Patterns of community composition and diversity in latent fungi of living Quercus serrata trunks across a range of oak wilt prevalence and climate variables in Japan

Given that forest dieback due to emerging pests is increasing under global warming, understanding the re-lationships between pests, climate, and forest biodiversity is an urgent priority. In Japan, mass attacks of an ambrosia beetle, vectoring a pathogenic fungus, cause oak wilt outbreaks in recent decades. Here, the associa-tions of oak wilt and climate with wood-inhabiting fungal communities in apparently healthy Quercus serrata trunks were investigated using DNA metabarcoding in seven sites along a climatic gradient in Japan. Amplicon sequencing of the fungal internal transcribed spacer 1 region generated 1,339,958 sequence reads containing 879 fungal operational taxonomic units (OTUs) in 234 wood samples. OTU compositions were significantly different between sites with and without oak wilt. OTU richness increased with temperature and precipitation at sites where oak wilt was present, but this relationship was not observed at sites without oak wilt, possibly due to interaction between oak wilt and climate.

Automated summary

This study investigates the relationships between oak wilt, climate, and wood-inhabiting fungal communities in apparently healthy Quercus serrata trunks in Japan. The results show that the composition and richness of fungal communities are significantly different between sites with and without oak wilt. Oak wilt is associated with increased richness of wood-inhabiting fungal communities, which is influenced by temperature and precipitation.