Limited sensitivity of permafrost soils to heavy rainfall across Svalbard ecosystems.

Autor: Magnússon RÍ; Plant Ecology & Nature Conservation Group, Wageningen University & Research, Droevendaalsesteeg 3a, 6708PB Wageningen, the Netherlands. Electronic address: runa.magnusson@wur.nl., Schuuring S; Department of Arctic Biology, the University Centre in Svalbard, P.O. Box 156, N-9171 Longyearbyen, Svalbard, Norway; Natural History Museum, University of Oslo. P. O. Box 1172, Blindern, 0318 Oslo, Norway., Hamm A; Department of Physical Geography, Stockholm University, SE-106 91 Stockholm, Sweden; Bolin Centre for Climate Research, Stockholm University, SE-106 91 Stockholm, Sweden., Verhoeven MA; Netherlands Institute of Ecology, Droevendaalsesteeg 10, 6708 PB Wageningen, the Netherlands; Department of Coastal Systems, Royal Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, the Netherlands., Limpens J; Plant Ecology & Nature Conservation Group, Wageningen University & Research, Droevendaalsesteeg 3a, 6708PB Wageningen, the Netherlands., Loonen MJEE; Arctic Centre, University of Groningen, PO Box 716, 9700 AS Groningen, the Netherlands., Lang SI; Department of Arctic Biology, the University Centre in Svalbard, P.O. Box 156, N-9171 Longyearbyen, Svalbard, Norway.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Sep 15; Vol. 943, pp. 173696. Date of Electronic Publication: 2024 Jun 05.
DOI: 10.1016/j.scitotenv.2024.173696
Abstrakt: Together with warming air temperatures, Arctic ecosystems are expected to experience increases in heavy rainfall events. Recent studies report accelerated degradation of permafrost under heavy rainfall, which could put significant amounts of soil carbon and infrastructure at risk. However, controlled experimental evidence of rainfall effects on permafrost thaw is scarce. We experimentally tested the impact and legacy effect of heavy rainfall events in early and late summer for five sites varying in topography and soil type on the High Arctic archipelago of Svalbard. We found that effects of heavy rainfall on soil thermal regimes are small and limited to one season. Thaw rates increased under heavy rainfall in a loess terrace site, but not in polygonal tundra soils with higher organic matter content and water tables. End-of-season active layer thickness was not affected. Rainfall application did not affect soil temperature trends, which appeared driven by timing of snowmelt and organic layer thickness, particularly during early summer. Late summer rainfall was associated with slower freeze-up and colder soil temperatures the following winter. This implies that rainfall impacts on Svalbard permafrost are limited, locally variable and of short duration. Our findings diverge from earlier reports of sustained increases in permafrost thaw following extreme rainfall, but are consistent with observations that maritime permafrost regions such as Svalbard show lower rainfall sensitivity than continental regions. Based on our experiment, no substantial in-situ effects of heavy rainfall are anticipated for thawing of permafrost on Svalbard under future warming. However, further work is needed to quantify permafrost response to local redistribution of active layer flow under natural rainfall extremes. In addition, replication of experiments across variable Arctic regions as well as long-term monitoring of active layers, soil moisture and local climate will be essential to develop a panarctic perspective on rainfall sensitivity of permafrost.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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