Organic carbon accumulation and sulfate reduction rates in slope and basin sediments of the Ulleung Basin, East/Japan Sea

As sediments play an important role as either a sink or a source of phosphorus (P) for water column, it is important to elucidate the major P fractions and behaviors (i.e., mobilization and immobilization) in the sediments to better understand P cycles in local and global scale. We investigated major P speciation associated with the partitioning of organic carbon (Corg) oxidation in the sediments to elucidate the P dynamics at two contrasting sediments in the continental shelf (EB1) and rise (EC1) in the Ulleung Basin (UB), East Sea. Sulfate reduction (SR) pre-dominated Corg oxidation at shelf site (EB 1), comprising % of Corg oxidation, whereas Mn- and Fe-reduction combined accounted for >80% of Corg oxidation in Mn-oxide and Fe-oxide-rich basin site (EC 1). Under SR-dominated condition (EB 1), H2S oxidation coupled to reductive dissolution of FeOOH to form precipitation of FeS induced the accumulation of dissolved iron and phosphate in the pore water. On the other hand, phosphate in the Mn- and Fe-oxide-rich basin sediments (EC 1) was depleted because the P released through organic matter decomposition or reductive dissolution of Fe oxide/Mn oxide was effectively adsorbed to the metal-oxides in the surface sediments. Sequential extraction of P phases revealed that Fe bound P (52-65% of total P) was the major phase in the surface sediments of both sites. Interestingly, the organic P (Porg) fraction was 2.4-times higher at the basin site (12 &#956;mol g-1) than at the shelf site (5 &#956;mol g-1). Corg : Porg ratios presented as redox proxies in sediments were 644 and 191 for EB1 and EC1, respectively,. The results indicate that Porg has an effective preservation relative to Corg under sub-oxic conditions (EC1), whereas Porg was preferentially regenerated under anoxic conditions (EB1). Overall, the dynamics of P in the UB sediments were largely regulated by the partitioning of Corg oxidation pathways (i.e., sulfate reduction vs. metal reduction) and resultant interaction between Fe/Mn-S-P.

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ORGANIC CARBON CYCLE IN THE ULLEUNG BASIN SEDIMENT, EAST/JAPAN SEA

Applied Ecology and Environmental Research ◽

10.15666/aeer/1705_1216512179 ◽

2019 ◽

Vol 17 (5) ◽

Author(s):

T LEE

Keyword(s):

Organic Carbon ◽

Carbon Cycle ◽

Japan Sea ◽

Ulleung Basin

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SULFATE REDUCTION RATES IN MICROBIAL MAT SEDIMENTS OF DIFFERING CHEMISTRIES: IMPLICATIONS FOR ORGANIC CARBON PRESERVATION IN SALINE LAKES

Sedimentology and Geochemistry of Modern and Ancient Saline Lakes ◽

10.2110/pec.94.50.0013 ◽

1994 ◽

pp. 13-20 ◽

Cited By ~ 3

Author(s):

W. BERRY LYONS ◽

MARK E. HINES ◽

WILLIAM M. LAST ◽

ROBERT M. LENT

Keyword(s):

Organic Carbon ◽

Sulfate Reduction ◽

Saline Lakes ◽

Microbial Mat ◽

Sulfate Reduction Rates

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Changes in sediment and organic carbon accumulation in a highly-disturbed ecosystem: The Sacramento-San Joaquin River Delta (California, USA)

Marine Pollution Bulletin ◽

10.1016/j.marpolbul.2009.03.025 ◽

2009 ◽

Vol 59 (4-7) ◽

pp. 154-163 ◽

Cited By ~ 26

Author(s):

Elizabeth A. Canuel ◽

Elizabeth J. Lerberg ◽

Rebecca M. Dickhut ◽

Steven A. Kuehl ◽

Thomas S. Bianchi ◽

...

Keyword(s):

Organic Carbon ◽

River Delta ◽

Carbon Accumulation ◽

San Joaquin River

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Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

Forest Ecosystems ◽

10.1186/s40663-020-00278-5 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Xiaodan Sun ◽

Gang Wang ◽

Qingxu Ma ◽

Jiahui Liao ◽

Dong Wang ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Content ◽

Fine Roots ◽

Soil Layer ◽

Carbon Accumulation ◽

Bulk Soil ◽

Organic Mulch ◽

The Impact ◽

Soc Fractions

Abstract Background Soil organic carbon (SOC) is important for soil quality and fertility in forest ecosystems. Labile SOC fractions are sensitive to environmental changes, which reflect the impact of short-term internal and external management measures on the soil carbon pool. Organic mulching (OM) alters the soil environment and promotes plant growth. However, little is known about the responses of SOC fractions in rhizosphere or bulk soil to OM in urban forests and its correlation with carbon composition in plants. Methods A one-year field experiment with four treatments (OM at 0, 5, 10, and 20 cm thicknesses) was conducted in a 15-year-old Ligustrum lucidum plantation. Changes in the SOC fractions in the rhizosphere and bulk soil; the carbon content in the plant fine roots, leaves, and organic mulch; and several soil physicochemical properties were measured. The relationships between SOC fractions and the measured variables were analysed. Results The OM treatments had no significant effect on the SOC fractions, except for the dissolved organic carbon (DOC). OM promoted the movement of SOC to deeper soil because of the increased carbon content in fine roots of subsoil. There were significant correlations between DOC and microbial biomass carbon and SOC and easily oxidised organic carbon. The OM had a greater effect on organic carbon fractions in the bulk soil than in the rhizosphere. The thinnest (5 cm) mulching layers showed the most rapid carbon decomposition over time. The time after OM had the greatest effect on the SOC fractions, followed by soil layer. Conclusions The frequent addition of small amounts of organic mulch increased SOC accumulation in the present study. OM is a potential management model to enhance soil organic matter storage for maintaining urban forest productivity.

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