Pollinators are an integral component of many food production systems and ecosystems. Urbanization is a factor contributing to the loss of abundance and diversity of many pollinators through habitat fragmentation, degradation, and destruction. Additionally, the phenological gap between some plants and pollinators is also adding to their decline. Green infrastructure, such as green roofs, provide opportunities for pollinator conservation in urban ecosystems by providing habitat and connecting existing habitat. This presentation investigates the quality, quantity, and temporal availability of pollinator forage opportunities provided by green roofs. The study presented utilizes an independent block design to compare floral phenology, abundance, and nectar quality of green roof plants to replicates of the same grown in a garden analog at grade on the Front Range in Fort Collins, Colorado. We have found floral abundance between green roof replicates and replicates grown at grade to be variable, depending on the plant species. However, all species of plants tested bloomed earlier when grown on the green roof than when grown at grade. These findings have implications for addressing the phenological mismatch between plants and pollinators by leveraging the earlier bloom time of plants grown on green roofs while also addressing some of the negative consequences of urbanization on habitat for pollinators.
