Floral enhancement of turfgrass lawns benefits wild bees and honey bees (Apis mellifera)

Abstract

The turfgrass lawn is a common feature of urban and suburban communities, often accounting for the largest green spaces by area in these landscapes. Flowering species within turfgrass lawns have the potential to serve as a source of forage for bee pollinators in urban and suburban areas. We intentionally introduced low-growing flowers to turfgrass lawns to promote bee diversity and reduce inputs, while maintaining the traditional aesthetics and recreational uses associated with lawns. We compared bee communities on lawns with naturally-occurring blooms of Trifolium repens to bee communities on florally-enhanced lawns that contained Prunella vulgaris ssp. lanceolata and Thymus serpyllum in addition to T. repens. Trifolium repens provided forage for both wild bee communities and Apis mellifera, with A. mellifera being the most common of the 56 species of bees observed on T. repens. We found that florally-enhanced lawns supported more diverse bee communities than lawns with just T. repens. Furthermore, the bee communities supported by florally-enhanced lawns were significantly different from the bee communities supported by lawns containing just T. repens based on presence-absence data (Jaccard’s dissimilarity index). Our research indicates that A. mellifera colonies and wild bee communities can be supported by allowing T. repens to bloom in turfgrass lawns, and that land managers can support more diverse bee communities by intentionally introducing low-growing species of flowers to lawns.