Patterns of free amino acids in tundra soils reflect mycorrhizal type, shrubification, and warming

Louise C. Andresen*, Samuel Bodé, Robert G. Björk, Anders Michelsen, Rien Aerts, Pascal Boeckx, J. Hans C. Cornelissen, Kari Klanderud, Richard S. P. van Logtestijn, Tobias Rütting

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

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Abstract

The soil nitrogen (N) cycle in cold terrestrial ecosystems is slow and organically bound N is an important source of N for plants in these ecosystems. Many plant species can take up free amino acids from these infertile soils, either directly or indirectly via their mycorrhizal fungi. We hypothesized that plant community changes and local plant community differences will alter the soil free amino acid pool and composition; and that long-term warming could enhance this effect. To test this, we studied the composition of extractable free amino acids at five separate heath, meadow, and bog locations in subarctic and alpine Scandinavia, with long-term (13 to 24 years) warming manipulations. The plant communities all included a mixture of ecto-, ericoid-, and arbuscular mycorrhizal plant species. Vegetation dominated by grasses and forbs with arbuscular and non-mycorrhizal associations showed highest soil free amino acid content, distinguishing them from the sites dominated by shrubs with ecto- and ericoid-mycorrhizal associations. Warming increased shrub and decreased moss cover at two sites, and by using redundancy analysis, we found that altered soil free amino acid composition was related to this plant cover change. From this, we conclude that the mycorrhizal type is important in controlling soil N cycling and that expansion of shrubs with ectomycorrhiza (and to some extent ericoid mycorrhiza) can help retain N within the ecosystems by tightening the N cycle.

OriginalsprogEngelsk
TidsskriftMycorrhiza
Vol/bind32
Udgave nummer3-4
Sider (fra-til)305-313
Antal sider9
ISSN0940-6360
DOI
StatusUdgivet - 2022

Bibliografisk note

Funding Information:
Open access funding provided by University of Gothenburg. The study was financed by the Swedish research council Formas 2011–716. Interact transnational access financed the visit to Finse research station in 2013.

Funding Information:
The Swedish strategic research area “Biodiversity and Ecosystem services in a Changing Climate—BECC” ( www.becc.lu.se/ ). We are grateful for help with field logistics from field assistants in Finse in 2013 and Ulf Molau in Latnajaure, and from the staff at Abisko Research Station for maintenance of the blanket bog experiment in Abisko. We thank the Swedish Polar Research Secretariat and SITES for the support of the work done at the Abisko Scientific Research Station. Gosha Sylvester is thanked for analysis of extracts at University of Copenhagen. Katja van Nieuland and Stijn Vandevoorde are thanked for help with GC-MS analysis at ISOFYS in Ghent.

Publisher Copyright:
© 2022, The Author(s).

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