Towards a common set of criteria and indicators to identify forest restoration priorities: An expert panel-based approach

Ecological restoration of forest ecosystems is increasingly being implemented in many parts of the world, as a response to widespread forest loss and degradation. In common with other conservation management interventions, restoration efforts should be directed towards areas where the maximum benefits are likely to be achieved. Such prioritisation requires the development of appropriate criteria and indicators (C&I), an issue poorly addressed by previous research. In particular, there is need for C&I that are operational, suitable for spatial analysis and mapping and applicable to a broad range of contexts. This investigation aimed to verify whether this might be achieved through the elicitation of experts’ opinion, when considering biodiversity conservation as the main objective of restoration. A Delphi process was performed, aimed at defining the key ecological criteria and a broad set of indicators. 389 criteria and 669 related indicators were provided in total and grouped into clusters relating to individual criteria. A total of 20 criteria referred to the need for restoration and 18 to its feasibility. In the second round of the Delphi process, 8 definitive criteria were identified along with some 90 related indicators. Finally, a face-to-face meeting was conducted to show how ready-to-use C&I can be obtained for application to a specific context starting from the Delphi's results. The study highlights the potential value of combining the Delphi process and face-to-face meetings for identifying practically applicable C&I for planning ecological restoration. However, the diversity of views identified within a single group of stakeholders suggests that the development of a generally applicable set of C&I for forest restoration will be difficult to achieve in practice.