In this paper, we summarize the published literature in the growing field of wild bee functional ecology and review which functional trait-based analyses have been carried out on wild bees in cities thus far, summarize which wild bee species traits have been considered and evaluate any consistent wild bee trait–environment relationships across studies.
„Wild bees in urban grasslands: Urbanisation, functional diversity and species traits“ has been published in Landscape and Urban Planning. We found that urbanisation was not related to neither taxonomic nor functional diversity in bee communities of urban grasslands. However, endangered bee species responded negatively to the isolation of grasslands but positively to flower coverage. Urbanisation, previous restoration efforts and site type filtered the functional composition of bee communities in terms of species traits related to diet and nesting. Our results substantiate the role of urban habitats for functionally diverse bee communities, including rare and endangered species, and indicate pathways towards enhancing habitat functions of urban grasslands for wild bees by improving the connectivity of urban grassland patches within the urban matrix, and more locally by adjusting management to maintain flower coverage in grasslands.
One of the main objectives of our project is to analyse interactions between honey bees and wild bees (and other wild pollinators) in urban habitats. Of particular interest is the question of whether there is food competition between honey and wild bees and which role environmental conditions – such as amount of flowering plants – play. We are currently conducting experiments to answer this question.
Implementing the Berlin Bee Strategy for conservation of bees and other pollinators in Berlin by optimising the protection of wild bees (funded bei Senatsverwaltung für Umwelt, Verkehr und Klimaschutz Berlin) – more info coming soon.
„Urbanisation modulates plant-pollinator interactions in invasive vs. native plant species“ has been published in Scientific Reports. The article is open access.
In this article, we show that invasive black locust (Robinia pseudoacacia) is a “pollinator-friendly” tree and attracts not only honey bees but also wild bees and other wild pollinators. However, we also found that attractiveness of black locust decreases with increasing urbanisation.
Recently, Märkische Entomologische Nachrichten has published two faunistic papers. The first one in on Carabid beetles (Coleoptera: Carabidae) of dry grasslands in Berlin (and Brandenburg). At 52 dry grassland sites in Berlin and Brandenburg we sampled 106 species including a new record for Berlin and numerous endangered species. The second one, Wild bees of dry grasslands in Berlin, summarises bee data from 49 dry grasslands in Berlin. Both papers highlight the importance of urban sites as secondary habitats for rare and endangered invertebrates.