A conceptual model of the social-ecological system of nature-based solutions in urban environments

Abstract

This article provides a perspective on nature-based solutions. First, the argument is developed that nature-based solutions integrate social and ecological systems. Then, theoretical considerations relating to relational values, multifunctionality, transdisciplinarity, and polycentric governance are briefly outlined. Finally, a conceptual model of the social-ecological system of nature-based solutions is synthesised and presented. This conceptual model comprehensively defines the social and ecological external and internal systems that make up nature-based solutions, and identifies theoretical considerations that need to be addressed at different stages of their planning and implementation The model bridges the normative gaps of existing nature-based solution frameworks and could be used for consistent, comprehensive, and transferable comparisons internationally. The theoretical considerations addressed in this article inform practitioners, policymakers, and researchers about the essential components of nature-based solutions. The conceptual model can facilitate the identification of social and ecological interconnections within nature-based solutions and the range of stakeholders and disciplines involved.

Keywords: Multifunctionality; Polycentric governance; Relational values; Sustainable urban planning; Transdisciplinarity.

Fig. 1

A conceptual model of the social–ecological system of nature-based solutions. This model can be used for conceptualising and for informing planning and implementing nature-based solutions at site level, at the neighbourhood scale, or at the municipal scale. The social–ecological system of a site (upper half of model, outer rectangle) comprises twelve external (A–L, squares) and twelve internal systems (a–l, squares). With regard to the site, external systems function slowly at large scales, and internal systems function fast at small, spatial, and temporal scales (upper and lower parts). Social external systems (A–F) are directly coupled (solid lines, tips on top left of squares) with social internal systems (a–f) of the site. Ecological external systems (G–L) are directly coupled (tips on top right of squares) with ecological internal systems (g–l) of the site. Dynamic and complex interactions, across spatial and temporal scales, indirectly couple (thin dashed lines) all social and ecological, external and internal, systems of the site. The social–ecological system of the site determines (light grey chevron, left) the planning and implementation of a nature-based solution (lower half of the model). The planning and implementation of a nature-based solution includes eight generalised stages (light grey boxes, left) each resulting in different design elements (dark grey boxes, right). Across stages, theoretical considerations emerge: relational values (RV), multifunctionality (MF), transdisciplinarity (TD), and polycentric governance (PG; black boxes, middle). Identifying, framing, and resolving these interrelated theoretical considerations inform (thin arrows, left to right) the design elements of a nature-based solution. Stages and associated design elements are successive (black solid arrow, left), but typically can also be repeated and reviewed for incorporating improvements (black dotted arrow, right). Through continuous iterative reviews, design elements ought to be (dark grey chevron, right) tailored to, and progressively covering the whole of, the social–ecological system of the site