Impact of alien tree species on the soil microbial community
Over the last 200-250 years, numerous species of non-native trees have been introduced into new areas for forestry and ornamental purposes. Their impacts above-ground are well documented and can include negative impacts on biodiversity and ecosystem services. Potential impacts on the soil microbial community are less well known. A study was conducted in 48 parks in the Czech Republic where alien and native trees were sampled along with their associated soil microbial communities. In total, 73 alien tree taxa were included in the study where the most frequently sampled tree taxa sampled were Pinaceae species including Pseudotsuga menziesii, Picea pungens and Pinus strobus. For the associated microbial community, 520 fungal communities were associated with alien tree taxa and 76 fungal communities with native tree taxa. The type of mycorrhizal association had an effect on the abundance of pathogens associated with alien trees. Alien tree taxa with ectomycorrhizal associations had a lower pathogen richness and relative abundance compared to alien tree taxa with arbuscular mycorrhizal associations. The alien trees’ arbuscular mycorrhizal had a threefold higher pathogen relative abundance compared to native assemblages. Thus, potentially, these non-native tree species could act as reservoirs for pathogens which can affect the neighbouring plant communities.
Sources
Vlk L, Odriozola I, Pergl J, Vĕtrovsky T, Kvasničková J, Krüger C, Petružálková M, Baldrian P, Vojík M, Sádlo J, Petřík P, Pyšek P, Kohout P (2026) From pathogens to partners: temporal and biogeographical patterns in fungal associations of alien trees. New Phytologist (early view), https://doi.org/10.1111/nph.71094