Abstract
According to its principles and standards, organic farming particularly rely on natural processes and functional agro-biodiversity (FAB) to benefit from essential ecosystem services. However, these processes are mostly complex, hardly visible and site-specific, thereby making it difficult to assess and manage on-farm. A European survey has been carried out among organic farmers and emphasizes the variability among countries with a diversity of techniques targeting different functional groups according to farming contexts and farmers' expectations. The different criteria used by farmers to evaluate FAB-techniques efficiency and implementation potential clearly illustrate the difficulty to assess the agroecosystem as a whole.