Organic and low-input farming systems have been shown to benefit farmland biodiversity although a generic indicator system to assess these benefits at the European level is lacking. The BIOBIO project will therefore pursue the following objectives: 1. Conceptualization of criteria for a scientifically-based selection of biodiversity indicators for organic/low-input farming systems; 2. Assessment and validation of a set of candidate biodiversity indicators in representative case studies across Europe (and in ICPC countries); 3. Preparation of guidelines for the implementation of biodiversity indicators for organic/low-input farming systems for Europe and beyond. Existing indirect farm management indicators as well as direct indicators for genetic, species and habitat diversity will be assessed for their scientific soundness, practicality, geographic scope and usefulness for stakeholders. Candidate indicators will be tested in a standardised design in twelve case studies across Europe and later in three ICPC countries. Case study regions will include pannonian, alpine, boreal, Atlantic and Mediterranean grassland systems (both organic and/or low-input), rain fed organic farms under temperate and Mediterranean conditions, mixed organic farming, organic special crops and low-input tree/agroforestry systems. Plot, farm and regional scales (where applicable) will be addressed. The investigation will include new agricultural practices, e.g. soil conservation, crop rotation management, seed and crop mixtures and economic issues relating to the costs of indicator measurement and to benefits of biodiversity as perceived by different groups of the population. Stakeholders (farming communities, conservation NGOs, administrators) will be integrated at critical stages of the indicator selection process. A handbook with factsheets will be produced for validated indicators and a sampling design for biodiversity monitoring in organic and low-input farming systems across Europe.