Ectomycorrhizal fungal communities of silver-fir seedlings regenerating in fir stands and larch forecrops

Abstract

Key message: The diversity of ECM communities of 1-year-old silver-fir seedlings regenerating in mature silver-fir stands is significantly higher than in neighboring larch forecrops. Abstract: Forecrop stands provide the necessary shade for shade preferring seedlings, such as silver-fir, which cannot be introduced as the first generation in open areas. Larch is a good candidate, recommended to be utilized as forecrop. Since fungal symbionts of Abies alba seedlings regenerating under larch canopy have not been investigated, we aimed to evaluate the diversity of ECM of 1-year-old silver-fir seedlings regenerating under canopy of larch and to compare these communities to those found in adjacent mature silver-fir stands. Three silver-fir stands (F) and three European larch forecrops (L) were selected to study. Seedling size did not differ between F and L stands. ECM colonization was observed in 100% silver-fir seedlings in F and 80% in L stands. The fine roots were highly colonized, and 91 and 87% of live ECM were found in seedlings from F and L stands, respectively. Sequencing analysis revealed a total 53 ECM taxa. The observed number of ECM taxa in the F stands was significantly higher (46) than that in the L forecrops (25), and 34% of taxa were common to both stands. The dominant ECM species in F were unidentified fungus 1, Piloderma sp., Tylospora asterophora and Russula integra. Fir seedlings regenerating in L forecrops formed ectomycorrhizas mostly with unidentified fungus 1, Tomentella sublilacina, Tylospora sp., Hydnotrya bailii and T. asterophora. Based on ANOSIM analysis, ECM communities have shown significant differences between study sites. The diversity of ECM fungal partners and the high colonization rate of silver-fir seedlings regenerating in larch forecrop stands should be sufficient to provide efficient afforestation of post-arable lands and gives the opportunity for their successful rebuilding.