Pollinator visits increase with bloom amount but decline with building height on extensive green roofs

Abstract

Green roofs provide foraging and nesting resources for pollinators that would otherwise be absent. However, green roofs are isolated from ground level, limiting habitat to only species that can reach them. In Eastern North America, green roof design often prioritises water conservation and plant survival, and so species in the genera Sedum and Phedimus (hereafter, stonecrops) that are hardy and drought tolerant are mainly planted.