Biomass of external mycelium of ectomycorrhizal fungi in Norway spruce stands in Poland

Abstract

Biomass of extramatrical mycorrhizal mycelium (EMM) was examined under canopies of mature Norway spruce trees grown in different forest stands in Poland. Two mountain forest sites (Brenna and Salmopol), one upland site (Zwierzyniec) and one lowland site (Mirachowo) have been investigated, using sand-filled mesh-bags method. The in-grow mesh-bags were buried in the soil for 12 months (since October up to the next October) or for 4 months (since June up to October) at four depths at each site: 5, 15, 30 and 45 cm (Brenna and Salmopol) or 60 cm (Zwierzyniec and Mirachowo). The mycelium biomass was estimated from the ergosterol content determined in the mesh-bags. The results indicated significant differences in EMM production and their vertical distribution between the mountain and the upland and lowland forest sites. The lowest EMM biomass was found at the experimental plot in the mountainious site Brenna. Considerable decrease of EMM biomass with the soil depth was recorded after 12 months of the mesh-bags incubation in soil in the upland and lowland sites, while in the mountain forests decrease of the EMM biomass in the lower soil depths diminished more gradually EMM biomass determined in the mesh-bags placed in soil at the upper 5 and 15 cm tended to be higher after 4 months than after 12 months of incubation period. Such results suggest that the time necessary for evaluation of EMM biomass in soil may be limited to the summer–autumn months, when the production of EMM is the highest. Variable stress factors can influence decreased ectomycorrhizal mycelium production and/or their destruction. Further research in different forest types and regions are needed for better understanding factors determining EMM biomass production and surviving in soil.

Keywords

• Picea abies
• ergosterol
• soil depth
• mesh-bags