Menu

Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

Anthropogenic nitrogen enrichment enhances soil carbon accumulation by impacting saprotrophs rather than ectomycorrhizal fungal activity

Author:
  • Nadia I. Maaroufi
  • Annika Nordin
  • Kristin Palmqvist
  • Niles J. Hasselquist
  • Benjamin Forsmark
  • Nicholas P. Rosenstock
  • Håkan Wallander
  • Michael J. Gundale
Publishing year: 2019-06-05
Language: English
Publication/Series: Global Change Biology
Document type: Journal article
Publisher: Wiley-Blackwell

Abstract english

There is evidence that anthropogenic nitrogen (N) deposition enhances carbon (C) sequestration in boreal forest soils. However, it is unclear how free-living saprotrophs (bacteria and fungi, SAP) and ectomycorrhizal (EM) fungi responses to N addition impact soil C dynamics. Our aim was to investigate how SAP and EM communities are impacted by N enrichment and to estimate whether these changes influence decay of litter and humus. We conducted a long-term experiment in northern Sweden, maintained since 2004, consisting of ambient, low N additions (0, 3, 6, and 12 kg N ha−1 year−1) simulating current N deposition rates in the boreal region, as well as a high N addition (50 kg N ha−1 year−1). Our data showed that long-term N enrichment impeded mass loss of litter, but not of humus, and only in response to the highest N addition treatment. Furthermore, our data showed that EM fungi reduced the mass of N and P in both substrates during the incubation period compared to when only SAP organisms were present. Low N additions had no effect on microbial community structure, while the high N addition decreased fungal and bacterial biomasses and altered EM fungi and SAP community composition. Actinomycetes were the only bacterial SAP to show increased biomass in response to the highest N addition. These results provide a mechanistic understanding of how anthropogenic N enrichment can influence soil C accumulation rates and suggest that current N deposition rates in the boreal region (≤12 kg N ha−1 year−1) are likely to have a minor impact on the soil microbial community and the decomposition of humus and litter.

Keywords

  • Soil Science
  • carbon sequestration
  • ecological stoichiometry
  • Gadgil effect
  • high-throughput sequencing
  • ingrowth mesh bags
  • ITS amplicons
  • litter decomposition
  • root exclosure
  • soil organic matter

Other

Epub
  • ISSN: 1354-1013
Nicholas Rosenstock
E-mail: nicholas [dot] rosenstock [at] cec [dot] lu [dot] se

Research group

Microbial Ecology

Projects

Downloads & links

 

Plant and fungi in pot