Organic sediment formed during inundation of a degraded fen grassland emits large fluxes of CH4 and CO2
Organic sediment formed during inundation of a degraded fen grassland emits large fluxes of CH4 and CO2
复制标题
退化沼泽草原被淹没时形成的有机沉积物释放出大量的 CH4 和 CO2
DOI：
10.5194/bg-8-1539-2011
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发表时间：
2010
期刊：
影响因子：
4.9
通讯作者：
A. Freibauer
中科院分区：
文献类型：
--
作者：
M. Hahn;D. Zak;M. Minke;J. Gelbrecht;J. Augustin;A. Freibauer
抽象的。通过淹没排水区恢复泥炭地可以改变当地的温室气体排放，如CO2和CH 4。可影响这些排放的因素包括厌氧降解过程可用的基质的质量和数量以及电子受体的来源和可用性。为了了解高CO2和CH 4的可能来源。排放量的再湿润退化沼泽草地，我们进行了孵化实验，测试了新鲜的植物凋落物的影响，淹没泥炭孔隙水化学和CO2和CH 4。生产和排放。在土壤剖面的预先存在的排水泥炭基质的位置影响初始速率的厌氧CO2生产后，洪水，最上层的泥炭层产生的最大的特定速率的CO2演变。CH 4产生速率取决于电子受体的可用性，并且仅当孔隙水中硫酸盐浓度降低时才显着。沃茨。在一个新的沉积层中观察到了非常高的CO2（最大值为412 mg C d−1 kg−1 C）和CH 4（788 mg C d−1 kg−1 C）的比生成率，该沉积层是在该地点被洪水淹没后的2.5年中积累起来的。这一新的沉积层的特点是整体低C含量，但代表了砂和相对容易分解的植物凋落物从芦苇金丝雀草被洪水杀死的混合物。排除了这一新沉积物层但包括被洪水淹没的草留下的完整根系的样品具有特定的CO2速率（最大值）。28 mg C d−1 kg−1 C）和CH4（max. 34 mg C d-1 kg-1 C）的产量比新沉积层低10-20倍，与新淹没的上部泥炭层相当。最低的厌氧CO2和CH 4产生率（范围为4-8 mg C d−1 kg−1 C，
Abstract. Peatland restoration by inundation of drained areas can alter local greenhouse gas emissions as CO2 and CH4. Factors that can influence these emissions include the quality and amount of substrates available for anaerobic degradation processes and the sources and availability of electron acceptors. In order to learn about possible sources of high CO2 and CH4. emissions from a rewetted degraded fen grassland, we performed incubation experiments that tested the effects of fresh plant litter in the flooded peats on pore water chemistry and CO2 and CH4. production and emission. The position in the soil profile of the pre-existing drained peat substrate affected initial rates of anaerobic CO2 production subsequent to flooding, with the uppermost peat layer producing the greatest specific rates of CO2 evolution. CH4 production rates depended on the availability of electron acceptors and was significant only when sulfate concentrations were reduced in the pore waters. Very high specific rates of both CO2 (maximum of 412 mg C d−1 kg−1 C) and CH4 production (788 mg C d−1 kg−1 C) were observed in a new sediment layer that accumulated over the 2.5 years since the site was flooded. This new sediment layer was characterized by overall low C content, but represented a mixture of sand and relatively easily decomposable plant litter from reed canary grass killed by flooding. Samples that excluded this new sediment layer but included intact roots remaining from flooded grasses had specific rates of CO2 (max. 28 mg C d−1 kg−1 C) and CH4 (max. 34 mg C d−1 kg−1 C) production that were 10–20 times lower than for the new sediment layer and were comparable to those of a newly flooded upper peat layer. Lowest rates of anaerobic CO2 and CH4 production (range of 4–8 mg C d−1 kg−1 C and