Evaluating the impact of policy options on agricultural landscapes: An alternative-futures approach

Alternative-futures analysis was used to analyze different scenarios of future growth patterns and attendant resource allocations on the agricultural system of Oregon's Willamette River Basin. A stakeholder, group formulated three policy alternatives: a continuation of current trends, an increased reliance on market forces to determine land use,, and an increased emphasis on environmental restoration programs. To model the alternative scenarios first required the development of a spatial representation of the current agricultural system. Next, rules and constraints based on the three policy scenarios were formulated. Then a spatially explicit, multi-attribute, decision-making model was used to model changes in agricultural land cover and land use. This procedure generated three future landscapes, each depicting an alternative state of the agricultural system in the year 2050. Finally, the agronomic and environmental condition of each agricultural system was evaluated by using landscape metrics and screening models. The results show that the type and amount of farmland conversion were the scenario elements that most distinguished the future agricultural landscapes. By continuing current land use policies, nearly all of the existing farmland was conserved for future agricultural use, while both the market-driven and environmental restoration scenarios converted. 15% or more of the agricultural land to other uses. The use of farmland for vegetation restoration activities was particularly successful in improving riparian habitat, while habitat quality over the region showed widespread improvement. The patterns of crop selection in each future followed general trends, but with variations among scenarios as crop selection decisions adapted to changing field And basin conditions.