Wetlands as large-scale nature-based solutions: Status and challenges for research, engineering and management

TLDR

Wetlands provide diverse social, economic, and environmental services, yet land‑use, water‑use, and climate changes that affect them operate at landscape scales beyond individual sites, while engineering and management decisions typically focus on local wetland projects. The study systematically examines how research has addressed large‑scale wetlandscape dynamics and proposes ways to reconcile the mismatch between large‑scale changes and the local scale of observations and implementation. We systematically review existing research on wetlandscape dynamics across multiple wetlands to assess their relevance for regional to global change impacts. Evidence indicates that aggregated effects of multiple wetlands differ markedly from individual wetland functions, largely driven by parallel and circular flow‑paths, and that bridging the scale mismatch can improve predictability and management.

Abstract

Wetlands are often considered as nature-based solutions that can provide a multitude of services of great social, economic and environmental value to humankind. Changes in land-use, water-use and climate can all impact wetland functions and services. These changes occur at scales extending well beyond the local scale of an individual wetland. However, in practical applications, engineering and management decisions usually focus on individual wetland projects and local site conditions. Here, we systematically investigate if and to what extent research has addressed the large-scale dynamics of landscape systems with multiple wetlands, hereafter referred to as wetlandscapes, which are likely to be relevant for understanding impacts of regional to global change. Although knowledge in many cases is still limited, evidence suggests that the aggregated effects of multiple wetlands in the landscape can differ considerably from the functions observed at individual wetland scales. This applies to provisioning of ecosystem services such as coastal protection, biodiversity support, groundwater level and soil moisture regulation, flood regulation and contaminant retention. We show that parallel and circular flow-paths, through which wetlands are interconnected in the landscape, may largely control such scale-function differences. We suggest ways forward for addressing the mismatch between the scales at which changes take place and the scale at which observations and implementation are currently made. These suggestions can help bridge gaps between researchers and engineers, which is critical for improving wetland function-effect predictability and management.