Comparable ectomycorrhizal fungal species richness but low species similarity among native Abies alba and alien Abies grandis from provenance trials in Poland

Abstract

Our study contributes to the understanding of the diversity of ectomycorrhizal fungal (ECMF) communities of native A. alba and alien A. grandis in provenance trials situated in lowland and montane regions in Poland (Central Europe). Ectomycorrhizal fungi were identified directly from field-collected root tips using PCR- and Sanger-sequencing-based methods. We found that the studied fir species had relatively high and comparable ECMF species richness (66 and 69 fungal taxa on A. grandis and A. alba, respectively). Twenty-six taxa were associated with both hosts and 83 taxa were found uniquely on one or the other fir species. The ECMF community composition and structure of A. alba and A. grandis differed substantially both at the species and the phylogenetic lineage levels. Soil parameters such as total nitrogen, magnesium and potassium content and C/N ratio appeared moderately but significantly correlated with the ECMF community assembly of both firs. The provenance of the host tree species did not appear to be a strong factor in structuring the ECMF communities. This was found despite the low number of common ECMF species and relatively high number of unique species among the individual provenances of both fir species. The results of the study suggest that locally based specificity in host–fungal communities is likely a contributing factor in the outcome of provenance trials. We posit that much insight into the role of tree provenances in shaping ECMF communities will be gained by further exploring this area of research. On the surveyed experimental forest sites of A. alba and A. grandis, fungal species of conservation concern – particularly those that were endangered and rare – have been reported. Our findings imply that tree species planted outside their natural range serve as ecologically important species because they may act as an excellent reservoir of ECMF diversity, a factor of importance in functioning forest ecosystems.