High fungal substrate specificity limits the utility of environmental DNA to detect fungal diversity in bogs

Fungi are a highly diverse group of organisms and play a significant role in decomposition and carbon cycling in boreal ecosystems. To determine how fungal communities are structured in peat bogs and how to obtain representative samples for monitoring fungal community changes, we separately sampled and sequenced (ITS2, Illumina MiSeq) peat, mixed litter and litter from individual dominant plant species in five permanent plots in raised bogs in the Jizerske Hory Mountains (Czech Republic). In total, we detected 68-103 OTUs per plot. The fungal assemblages were mostly influenced by substrate identity, whereas the effect of the site was minimal. Only a few identified OTUs behave like generalists. The most specific fungi were found in dead parts of Cantina yidgaris, Trichophorum cespitosum and Drosera rotundifolia. The high substrate heterogeneity means that sequencing soil core samples does not provide an exhaustive inventory of the fungal diversity in bogs. Poor correspondence was observed between the recorded OTUs and either visually inspected fruitbodies or literature reports on the fungal taxa associated with the analysed substrates.

Automated summary

The study revealed that fungal communities in boreal ecosystems are primarily influenced by substrate identity rather than site differences. Only a few fungi behave as generalists across different plant species, while most specific fungi are found in dead parts of specific plants.