Production and turnover of ectomycorrhizal extramatrical mycelial biomass and necromass under elevated CO2 and nitrogen fertilization

Sammanfattning

Extramatrical mycelia (EMM) of ectomycorrhizal fungi are important in carbon (C) and nitrogen (N) cycling in forests, but poor knowledge about EMM biomass and necromass turnovers makes the quantification of their role problematic. We studied the impacts of elevated CO2 and N fertilization on EMM production and turnover in a Pinus taeda forest. EMM C was determined by the analysis of ergosterol (biomass), chitin (total bio- and necromass) and total organic C (TOC) of sand-filled mycelium in-growth bags. The production and turnover of EMM bio- and necromass and total C were estimated by modelling. N fertilization reduced the standing EMM biomass C to 57% and its production to 51% of the control (from 238 to 122kgCha(-1)yr(-1)), whereas elevated CO2 had no detectable effects. Biomass turnover was high (13yr(-1)) and unchanged by the treatments. Necromass turnover was slow and was reduced from 1.5yr(-1) in the control to 0.65yr(-1) in the N-fertilized treatment. However, TOC data did not support an N effect on necromass turnover. An estimated EMM production ranging from 2.5 to 6% of net primary production stresses the importance of its inclusion in C models. A slow EMM necromass turnover indicates an importance in building up forest humus.

Nyckelord

Duke Forest free-air CO2 enrichment (FACE); ectomycorrhiza; elevated CO2; extramatrical mycelium; fungal biomass; nitrogen (N) fertilization; stable isotopes; turnover

Publicerad i

New Phytologist
2016, volym: 211, nummer: 3, sidor: 874-885

SLU författare

• Ekblad, Alf

  • Örebro Universitet

• Ågren, Göran

  • Institutionen för ekologi, Sveriges lantbruksuniversitet
    

• Menichetti, Lorenzo

  • Agroscope

Associerade SLU-program

SLU Nätverk växtskydd

UKÄ forskningsämne

Miljövetenskap
Mikrobiologi
Ekologi

Publikationens identifierare

• DOI: https://doi.org/10.1111/nph.13961

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/81079