Evaluation of wildlife management through organic farming

Organic farming has often been suggested as a way of increasing biodiversity in agricultural landscapes, but literature reports a variable success. The drivers in play are multi-factorial and include the particular species groups under consideration, the precise form of organic management, the landscape structural and management context, the area and scale considered, and the historical context. Here ALMaSS, a comprehensive agent-based model simulation system, was used to produce an assessment of the impact of organic and conventional farm types, landscape structure, and management context for six common agricultural wildlife species. ALMaSS outputs can be expressed as a simple index of relative change in abundance and distribution, allowing easy comparison between scenarios. Results indicate that organic farming generally had a beneficial effect, but the degree was variable with all factors considered and there were strong interactions between factors. Targeted managements provided much greater impacts than changes in farm types. Predictions of biodiversity impacts depended on precise inputs, underlying both the view of this system as being complex, and the necessity for detailed knowledge. However, this combination of detailed modelling platform with a simple index of impact provides an easily interpreted method for objective evaluation of impacts of potential policy scenarios. (C) 2011 Elsevier B.V. All rights reserved.