted 53% (5.0 (±1.8) g C m−2 yr−1) of the entire stream C flux (9.6 (±2.4) g C m−2 yr−1) (lateral as DIC, DOC and vertical as CO2). In addition, 72% of the total CO2 loss took place already in the 1st and 2nd order streams. This study demonstrates the importance of including CO2 evasion from low-order boreal streams into landscape C budgets since it more than doubled the magnitude of the aquatic conduit for C from this landscape. Neglecting this term will consequently result in an overestimation of the terrestrial C sink strength in the boreal landscape.
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