Pollinators in Urban Landscapes : Local and landscape factors impact on pollinator species richness and abundance

Abstract: Increasing human populations results in fast-growing urbanization. Natural and semi-natural landscapes are replaced with urban landscape features like roads, sidewalks, industrial and residential buildings. The remnants of the natural landscapes are left fragmented and are often managed by frequent mowing and trimming of the vegetation. This development has had a negative impact on pollinators such as bees and wasps. Bees and wasps are pollinating insects providing an ecosystem service that sustain the global food supply. Pollinators are important also in urban landscapes where their services are needed for ecological stability and biodiversity. This study compares 23 locations in Sollentuna municipality, to investigate if species richness and abundance of bees and wasps are correlated with local factors, landscape factors or both. The available food resources are measured in buffer zones with 200m radius. Local variables are: dead wood, exposed sand, extended edge zones, flowering plant species richness and unmanaged habitat. The result showed that the landscape factor of food availability was more important for the abundance of pollinators while local variables together with the landscape factor of food availability had a positive effect on the species richness.