IVL Swedish Environmental Research Institute

ivl.se
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Positive response of soil microbes to long-term nitrogen input in spruce forest: Results from Gårdsjön whole-catchment N-addition experiment.
IVL Swedish Environmental Research Institute.
Show others and affiliations
2020 (English)In: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 143, article id 107732Article in journal (Refereed) Published
Abstract [en]

Chronic nitrogen (N) deposition from anthropogenic emissions alter N cycling of forests in Europe and in other impacted areas. It disrupts plant/microbe interactions in originally N-poor systems, based on a symbiosis of plants with ectomycorrhizal fungi (ECM). ECM fungi that are capable of efficient nutrient mining from complex organics and their long-distance transport play a key role in controlling soil N mineralization and immobilization, and eventual nitrate (NO3) leaching. Current meta-analyses highlight the importance of ECM biomass in securing the large soil N pool. At the same time, they point to the adverse effect of long-term N input on ECM fungi. The functioning of N-poor and N-overloaded forests is well understood, while the transient stages are much less explored. Therefore, we focused on the spruce-forest dominated catchment at Gårdsjön (Sweden) that received N addition of 40 kg N ha−1yr−1 over 24 years (a cumulative N input of >1200 kg N ha−1) but still loses via runoff only <20% of annual N input (deposition + addition) as NO3. We found that, compared to the control, the N-addition catchment had a much larger soil microbial biomass. The N addition did not change the fungi/bacteria ratio, but a larger share of the bacterial community was made up of copiotrophs. Furthermore, fungal community composition shifted to more nitrophilic ECM fungi (contact and short exploration type ECM species) and saprotrophs. Such a restructured community has been more active, possessed a higher specific respiration rate, enhanced organic P and C mining through enzymatic production and provided faster net N mineralization and nitrification. These may be early indications of alleviation of N limitation of the system. We observed no signs of soil acidification related to N additions. The larger, structurally and functionally adapted soil microbial community still provides an efficient sink for the added N in the soil and is likely to be one of the explanations for low NO3 leaching that have stabilized in the last decade. Our results suggest that a microbial community can contribute to effective soil N retention in spite of the partial relative retreat (20–30%) of nitrophobic ECM fungi with large external mycelia, provided the fungal biomass remains high because of replacement by other ECM and saprotrophic fungi. Furthermore, we assume that N retention of similar C-rich boreal forests (organic soil molar C/N ~35) is not necessarily threatened by a large cumulative N dose provided N enters at a moderate rate, does not cause acidification and the soil microbial community has time to adapt through structural and functional changes.

Place, publisher, year, edition, pages
2020. Vol. 143, article id 107732
Identifiers
URN: urn:nbn:se:ivl:diva-3321DOI: 10.1016/j.soilbio.2020.107732OAI: oai:DiVA.org:ivl-3321DiVA, id: diva2:1554907
Note

A-rapport, A2479

Available from: 2021-05-17 Created: 2021-05-17 Last updated: 2021-05-17Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Moldan, Filip
By organisation
IVL Swedish Environmental Research Institute
In the same journal
Soil Biology and Biochemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 42 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf