Abstract
In-growth bags are increasingly used to study extramatrical mycelium (EMM) of ectomycorrhizal fungi in forest soils. In this paper we tested whether bag size and presence of soil fauna in bags influence the production, isotopic composition, carbon (C) and nitrogen (N) content of the EMM. Cylindrical in-growth mesh bags (2- or 5-cm-diameter; with or without openings - (1 or 2mm), allowing faunal colonization or not) were harvested 37, 48, 81 and 283 days after installation in July and the EMM biomass was determined from elemental analyses of the extractable amount of mycelia. The occurrence of openings allowed animals to invade the bags but this did not affect the amount of EMM. We suggest further studies in this matter since the number of animals was low and variable. In the first harvest, mycelial biomass C was three times greater in 2-cm than in 5-cm-bags. After 81 days, mycelial biomass C was 54% greater in the 2-cm (54kgha-1) than in the 5-cm bags (35kgha-1). While total mycelial C did not change over winter, N content increased suggesting a role for the EMM in the storage of N from autumn to spring. The δ13C and δ15N of the EMM changed between the first three harvests. We hypothesize these changes to be mainly driven by changes in plant C and N sinks. The relation between the isotopic composition of sporocarp exploration type, plant roots and EMM is discussed.
Original language | English |
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Pages (from-to) | 154-162 |
Number of pages | 9 |
Journal | Soil Biology and Biochemistry |
Volume | 66 |
DOIs | |
Publication status | Published - Nov 2013 |
Bibliographical note
Funding Information:We thank Carin Arnesson and Marie Lundgren for assistance in the field and the Swedish Research Council for founding (grant number 2002-4796 ) to Alf Ekblad.
Keywords
- Ectomycorrhiza
- Extramatrical mycelium
- Forest
- In-growth mesh bags
- Norway spruce
- Picea abies
- Stable isotopes