This report provides a synthesis of argumentation analysis in real-world cases in “multi-level biodiversity governance”, investigated within the BESAFE project. The following broad research questions guided the synthesis of argumentation analysis in the case studies: • Which (different types of) arguments can be identified at different levels and units of biodiversity governance? • How are these arguments exchanged and put to work in multi-level and networked interactions (i.e. within and across different levels and units of biodiversity governance)? • How are these arguments rooted in and how do they feed into different perspectives, worldviews and functioning of social groups or institutions at the different levels and units of biodiversity governance? The study’s approach to answering these questions is guided by a three layer analytical framework. This framework comprises three different perspectives to argument-making practice. Together these enable a comprehensive understanding of the role of argumentation in multi-level biodiversity governance. The first layer takes the perspective that arguments are “products” of communication. The analysis focuses on the verbal content of arguments, i.e. what these arguments “say”. By comparing argument contents between global, European, national, regional and local governance levels, it was revealed that at both global and regional level, social arguments were most dominant, while at the European level economic arguments were more prominent. Comparison between European and national governance levels revealed little differences. Comparison between types of actors showed some differences of emphasis. Whereas most actors use the argument that biodiversity should be protected because of its inherent value, regional authorities more often referred to social wellbeing and national authorities to legal obligation. The analysis also considered variety of arguments. In general, variety was very limited. Politicians used the smallest variety of arguments, while the largest variety was found in the science actors. Furthermore, variety depended on communication channels (e.g. internet forums showed much variety). Lastly, arguments do change over time. Arguments on ecosystem services, for instance, became prominent at both global and European levels, but they often do not reach or persist at local levels of governance. The second layer of the framework uses the perspective of arguments being transactions between arguers and audiences. The focus here is on what actors “do” D3.1 Final report synthesising the analysis of argumentation in multi-level governance interactions in case studies 5 with arguments, that is, what they aim to achieve with the arguments and what strategies they use. Plenty of strategies were identified, such as particularisation (e.g. stressing the uniqueness of a natural area to increase policy attention), up-scaling (e.g. situating a biodiversity problem at a higher level of space or time to make it more important), dichotomisation (e.g. polarising between two alternatives to exclude the possibility of an intermediate solution) and aligning arguments to the goals and interests of others to affect policy outcomes in a way that suits own interests. Finally, actors used various channels to transmit argument. Main examples were local politicians, NGOs and mass media. The third layer takes the perspective of arguments as being conditioned by the social-institutional networks in which they are transmitted. The analysis focuses on how the arguments and the reasoning they communicate “fit” into the different perspectives, worldviews and functioning of social groups and institutions. It was shown that argumentation was highly conditioned by law and regulations, institutional roles and established practices. International obligation, in particular, empowered member states to implement biodiversity policy and to finish disputes. But legislation (and uncertainty about it) also hampered conservation efforts. Furthermore, established criteria used in conservation practice (e.g. rarity, threat and species richness) supported justification of the need for implementing biodiversity conservation measures. Finally, what actors considered as their interests and what they valued as a legitimate policy process (democratic, science-based and sufficient societal support) conditioned the argumentation.