Research Scientist Helmholtz Centre for Environmental Research - UFZ, Germany
Background/Question/Methods Nature-based solutions (NBS) protect, manage, and restore environments in ways that promote both biodiversity and human wellbeing. NBS have come into focus as these are two important aims of urban research, planning, and policy. An important question is whether these aims form synergies or conflict with one another.
Controlled experiments show that different aspects of biodiversity (genetic, taxonomic, functional, phylogenetic, habitat) and species groups (rare vs. common, native vs. non-native, functional groups) can support ecosystem stability, productivity, and resilience, and thus should also support the provision of ecosystem services by NBS in the long term. These can assist with identifying key-contributors to NBS. For example, plant functional diversity supports water capture on green roofs. If correctly integrated into the urban fabric in terms of where, what, and how, NBS could also provide wildlife habitat and help cities achieve conservation targets.
Here we present the importance of biodiversity for NBS ecosystem service delivery and NBS for biodiversity conservation, highlighting two major components of urban NBS that gain in importance with changing climate: street trees and green roofs. We describe how biodiversity supports ecosystem stability, resilience, and multifunctionality, and what benefits there are using single vs. multiple species.
Results/Conclusions NBS have the potential to support both the delivery of ecosystem services and the conservation of biodiversity but there is no one-size-fits-all solution. We offer a ‘way forward’, recommending 1) NBS success results from local knowledge about setting and species, 2) that those aspects of biodiversity that are well studied and are best manageable (e.g., species richness, abundance, and traits) should be selected by practitioners, 3) that so far unexplored biodiversity-ecosystem service relationships require additional research attention, and 4) that communication and co-design involving various stakeholder groups will yield solutions broadly appreciated.
From our investigation we suggest that over short terms, at small spatial scales, and for single NBS, species exist that can provide maximum ecosystem service benefits on their own. An example are street trees used for the decontamination of polluted soils. However, for the provision of multiple ecosystem services, multifunctional NBS, and over long time periods, prioritizing biodiversity conservation is an indispensable strategy for the stability, resilience, and thus also productivity and efficiency of NBS.
