Effect of N deposition in a highly N-limited habitat: deadwood

Nitrogen deposition can strongly affect biodiversity, but its specific effects on terrestrial microbial communities are still unclear. Here, we used deadwood and wood-inhabiting fungi (WIF) as a model system to investigate the impacts of N deposition on a highly N-limited habitat. We used pyrotag high-throughput sequencing for characterizing the WIF communities. The N deposition experiment was set up in September 2011. The general experimental design was based on a pairwise sampling technique: 2 treatments (control and N addition) x 12 tree species x 4 replicates (located at different forest sites). Deadwood logs were sampled 2 times in 2011 (0 time point) and 2013 (2 years). We show that N addition has no significant effect on overall fungal diversity and community composition. Nevertheless, we detected several switches in presence /absence (gain or loss) and abundances of wood-inhabiting fungal OTUs due to the effect of N addition. These results contradict previous studies carried out in soil and leaf-litter which represent less N-limited fungal habitats.