University of Oulu

Maria Väisänen, Eveline J. Krab, Sylvain Monteux, Laurenz M. Teuber, Konstantin Gavazov, James T. Weedon, Frida Keuper, Ellen Dorrepaal, Meshes in mesocosms control solute and biota exchange in soils: A step towards disentangling (a)biotic impacts on the fate of thawing permafrost, Applied Soil Ecology, Volume 151, 2020, 103537, ISSN 0929-1393, https://doi.org/10.1016/j.apsoil.2020.103537

Meshes in mesocosms control solute and biota exchange in soils : a step towards disentangling (a)biotic impacts on the fate of thawing permafrost

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Author: Väisänen, Maria1,2,3; Krab, Eveline J.1,4; Monteux, Sylvain1,4;
Organizations: 1Climate Impacts Research Centre, EMG, Umeå University, Vetenskapens väg 38, SE-981 07 Abisko, Sweden
2Arctic Center, University of Lapland, P. O. Box 8000, FI-96 100 Rovaniemi, Finland
3Ecology and Genetics Research Unit, University of Oulu, P. O. Box 8000, 90014 Oulu, Finland
4Department of Soil and Environment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, SE-750 07 Uppsala, Sweden
5Experimental Plant Ecology, Institute for Botany and Landscape Ecology, University of Greifswald, 17489 Greifswald, Germany
6Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Case postale 96, 1015 Lausanne, Switzerland
7Systems Ecology, Department of Ecological Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, the Netherlands
8French National Research Institute for Agriculture, Food and the Environment, INRAE, AgroImpact, F-02000 Barenton-Bugny, France
Format: article
Version: accepted version
Access: embargoed
Persistent link: http://urn.fi/urn:nbn:fi-fe2020041516709
Language: English
Published: Elsevier, 2020
Publish Date: 2022-02-01
Description:

Abstract

Environmental changes feedback to climate through their impact on soil functions such as carbon (C) and nutrient sequestration. Abiotic conditions and the interactions between above- and belowground biota drive soil responses to environmental change but these (a)biotic interactions are challenging to study. Nonetheless, better understanding of these interactions would improve predictions of future soil functioning and the soil-climate feedback and, in this context, permafrost soils are of particular interest due to their vast soil C-stores. We need new tools to isolate abiotic (microclimate, chemistry) and biotic (roots, fauna, microorganisms) components and to identify their respective roles in soil processes. We developed a new experimental setup, in which we mimic thermokarst (permafrost thaw-induced soil subsidence) by fitting thawed permafrost and vegetated active layer sods side by side into mesocosms deployed in a subarctic tundra over two growing seasons. In each mesocosm, the two sods were separated from each other by barriers with different mesh sizes to allow varying degrees of physical connection and, consequently, (a)biotic exchange between active layer and permafrost. We demonstrate that our mesh-approach succeeded in controlling 1) lateral exchange of solutes between the two soil types, 2) colonization of permafrost by microbes but not by soil fauna, and 3) ingrowth of roots into permafrost. In particular, experimental thermokarst induced a ~60% decline in permafrost nitrogen (N) content, a shift in soil bacteria and a rapid buildup of root biomass (+33.2 g roots m−2 soil). This indicates that cascading plant-soil-microbe linkages are at the heart of biogeochemical cycling in thermokarst events. We propose that this novel setup can be used to explore the effects of (a)biotic ecosystem components on focal biogeochemical processes in permafrost soils and beyond.

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Series: Applied soil ecology
ISSN: 0929-1393
ISSN-E: 1873-0272
ISSN-L: 0929-1393
Volume: 151
Article number: 103537
DOI: 10.1016/j.apsoil.2020.103537
OADOI: https://oadoi.org/10.1016/j.apsoil.2020.103537
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Subjects:
Funding: This project was funded by grants from Vetenskapsrådet (621-2011-5444), Formas (214-2011-788), and a Wallenberg Academy Fellowship (KAW 2012.0152 and KAW 2017.0298) to ED.
Copyright information: © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.
  https://creativecommons.org/licenses/by-nc-nd/4.0/