Methane Production and Oxidation in Mangrove Soils Assessed by Stable Isotope Mass Balances

Sánchez-Carrillo, Salvador; Garatuza‐Payán, Jaime; Sánchez-Andrés, R.; Cervantes, Francisco J.; Bartolomé, M.C.; Merino–Ibarra, Martín; Thalasso, Frédéric

doi:10.3390/w13131867

Cited by 5 publications

(2 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our solid phase analyses of the sediment supported this hypothesis as the sediments were rich in organic carbon (Figure S4). NOM‐driven AOM has been shown in several ecosystems, such as rice paddy soils (Fan et al, 2020), marine anoxic waters (van Grinsven et al, 2020), mangrove soils (Sánchez‐Carrillo et al, 2021), and anoxic lake sediments (Vigderovich et al, 2022). These data, combined with our results, suggest that redox‐active NOM may also act as the dominant electron acceptor for AOM in Amsterdam urban canals.…”

Section: Discussionmentioning

confidence: 99%

Anaerobic methanotrophy is stimulated by graphene oxide in a brackish urban canal sediment

Pelsma,

van Helmond,

Lenstra

et al. 2023

Environmental Microbiology

View full text Add to dashboard Cite

Anthropogenic activities are influencing aquatic environments through increased chemical pollution and thus are greatly affecting the biogeochemical cycling of elements. This has increased greenhouse gas emissions, particularly methane, from lakes, wetlands, and canals. Most of the methane produced in anoxic sediments is converted into carbon dioxide by methanotrophs before it reaches the atmosphere. Anaerobic oxidation of methane requires an electron acceptor such as sulphate, nitrate, or metal oxides. Here, we explore the anaerobic methanotrophy in sediments of three urban canals in Amsterdam, covering a gradient from freshwater to brackish conditions. Biogeochemical analysis showed the presence of a shallow sulphate–methane transition zone in sediments of the most brackish canal, suggesting that sulphate could be a relevant electron acceptor for anaerobic methanotrophy in this setting. However, sediment incubations amended with sulphate or iron oxides (ferrihydrite) did not lead to detectable rates of methanotrophy. Despite the presence of known nitrate‐dependent anaerobic methanotrophs (Methanoperedenaceae), no nitrate‐driven methanotrophy was observed in any of the investigated sediments either. Interestingly, graphene oxide stimulated anaerobic methanotrophy in incubations of brackish canal sediment, possibly catalysed by anaerobic methanotrophs of the ANME‐2a/b clade. We propose that natural organic matter serving as electron acceptor drives anaerobic methanotrophy in brackish sediments.

show abstract

Section: Discussionmentioning

confidence: 99%

Anaerobic methanotrophy is stimulated by graphene oxide in a brackish urban canal sediment

Pelsma,

van Helmond,

Lenstra

et al. 2023

Environmental Microbiology

View full text Add to dashboard Cite

show abstract

“…While these methanogenic taxa were found throughout the soil profile, they generally increased with depth, particularly below −15 cm, where the percentage of taxa associated with sulfate reduction started to decline. The presence of the taxa associated with hydrogenotrophic methanogenesis has been found in coastal wetlands (Sánchez-Carrillo et al, 2021;Xiang et al, 2015;Yuan et al, 2019). However, few studies have assessed the presence of methylotrophic methanogens within soils because they have been thought to be less important than acetoclastic and hydrogenotrophic methanogens (Söllinger & Urich, 2019).…”

Section: Ch 4 Production Within the Soilmentioning

confidence: 99%

High methane concentrations in tidal salt marsh soils: Where does the methane go?

Capooci,

Seyfferth,

Tobias

et al. 2023

Global Change Biology

View full text Add to dashboard Cite

Tidal salt marshes produce and emit CH4. Therefore, it is critical to understand the biogeochemical controls that regulate CH4 spatial and temporal dynamics in wetlands. The prevailing paradigm assumes that acetoclastic methanogenesis is the dominant pathway for CH4 production, and higher salinity concentrations inhibit CH4 production in salt marshes. Recent evidence shows that CH4 is produced within salt marshes via methylotrophic methanogenesis, a process not inhibited by sulfate reduction. To further explore this conundrum, we performed measurements of soil–atmosphere CH4 and CO2 fluxes coupled with depth profiles of soil CH4 and CO2 pore water gas concentrations, stable and radioisotopes, pore water chemistry, and microbial community composition to assess CH4 production and fate within a temperate tidal salt marsh. We found unexpectedly high CH4 concentrations up to 145,000 μmol mol−1 positively correlated with S2− (salinity range: 6.6–14.5 ppt). Despite large CH4 production within the soil, soil–atmosphere CH4 fluxes were low but with higher emissions and extreme variability during plant senescence (84.3 ± 684.4 nmol m−2 s−1). CH4 and CO2 within the soil pore water were produced from young carbon, with most Δ14C‐CH4 and Δ14C‐CO2 values at or above modern. We found evidence that CH4 within soils was produced by methylotrophic and hydrogenotrophic methanogenesis. Several pathways exist after CH4 is produced, including diffusion into the atmosphere, CH4 oxidation, and lateral export to adjacent tidal creeks; the latter being the most likely dominant flux. Our findings demonstrate that CH4 production and fluxes are biogeochemically heterogeneous, with multiple processes and pathways that can co‐occur and vary in importance over the year. This study highlights the potential for high CH4 production, the need to understand the underlying biogeochemical controls, and the challenges of evaluating CH4 budgets and blue carbon in salt marshes.

show abstract

Efficient oxidation attenuates porewater‐derived methane fluxes in mangrove waters

Yau,

Cabral,

Reithmaier

et al. 2024

Limnology & Oceanography

View full text Add to dashboard Cite

Mangroves store significant amounts of carbon in both sediment and water. Methane (CH4) is often produced in anoxic, organic‐rich sediments during carbon degradation and released to overlying waters via porewater exchange. Yet, a portion of CH4 can be oxidized to CO2 before emission. Here, we investigate whether CH4 oxidation impacts its emissions using high‐temporal resolution CH4 concentration and stable isotope (δ13C‐CH4) observations collected over 14 tidal cycles in 2 Brazilian mangrove creeks with no river inputs. We found higher CH4 concentrations (~ 150 nM) more depleted in 13C (−75‰) during low tide than high tide at both creeks. Similar δ13C‐CH4 values between low tide surface waters and porewaters further suggest tidally driven porewater exchange as the main source of CH4. More 13C‐enriched CH4 in surface waters and surface sediments than deep sediments indicate partial CH4 oxidation prior to exchange with the atmosphere. A stable isotope mass balance revealed that 17–58% of CH4 was oxidized at rates of 3–25 μmol m−2 d−1 in the water column of tidal creeks. A larger portion of deep porewater CH4 (45–61%) was oxidized in sediments prior to porewater exchange with surface creek waters. The two mangrove creeks had average water–air CH4 fluxes of 51–109 μmol m−2 d−1 over spring‐neap tidal cycles. These aquatic CH4 emissions offset only < 3% of the mangroves' soil carbon sequestration. Overall, CH4 oxidation in both surface water and sediment attenuated CH4 emissions to the atmosphere.

show abstract

Methane Production and Oxidation in Mangrove Soils Assessed by Stable Isotope Mass Balances

Cited by 5 publications

References 74 publications

Anaerobic methanotrophy is stimulated by graphene oxide in a brackish urban canal sediment

Anaerobic methanotrophy is stimulated by graphene oxide in a brackish urban canal sediment

High methane concentrations in tidal salt marsh soils: Where does the methane go?

Efficient oxidation attenuates porewater‐derived methane fluxes in mangrove waters

Contact Info

Product

Resources

About