Environmental scenarios for ApisRAM version 3, a honey bee colony model for pesticides risk assessment

Environmental scenarios were established for ApisRAM, a honey bee colony model currently under implementation towards version 3, i.e. for its regulatory use in the risk assessment of pesticides. These scenarios need to represent the diversity of European environments in terms of risks for honey bees, addressing the regulatory question as outlined in the problem formulation (i.e., the risk characterisation for bees following individual pesticide uses) and taking account of the specific protection goals as defined by EFSA for honey bees. The scenarios are composed of a baseline scenario, defining the ecological quality, and the case scenarios, where pesticide application related aspects as defined in the GAP are given. The ecological quality is defined in typical “landscape windows” and classified along two dimensions, i.e. the floral resource diversity, as a proxy for the number of floral plant species, and the floral resource quality, as a proxy for the amount of nectar, sugar, and pollen produced by the respective plants. The scenario definition is closely related to ALMaSS, a dynamic landscape model and the platform on which ApisRAM runs, that is operating on landscape windows of 10x10 km with information on weather, crop and non-crop phenology, land use and landscape structure. Based on landscape information, three levels (low, medium, high) each of floral resource diversity and quality are defined, resulting in a factorial design of 9 baseline scenarios in 3 scenario groups (most, moderately and least favourable). For the assessment of risks, the use of a “risk matrix” is suggested, where for each of the 3 scenario groups, and for a given GAP, the respective case scenario will be evaluated. Further, by using exposure modification factors, the margins of safety can be determined. In conclusion, potential applications of those environmental scenarios in a broader context are suggested along with some specific recommendations.