NovaCity: Associated biodiversity of urban native and non-native trees

This project assesses whether native and non-native urban trees support similar levels of canopy-associated biodiversity. Focusing on three common urban tree genera (Acer, Fraxinus and Quercus), the study will compare microbial and insect communities associated with native and non-native congeneric tree species across five Swiss cities. Additionally, the project will evaluate Asian ash species as alternatives to European and North American ashes in urban areas, given increasing invasive threats, by assessing their associated biodiversity in botanical gardens. Biodiversity will be assessed using environmental DNA from rainwater passing through tree canopies, capturing DNA from organisms inhabiting aboveground tree compartments. Results will reveal whether non-native tree species support comparable biodiversity to native species in urban environments, thereby informing tree selection strategies. Ultimately, the project will contribute to resilient and functionally diverse urban forests.