A frozen feast: thawing permafrost increases plant-available nitrogen in subarctic peatlands

F. Keuper, P.M. van Bodegom, E. Dorrepaal, J.T. Weedon, J.R. van Hal, R.S.P van Logtestijn, R. Aerts

    Research output: Contribution to JournalArticleAcademicpeer-review

    Abstract

    Many of the world's northern peatlands are underlain by rapidly thawing permafrost. Because plant production in these peatlands is often nitrogen (N)-limited, a release of N stored in permafrost may stimulate net primary production or change species composition if it is plant-available. In this study, we aimed to quantify plant-available N in thawing permafrost soils of subarctic peatlands. We compared plant-available N-pools and -fluxes in near-surface permafrost (0-10 cm below the thawfront) to those taken from a current rooting zone layer (5-15 cm depth) across five representative peatlands in subarctic Sweden. A range of complementary methods was used: extractions of inorganic and organic N, inorganic and organic N-release measurements at 0.5 and 11 °C (over 120 days, relevant to different thaw-development scenarios) and a bioassay with Poa alpina test plants. All extraction methods, across all peatlands, consistently showed up to seven times more plant-available N in near-surface permafrost soil compared to the current rooting zone layer. These results were supported by the bioassay experiment, with an eightfold larger plant N-uptake from permafrost soil than from other N-sources such as current rooting zone soil or fresh litter substrates. Moreover, net mineralization rates were much higher in permafrost soils compared to soils from the current rooting zone layer (273 mg N m
    Original languageEnglish
    Pages (from-to)1998-2007
    JournalGlobal Change Biology
    Volume18
    Issue number6
    Early online date13 Mar 2012
    DOIs
    Publication statusPublished - 2012

    Fingerprint

    Dive into the research topics of 'A frozen feast: thawing permafrost increases plant-available nitrogen in subarctic peatlands'. Together they form a unique fingerprint.

    Cite this