Functional Biodiversity in Organic Systems: The Way Forward?.

For consumers, one important motivation to buy organic food is the contribution to environmental protection, which includes conservation of biodiversity. Trends in EU agricultural policies recognize an increasingly important role to biodiversity conservation and use in agroecosystems, including non organic ones. Concurrently, the rise of organic farming poses a risk of ‘conventionalization’ of organic systems, i.e. the prevalence of an input substitution approach on a systems approach for crop management. Understanding the importance and potential of functional biodiversity may revert this trend and help strengthen the image of organic farming as a reference management system towards agricultural sustainability. Here functional biodiversity is defined as the diversity of any element at the gene, species or habitat level whose implementation improves provision of production-related agroecosystem services. Three categories of functional biodiversity and a four-step methodological approach to its study and management are presented along with some examples of application in organic arable and vegetable cropping systems stemming from research and monitoring projects carried out in Italy. These examples address genetic and species diversity in common wheat, genetic, species and management diversity in processing tomato, and habitat diversity in an arable crop rotation including cereals and pulses. The target agroecosystem services are crop production, weed reduction, soil fertility, produce quality and biological pest control. Results show that (i) it is possible to identify a ‘best’ functional biodiversity component to optimize provision of a target service but no generalization is possible; (ii) a given functional biodiversity component may create conflicts between different target agroecosystem services, thus in those cases prioritization of services is required.