Participatory modelling of social and ecological dynamics in mountain landscapes subjected to spontaneous ash reforestation

Abstract

The future of the agriculture in mountain areas constitutes an important stake for sustainable development in relation to landscape functions and their role in local economies. This future depends highly on its ability to develop innovative and multifunctional agricultural systems and to preserve its attractiveness for future generations. Encroachment and reforestation of landscapes, which comes from land abandonment and extensification of land use, raise important topical issues. In Pyrenean valleys, where the land is colonised by the ash tree (Fraxinus excelsior), local land managers and policy-makers want to understand better the relationships between the ecological and social processes in order to assist in the design of policies supporting constructive change. Here we present the “companion modelling” approach in which we are all together constructing a simulation model for carrying out a prospective study of land use and landscape changes in the region. According to the principles of this participatory approach, we started developing a spatialised multi-agent model, whose main conceptual aspects are presented here below. The model simulates the evolution of land cover of the agricultural landscape in relation to both the natural and anthropogenic dynamics. Ecological field studies having stressed the role of mowing and grazing practices at the parcel level on colonisation of the local landscape by the ash tree, we focus on the account of prospective change in farmers’ land management practices (viewed as a set of decision rules) and their impact. This ongoing study underlines the interest of spatially explicit modelling of the inter-relationships between social and ecological dynamics at the agricultural landscape scale based on an interdisciplinary approach for dealing with rural development topical issues. Both the advantages gained and the difficulties raised are discussed.