Promoting biodiversity in urban green spaces: Recent hurdles and opportunities identified in the Ruhr Area

Urban green spaces (UGS) provide crucial benefits for urban climate regulation, human well-being, and biodiversity conservation. However, actively promoting urban biodiversity and associated ecosystem services faces multiple challenges, including habitat loss due to densification, limited implementation, and competing land-use demands. While ecologically designed UGS better support species diversity than classical ornamental UGS, they often conflict with societal expectations for appearance, order, safety, and usability and may require additional management costs. This perspective paper synthesizes insights from a stakeholder workshop held in the highly urbanized Ruhr region in Germany, where 16 experts from city administrations, green space management, regional planning, research, and conservation practice discussed current hurdles and opportunities for urban biodiversity in public UGS. Participants identified and discussed four key hurdles, each aligned with a corresponding opportunity to improve the shortcoming: (1) high costs and legal constraints for disposing or using grass cuttings, addressed through municipal cooperation for biomass management and urban grazing initiatives; (2) low staff engagement for implementing rather “modern” biodiversity-oriented management, mitigated by targeted training and public engagement, (3) the public favoring highly maintained UGS, countered by promoting broader acceptance of “wilder” or “untidy” UGS through public participation and co-design activities, and (4) pressures from urban densification and competing land uses, addressed via strategic safeguarding of brownfields and other open spaces, better integration of compensatory measures into urban planning, and creation of multifunctional, climate-adaptive habitats. We conclude that addressing these hurdles to promote urban biodiversity in metropolitan regions requires integrating ecological, social, political, and operational considerations. Capturing practitioner perspectives via collaborative workshops therefore provides actionable recommendations for designing, managing, and communicating UGS strategies that enhance biodiversity while addressing societal and governance hurdles, offering guidance for cities around the globe to reconcile conservation goals with urban development pressures.