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Nat, F. J. van der; Middelburg, Jack J.

doi:10.1023/a:1006333225100

Cited by 140 publications

(25 citation statements)

References 40 publications

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“…Methanogenesis is therefore expected to be an important degradation process in organic-rich, freshwater sediments, such as the ones studied here (Middelburg et al 1995;Van der Nat et al 1998;Van der Nat and Middelburg 2000;Hellings et al 2000). The low rates of CH 4 release from the unamended reactors are thus somewhat surprising.…”

Section: Dic Release By Caco 3 Dissolution Iron Reduction and Methanmentioning

confidence: 87%

Bioavailability of organic matter in a freshwater estuarine sediment: long-term degradation experiments with and without nitrate supply

2009

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Organic carbon degradation experiments were carried out using flow-through reactors with sediments collected from an intertidal freshwater marsh of an eutrophic estuary (The Scheldt, Belgium). Concentrations of nitrate, nitrite, dissolved inorganic carbon (DIC), dissolved organic carbon, methane, dissolved cations (Ca 2? , Mg 2? , Na ? and K ? ), total dissolved Fe, phosphate and alkalinity were measured in the outflow solutions from reactors that were supplied with or without the terminal electron acceptor nitrate. Organic carbon mineralization rates were computed from the release rates of DIC after correcting for the contribution of carbonate mineral dissolution. The experiments ran for several months until nitrate reducing activity could no longer be detected. In the reactors supplied with nitrate, 10-13% of the bulk sedimentary organic carbon (SOC) was mineralized by the end of the experiments. In reactors receiving no nitrate, only 3-9% of the initial SOC was mineralized. Organic matter utilization by nitrate reducers could be described as the simultaneous degradation of two carbon pools with different maximum oxidation rates and half-saturation constants. Even when nitrate was supplied in non-limiting concentrations about half of the carbon mineralization in the reactors was due to fermentative processes, rather than being coupled to nitrate respiration. Fermentation may thus be responsible for a large fraction of the DIC efflux from organic-rich, nearshore sediments.

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Section: Dic Release By Caco 3 Dissolution Iron Reduction and Methanmentioning

confidence: 87%

Bioavailability of organic matter in a freshwater estuarine sediment: long-term degradation experiments with and without nitrate supply

2009

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“…[33] On the other hand, if the vegetation exploits the convective transport mechanism, CH 4 emission should decrease significantly when the aboveground part of the vegetation is clipped under light conditions, because the capacity for pressurized transport was eliminated [Van der Nat and Middelburg, 2000]. In our clipping experiment, clipping the aboveground portion of S. mariqueter significantly decreased the CH 4 emission flux in CD ML July (p < 0.001), but significantly increased the CH 4 emission fluxes in all other months in both light and dark chambers.…”

Section: Effect Of S Mariqueter On Ch 4 Fluxesmentioning

confidence: 99%

Methane emission from Yangtze estuarine wetland, China

Wang

Chen

2009

J. Geophys. Res.

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[1] Yangtze estuary, lying in the subtropical monsoon region of China, is characterized by a unique environmental setting and endemic wetland plant species (Scirpus mariqueter). Methane (CH 4 ) emission fluxes were measured at the Yangtze estuarine wetland, Chongming Dongtan (CD), by a static closed chamber technique from May 2004 to April 2005. The results showed that CD is the source of atmospheric CH 4 , and emission fluxes had significant diurnal and seasonal variation. The annual average CH 4 emission flux was 2.06 mg m À2 h À1 at the CD marsh site and 0.04 mg m À2 h À1 at the CD bare tidal flat (nonvegetated). Wetland plant species (S. mariqueter) and temperature were the primary factors controlling the CH 4 emission. The results of the light and dark chamber comparison and plant shoot clipping experiment suggest that molecular diffusion and convective gas flow methods were the two main mechanisms of CH 4 transported via S. mariqueter plants in July. However, molecular diffusion was believed to be the primary transport mechanism from August to October, with leaf resistance as one of the factors regulating CH 4 diffusion. There was significant correlation between CH 4 fluxes and temperature, especially the 10 cm depth ground temperature (R 2 = 0.7784). Although sediment organic carbon content did not determine CH 4 fluxes, net ecosystem production was significantly correlated with CH 4 fluxes, suggesting that the photosynthates of S. mariqueter effectively provided the substrate for methanogenic bacteria.

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“…While an increasing number of studies has reported that vegetation affects gas emissions through regulating production and transport in wetland ecosystems worldwide (e.g., Van der Nat and Middelburg 2000;Cheng et al 2007;Wilson et al 2009), several studies have indicated that belowground parts of vegetation (decaying plant materials and fresh root exudates) could provide the substrates for methanogenesis (Whiting and Chanton 1993;Joabsson et al 1999), which promote CH 4 production (Whiting and Chanton 1993; Van der Nat and Middelburg 2000).…”

Section: Introductionmentioning

confidence: 99%

“…Cheng et al (2007) have compared trace gas emissions from S. alterniflora with those from a native Phragmites australis by establishing brackish marsh mesocosms to experimentally assess the effects of plant species, flooding status, and clipping on trace gas emissions. It is well known that the CH 4 emissions via plant pathway contribute significantly to the total CH 4 emission from wetland ecosystems (e.g., Schimel 1995;Van der Nat and Middelburg 2000;Chanton et al 2002). Little effort, however, has been made to assess the impact of invasive plants on CH 4 emissions and its 13 C-isotopic signature from the soil associated with soil substrates in natural marsh ecosystems.…”

Section: Introductionmentioning

confidence: 99%