Carbon dynamics in boreal peatlands of the Yenisey region, western Siberia

[摘要] Here we investigate the vegetation history and peat accumulation at theeastern boarder of the West Siberian Plain, near the Yenisey River, south ofpermafrost. In this region, peat started to accumulate 15 000 years ago asgyttja of shallow lakes in ancient river valleys. This peat is older thanpreviously reported, mainly due to separating particulate organic carbon(POC) from dissolved organic carbon (DOC), which was 1900–6500 yearsyounger than POC. The probability of finding peat layers older than 12 000 years isabout 2 %. Peat accumulated as fen peat at a constant rate of0.2 mm yr⁻¹ and 0.01 kg C m⁻² yr⁻¹. The accumulation washigher in ancient river valley environments. Over the last 2000 years these bogschanged into Sphagnum mires which have accumulated up to about 0.1 kg C m⁻² yr⁻¹until present.

The long-lasting fen stage, which makes the Yenisey bogs distinct from thewestern Siberian bogs, is discussed as a consequence of the local hydrology. Thehigh accumulation rate of peat in unfrozen mires is taken as an indicationthat thawing of permafrost peat may also change northern peatlands intolong-lasting carbon sinks.

[学科分类] 地球化学与岩石