Cities are increasingly important areas for the preservation of biodiversity, ecological communities, and ecosystem services. At the same time, they place a unique combination of stressors on plants, animals, and the interactions between them. Bees comprise an invaluable pollinator group essential for both human food production and reproduction of wild or managed plant communities. While urbanization is predicted and, in some cases, demonstrated to negatively impact bee richness and diversity, these effects can be highly variable or even positive, likely due to differences such as bee functional traits or behavior. Similarly, pollination services and plant-pollinator networks may be impacted by urban stressors, however these relationships are even less understood.

On the other hand, urban areas often boast highly diverse and heterogeneous plant communities due to local management in areas like gardens, parks, or road margins. This management can provide floral resources across space and time that may mitigate negative impacts of urbanization or interact with urban stressors in their impacts on pollinators and pollination services.

Urban gardens create a unique framework in which to investigate these questions regarding plants, pollinators, local habitat management, and landscape-level characteristics across urban areas.

In the CityBees project, we work with urban community gardens across the cities of Munich and Berlin to understand how urbanization shapes bee and plant communities, their resilience, and the services they provide. We take a trait-based approach aimed at teasing apart (1) how two major urban environmental stressors, impervious surface and urban heat, impact inter- and intra-specific variation and interactions between bees and plants; (2) how these relationships influence associated functions in the pollination services provided to plants by bees, and provisioning resources provided to bees by plants; and (3) how landscape-scale stressors interact with local habitat and resource management in structuring these systems.

This research is a collaboration with the Professorship for Plant-Insect-Interactions (PI Prof. Sara Leonhardt) and is led by two PhD candidates, Alex Zink (UPE) and Gaya ten Kate (PII), as well as supported by technicians Agata Cybinska (UPE), Regina Hüttle (UPE) and Michael Miesl (UPE). The research also works closely with the BioDivHubs Project in Munich and the Museum für Naturkunde Berlin in Berlin.  

Partner

• Professorship for Plant-Insect Interactions (PI Prof. Sara Leonhardt)

Funding

DFG – Deutsche Forschungsgemeinschaft 

Timespan

10.2023 till 10.2026

Team and Contact

Alex Zink (PhD, TUM-UPE): alex.zink(at)tum.de

Gaya ten Kate (PhD, TUM-PII): gaya.ten.kate@tum.de 

Monika Egerer (PI, TUM-UPE): monika.egerer(at)tum.de