Restoration tools and strategies for afforested Mediterranean coastal grasslands: is eucalypt removal alone enough to kickstart ecosystem recovery?

Introduction Afforestation with non‐native trees has profoundly altered coastal dune grasslands worldwide, creating persistent ecological legacies that constrain ecosystem recovery. Objectives We evaluated the cost‐effectiveness of two restoration approaches, distinguished by their respective demands for resource investment: Moderately Assisted Recovery (MAR: non‐native tree removal only) and Intensively Assisted Recovery (IAR: tree and litter removal with a front‐end loader plus manual seeding of native species). Methods The experiment comprised 10 blocks with afforested controls, coastal grassland references, MAR, and IAR plots, monitored annually for 3 years across vascular plants, arthropods, and lizards, representing multiple trophic and functional groups. Results Across 21 variables modeled, IAR aligned with coastal‐grassland reference, while MAR aligned mostly with afforested plots. MAR reduced plantation‐associated species and supported higher richness of annual herbs (compared to afforested plots), whereas IAR further promoted psammophile and endemic plants, annual and perennial herbs, and open‐habitat arthropods. Arthropod abundance increased under both treatments, but richness converged toward reference conditions only with IAR treatment. Lizard responses to restoration treatments were species‐specific, driven by opposing responses of psammophile and litter‐dwelling species. Conclusion Our results demonstrate that only IAR effectively reset abiotic and biotic processes and initiated a trajectory closer to reference coastal grasslands. MAR plots appeared to remain “locked” in afforestation legacies, with dense perennial cover and litter‐dependent taxa. MAR and IAR did not represent different rates of recovery along a single continuum, but rather distinct ecological pathways with contrasting implications and prospects for biodiversity persistence, ecosystem functioning, and resilience.