scholarly journals Dissolved organic carbon vertical movement and carbon accumulation in West Siberian peatlands

2021 ◽  
Author(s):  
Evgeny A. Zarov ◽  
Elena D. Lapshina ◽  
Iris Kuhlmann ◽  
Ernst-Detlef Schulze
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Accumulation Rate ◽  
Bottom Layer ◽  
Vertical Movement ◽  
Carbon Accumulation ◽  
Downward Movement ◽  
Average Value ◽  
Lack Of Information ◽  
Lake Bottom

Abstract. Dissolved organic carbon is an additional path of carbon cycle but there is a lack of information about its distribution in peatland and rates of downward movement. We dated seven peat cores (separately the dissolved (DOC) and particulate (POC) organic carbon) from Mukhrino peatland (typical zonal oligotrophic bog) in western Siberia to assess the date distribution between those two peat fractions. Our results revealed that the DOC is younger than POC for the surface peatland layers (0–150 cm) and older for the deeper layers. The date differences increases with depth and reaches 2000–3000 years at the bottom layer (430–530 cm). In our hypothesis this date discrepancy caused by more young DOC moving to the deeper and older peat layers. The estimated average value of DOC downward movement was 0.047 ± 0.019 cm yr−1. Th oldest dates found at the lake bottom and ancient riverbed were 10 053 and 10 989 cal yr BP correspondingly. For the whole period of peatland functioning the average peat accumulation rate was estimated as 0.067 ± 0.018 cm yr−1 (0.013–0.332 cm yr−1), the carbon accumulation rate was estimated as 38.56 ± 12.21 g С m−2 yr−1 (28.46–57.91 g С m−2 yr−1).

scholarly journals Distribution and bacterial availability of dissolved neutral sugars in the South East Pacific

2008 ◽  
Vol 5 (1) ◽  
pp. 725-750 ◽  
Author(s):  
R. Sempéré ◽  
M. Tedetti ◽  
C. Panagiotopoulos ◽  
B. Charrière ◽  
F. Van Wambeke
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Carbon Accumulation ◽  
Detectable Effect ◽  
Neutral Sugar ◽  
The South ◽  
East Pacific ◽  
Significant Stimulation ◽  
Neutral Sugars ◽  
Productive Area

Abstract. The distribution and bacterial availability of dissolved neutral sugars were studied in the South East Pacific from October to December 2004 during the BIOSOPE cruise. Four contrasted sites were investigated: Marquesas Islands (MAR), the hyper-oligotrophic South Pacific Gyre (GYR), the eastern part of the Gyre (EGY), and the coastal waters associated to upwelling of Chile (UPW). Total (free and combined) dissolved neutral sugar (TDNS) concentrations were higher in UPW (149–329 nM) and MAR (111–540 nM), than in GYR (79–390 nM) and EGY (58–492 nM). Nevertheless, their contribution to dissolved organic carbon (TDNS-C/DOC%) was generally low for all sites varying from 0.5% to 4% indicating that our South East Pacific surface waters were relatively poor in neutral sugars. Free dissolved neutral sugar (FDNS; e.g. sugars analyzed without hydrolysis) concentrations were very low within the detection of our method (5–10 nM) accounting <5% of the TDNS. In general, the predominant sugars within the TDNS pool were glucose, xylose, arabinose, and galactose while in the FDNS pool only glucose was present. TDNS stock to bacterial production ratios (integrated values from the surface to the deep chlorophyll maximum) were relatively high in GYR with respect to the low primary production, whereas the opposite trend was observed in the highly productive area of UPW. Intermediate situations were observed for MAR and EGY. Bioavailability of dissolved organic matter (DOM) exposed to natural solar radiation was also experimentally studied and compared to dark treatments. Our results showed no or little detectable effect of sunlight on DOM bacterial assimilation in UPW and in GYR while a significant stimulation was found in MAR and EGY. The overall results clearly suggest the semi-labile character of DOM in GYR compared to the labile of UPW and are consistent with dissolved organic carbon accumulation and the elevated C/N ratios reported by Raimbault et al. (2007).

scholarly journals Spatial and temporal organic carbon burial along a fjord to coast transect: A case study from Western Norway

The Holocene ◽  
2017 ◽  
Vol 27 (9) ◽  
pp. 1325-1339 ◽  
Author(s):  
CJ Duffield ◽  
E Alve ◽  
N Andersen ◽  
TJ Andersen ◽  
S Hess ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Isotopes ◽  
Accumulation Rate ◽  
Carbon Accumulation ◽  
Individual Species ◽  
Accumulation Rates ◽  
Foraminiferal Assemblage ◽  
Assemblage Composition ◽  
Western Norway ◽  
Carbon Accumulation Rates

We investigated spatial and temporal changes in accumulation rate and source of organic carbon on a gradient along the Lysefjord and the more coastal Høgsfjord, Western Norway. This was achieved through analysis of total organic carbon and nitrogen content of sediment cores, which were radiometrically dated to the early 19th and 20th centuries for the Høgsfjord and Lysefjord, respectively. Benthic foraminifera (protists) were utilized to determine changes in organic carbon supply and Ecological Quality Status (EcoQS) by their accumulation rate (benthic foraminiferal accumulation rate (BFAR)), assemblage composition, species diversity, individual species responses and the composition of stable carbon isotopes of the tests (shells) of Cassidulina laevigata, Hyalinea balthica and Melonis barleeanus. Organic carbon accumulation rates were greatest closest to the river Lyse at the head of the Lysefjord (83–171 g C m−2 yr−1). The organic carbon at the head of the fjord is mainly terrestrial in origin, and this terrestrial influence becomes progressively less seaward. The δ13C in H. balthica tests as well as the benthic foraminiferal assemblage composition also showed a clear fjord to coast gradient. Organic carbon accumulation rates were lower and less variable at the seaward study sites (13–61 g C m−2 yr−1). We observe no temporal trend in organic carbon, carbon isotopes, EcoQS or foraminiferal assemblage composition in the Lysefjord. In contrast, in the Høgsfjord, there seems to have been an increase in organic carbon accumulation rates during the 1940s. Subsequent accumulation rates are stable. The foraminiferal assemblages in the surface sediments reflect a recent transition from good/moderate to moderate/bad EcoQS.

scholarly journals Source and quantity of carbon influence its sequestration in Rostherne Mere (UK) sediment: a novel application of stepped combustion radiocarbon analysis

2020 ◽  
Vol 64 (4) ◽  
pp. 347-363
Author(s):  
Evelyn M. Keaveney ◽  
Alan D. Radbourne ◽  
Suzanne McGowan ◽  
David B. Ryves ◽  
Paula J. Reimer
Keyword(s):  
Carbon Source ◽  
Organic Carbon ◽  
Accumulation Rate ◽  
Carbon Sources ◽  
Carbon Accumulation ◽  
Phytoplankton Production ◽  
Catchment Management ◽  
Sediment Organic Carbon ◽  
Rostherne Mere ◽  
Recalcitrant Carbon

Abstract We explored the roles of phytoplankton production, carbon source, and human activity on carbon accumulation in a eutrophic lake (Rostherne Mere, UK) to understand how changes in nutrient loading, algal community structure and catchment management can influence carbon sequestration in lake sediments. Water samples (dissolved inorganic, organic and particulate carbon) were analysed to investigate contemporary carbon sources. Multiple variables in a 55-cm sediment core, which represents the last ~ 90 years of accumulation, were studied to determine historical production rates of algal communities and carbon sources. Fluctuations in net primary production, inferred from sedimentary diatom abundance and high-performance liquid chromatography (HPLC) pigment methods, were linked to nutrient input from sewage treatment works (STW) in the catchment. Stepped combustion radiocarbon (SCR) measurements established that lake sediment contains between 11% (~ 1929 CE) and 69% (~ 1978 CE) recalcitrant carbon, with changes in carbon character coinciding with peaks in accumulation rate and linked to STW inputs. Catchment disturbance was identified by radiocarbon analysis, and included STW construction in the 1930s, determined using SCR analysis, and recent nearby highway construction, determined by measurements on dissolved organic carbon from the lake and outflow river. The quantity of autochthonous carbon buried was related to diatom biovolume accumulation rate (DBAR) and decreased when diatom accumulation rate and valve size declined, despite an overall increase in net carbon production. HPLC pigment analysis indicated that changes in total C deposition and diatom accumulation were related to proliferation of non-siliceous algae. HPLC results also indicated that dominance of recalcitrant carbon in sediment organic carbon was likely caused by increased deposition rather than preservation factors. The total algal accumulation rate controlled the sediment organic carbon accumulation rate, whereas DBAR was correlated to the proportion of each carbon source buried.

scholarly journals Holocene development of subarctic permafrost peatlands in Finnmark, northern Norway

The Holocene ◽  
2018 ◽  
Vol 28 (12) ◽  
pp. 1855-1869 ◽  
Author(s):  
Sofia E Kjellman ◽  
Pia E Axelsson ◽  
Bernd Etzelmüller ◽  
Sebastian Westermann ◽  
A Britta K Sannel
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Accumulation Rate ◽  
Time Lag ◽  
Plant Macrofossils ◽  
Carbon Accumulation ◽  
Northern Norway ◽  
Geochemical Properties ◽  
Peatland Development ◽  
The Mean

Subarctic permafrost peatlands are important soil organic carbon pools, and improved knowledge about peat properties and peatland sensitivity to past climate change is essential when predicting future response to a warmer climate and associated feedback mechanisms. In this study, Holocene peatland development and permafrost dynamics of four subarctic peat plateaus in Finnmark, northern Norway have been investigated through detailed analyses of plant macrofossils and geochemical properties. Peatland inception occurred around 9800 cal. yr BP and 9200 cal. yr BP at the two continental sites Suossjavri and Iskoras. Younger basal peat ages were found at the two coastal locations Lakselv and Karlebotn, at least partly caused by the time lag between deglaciation and emergence of land by isostatic uplift. Here, peatland development started around 6150 cal. yr BP and 5150 cal. yr BP, respectively. All four peatlands developed as wet fens throughout most of the Holocene. Permafrost aggradation, causing frost heave and a shift in the vegetation assemblage from wet fen to dry bog species, probably did not occur until during the last millennium, ca. 950 cal. yr BP in Karlebotn and ca. 800 cal. yr BP in Iskoras, and before ca. 150 cal. yr BP in Lakselv and ca. 100 cal. yr BP in Suossjavri. In Karlebotn, there are indications of a possible earlier permafrost phase around 2200 cal. yr BP due to climatic cooling at the late Subboreal to early Subatlantic transition. The mean long-term Holocene carbon accumulation rate at all four sites was 12.3 ± 4.1 gC m−2 yr−1 (±SD) and the mean soil organic carbon storage was 97 ± 46 kgC m−2.

scholarly journals New nutrients exert fundamental control on dissolved organic carbon accumulation in the surface Atlantic Ocean

2016 ◽  
Vol 113 (38) ◽  
pp. 10497-10502 ◽  
Author(s):  
Cristina Romera-Castillo ◽  
Robert T. Letscher ◽  
Dennis A. Hansell
Keyword(s):  
Organic Carbon ◽  
Atlantic Ocean ◽  
Dissolved Organic Carbon ◽  
Euphotic Zone ◽  
Carbon Accumulation ◽  
Global Ocean ◽  
Biological Pump ◽  
Nutrient Input ◽  
Order Of Magnitude

The inventories of carbon residing in organic matter dissolved in the ocean [dissolved organic carbon (DOC)] and in the atmosphere as CO2 are of the same order of magnitude, such that small changes in the DOC pool could have important consequences in atmospheric carbon and thus climate. DOC in the global ocean is largely formed in the sunlit euphotic zone, but identifying predictable controls on that production is an important yet unrealized goal. Here, we use a testable and causative correlation between the net production of DOC and the consumption of new nutrients in the euphotic zone of the Atlantic Ocean. We demonstrate that new nutrients introduced to the euphotic zone by upwelling in divergence zones and by winter convective overturn of the water column, and the primary production associated with those nutrients, are the ultimate driver of DOC distributions across the Atlantic basins. As new nutrient input will change with a changing climate, the role of DOC in the ocean’s biological pump should likewise be impacted.

scholarly journals Sources of Particulate Organic Matter across Mangrove Forests and Adjacent Ecosystems in Different Geomorphic Settings

Wetlands ◽  
2020 ◽  
Vol 40 (5) ◽  
pp. 1047-1059
Author(s):  
Daniel A. Saavedra-Hortua ◽  
Daniel A. Friess ◽  
Martin Zimmer ◽  
Lucy Gwen Gillis
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Particulate Organic Matter ◽  
Coastal Ecosystems ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Mangrove Forests ◽  
Terrestrial Plants ◽  
Suspended Particulate

Abstract Mangrove forests are among the world’s most productive ecosystems and provide essential ecosystem services such as global climate regulation through the sequestration of carbon. A detailed understanding of the influence of drivers of ecosystem connectivity (in terms of exchange of suspended particulate organic matter), such as geomorphic setting and carbon stocks, among coastal ecosystems is important for being able to depict carbon dynamics. Here, we compared carbon stocks, CO2 fluxes at the sediment-air interface, concentrations of dissolved organic carbon and suspended particulate organic carbon across a mangrove-seagrass-tidal flat seascape. Using stable isotope signatures of carbon and nitrogen in combination with MixSIAR models, we evaluated the contribution of organic matter from different sources among the different seascape components. Generally, carbon concentration was higher as dissolved organic carbon than as suspended particulate matter. Geomorphic settings of the different locations reflected the contributions to particulate organic matter of the primary producers. For example, the biggest contributors in the riverine location were mangrove trees and terrestrial plants, while in fringing locations oceanic and macroalgal sources dominated. Anthropogenic induced changes at the coastal level (i.e. reduction of mangrove forests area) may affect carbon accumulation dynamics in adjacent coastal ecosystems.

scholarly journals Towards an improved organic carbon budget for the Barents Sea shelf, marginal Arctic Ocean

2013 ◽  
Vol 9 (4) ◽  
pp. 4939-4986 ◽  
Author(s):  
I. Pathirana ◽  
J. Knies ◽  
M. Felix ◽  
U. Mann
Keyword(s):  
Organic Carbon ◽  
Primary Productivity ◽  
Barents Sea ◽  
Accumulation Rate ◽  
Regional Distribution ◽  
Carbon Accumulation ◽  
Carbon Fractions ◽  
Organic Facies ◽  
Organic Carbon Fractions ◽  
Facies Modelling

Abstract. There is generally a lack of knowledge on how marine organic carbon accumulation is linked to vertical export and primary productivity patterns. In this study, a multi-proxy geochemical and organic-sedimentological approach is coupled with organic facies modelling focusing on regional calculations of carbon cycling and carbon burial on the western Barents shelf between northern Scandinavia and Svalbard. OF-Mod 3D, an organic facies modelling software tool, is used to reconstruct the marine and terrestrial organic carbon fractions and to make inferences about marine primary productivity in this region. The model is calibrated with an extensive sample dataset and reproduces the present-day regional distribution of the organic carbon fractions well. Based on this new organic facies model, we present regional carbon mass accumulation rate calculations for the western Barents Sea.

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