| 1. |
- Karlsson, Jan, 1974-, et al.
(författare)
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Ice-melt period dominates annual carbon dioxide evasion from clear-water Arctic lakes
- 2024
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Ingår i: Limnology and Oceanography Letters. - : John Wiley & Sons. - 2378-2242. ; 9:2, s. 112-118
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Tidskriftsartikel (refereegranskat)abstract
- Current estimates of carbon dioxide (CO2) evasion from Arctic lakes are highly uncertain because few studies integrate seasonal variability, specifically evasion during spring ice-melt. We quantified annual CO2 evasion for 14 clear-water Arctic lakes in Northern Sweden through mass balance (ice-melt period) and high-frequency loggers (open-water period). On average, 80% (SD: ± 18) of annual CO2 evasion occurred within 10 d following ice-melt. The contribution of the ice-melt period to annual CO2 evasion was high compared to earlier studies of Arctic lakes (47% ± 32%). Across all lakes, the proportion of ice-melt : annual CO2 evasion was negatively related to the dissolved organic carbon concentration and positively related to the mean depth of the lakes. The results emphasize the need for measurements of CO2 exchange at ice-melt to accurately quantify CO2 evasion from Arctic lakes.
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| 2. |
- Serikova, Svetlana, 1989-, et al.
(författare)
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Carbon emission from the boreal floodplain of Ob’ River
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Ob’ River floodplain is the second largest floodplain in the world. Despite its vast area, estimates of carbon (C) emissions from the Ob’ River floodplain are largely absent. Here we present seasonal C emission and water area extent from the main channel and the floodplain along a ~4 km reach in the boreal zone of the Ob’ River. We find strong seasonality in water area extent of the Ob’ main channel (~1.8 km2) and floodplain (~3 km2) with water covering 34% of land during flood and subsequently declining to ~16 and 14% during summer and autumn baseflow, respectively. The C emissions also showed seasonal differences over the open water period ranging from 4.66 to -4.25 g C m-2 d-1 for the Ob’ main channel and from 0.03 to 1.42 g C m-2 d-1 for the floodplain. The total annual C emission from the study reach was ~940 ± 744 t C yr-1 with the floodplain accounting for ~16%. The contribution of the floodplain to the net river C evasion can be even greater in northern regions of the Ob’ River basin, where floodplain soils are more C-rich and are underlain by permafrost, and in years with more extensive flooding.
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| 3. |
- Vachon, Dominic, et al.
(författare)
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Controls on terrestrial carbon fluxes in simulated networks of connected streams and lakes
- 2023
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Ingår i: Global Biogeochemical Cycles. - : John Wiley & Sons. - 0886-6236 .- 1944-9224. ; 37:3
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Tidskriftsartikel (refereegranskat)abstract
- Inland waters play a critical role in the carbon cycle by emitting significant amounts of land-exported carbon to the atmosphere. While carbon gas emissions from individual aquatic systems have been extensively studied, how networks of connected streams and lakes regulate integrated fluxes of organic and inorganic forms remain poorly understood. Here, we develop a process-based model to simulate the fate of terrestrial dissolved organic carbon (DOC) and carbon dioxide (CO2) in artificial inland water networks with variable topology, hydrology, and DOC reactivity. While the role of lakes is highly dependent on DOC reactivity, we find that the mineralization of terrestrial DOC is more efficient in lake-rich networks. Regardless of typology and hydrology, terrestrial CO2 is emitted almost entirely within the network boundary. Consequently, the proportion of exported terrestrial carbon emitted from inland water networks increases with the CO2 versus DOC export ratio. Overall, our results suggest that CO2 emissions from inland waters are governed by interactions between the relative amount and reactivity of terrestrial DOC and CO2 inputs and the network configuration of recipient lakes and streams.
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| 4. |
- Vachon, Dominic, et al.
(författare)
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Integrating carbon emission, accumulation and transport in inland waters to understand their role in the global carbon cycle
- 2021
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 27:4, s. 719-727
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Tidskriftsartikel (refereegranskat)abstract
- Inland waters receive a significant quantity of carbon (C) from land. The fate of this C during transit, whether it is emitted to the atmosphere, accumulated in sediments or transported to the ocean, can considerably reshape the landscape C balance. However, these different fates of terrestrial C are not independent but are instead linked via several catchment and aquatic processes. Thus, according to mass conservation, any environmental change inducing a shift in a particular C fate should come at the expense of at least one other fate. Nonetheless, studies that have investigated C emission, accumulation and transport concertedly are scarce, resulting in fragmented knowledge of the role of inland waters in the global C cycle. Here, we propose a framework to understand how different C fates in aquatic systems are interlinked and covary under environmental changes. First, to explore how C fates are currently distributed in streams, rivers, reservoirs and lakes, we compiled data from the literature and show that 'C fate allocation' varies widely both within and among inland water systems types. Secondly, we developed a framework that integrates C fates in any inland water system by identifying the key processes underlying their linkages. Our framework places the partitioning between the different C forms, and how this is controlled by export from land, internal transformations and hydrology, as central to understanding C fate allocation. We argue that, by focusing on a single fate, studies could risk drawing misleading conclusions regarding how environmental changes will alter the role of inland waters in the global C cycle. Our framework thus allows us to holistically assess the consequences of such changes on coupled C fluxes, setting a foundation for understanding the contemporary and future fate of land-derived C in inland water systems.
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| 5. |
- Vachon, Dominic, et al.
(författare)
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Paired O2-€“CO2 measurements provide emergent insights into aquatic ecosystem function
- 2020
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Ingår i: Limnology and Oceanography Letters. - : Wiley. - 2378-2242. ; 5:4, s. 287-294
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Tidskriftsartikel (refereegranskat)abstract
- Metabolic stoichiometry predicts that dissolved oxygen (O 2) and carbon dioxide (CO 2) in aquatic ecosystems should covary inversely; however, field observations often diverge from theoretical expectations. Here, we propose a suite of metrics describing this O 2 and CO 2 decoupling and introduce a conceptual framework for interpreting these metrics within aquatic ecosystems. Within this framework, we interpret cross-system patterns of high-frequency O 2 and CO 2 measurements in 11 northern lakes and extract emergent insights into the metabolic behavior and the simultaneous roles of chemical and physical forcing in shaping ecosystem processes. This approach leverages the power of high-frequency paired O 2-CO 2 measurements, and yields a novel, integrative aquatic system typology which can also be applicable more broadly to streams and rivers, wetlands and marine systems. Dissolved oxygen (O 2) remains one of the most studied attributes of aquatic ecosystems since the beginning of modern ecology. In 1957, G. E. Hutchinson famously wrote "A skillful limnologist can probably learn more about the nature of a lake from a series of oxygen determinations than from any other kind of chemical data" (Hutchinson 1957). The value of oxygen as an indicator of ecosystem function stems from its role in biogeochemical reactions, where it regulates
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