Iron, sulfur, and dissolved carbon dynamics in a northern peatland
Iron, sulfur, and dissolved carbon dynamics in a northern peatland
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DOI：
10.1127/archiv-hydrobiol/154/2002/561
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发表时间：
2002-08
期刊：
影响因子：
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通讯作者：
C. Blodau;C. Roehm;T. Moore
中科院分区：
文献类型：
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作者：
C. Blodau;C. Roehm;T. Moore
我们研究了三种不同类型的北方泥炭地沉积物（贫营养沼泽，海狸池塘，和过渡网站）沿着泥炭地横断面在安大略，加拿大的水和固相地球化学。孔隙水浓度（pH，Fe 2+，Fe 3+，SO 42-，H2S，CH 4，CO2和脂肪酸）进行了季节性监测，固相剖面（Fe（II），Fe（III），还原无机硫）进行了测量，并测定了泥炭泥浆中CO2，CH 4，Fe 2+和H2S的潜在产生率。溶解态CO2（≤ 6 mmol/L）和CH 4（≤ 1 mmol/L）是各站位的优势组分。在酸性沼泽乙酸盐（高达1 mmol/L）和少量的丙酸盐和丁酸盐存在于孔隙水中。溶解态Fe 2+（<5-150 μmol/L）、SO 42-（10-50 μmol/L）和H2S（0 ~ 10 μmol/L）浓度均较低。Fe（II）的生成速率（0.6- 7.2mmol m-2d-1）小于CO2（38-46 mmol m-2d-1）和CH 4（14-29 mmol m-2d-1）的生成速率。低浓度的活性Fe（III）（5-75 μmol/g）表明Fe（II）的还原速率受活性Fe（III）的限制。在用硫酸盐（0.5mM）修正的浆料中，硫酸盐还原的潜力是实质性的，并且CH 4产生速率降低48 - 86%。在原位积累的乙酸，丙酸和丁酸在酸性沼泽是一致的，缺乏刺激的CO2和CH 4的生产过程中，厌氧培养乙酸修正。尽管站点之间的差异Fe还原是整体的碳流的意义不大。根据孵育结果，硫酸盐还原可能更为重要。在沼泽中，乙酸盐和丙酸盐的积累证实了厌氧代谢过程的解耦和脂肪酸动力学在酸性北方泥炭地碳循环中的重要作用。
We examined the aqueous and solid-phase biogeochemistry of three different types of northern peatland sediments (oligotrophic bog, beaver pond, and transition site) along a peatland transect in Ontario, Canada. Pore water concentrations (pH, Fe 2+ , Fe 3+ , SO 4 2-, H 2 S, CH 4 , CO 2 and fatty acids) were monitored seasonally, solid phase profiles (Fe(II), Fe(III), reduced inorganic sulfur) measured, and potential rates of CO 2, CH 4 , Fe 2+ , and H 2 S production determined in slurries of peat. Dissolved CO 2 (up to 6 mmol/L) and CH 4 (up to 1 mmol/L) were the predominant species at all sites. In the acidic bog acetate (up to 1 mmol/L) and smaller quantities of propionate and butyrate were present in the pore water. Dissolved Fe 2+ (<5-150 μmol/L), SO 4 2- (10-50 μmol/L), and H 2 S (0 to 10 μmol/L) concentrations were much lower in comparison. The Fe(II) production rates (0.6-7.2 mmol m -2 d -1 ) were small compared to production rates of CO 2 (38-46 mmol m -2 d -1 ) and CH4 (14-29 mmol m -2 d -1 ). Low concentrations of reactive Fe(III) (5-75 μmol/g) suggested that the Fe(II) reduction rate was limited by reactive Fe(III). In slurries amended with sulfate (0.5 mM) the potential for sulfate reduction was substantial and rates of CH 4 production decreased by 48 - 86 %. The in situ accumulation of acetate, propionate and butyrate in the acidic bog was consistent with a lack of stimulation of CO 2 and CH 4 production during anaerobic incubation amended with acetate. Despite differences between sites Fe reduction was overall of little significance for the carbon flow. Sulfate reduction might have been more important based on the results from the incubations. In the bog, the accumulation of acetate and propionate confirmed the decoupling of anaerobic metabolic processes and the important role of fatty acid dynamics in the carbon cycle of acidic northern peatlands.