Late Holocene ice-wedge polygon dynamics in northeastern Siberian coastal lowlands

• Published in: Arctic, Antarctic, and Alpine Research
• Main Authors: Schirrmeister, Lutz, Bobrov, Anatoly, Raschke, Elena, Herzschuh, Ulrike, Strauss, Jens, Pestryakova, Luidmila A., Wetterich, Sebastian
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2018
• Subjects: Antarctic and Alpine Research; Arctic; Tundra
• Online Access: https://epic.awi.de/id/eprint/50343/; https://epic.awi.de/id/eprint/50343/1/Schirrmeister_et_al_AAAR_2018.pdf; https://doi.org/10.1080/15230430.2018.1462595; https://hdl.handle.net/10013/epic.9f9b9758-be94-4e99-af3e-8d62ec01f4f7

Ice-wedge polygons are common features of northeastern Siberian lowland periglacial tundra landscapes. To deduce the formation and alternation of ice-wedge polygons in the Kolyma Delta and in the Indigirka Lowland, we studied shallow cores, up to 1.3 m deep, from polygon center and rim locations. The formation of well-developed low-center polygons with elevated rims and wet centers is shown by the beginning of peat accumulation, increased organic matter contents and changes in vegetation cover from Poaceae-, Alnus-, and Betula-dominated pollen spectra to dominating Cyperaceae and Botryoccocus presence, and Carex and Drepanocladus revolvens macro-fossils. Tecamoebae data support such a change from wetland to open-water conditions in polygon centers by changes from dominating eurybiontic and sphagnobiontic to hydrobiontic species assemblages. The peat accumulation indicates low-center polygon formation and started between 2380 ± 30 and 1676 ± 32 years before present (BP) in the Kolyma Delta. We recorded an opposite change from open-water to wetland conditions due to rim degradation and consecutive high-center polygon formation in the Indigirka Lowland between 2144 ± 33 and 1632 ± 32 yrs BP. The late Holocene records of polygon landscape development reveal changes in local hydrology and soil moisture.