The role of inland waters in the carbon cycle at high latitudes
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 emission...
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Umeå universitet, Institutionen för ekologi, miljö och geovetenskap
2014
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ftumeauniv:oai:DiVA.org:umu-84541 2023-10-09T21:48:48+02:00 The role of inland waters in the carbon cycle at high latitudes Lundin, Erik 2014 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-84541 eng eng Umeå universitet, Institutionen för ekologi, miljö och geovetenskap Umeå : Umeå universitet http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-84541 urn:isbn:978-91-7459-781-3 info:eu-repo/semantics/openAccess lakes streams carbon (C) carbon dioxide (CO2) methane (CH4) dissolved inorganic carbon (DIC) boreal sub-arctic arctic emission sediments burial budget Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2014 ftumeauniv 2023-09-22T13:49:25Z 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 ... Doctoral or Postdoctoral Thesis Arctic Climate change Northern Sweden Subarctic Umeå University: Publications (DiVA) Arctic |
institution |
Open Polar |
collection |
Umeå University: Publications (DiVA) |
op_collection_id |
ftumeauniv |
language |
English |
topic |
lakes streams carbon (C) carbon dioxide (CO2) methane (CH4) dissolved inorganic carbon (DIC) boreal sub-arctic arctic emission sediments burial budget Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
spellingShingle |
lakes streams carbon (C) carbon dioxide (CO2) methane (CH4) dissolved inorganic carbon (DIC) boreal sub-arctic arctic emission sediments burial budget Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Lundin, Erik The role of inland waters in the carbon cycle at high latitudes |
topic_facet |
lakes streams carbon (C) carbon dioxide (CO2) methane (CH4) dissolved inorganic carbon (DIC) boreal sub-arctic arctic emission sediments burial budget Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
description |
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 ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Lundin, Erik |
author_facet |
Lundin, Erik |
author_sort |
Lundin, Erik |
title |
The role of inland waters in the carbon cycle at high latitudes |
title_short |
The role of inland waters in the carbon cycle at high latitudes |
title_full |
The role of inland waters in the carbon cycle at high latitudes |
title_fullStr |
The role of inland waters in the carbon cycle at high latitudes |
title_full_unstemmed |
The role of inland waters in the carbon cycle at high latitudes |
title_sort |
role of inland waters in the carbon cycle at high latitudes |
publisher |
Umeå universitet, Institutionen för ekologi, miljö och geovetenskap |
publishDate |
2014 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-84541 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Climate change Northern Sweden Subarctic |
genre_facet |
Arctic Climate change Northern Sweden Subarctic |
op_relation |
http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-84541 urn:isbn:978-91-7459-781-3 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1779311882260185088 |