University of Oulu

Jespersen, R. G., Leffler, A. J., Väisänen, M., & Welker, J. M. (2022). Resistance and change in a High Arctic ecosystem, NW Greenland: Differential sensitivity of ecosystem metrics to 15 years of experimental warming and wetting. Global Change Biology, 28, 1853–1869. https://doi.org/10.1111/gcb.16027

Resistance and change in a High Arctic ecosystem, NW Greenland : differential sensitivity of ecosystem metrics to 15 years of experimental warming and wetting

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Author: Jespersen, R. Gus1,; Leffler, A. Joshua2; Väisänen, Maria3,4;
Organizations: 1Department of Biological Sciences, University of Alaska-Anchorage, Anchorage Alaska, 99508 USA
2Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota, 57007 USA
3Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
4Arctic Centre, University of Lapland, Rovaniemi, Finland
5University of Oulu, Oulu, Finland
6University of Alaska Anchorage, Anchorage Alaska, 99508 USA
Format: article
Version: accepted version
Access: embargoed
Persistent link: http://urn.fi/urn:nbn:fi-fe2021121761688
Language: English
Published: John Wiley & Sons, 2022
Publish Date: 2022-12-06
Description:

Abstract

Dramatic increases in air temperature and precipitation are occurring in the High Arctic (>70 °N), yet few studies have characterized the long-term responses of High Arctic ecosystems to the interactive effects of experimental warming and increased rain. Beginning in 2003, we applied a factorial summer warming and wetting experiment to a polar semidesert in northwest Greenland. In summer 2018, we assessed several metrics of ecosystem structure and function, including plant cover, greenness, ecosystem CO₂ exchange, aboveground (leaf, stem) and belowground (litter, root, soil) carbon (C) and nitrogen (N) concentrations (%) and pools, as well as leaf and soil stable isotopes (δ¹³C and δ¹⁵N). Wetting induced the most pronounced changes in ecosystem structure, accelerating the expansion of S. arctica cover by 370% and increasing aboveground C, N, and biomass pools by 94–101% and root C, N, and biomass pools by 60–122%, increases which coincided with enhanced net ecosystem CO₂ uptake. Further, wetting combined with warming enhanced plot-level greenness, whereas in isolation neither wetting nor warming had an effect. At the plant level the effects of warming and wetting differed among species and included warming-linked decreases in leaf N and δ¹⁵N in Salix arctica, whereas leaf N and δ¹⁵N in Dryas integrifolia did not respond to the climate treatments. Finally, neither plant- nor plot-level C and N allocation patterns nor soil C, N, δ¹³C, or δ¹⁵N concentrations changed in response to our manipulations, indicating that these ecosystem metrics may resist climate change, even in the longer term. In sum, our results highlight the importance of summer precipitation in regulating ecosystem structure and function in arid parts of the High Arctic, but they do not completely refute previous findings of resistance in some High Arctic ecosystem properties to climate change.

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Series: Global change biology
ISSN: 1354-1013
ISSN-E: 1365-2486
ISSN-L: 1354-1013
Volume: 28
Issue: 5
Pages: 1853 - 1869
DOI: 10.1111/gcb.16027
OADOI: https://oadoi.org/10.1111/gcb.16027
Type of Publication: A1 Journal article – refereed
Field of Science: 1181 Ecology, evolutionary biology
Subjects:
Funding: NSF Biocomplexity in the High Arctic funded the initiation of this program with support from ARCSS grant 0221606 awarded to JMW that was followed by ARCSS, ANS and AON awards; 0508405, 0856728, 0909538, 0119279, 1433063, 1504141 awarded to JMW and colleagues that made this program possible.
Copyright information: © 2021 John Wiley & Sons Ltd. This article is protected by copyright. All rights reserved. This is the peer reviewed version of the following article: Jespersen, R. G., Leffler, A. J., Väisänen, M., & Welker, J. M. (2022). Resistance and change in a High Arctic ecosystem, NW Greenland: Differential sensitivity of ecosystem metrics to 15 years of experimental warming and wetting. Global Change Biology, 28, 1853–1869, which has been published in final form at https://doi.org/10.1111/gcb.16027. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."