Year: 2025
Type: article
Study designs: Systematic Review, Meta-Analysis
Abstract: Rewilding -- the large-scale restoration of self-regulating ecosystems through reintroduction of keystone species, removalof human interventions, and reconnection of landscape fragments -- has emerged as one of the most ambitious andscientifically contested approaches to ecological restoration. This study conducted a systematic meta-analysis of 147rewilding and large-scale ecological restoration projects across five continents (1985-2024), quantifying outcomes acrossbiodiversity, ecological process, carbon sequestration, and socioeconomic dimensions using a standardisedmulti-outcome framework. Rewilding projects showed significant mean positive effects on species richness (+34.7% +-8.4% relative to degraded reference sites), trophic chain length (+1.24 +- 0.38 trophic levels), ecosystem carbon stocks(+47.4% +- 12.4%), and visitor numbers (+284% +- 84%), but with substantial heterogeneity (I2 = 74.8%) explained byproject design factors. Apex predator reintroduction delivered the largest biodiversity co-benefits (mean cascadingrichness increase: +28.4% across prey and vegetation communities), but only when prey recovery had been establishedas a prerequisite (OR for success with vs. without prey recovery: 4.84, p < 0.001). Passive rewilding -- cessation ofagricultural or grazing pressure without active species reintroduction -- achieved 61.4% of the biodiversity gain of activerewilding at 12.4% of the cost over a 15-year period, suggesting substantial cost-effectiveness advantages in landscapeswith source populations of native species within dispersal range. Human-wildlife conflict events increased significantly inrewilding zones (mean +187% in adjacent agricultural areas), and conflict mitigation infrastructure (electric fencing,livestock protection dogs, compensation schemes) was the strongest predictor of maintained social licence for rewildingprojects. These results provide the first quantitative evidence synthesis on which to base evidence-informed rewildingprogramme design at the scale required by the EU Nature Restoration Law and GBF Targets 2 and 3
Authors: Elena Garcia, Marco Horvath, Daniel Petrov
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life on land
Open Access status: diamond
Funder: Agencia Estatal de Investigación
OpenAlex ID: W7203474080