Meta-analysis reveals the effectiveness and best practices for the iconic Mediterranean seagrass restoration

Seagrass forest restoration programs have become a global priority to reverse their decline and regain the ecosystem services they provide. However, defining the restoration outcomes has remained controversial, probably due to the wide portfolio of practices experienced mainly on short-term periods and local scales. Scientific literature from 40 years of experience on experimental efforts and active restoration interventions of the Mediterranean foundation seagrass Posidonia oceanica has been systematically summarized through a meta-analysis. Variables concerning the characteristics of the site selection, procedural context, and plant performance evidenced the best practices for the seagrass restoration. Here, the dataset pf the collated evidence is provided.

Methods
The file contains all the information extracted from the literature searching process conducted to consider peer-reviewed literature, conference proceedings and patents published with no temporal scale or language restriction and a final search date on the 24th of January 2024. Selection criteria included all studies that reported on a receiving site in which human-mediated actions were performed to re-habilitate, re-create or enhance recovery of a degraded or changed P. oceanica habitat type, where response variables were quantitatively expressed as a measure of transplanting intervention outcome. Only those studies in which the transplanted P. oceanica plants could be compared with a control group, (i.e., an untreated reference meadow and initial restoration time) were selected. Secondary documents such as reviews, studies on restoration technique insight, mesocosm experiments, or documents with insufficient data were excluded. Moreover, studies that did not report the mean values of measured response variables, the number of replicates per treatment, or the measures of variability around the mean, were necessarily excluded from the analysis. The suitable records were included for the data extraction and analysis, and when a document contained more than one type of information, each one was divided into different case studies.