Seasonal distribution of the North American beech leaf nematode (Litylenchus crenatae ssp. mccannii) in soil and leaf litter in a temperate hardwood forest.

Fagus grandifolia (American beech) is a widespread and important tree species in North America and is often the dominant tree in some temperate forests. Since 2012, American beech trees have been affected by beech leaf disease (BLD), which causes dark interveinal banding of the leaves. The North American beech leaf nematode (Litylenchus crenatae ssp. mccannii) is the causative agent of BLD. Although the etiology of BLD is still not well understood, the nematodes can overwinter in buds and inhabit leaves. However, it is uncertain to what degree forest leaf litter and soil might act as a reservoir for this nematode, and how this may change seasonally. In this study, we examined the presence of Litylenchus crenatae ssp. mccannii in leaf litter and soil throughout the course of the year, and how nematode communities in these substrates changed using high throughput sequencing.