Local-and regional-scale spatial patterns of two fungal pathogens of Miscanthus sinensis in grassland communities

•The spatio-temporal patterns in two pathogens of Miscanthus sinensis were revealed.•Sporisorium kusanoi was widely distributed within the region.•Naemacyclus culmigenus was restricted within a specific site.•The two fungi were observed in 17.2% and 47.3% subplots in the specific site.•Their disease symptoms emerged early in June and peaked early in July.

We studied the spatio-temporal patterns in two fungal pathogens, Sporisorium kusanoi, along with Naemacyclus culmigenus, of the Japanese pampas grass (Miscanthus sinensis) in grassland communities on the Sugadaira plateau, Japan. Their disease symptoms emerged early in June, increased rapidly during the month and peaked early in July. We checked their presence at 11 sites (the regional-scale census) and recorded their presence in 6000 1 × 1-m subplots within a 60 × 100-m area at the specific site (the local-scale census). Sporisorium kusanoi and N. culmigenus were observed at eight and one sites in the regional-scale census, and in 987 and 2708 subplots in the local-scale census, respectively. The respective spatial distributions of S. kusanoi and N. culmigenus aggregated at the spatial scales of 13 m and 33 m. However, the spatial positions of the two fungi were slightly repulsive each other. Our results found that S. kusanoi was widely distributed within the region, whereas N. culmigenus was restricted within the specific site but had a higher frequency compared to S. kusanoi. The contrasting spatial patterns of the two pathogens may reflect differences in their dispersal processes.