Fig. 4: Performance summary of the different coastal defence options.

Panel a compares performance between soft, hybrid, and hard measures with natural measures. Panel b compares performance between soft, hybrid, and hard measures with unvegetated natural systems. Panel c compares performance of hybrid measures with soft and hard measures. Each arrow visually represents all observations elicited from the literature for a given comparison and function, and analysed in Fig. 1. The numbers in parentheses indicate the number of observations. The upward and downward direction of the arrow denote respectively higher and lower performance of the coastal defence option on the left of ‘vs.’ compared to the option on the right of ‘vs.’ Colours denote the range of effect size. Green: small effect (absolute value: 0–1), yellow: medium effect (absolute value: 1–3), orange: large effect (absolute value: 3–5), and red: very large effect (absolute value > 5). The above colours indicate that the respective 95% CIs do not intersect with zero. The white colour indicates there is no major difference between the two respective coastal defence options (i.e. the respective 95% CIs intersect with zero). The cross bar indicates no applicable data. Arrows indicated with ‘#’ denote aggregate functions with a small number of observations that require cautious interpretation and generalisation. Figure ideas are adapted from: Su, J., Friess, D. A. & Gasparatos, A. A meta-analysis of the ecological and economic outcomes of mangrove restoration. Nat. Commun. 12, (2021), which is licensed under a Creative Commons Attribution 4.0 International License: https://creativecommons.org/licenses/by/4.0/.