Journal Article

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

Ekblad, Alf, Vilgalys, Rytas, Mikusinska, Anna, Wallander, Håkan, Bahr, Adam, Ågren, Göran I., Menichetti, Lorenzo, Eriksson, Ulrika

2016

Overview

Summary 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 122 kg C ha−1 yr−1), whereas elevated CO2 had no detectable effects. Biomass turnover was high (˜13 yr−1) and unchanged by the treatments. Necromass turnover was slow and was reduced from 1.5 yr−1 in the control to 0.65 yr−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.

• Publisher: Wiley Subscription Services, Inc
• Subject: bags / Biologi / Biological Sciences / Biomass / carbon / Carbon - metabolism / Carbon dioxide / Carbon Dioxide - pharmacology / carbon dioxide enrichment / Carbon Isotopes / Chitin / Chitin - metabolism / Decomposing organic matter / Duke Forest free‐air CO2 enrichment (FACE) / Earth and Related Environmental Sciences / Ecology / Ecology (including Biodiversity Conservation) / ectomycorrhiza / ectomycorrhizae / Ekologi / elevated CO2 / Environmental Sciences / ergosterol / Ergosterol - metabolism / extramatrical mycelium / fertilizer analysis / fertilizer application / Fertilizers / Forests / fungal biomass / Geovetenskap och relaterad miljövetenskap / Humus / Microbiology / Mikrobiologi / Miljövetenskap / Models, Biological / mycelium / Mycelium - drug effects / Mycelium - growth & development / mycorrhizal fungi / Natural Sciences / Naturvetenskap / necromass / Nitrogen / nitrogen (N) fertilization / Nitrogen - pharmacology / nitrogen cycle / nitrogen fertilizers / Pine trees / Pinus taeda / Pinus taeda - drug effects / Pinus taeda - physiology / Primary production / primary productivity / stable isotopes / Time Factors / turnover