Trade-offs and synergies in urban green infrastructure: A systematic review

The incorporation of green infrastructure (GI) into urban systems has emerged as an important climate change mitigation and adaptation strategy. The rationale for incorporating GI is based on the premise that ecosystem services (ESs) supplied by GI significantly improve the liveability and resilience of urban systems to natural hazards. However, research has also highlighted the presence of ecosystem disservices (EDs) associated with GI. To optimise the delivery of ESs outcomes, research has sought to explore the interrelations between ESs and EDs supplied by GI through a better understanding of trade-offs and synergies. This paper presents a review of 96 case studies globally of the interrelations between ESs and EDs provided by GI in urban areas. The results show that relationships between ESs and EDs are variable and highly context-dependent in relation to the characteristics of GI components, biophysical conditions, and the perceptions of local stakeholders. The conventional approach of bundling ESs to analyse correlations between them does not adequately capture these complex relationships, making it difficult to predict optimal outcomes for GI investment. We suggest that analysing the functional traits of GI is a more effective approach to explore the causation of trade-offs and synergies. This would provide a more robust and nuanced understanding of the dynamic relationships between ESs and EDs and facilitate GI parameterisation for optimising benefits. Policymakers and planners could integrate this biophysical assessment with socioeconomic information in guiding GI planning to provide the most effective ESs outcomes while minimising EDs.