Our capacity to effectively sustain biodiversity across spatial and temporal scales is an essential component of European environmental sustainability. Anthropogenic and environmental pressures on biodiversity act differently at different scales. Consequently, effective conservation responses to these threats must explicitly consider the scale at which effects occur, and therefore it is crucial that administrative levels and planning scales match the relevant biological scales. The SCALES project will provide the scientific and policy research needed to guide scale-dependent management actions. It will assess and model the scaling properties of natural and anthropogenic processes and the resulting scale-dependencies of the impacts of these pressures on various levels of biodiversity from genes to ecosystem functions. To facilitate these assessment methods for upscaling and downscaling biodiversity data will be reviewed and improved. SCALES will further evaluate the effectiveness of management and policy responses to biodiversity loss in terms of their scale-relevance and will develop new tools for matching their scales to relevant biological scales. Finally, a resulting methodological and policy framework for enhancing the effectiveness of European biodiversity conservation across scales will be developed and tested. This framework focuses on networks of protected areas and regional connectivity. This framework will be disseminated to a wide range of relevant users via a web based support tool kit (SCALE-TOOL) and by means of further dissemination channels, such as conferences, publications, and the mass media.