title: Ectomycorrhizal fungi - potential organic matter decomposers, yet not saprotrophs.
abstract: Although hypothesized for many years, the involvement of ectomycorrhizal fungi in decomposition of soil organic matter remains controversial and has not yet been fully acknowledged as an important factor in the regulation of soil carbon (C) storage. Here, we review recent findings, which support the view that some ectomycorrhizal fungi have the capacity to oxidize organic matter, either by 'brown-rot' Fenton chemistry or using 'white-rot' peroxidases. We propose that ectomycorrhizal fungi benefit from organic matter decomposition primarily through increased nitrogen mobilization rather than through release of metabolic C and question the view that ectomycorrhizal fungi may act as facultative saprotrophs. Finally, we discuss how mycorrhizal decomposition may influence organic matter storage in soils and mediate responses of ecosystem C sequestration to environmental changes.
authors.affiliation: Department of Soil and Environment, Swedish University of Agricultural Sciences, Box 7014, SE-750 07, Uppsala, Sweden.
authors.forename: Björn D
authors.initials: BD
authors.lastname: Lindahl
authors.affiliation: Microbial Ecology Group, Department of Biology, Lund University, Ecology Building, SE-22 362, Lund, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Tunlid
mesh_terms: D002244:Carbon / Q000378:metabolism; D020869:Gene Expression Profiling; D023281:Genomics; D038821:Mycorrhizae / Q000378:metabolism*; D009930:Organic Chemicals / Q000378:metabolism*; D013057:Spectrum Analysis
chemical_list: D009930:Organic Chemicals; D002244:Carbon
keywords: carbon sequestration; decomposition; ectomycorrhiza; nitrogen cycling; organic matter oxidation; priming effect