A step-by step approach to build-up land management scenarios based on multiple viewpoints on multi-agent system simulations

A multi-agent system was developed to simulate strategies of natural resources management in the remarkable site of the Causse Méjan, a limestone plateau dominated by a rare pseudo-steppe endangered by pine encroachment. To stimulate the emergence of alternative long-term management strategies of the sheep farms and of the woodlands, contrasting dynamic viewpoints on land resources were designed at different space scales. In a first step, they were individually used to validate the model with each main stakeholder (foresters, farmers and the National Park of Cévennes rangers), to improve it and to propose individual scenarios of natural resources management. Once the model adapted to these scenarios, the set of viewpoints permitted to assess the impact of these basic management strategies on the main productive (sheep stocking rate, timber growth) and environmental (endangered species, landscape value) stakes on any spatial entity considered as relevant by any stakeholder. As the different points of view were collectively viewed and confronted, the need to agree to a compromise raised up and lead to new scenarios based on a more collective management of the pine woodlands. The results of these alternative scenarios were newly collectively evaluated and permitted to select a set of feasible scenarios according to the current actors’ perceptions and practices and to suggest alternative sylvopastoral management based on innovative practices. The paper underlines the usefulness of viewpoints representations to allow for scenario description and impact assessment of the compared management strategies. It also points out how the step-by-step approach contributed to improve the decision making by the managers of the National Park.