Vacant land has become abundant in cities throughout the Midwestern United States as a result of protracted economic decline and population loss. This form of greenspace contains weedy early successional plant species that are maintained with monthly mowing. Pocket prairies are an alternative habitat management strategy where vacant land is seeded with native wildflowers and mowed annually. These greenspaces represent viable conservation spaces for insects such as beetles that contribute to essential ecosystem services including pest suppression, decomposition, and nutrient cycling. However, the inherent heterogeneity of cities poses challenges for beetle dispersal from source populations, while the urban environment may constrain establishment. The objective of this study was to investigate the constraints to ground-dwelling beetle community assembly in vacant lots and pocket prairies of Cleveland, Ohio using a functional trait-based approach. Functional traits with a strong predictive capacity for ecological functions were measured on beetle species collected via pitfall traps.
Results/Conclusions
Assembly of ground-dwelling beetle communities was primarily constrained by dispersal limitations to colonization. Over 90% of species found within vacant lot and prairie treatments were capable of flight, and functional beta-diversity of beetle communities was higher across all treatments than expected by chance. Once beetles colonized, successful establishment was influenced by heavy metal contamination and mowing frequency, with these disturbances shaping communities based on body size, antennae length, and origin. Colonization of dispersal limited species such as ground-dwelling beetles could be facilitated by increasing connectivity between greenspaces in cities, while establishment could be enhanced by managing local environmental conditions. Understanding how insect communities are structured in urban landscapes will provide context for observed patterns in biodiversity, advance conservation efforts, and foster essential ecosystem services.