The value of forests for supporting ground-dwelling predator communities in urban greenspaces

There is growing evidence that insect populations are declining globally due to chronic anthropogenic stressors including habitat loss and fragmentation. While conservation strategies often focus on local interventions to increase insect biodiversity, management approaches implemented at the landscape scale are required to support regional species pools. Community assembly is the process by which local communities are organized and maintained from the regional species pool. While urban landscapes strongly influence the assembly of insect communities in urban greenspaces, how the configuration and connectivity of natural habitat patches support source populations of insects is understudied. Remnant urban forest patches are being reexamined for their potential to support landscape-scale biodiversity and aid in achieving conservation goals, especially in legacy cities that have an overabundance of vacant land holdings. The objective of this study was to investigate the assembly of predator communities in greenspaces that vary in habitat design, management intensity, and landscape context in Cleveland, Ohio using a functional trait-based approach. Functional traits with a strong predictive capacity for ecological functions were measured on ground beetle species collected via pitfall traps in 2019 in four habitats: 1) vacant lots mown monthly; 2) urban pocket prairies seeded with wildflowers; 3) Metropark forests; and 5) Metropark old fields. Understanding how remnant patches of natural habitat such as forests support communities of beneficial insects in urban ecosystems will inform the implementation of conservation strategies at larger spatial scales.