Mycological Progress

, Volume 11, Issue 1, pp 287–297

Exploration type-specific standard values of extramatrical mycelium – a step towards quantifying ectomycorrhizal space occupation and biomass in natural soil

  • Rosemarie B Weigt
  • Stefan Raidl
  • Rita Verma
  • Reinhard Agerer
Original Article


The present study aims at providing standard values for the exploration type (ET)-specific quantification of extramatrical mycelium (EMM) of ectomycorrhizal fungi applicable to ecological field studies. These values were established from mycelial systems of ectomycorrhizae (ECM) synthesized in rhizotrons with near-to-natural peat substrate. Based on image analysis, the “Specific Potential Mycelial Space Occupation” (sPMSO), i.e. the ET-specific complete area that is covered by the EMM systems (mm2 cm−1 ECM−1), and the “Specific Actual Mycelial Space Occupation” (sAMSO), i.e. the projection area of mycelial systems (mm2 cm−1 ECM−1), were analyzed as an extension of a previously described approach. The “Specific Extramatrical Mycelial Length” (sEML) [m cm−1 ECM−1] and the “Specific Extramatrical Mycelial Biomass” (sEMB) (μg cm−1 ECM−1) were calculated for each of the ET via the proportion of hyphal projected area, hyphal length and biomass, the latter two being derived from previous measurements on Piloderma croceum, a “Medium-Distance” (MD)-ET. Both sPMSO and sAMSO were highest for the “Long-Distance” (LD)-ET, whereas those of the “Short-Distance” (SD)-ET and MD-ET were similar, although showing high variation. In contrast, mycelial density per occupied area of the MD-ET was twice as high as that of the LD-ET. Proportional to the sAMSO, the EMM length and biomass differed considerably between the three ET with values of the MD-ET being 1.9 times higher than those of SD-ET, and those of the LD-ET being 15 times higher than those of the SD-ET. These standards in relation to ECM length may ease quantification of mycelial space occupation and biomass in a relatively simple way. Thereby, the ET-specific contribution of EMM can be distinguished—also of non-cultivable species—and up-scaling to large-scale estimation of cost/benefit relations is possible.


Ectomycorrhiza Extramatrical mycelium Exploration type Space occupation Mycelial biomass 


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Copyright information

© German Mycological Society and Springer 2011

Authors and Affiliations

  • Rosemarie B Weigt
    • 1
  • Stefan Raidl
    • 1
  • Rita Verma
    • 1
  • Reinhard Agerer
    • 1
  1. 1.Department of Biology I and GeoBio-Center (LMU), Division of Organismic Biology: MycologyLudwig-Maximilians-Universität MünchenMunichGermany

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