Organic and low-input farming practices are considered keystones for the conservation of biodiversity in semi-natural systems. Accordingly, attention to the assessment of the benefits stemming from these activities is increasing in order to provide a solid base for the adoption of agro-environmental incentives and to support their monitoring and evaluation. The evaluation of the positive effects of organic and low-input farming activities on biodiversity is limited mainly by the difficulty in proposing simple and widely-applicable indicators of biodiversity, and the substantial lack of data concerning the costs of measuring biodiversity an essential element for the cost-effectiveness analysis of indicators. Moreover, the limited scientific ...