Change search
ReferencesLink to record
Permanent link

Direct link
A frozen feast: thawing permafrost increases plant-available nitrogen in subarctic peatlands
Vrije Univ Amsterdam, Dept Ecol Sci, NL-1081 HV Amsterdam, Netherlands .
Vrije Univ Amsterdam, Dept Ecol Sci, NL-1081 HV Amsterdam, Netherlands .
Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences. (Arcum)
Vrije Univ Amsterdam, Dept Ecol Sci, NL-1081 HV Amsterdam, Netherlands .
Show others and affiliations
2012 (English)In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 18, no 6, 1998-2007 p.Article in journal (Refereed) Published
Abstract [en]

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 (010cm below the thawfront) to those taken from a current rooting zone layer (515cm 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 degrees C (over 120days, 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 (273mgNm-2 and 1348mgNm-2 per growing season for near-surface permafrost at 0.5 degrees C and 11 degrees C respectively, compared to -30mgNm-2 for current rooting zone soil at 11 degrees C). Hence, our results demonstrate that near-surface permafrost soil of subarctic peatlands can release a biologically relevant amount of plant available nitrogen, both directly upon thawing as well as over the course of a growing season through continued microbial mineralization of organically bound N. Given the nitrogen-limited nature of northern peatlands, this release may have impacts on both plant productivity and species composition.

Place, publisher, year, edition, pages
2012. Vol. 18, no 6, 1998-2007 p.
Keyword [en]
bioassay, climate change, nitrogen cycling, nutrients, palsa mire, Permafrost degradation, Poa alpina, subarctic
National Category
Earth and Related Environmental Sciences Ecology
URN: urn:nbn:se:umu:diva-56205DOI: 10.1111/j.1365-2486.2012.02663.xISI: 000303763600019OAI: diva2:532891
Available from: 2012-06-12 Created: 2012-06-12 Last updated: 2016-05-20Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Dorrepaal, Ellen
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Global Change Biology
Earth and Related Environmental SciencesEcology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 138 hits
ReferencesLink to record
Permanent link

Direct link