Abstract
Environmental Impact Assessments (EIAs) that are applied in the planning phases of large land-use and construction projects are aimed at aiding decision-making and mitigating significant environmental impacts. In light of the global biodiversity crisis, conducting high-quality biodiversity impact assessments is important, as biodiversity information, among other factors, has the potential to influence how projects will be implemented in the end. We investigated the biodiversity and bird surveys conducted and the number of bird species of conservation concern in peat extraction and wind farm projects to which an EIA was applied to in 1995–2016 in Finland and compared whether these factors differed between the project types and between implemented and unimplemented projects. We also studied the availability of follow-up monitoring data of biodiversity impacts within the two project types. The number of nationally threatened breeding birds was significantly lower in implemented than in unimplemented peat extraction projects. The overall probability of being implemented was significantly negatively associated with the year the EIA began for both project types. All permitted peat extraction projects and 22% of wind farm projects conducted post-construction biodiversity monitoring; however, only some projects enabled before-after comparisons. Our results are in line with earlier findings that demonstrate the difficulty of showing the direct impacts of biodiversity information on EIA decision-making and to what extent it is related to project approval or rejection. The role of follow-up monitoring in the EIA and project development could also be strengthened.