The effort was coordinated by the Spanish National Research Council (CSIC) within the SUPERB project, an EU-funded consortium dedicated to upscaling ecosystem restoration for forest-related biodiversity and ecosystem services. Key contributions came from the Austrian Federal Forestry Research Centre (BFW) and the Forest Science and Technology Centre of Catalonia (CTFC), while the questionnaire itself was scrutinised through multiple rounds of expert review by partners including the European Forest Institute, the Swiss Federal Research Institute WSL, Wageningen University & Research, the University of Freiburg, the University of Copenhagen, the Swedish University of Agricultural Sciences and ETH Zürich. That collaborative design was deliberate: ecological restoration is not merely a biological exercise but a socio-ecological process in which ecological recovery, stakeholder livelihoods and governance frameworks interact in complex feedback loops. A database that captured only one dimension would miss the forces that most often determine whether a project endures.

The final questionnaire comprised 112 questions organised into thematic blocks covering general project characteristics such as geographic scope, duration and funding sources; the ecological approaches applied, including techniques and target species; socio-economic and governance dimensions such as stakeholder engagement and policy frameworks; and, crucially, a set of standardised success indicators for quantifying outcomes. Forty-five indicators were integrated in total, split between 35 project-specific quantitative measures and 10 broader evaluation criteria aligned with the Society for Ecological Restoration’s Primer, a widely recognised framework for assessing ecological integrity and sustainability. The project-specific indicators were selected through a systematic literature review: for each potential restoration objective, the team identified the measures most frequently used in published studies and those easiest to generalise across contexts. Examples include the abundance or density of target species, regeneration cover where the aim is to promote tree or plant regrowth, and the number of habitat connections, average patch size and number of patch types where the goal is landscape connectivity.

To keep respondents engaged without sacrificing data quality, the survey employed adaptive question logic. The sequence and depth of questions adjusted dynamically to each respondent’s profile, whether practitioner, policy-maker or researcher; to the implementation stage of the project, whether planned, ongoing or completed; and to the restoration type and objectives. This meant the effective questionnaire length ranged from 50 to 88 questions while preserving internal coherence. The survey ran on a multilingual online platform in English, Spanish, German, Polish, Italian and French from April 2023 to December 2024. Recruitment was aggressive and multi-channel: more than 1,500 personalised email invitations, presentations at international and national congresses in Spain, Sweden, Portugal and Estonia, and on-site workshops in Spain and Italy where practitioners and landowners filled in questions together. Recognising the length of the instrument, the team allowed partial completion, retaining surveys that answered only the questions respondents deemed relevant.

The resulting database, published in OpenDocument Database format and openable with free software such as LibreOffice Base, contains responses from 404 participants. Because of the adaptive logic and partial completions, coverage varies by topic: 404 entries record general participant information, 227 document implemented restoration actions and 209 capture restoration objectives. Each respondent could describe one or more restoration projects, potentially spanning several countries. Structurally, the database is organised into 57 interconnected tables that can be cross-referenced through a unique identifier assigned to each respondent. A systematic codification scheme classifies the tables into three types: a master explanation table describing the entire structure, descriptor tables that decode coded variables, and the survey data tables themselves, each field linked back to the specific questionnaire item that generated it. Supplementary materials provide the complete questionnaire and a field-by-field guide, making the resource genuinely reusable rather than a black box.

What makes this dataset scientifically valuable is precisely what makes it unusual: it captures the reported causes of success and failure as seen from the ground, alongside the diverse perspectives associated with respondents’ different roles in restoration. Early analysis, published separately by the same team, has already yielded striking findings. The most frequent initiatives across Europe were those aimed at increasing species populations or expanding their distribution ranges, whereas projects targeting landscape connectivity or contributions to human well-being, both explicitly promoted in the EU Biodiversity Strategy for 2030, and the provision of non-timber forest products, highlighted in the EU Forest Strategy, were scarcely represented. That imbalance suggests current restoration practice is drifting away from several policy priorities, a mismatch the database can now help quantify and correct.

The study also arrives at a moment when Europe’s restoration data infrastructure is maturing rapidly. Platforms such as Restor, an open-access geospatial service integrating satellite imagery and biophysical layers; the IUCN Restoration Barometer, which standardises national reporting on governance, investments and socioecological outcomes; and the FAO’s Framework for Ecosystem Restoration Monitoring, which defines official indicators for the UN Decade on Ecosystem Restoration, have collectively improved transparency and consistency across scales. The new survey database complements these tools from a different angle: rather than remote sensing or top-down reporting, it records the practitioner knowledge, stakeholder perceptions and implementation constraints that satellite pixels cannot see. It sits alongside national strategies such as Germany’s Blaues Band Deutschland for waterway connectivity, Spain’s green infrastructure strategy and France’s Trame Verte et Bleue, offering a pan-European lens on how those frameworks play out in practice.

The urgency of the task is hard to overstate. According to the European Environment Agency, 85 percent of forest habitats and species in the EU are assessed as having an unfavourable conservation status, despite decades of policy layering from the Nature Directives, the Water Framework Directive and the Common Agricultural Policy. Long-term effectiveness remains poorly documented, particularly for ecosystem service provision, and the EU’s new regulation explicitly demands monitoring strategies spanning decades. Interventions driven by political and financial constraints, without evidence of what works in comparable contexts, risk being inadequate or insufficient to achieve durable outcomes. A structured record of 404 real projects, with their funding sources, techniques, governance arrangements and measured indicators, is exactly the kind of evidence base that can separate effective investment from well-intentioned failure.

The re-use potential extends well beyond the analyses already conducted. Future studies could examine how perceptions differ across stakeholder groups or geographical regions; investigate the determinants of restoration success or failure; or test whether stakeholder participation and perceived success vary according to the objectives pursued. The authors suggest the dataset offers a preliminary basis for developing standardised, broadly applicable indicators for future restoration efforts, improving the assessment, comparability and synthesis of outcomes across the continent. For researchers, policy-makers and the practitioners whose knowledge it preserves, the database transforms scattered, anecdotal restoration wisdom into a queryable European resource, one that arrives just as legally binding restoration targets make every lesson learned a matter of policy consequence.

Subject of Research: A survey-based database of European ecological restoration initiatives compiled from 404 stakeholder responses

Article Title: Restoration information: A European database of ecological restoration knowledge from stakeholder surveys

Article References: Rubio-Cuadrado, Á., Menéndez-Miguélez, M., Cañellas, I., de-Miguel, S., Erdozain, M., Hoffmann, J., Lapin, K., Werden, L. K., & Alberdi, I. (2026). Restoration information: A European database of ecological restoration knowledge from stakeholder surveys. One Ecosystem, 11, Article e161148. https://doi.org/10.3897/oneeco.11.e161148

Image Credits: AI Generated

DOI: 10.3897/oneeco.11.e161148

Keywords: ecological restoration, database, stakeholder surveys, EU Nature Restoration Regulation, biodiversity, ecosystem services, forest habitats, governance, success indicators, SUPERB project, One Ecosystem, Europe