Vegetation richness, diversity, and structure influence arthropod communities of native and restored northern mixed‐prairies

Abstract

We studied the effects of vegetation species richness, diversity, and structure on grassland arthropod communities of 23 sites in northeastern South Dakota and southeastern North Dakota. Sites were selected to represent a vegetation species diversity gradient, and three vegetation cover types, including native unseeded grassland, low‐diversity seeding known as dense nesting cover (DNC) for waterfowl, and high‐diversity seed mix. During July of 2016, pan traps and sweep nets were used to survey the grassland arthropod community. A total of 25,521 arthropods representing 107 taxonomic families were collected. Richness, diversity, and biomass of arthropods did not differ among cover types. Vegetation richness and diversity, cover type, percent live vegetation and native cover, and litter depth were important predictors of arthropod community measures, and multivariate analysis of the arthropod community indicated significant differences between native and DNC study sites; explained by differences in vegetation richness, percent forb cover, and litter depth. Results of our study suggest that species richness of grassland restoration seeding mixes likely impacts arthropod richness and diversity, and DNC does not produce arthropod communities similar to native prairie. Additionally, because vegetation structural variables were important determinants of arthropod community measures, grassland management practices will influence the resulting arthropod community and influence the success of grassland restoration using high‐diversity seed mixes. Results of our study promote the potential for successful restoration outcomes using high‐diversity seed mixes, and indicate that low‐diversity, non‐native seed mixes, such as DNC, do not fully restore native grassland arthropod communities.