| 1. |
- Barros, Nathan, et al.
(författare)
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Carbon emission from hydroelectric reservoirs linked to reservoir age and latitude
- 2011
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Ingår i: Nature Geoscience. - : Nature Publishing Group. - 1752-0894 .- 1752-0908. ; 4:9, s. 593-596
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Tidskriftsartikel (refereegranskat)abstract
- Hydroelectric reservoirs cover an area of 3.4 x 10(5) km(2) and comprise about 20% of all reservoirs. In addition, they contain large stores of formerly terrestrial organic carbon. Significant amounts of greenhouse gases are emitted(2), especially in the early years following reservoir creation, but the global extent of these emissions is poorly known. Previous estimates of emissions from all types of reservoir indicate that these human-made systems emit 321 Tg of carbon per year (ref. 4). Here we assess the emissions of carbon dioxide and methane from hydroelectric reservoirs, on the basis of data from 85 globally distributed hydroelectric reservoirs that account for 20% of the global area of these systems. We relate the emissions to reservoir age, location biome, morphometric features and chemical status. We estimate that hydroelectric reservoirs emit about 48 Tg C as CO(2) and 3 Tg C as CH(4), corresponding to 4% of global carbon emissions from inland waters. Our estimates are smaller than previous estimates on the basis of more limited data. Carbon emissions are correlated to reservoir age and latitude, with the highest emission rates from the tropical Amazon region. We conclude that future emissions will be highly dependent on the geographic location of new hydroelectric reservoirs.
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| 2. |
- Tranvik, Lars, et al.
(författare)
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The study of carbon in inland waters-from isolated ecosystems to players in the global carbon cycle
- 2018
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Ingår i: Limnology and Oceanography Letters. - : Wiley. - 2378-2242. ; 3:3, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- This essay describes the evolution of our understanding of the carbon cycle of inland waters. Research has evolved from studies of individual lakes with limited attention to the surrounding landscapes, to a focus on how lakes are affected by external factors such as import of organic matter from the watershed, thereafter increasingly addressing how inland waters impact the carbon cycle beyond their own limits, for example by emission of gases to the atmosphere. Major steps are described toward the now widely applied concept of the aquatic “active pipe,” and the development of global quantification of inland water carbon cycling. Despite the great progress in understanding of the carbon cycle during the last decades, we argue that there is still a need for better integration of inland waters with other habitats in studies of carbon biogeochemistry.
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| 3. |
- Weyhenmeyer, Gesa A., et al.
(författare)
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Browning of Boreal Freshwaters Coupled to Carbon-Iron Interactions along the Aquatic Continuum
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:2, s. e88104-
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Tidskriftsartikel (refereegranskat)abstract
- The color of freshwaters, often measured as absorbance, influences a number of ecosystem services including biodiversity, fish production, and drinking water quality. Many countries have recently reported on increasing trends of water color in freshwaters, for which drivers are still not fully understood. We show here with more than 58000 water samples from the boreal and hemiboreal region of Sweden and Canada that absorbance of filtered water (a(420)) co-varied with dissolved organic carbon (DOC) concentrations (R-2 = 0.85, P<0.0001), but that a(420) relative to DOC is increased by the presence of iron (Fe). We found that concentrations of Fe significantly declined with increasing water retention in the landscape, resulting in significantly lower Fe concentrations in lakes compared to running waters. The Fe loss along the aquatic continuum corresponded to a proportional loss in a(420), suggesting a tight biogeochemical coupling between colored dissolved organic matter and Fe. Since water is being flushed at increasing rates due to enhanced runoff in the studied regions, diminished loss of Fe along the aquatic continuum may be one reason for observed trends in a(420), and in particular in a(420)/DOC increases. If trends of increased Fe concentrations in freshwaters continue, water color will further increase with various effects on ecosystem services and biogeochemical cycles.
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