Beech Leaf Disease Associated With Changes in Litter Decomposition and Fungal Communities.

Forest pests and diseases may indirectly drive critical shifts in rates of litter decomposition, ultimately impacting carbon and nutrient cycling. Beech leaf disease (BLD) is a rapidly emerging forest disease affecting American beech and driving significant changes in leaf traits and associated microbial communities-both critical drivers of decomposition. However, the extent to which these BLD-driven changes may alter rates of litter decomposition remains unknown. Here, we explore rates of decomposition in BLD symptomatic and asymptomatic leaf litter using a field-based litterbag experiment. In addition to monitoring rates of decomposition, we also explored differences in the associated fungal communities. We found that BLD-symptomatic litter decomposed more quickly than asymptomatic litter. Furthermore, fungal communities differed in composition across symptomatic and asymptomatic leaf litter, with higher abundances of saprotrophic fungi found on symptomatic litter throughout the decomposition process. Given the dominance of American beech in many forested systems in northeastern North America, these shifts in litter decomposition rates driven by BLD may have important consequences for nutrient and carbon cycling in many deciduous forests.