Predation risk shaped by habitat and landscape complexity in urban environments

1. Habitat loss and modification are hallmarks of anthropogenic ecosystems, but the consequences for ecosystem functions and services often remain unclear. Understanding these links in cities is complicated by strong but fine-scale differences in habitat structure among green space patches, and a high variance in habitat amount across urban landscapes.
2. We used airborne laser scanning (ALS) data to disentangle the effects of 3D woody habitat heterogeneity of urban home gardens, and woody habitat amount at four landscape spatial scales (50, 100, 250, 500 m), on the predation risk of artificial sentinel prey by birds and arthropods.
3. In both predator groups, and at all the investigated spatial scales, cross-scale interactive effects between garden habitat heterogeneity and habitat amount in the urban landscape were the main drivers of predation. Risk of bird predation by birds was highest in heterogeneous garden habitats, but only in densely built urban landscapes where habitat amo...