Groundcovers and Rain Shelters Alter Co-Occurrence Patterns among Ground Beetle Communities in an Organic Raspberry Crop

SIMPLE SUMMARY: Rain shelters and reflective groundcovers improve the economic and environmental sustainability of organic fruit crops affected by a number of plant pathogens. In this study, we examined whether these structures also affect the communities of species that inhabit the soil surface, particularly ground beetles, in organic red raspberry crops. Our results indicate that ground beetle species richness, activity and functional traits differed in the presence of rain shelters and reflective groundcovers, but these effects were relatively minor. Thus, this study suggests that these structures, which have known benefits against plant pathogens, had no detrimental impact on ground beetle communities. ABSTRACT: The use of rain shelters and reflective groundcovers has been shown to improve the economic and environmental sustainability of organic fruit crops prone to rain-driven epidemics of phytopathogens. Here, we tested whether these structures affect communities of epigean species. To this end, we studied rain shelters and white, synthetic reflective groundcovers placed in a red raspberry organic cropping system in New Brunswick, Canada, during two subsequent summers to assess their independent and combined effects on ground beetles (Coleoptera: Carabidae). 18,445 ground beetles belonging to 54 species were collected. Rain shelters and reflective groundcovers altered patterns of ground beetle species richness, activity density and functional diversity compared to the control, but to a limited extent. Thus, this study suggests that these structures, which have known benefits against phytopathogens, have no detrimental impact on epigean fauna.