Marschner Review

Plant and Soil

, Volume 366, Issue 1, pp 1-27

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

The production and turnover of extramatrical mycelium of ectomycorrhizal fungi in forest soils: role in carbon cycling

  • A. EkbladAffiliated withSchool of Science & Technology, Örebro University Email author 
  • , H. WallanderAffiliated withDepartment of Biology, Microbial Ecology Group, Ecology Building, Lund University
  • , D. L. GodboldAffiliated withInstitute of Forest Ecology, Universität für Bodenkultur
  • , C. CruzAffiliated withPlant Biology, University of Lisbon
  • , D. JohnsonAffiliated withInstitute of Biological and Environmental Sciences, University of Aberdeen
  • , P. BaldrianAffiliated withLaboratory of Environmental Microbiology, Institute of Microbiology ASCR
  • , R. G. BjörkAffiliated withSchool of Science & Technology, Örebro UniversityDepartment of Earth Sciences, University of Gothenburg
  • , D. EpronAffiliated withUMR INRA-UL Forest Ecology and Ecophysiology, Université de Lorraine
  • , B. Kieliszewska-RokickaAffiliated withInstitute of Environmental Biology, Kazimierz Wielki University
    • , R. KjøllerAffiliated withTerrestrial Ecology, Biological Institute, University of Copenhagen
    • , H. KraigherAffiliated withSlovenian Forestry Institute
    • , E. MatznerAffiliated withSoil Ecology, University of Bayreuth
    • , J. NeumannAffiliated withSoil Ecology, University of Bayreuth
    • , C. PlassardAffiliated withINRA, UMR Eco & Sols


There is growing evidence of the importance of extramatrical mycelium (EMM) of mycorrhizal fungi in carbon (C) cycling in ecosystems. However, our understanding has until recently been mainly based on laboratory experiments, and knowledge of such basic parameters as variations in mycelial production, standing biomass and turnover as well as the regulatory mechanisms behind such variations in forest soils is limited. Presently, the production of EMM by ectomycorrhizal (EM) fungi has been estimated at ~140 different forest sites to be up to several hundreds of kg per ha per year, but the published data are biased towards Picea abies in Scandinavia. Little is known about the standing biomass and turnover of EMM in other systems, and its influence on the C stored or lost from soils. Here, focussing on ectomycorrhizas, we discuss the factors that regulate the production and turnover of EMM and its role in soil C dynamics, identifying important gaps in this knowledge. C availability seems to be the key factor determining EMM production and possibly its standing biomass in forests but direct effects of mineral nutrient availability on the EMM can be important. There is great uncertainty about the rate of turnover of EMM. There is increasing evidence that residues of EM fungi play a major role in the formation of stable N and C in SOM, which highlights the need to include mycorrhizal effects in models of global soil C stores.


Decomposition Exploration type Extramatrical mycelium In-growth bag Minirhizotron Soil organic matter Rhizomorphs Turnover rates