Plant and Soil

, Volume 352, Issue 1, pp 405–417

Application of nitrogen fertilizer to a boreal pine forest has a negative impact on the respiration of ectomycorrhizal hyphae

  • Harry W. Vallack
  • Vincenzo Leronni
  • Daniel B. Metcalfe
  • Peter Högberg
  • Phil Ineson
  • Jens-Arne Subke
Regular Article

DOI: 10.1007/s11104-011-1005-6

Cite this article as:
Vallack, H.W., Leronni, V., Metcalfe, D.B. et al. Plant Soil (2012) 352: 405. doi:10.1007/s11104-011-1005-6

Abstract

Aims

There is evidence that increased N inputs to boreal forests, via atmospheric deposition or intentional fertilization, may impact negatively on ectomycorrhizal (ECM) fungi leading to a reduced flux of plant-derived carbon (C) back to the atmosphere via ECM. Our aim was to investigate the impact of N fertilization of a Pinus sylvestris (L.) forest stand on the return of recently photoassimilated C via the ECM component of soil respiration.

Methods

We used an in situ, large-scale, 13C-CO2 isotopic pulse labelling approach and monitored the 13C label return using soil gas efflux chambers placed over three different types of soil collar to distinguish between heterotrophic (RH), autotrophic (RA; partitioned further into contributions from ECM hyphae and total RA) and total (RS) soil respiration.

Results

The impact of N fertilization was to significantly reduce RA, particularly respiration via extramatrical ECM hyphae. ECM hyphal flux in control plots showed substantial spatial variability, resulting in mean flux estimates exceeding estimates of total RA, while ECM contributions to RA in N treated plots were estimated at around 30%.

Conclusion

Significant impacts on soil C cycling may be caused by reduced plant C allocation to ECM fungi in response to increased N inputs to boreal forests; ecosystem models so far lack this detail.

Keywords

13CO2Pulse labellingSoil CO2 effluxEctomycorrhizasSoil respirationBoreal forest

Abbreviations

ANOVA

Analysis of variance

ECM

Ectomycorrhiza

C

Carbon

CO2

Carbon dioxide

CF-IRMS

Continuous-flow isotope ratio mass spectrometer

N

Nitrogen

PVC

Polyvinyl chloride

RS

Soil respiration

RA

Autotrophic soil respiration

RH

Heterotrophic soil respiration

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Harry W. Vallack
    • 1
  • Vincenzo Leronni
    • 2
  • Daniel B. Metcalfe
    • 3
  • Peter Högberg
    • 3
  • Phil Ineson
    • 1
  • Jens-Arne Subke
    • 4
  1. 1.Stockholm Environment InstituteUniversity of YorkYorkUK
  2. 2.Department of Agro-Environmental and Territorial SciencesUniversity of BariBariItaly
  3. 3.Department of Forest Ecology and ManagementSwedish University of Agricultural Sciences (SLU)UmeåSweden
  4. 4.School of Natural Sciences, Biological and Environmental SciencesUniversity of StirlingStirlingUK