Identifying linkages between urban green infrastructure and ecosystem services using an expert opinion methodology

Abstract

Stormwater green infrastructure (GI) has the potential to provide ecosystem services (ES) that are currently lacking in many urban environments. Nevertheless, while stormwater GI presents a major opportunity for cities to enhance urban ES, there is insufficient evidence to link the complex social and ecological benefits of ES to different GI types for holistic urban planning. This study used an expert opinion methodology to identify linkages between 22 ES and 14 GI types within a New York City context. An analysis of results from five interdisciplinary workshops engaging 46 academic experts reveals that expert judgement of ES benefits is highest for larger green spaces, which are not universally considered for stormwater management, and lowest for vacant land and non-vegetated GI types. Overall, cultural services were identified as those most universally provided by GI. The results of this study highlight potential significant variations in ES benefits between different GI types, and indicate the importance of considering cultural services in future GI research and planning efforts. In the current absence of robust quantitive measurements linking ES and stormwater GI, increased qualitative insight could be obtained by expanding the methodology used in this work to include non-academic experts and other urban stakeholders. We therefore offer recommendations and learnings based on our experience with the approach.

Keywords: Co-benefits; Ecosystem services; Expert opinion; Green infrastructure; Holistic planning; Matrix model.

Fig. 1

Flowchart presenting phases of research methodology

Fig. 2

The examined categories of green infrastructure and their placement in the urban environment including vacant land, extensive green roofs, community gardens, street trees, bioswales and stormwater green streets, green facades and living walls, cisterns and rain barrels, rain gardens, intensive green roofs, vine canopies, permeable paving, parks, detention and retention ponds, and wetlands

Fig. 3

Box-plots of the AGEL scores for GI grouped into three functional categories: vegetated land (parks, wetlands, and community gardens), vegetated stormwater GI (intensive green roofs, extensive green roofs, bioswales and green streets, detention and retention ponds, and rain gardens), and non-vegetated stormwater GI (permeable paving, and cisterns and rain barrels). Within each type of ecosystem service (provisioning, regulating, supporting, and cultural), the statistical difference between GI categories, as determined using Mann–Whitney non-parametric U tests (p < 0.05), is annotated with letters (A, AB, B, C)

Fig. 4

Average Green Infrastructure Ecosystem Service Linkage (AGEL) for all services (A) Cultural Services (B) Regulating, Supporting, and Maintenance Services (C) and Provisioning Services (D); AS: Applied Sciences; NS: Natural Sciences; LPE = Law, Policy, Economics, SS: Social Sciences; PH: Public Health