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The role of inland ...
The role of inland waters in the carbon cycle at high latitudes
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- Lundin, Erik, 1982- (författare)
- Umeå universitet,Institutionen för ekologi, miljö och geovetenskap,Arcum
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- Karlsson, Jan, Professor (preses)
- Umeå universitet,Institutionen för ekologi, miljö och geovetenskap
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- Giesler, Reiner, Professor (preses)
- Umeå universitet,Institutionen för ekologi, miljö och geovetenskap
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- Striegl, Robert, Dr (opponent)
- National Research Program, U.S. Geological Survey, USA
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(creator_code:org_t)
- ISBN 9789174597813
- Umeå : Umeå universitet, 2014
- Engelska 17 s.
- Relaterad länk:
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https://umu.diva-por... (primary) (Raw object)
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https://urn.kb.se/re...
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Abstract
Ämnesord
Stäng
- Understanding the drivers of climate change requires knowledge about the global carbon (C) cycle. Although inland waters play an important role in the C cycle by emitting and burying C, streams and lakes are in general overlooked in bottom-up approached C budgets. In this thesis I estimated emissions of carbon dioxide (CO2) and methane (CH4) from all lakes and streams in a 15 km2 subarctic catchment in northern Sweden, and put it in relation to the total catchment C exchange. I show that high-latitude aquatic systems in general and streams in particular are hotspots for C emission to the atmosphere. Annually, the aquatic systems surveyed in this study emitted about 10.8 ± 4.9 g C m-2 yr-1 (ca. 98 % as CO2) which is more than double the amount of the C laterally exported from the catchment. Although the streams only covered about 4% of the total aquatic area they emitted ca. 95% of the total aquatic C emission. For lake emissions, the ice break-ups were the most important annual events, counting for ca. 45% of the emissions. Overall, streams dominated the aquatic CO2 emission in the catchment while lakes dominated CH4 emission, 96 % and 62 % of the totals, respectively. When summing terrestrial and aquatic C fluxes together it showed that the aquatic emissions alone account for approximately two thirds of the total annual catchment C loss. The consequence of not including inland waters in bottom-up derived C budgets is therefore a risk of overestimating the sink capacity of the subarctic landscape. However, aquatic systems can also act as C sinks, by accumulating C in sediment and thereby storing C over geological time frames. Sediment C burial rates were estimated in six lakes from a chronology based on 210Pb dating of multiple sediment cores. The burial rate ranged between 5 - 25 g C m-2 yr-1, which is of the same magnitude as lake C emissions. I show that the emission:burial ratio is about ten times higher in boreal compared to in subarctic-arctic lakes. These results indicate that the balance between lakes C emission and burial is both directly and indirectly dependent on climate. This process will likely result in a future increase of C emissions from high-latitude lakes, while the C burial capacity of these same lakes sediments weaken.
Ämnesord
- NATURVETENSKAP -- Geovetenskap och miljövetenskap (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences (hsv//eng)
Nyckelord
- lakes
- streams
- carbon (C)
- carbon dioxide (CO2)
- methane (CH4)
- dissolved inorganic carbon (DIC)
- boreal
- sub-arctic
- arctic
- emission
- sediments
- burial
- budget
- limnologi
- Limnology
- Earth Sciences with Specialization Environmental Analysis
- geovetenskap med inriktning mot miljöanalys
- naturgeografi
- Physical Geography
Publikations- och innehållstyp
- vet (ämneskategori)
- dok (ämneskategori)
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