Abstract. Northern latitude peatlands act as important carbon sources and sinks but little is known about the greenhouse gas (GHG) budget of peatlands submerged beneath the North Sea during the last glacial-interglacial transition. We found that whilst peat formation was diachronous, commencing between 13,680 and 8,360 calibrated years before the present, stratigraphic layering and local vegetation succession were consistent across a large study area. The CH₄ concentrations of the sediment pore waters were low at most sites, with the exception of two locations, and the stored carbon was large. Incubation experiments in the laboratory revealed molecular signatures of methanogenic archaea, with strong increases in rates of activity upon methylated substrate amendment. Remarkably, methanotrophic activity and the respective diagnostic molecular signatures could be not be detected. Heterotrophic Bathyarchaeia dominated the archaeal communities and bacterial populations were dominated by candidate phylum JS1 bacteria. Although CH₄ accumulation is low at most sites, the presence of in situ methanogenic micro-organisms, the absence of methanotrophy, and large widespread stores of carbon hold the potential for GHG production if catalysed by a change in environmental conditions. Despite being earmarked as a critical source of CH₄ seepage, seepage from these basal-peat deposits is restricted, as evidenced by low in situ CH₄ concentrations.

中文翻译：

---

全新世北海泥炭的微生物活性，甲烷产量和碳储量

摘要。北部纬度泥炭地是重要的碳源和汇，但对最后一次冰川-冰川间过渡期间淹没在北海之下的泥炭地的温室气体（GHG）预算知之甚少。我们发现，尽管泥炭形成是历时的，但从现在开始的13680年到8360年之间已校准，地层分层和局部植被演替在一个较大的研究区域内是一致的。CH ₄除两个地点外，大多数地点的沉积物孔隙水浓度都较低，并且所储存的碳很大。实验室的温育实验揭示了产甲烷古菌的分子特征，甲基化底物修饰后活性速率大大提高。值得注意的是，无法检测到甲烷营养活性和相应的诊断分子标记。异养的细菌质支原体占主导，古细菌群落和细菌种群由候选门JS1细菌主导。尽管大多数位置的CH ₄积累量很低，但原位存在如果受到环境条件的变化的催化，则甲烷化甲烷，缺乏甲烷甲烷化菌和大量广泛的碳储存具有产生温室气体的潜力。尽管已被指定为CH ₄渗漏的重要来源，但这些原基豌豆沉积物的渗漏仍然受到限制，这由低原位CH ₄浓度所证明。