Data from: Host and tissue variation overshadow the response of boreal moss-associated fungal communities to increased nitrogen load

Human activity has more than doubled the amount of nitrogen entering the
global nitrogen cycle, and the boreal forest biome is a nitrogen-limited
ecosystem sensitive to nitrogen load perturbation. Although
bryophyte-associated microbes contribute significantly to boreal forest
ecosystem function, particularly in carbon and nitrogen cycling, little is
known about their responses to anthropogenic global change. Amplicon
pyrosequencing of the ITS2 region of rDNA was used to investigate how
fungal communities associated with three bryophyte species responded to
increased nitrogen loads in a long-term fertilization experiment in a
boreal Picea abies forest in southern Norway. Overall, OTU richness,
community composition, and the relative abundance of specific ecological
guilds were primarily influenced by host species identity and tissue-type.
Although not the primary factor affecting fungal communities, nitrogen
addition did impact the abundance of specific guilds of fungi and the
resulting overall community composition. Increased nitrogen loads
decreased ectomycorrhizal abundance, with Amphinema, Cortinarius, Russula,
and Tylospora OTUs responding negatively to fertilization. Pathogen
abundance increased with fertilization, particularly in the moss pathogen
Eocronartium. Saprophytic fungi were both positively and negatively
impacted by the nitrogen addition, indicating a complex community level
response. The overshadowing of the effects of increased nitrogen loads by
variation related to host and tissue-type highlights the complexity of
bryophyte-associated microbial communities and the intricate nature of
their responses to anthropogenic global change.