Relationship between the decomposition process of coarse woody debris and fungal community structure as detected by high-throughput sequencing in a deciduous broad-leaved forest in Japan.

We examined the relationship between the community structureof wood-decaying fungi, detected by high-throughput sequencing, and the decompositionrate using 13 years of data from a forest dynamicsplot. For molecular analysis and wood density measurements, drill dust samples were collected from logs and stumps of Fagus and Quercus in the plot. Regression using a negative exponential model between wood density and time since death revealed that the decompositionrate of Fagus was greater than that of Quercus. The residual between the expected value obtained from the regression curve and the observed wood density was used as a decompositionrate index. Principal component analysis showed that the fungal community compositions of both Fagus and Quercus changed with time since death. Principal component analysis axis scores were used as an index of fungal community composition. A structural equation model for each wood genus was used to assess the effect of fungal community structuretraits on the decompositionrate and how the fungal community structurewas determined by the traits of coarse woody debris. Results of the structural equation model suggested that the decompositionrate of Fagus was affected by two fungal community composition components: one that was affected by time since death and another that was not affected by the traits of coarse woody debris. In contrast, the decompositionrate of Quercus was not affected by coarse woody debristraits or fungal community structure. These findings suggest that, in the case of Fagus coarse woody debris, the fungal community structureis related to the decompositionprocess of its host substrate. Because fungal community structureis affected partly by the decay stage and wood density of its substrate, these factors influence each other. Further research on interactive effects is needed to improve our understanding of the relationship between fungal community structureand the woody debris decompositionprocess.