Floral richness and seasonality influences bee and non-bee flower interactions in urban community gardens

Abstract Pollinating insects are essential for food production. Both bee and non-bee pollinators undergoing dramatic declines due to land use intensification its consequences on native ecosystems. While interactions between crops well studied, our understanding of the pollination service provided by flower visitors including flies, ants, beetles others is still limited. Moreover, effects landscape urbanization changes in floral nesting resource availability network structure with both cultivated wild plants have been poorly studied. We assessed which common visitor groups dominate (e.g. Trifolium pratense , Taraxacum officinales ) Fragaria ananassa Cucurbita pepo urban community gardens Berlin Munich explored how these change over growing season. further investigated effect surrounding gardens, resources within complexity (i.e. nestedness, linkage density, connectance) interaction networks. observed 20 focal plant species 13 30 gardens. found that dominant changed season, ants flies as early season visitors, important later Nestedness increased increases richness while neither abundance nor impervious surface garden size or strongly influenced Our findings suggest high may ensure and, thus, stability Findings role should be considered provision especially shoulder seasons. Finally, results emphasize gardeners play a key mediating through their gardening practices.