Drained peatlands in temperate Europe are a globally important source of greenhouse gas (GHG) emissions. This article outlines a methodology to assess emissions and emission reductions from peatland rewetting projects using vegetation as a proxy. Vegetation seems well qualified for indicating GHG fluxes from peat soils as it reflects long-term water level, affects GHG emissions via assimilate supply and aerenchyma and allows fine-scaled mapping. The methodology includes mapping of vegetation types characterised by the presence and absence of species groups indicative for specific water level classes. GHG flux values are assigned to the vegetation types following a standardized protocol and using published emission values from plots with similar vegetation and water level in regions with similar climate and flora. Carbon sequestration in trees is accounted for by estimating the annual sequestration in tree biomass from forest inventory data. The method follows the criteria of the Voluntary Carbon Standard and is illustrated using the example of two Belarusian peatlands.

Abstract. Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover), soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years. Data related to this article are archived under: http://doi. pangaea.de/10.1594/PANGAEA.806233 .

Abstract. Peatland restoration by inundation of drained areas can alter local greenhouse gas emissions as CO 2 and CH 4 . 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 CO 2 and CH 4 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 CO 2 and CH 4 production and emission.The position in the soil profile of the pre-existing drained peat substrate affected initial rates of anaerobic CO 2 production subsequent to flooding, with the uppermost peat layer producing the greatest specific rates of CO 2 evolution. CH 4 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 CO 2 (maximum of 412 mg C d −1 kg −1 C) and CH 4 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 CO 2 (max. 28 mg C d −1 kg −1 C) and CH 4 (max. 34 mg C d −1 kg −1 C) production that were Correspondence to: M. Hahn-Schöfl (maria.hahn@yahoo.de) 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 CO 2 and CH 4 production (range of 4-8 mg C d −1 kg −1 C and <1 mg C d −1 kg −1 C) were observed when all fresh organic matter sources (plant litter and roots) were excluded. In conclusion, the presence of fresh organic substrates such as plant and root litter originating from plants killed by inundation has a high potential for CH 4 production, whereas peat without any fresh plant-derived material is relatively inert. Significant anaerobic CO 2 and CH 4 production in peat only occurs when some labile organic matter is available, e.g. from remaining roots or root exudates.

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Mapping of two low‐centred ice‐wedge polygons in the Yakutian tundra (NE Siberia) along a regular grid with 1‐m spacing revealed large spatial variability in thaw depths and strong correlation with relief, water and vegetation. Average thaw depths in polygon ridges (23 cm and 31 cm) were smaller than in depressions (33 cm and 40 cm, respectively). The greatest thaw depths, however, were also found in the ridges and probably result from thermal erosion by water flow. Copyright © 2009 John Wiley & Sons, Ltd.