Cyclic Development of Permafrost in the Peatlands of Northwestern Alberta, Canada

Abstract

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Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production

“…Our site selections are based on these studies, which provide direct evidence that at minimum, six of our sites (Table 1 and Table S1) were once palsa (sites named PHS, PHB, S, and E) or likely palsa (sites named Bog1 and Fen1) underlain by permafrost (22)(23)(24). Similar processes are known to occur in other Arctic peatlands, where permafrost thaw creates wet depressions that are colonized first by Sphagnum and then by sedge species as the ground collapses with increasing thaw (25)(26)(27).…”

Long‐term Arctic peatland dynamics, vegetation and climate history of the Pur‐Taz region, Western Siberia

“…Because the area today is mapped as continuous permafrost in this part of western Siberia, we attribute many of the changes in peat type to be a result of local hydrological changes (thermokarst action, stream movement), or even beaver activity (Levina & Nikitin 1973) within a changing climate. However, the proximity of discontinuous permafrost to the south (Shpolyanskaya 1981) suggests that during the early Holocene discontinuous permafrost may have affected this region, resulting in palsas and collapse scars (Zoltai 1993). Further highresolution research on West Siberian peatlands should reveal whether the peatland stratigraphic patterns we found from 9300-4500 BP are repeated, and therefore represent regional rather than local conditions.…”

“…It is not possible to determine whether the marine diatoms are of eolian origin or in sifu; their presence is inconclusive in supporting the suggestion of a Kargian age (35 000 26000 BP) Kara Sea transgression in the region (Danilov 1987). The basal charcoal may indicate a local pyric origin for the formation of the lake, as fire today plays a significant role in lake formation in permafrost regions (Zoltai 1993). Lurix sibiricu needles, seeds and a cone scale, along with Botulu puhcscens seeds and bracts are present.…”

Controls on CH4 emissions from a northern peatland

“…Permafrost, while absent in the wetlands, is present in the surrounding elevated peat plateaus. The degradation of this permafrost continues to expand the wetland, creating "collapse" areas which can develop into bogs or fens, depending on the importance of groundwater influence on the site [Zoltai, 1993] …”