Key periods of peatland development and environmental changes in the middle taiga zone of Western Siberia during the Holocene

Abstract

The response of peatlands to climate change can be highly variable. Through understanding past changes we can better predict the response of peatlands to future climate change. We use a multi-proxy approach to reconstruct the surface wetness and carbon accumulation of the Mukhrino mire (Western Siberia), describing the development of the mire since peat formation in the early Holocene, around 9360 cal. year BP. The mire started as a rich fen which initiated after paludification of a spruce forest (probably in response to a wetter climate), while the Mukhrino mire progressed to ombrotrophic bog conditions (8760 cal. year BP). This transition coincided with the intensive development of mires in Western Siberia and was associated with active carbon accumulation (31 g m^-2 year^-1). The ecosystem underwent a change to a tree-covered state around 5860 cal. year BP, likely in response to warming and possible droughts and this accompanied low carbon accumulation (12 g m² year^-1). If the future climate will be warmer and wetter, then regional mires are likely to remain a carbon sink, alternatively, a reversion to the wooded state with reduced carbon sink strength is possible.

Keywords: Carbon content; Peat humification; Peatland development; Plant macrofossils; Testate amoebae; n-Alkanes.