Ecological surveys have historically focused on species abundance and diversity assessments to determine the biological relevance of a habitat. However, these indices do not explain how managed habitat design structures wildlife assemblages. Our goal was to determine how the conversion of vacant lots into other forms of urban greenspaces influenced beetle communities. With a focus on Carabidae and Staphylinidae, we aimed to test the hypothesis that variation in both taxonomic composition and functional trait variables results from variation in greenspace design and management as well as surrounding landscape context. We sampled beetles from eight vacant lots, eight community farms, and seven urban prairies in Cleveland, Ohio. Pitfall traps were deployed for seven consecutive days monthly in June-August in 2011 and 2012. Carabidae was identified to species, whereas Staphylinidae was identified to genus. We used linear models to analyze richness, abundance, and seven different carabid species traits. To determine whether beetle assemblages differ among habitat types, we performed an ANOSIM test. We also evaluated six CCA models using ANOVA to examine if local and landscape variables influence beetle species composition.
We collected 1,813 beetles from 23 sites in 2011 and 2012 belonging to 87 beetle taxa. We found that Carabidae abundance was higher in prairies, while richness was higher in farms and prairies. For Staphylinidae, both abundance and richness were highest in farms. Additionally, we found variation in carabid functional traits among greenspaces; a higher abundance and richness of xerophilous species and those associated with open habitats were found in farms, whereas hygrophilous and shade-tolerant species were most common in urban prairies. We also found that short-winged (brachypterous) beetle abundance and richness were highest in prairies; this illustrates that prairies are likely supporting wingless species throughout their development and reproduction as they exhibit a low capacity for dispersal. Interestingly, winged species (macropterous) richness was higher farms wherein frequent disturbance could require frequent recolonization from surrounding patches. This demonstrates that analyzing species traits reveals distribution patterns among beetle communities that diversity cannot discern. Ordination analysis revealed that local habitat structure and landscape variables impact beetle communities, thus both are important to achieve conservation goals. Based on these results, we find that urban greenspace design plays a critical role in shaping arthropod biodiversity in cities, and maintaining habitats that vary in design and management is important for conservation.