Cover crop species alter tallgrass prairie community assembly

Cover crops are increasingly being used in ecological restoration projects, and are hypothesized to facilitate establishment of sown species by reducing weed abundances without competing with the target mix. We tested these predictions and examined the role of cover crop species on later species composition and diversity using cover crop seed treatments. Treatments included a fall seeding of one annual (Raphanus sativus or Avena sativa), one biennial (Oenothera biennis), one perennial species (Elymus canadensis), two grass-forb species combinations, or nothing as a control. All plots received the same diverse tallgrass prairie seed mix in March of the following year. Plant communities were sampled through five growing seasons. The files associated with this experiment include data on community composition in 70 experimental plots (10 per treatment) taken on five different sample dates from 2016 to 2020. We also include data on aboveground biomass and canopy height measured in May and July of 2018. This constitutes the raw data used to perform all analyses associated with the manuscript.