Beneficial arthropod communities associated with native floral plantings

Declines in species diversity resulting from anthropogenic alterations of the environment have highlighted the need to develop management strategies that conserve species and ecosystem services. This study examined how native plant species and planting diversity influence the abundance and diversity of beneficial arthropods, a functionally important group that performs ecosystem services such as pollination and natural pest suppression. Beneficial arthropods were sampled in replicated study plots containing native perennials planted in 1, 2, and 7 species mixes. We found planting diversity had a positive impact on arthropod diversity but not arthropod abundance. Among the most attractive flower species both in terms of arthropod diversity and abundance were Monarda fistulosa and Pycanantheum tenufolium. An analysis of arthropod community composition revealed each flower species attracted a different assemblage of beneficial arthropods. Moreover, the 7 species mix also attracted a distinct arthropod community. Arthropod assemblages collected from 7 species plots were non-additive, but the composition of species closely resembled an additive community, which would result if the arthropod assemblages collected from single species plots were summed. The arthropod communities collected from the 2 species mixes also produced non-additive assemblages, but instead the arthropod assemblages tended to be dominated by one of the flower species in the planting. This finding suggests the variability in arthropod community composition decreases with planting diversity. Our study demonstrated arthropod abundance and diversity can be augmented through plant selection and planting diversity, indicating disturbed landscapes can potentially support diverse beneficial insect assemblages capable of providing arthropod mediated ecosystem services.