Designing a hedgerow network in a multifunctional agricultural landscape: Balancing trade-offs among ecological quality, landscape character and implementation costs

Spatial planning aimed at multifunctional agriculture can be seen as a negotiation process on environmental, social and economic aspects of land use. Complexity arises due to the high number of stakeholders and due to the limited knowledge, which is often organized along disciplinary divides. This paper sets out from the premise that the role of agronomy in such land use planning processes can be strengthened by approaches that allow multi-objective and multi-scale evaluation of spatially explicit land use alternatives. We present an application of the explorative Landscape IMAGES framework, which employs the Differential Evolution optimization strategy and the concepts of Pareto optimality that are relatively easy to implement and to combine with spatially explicit indicator assessments. This technique yields a set of solutions, each representing a spatial configuration of hedgerows in a landscape along with the performance of the landscape in terms of Pareto rank and efficiency. The methodology was applied in a redesign of the structure of linear landscape elements in an agri-ecological zone in The Netherlands where 7 indicators representing ecological quality, landscape character and implementation costs were considered. The case study was developed in interaction with an NGO involved in landscape management planning and implementation. Spatial cohesion in the landscape was found to increase with larger total hedgerow length, but could also be improved without increasing the total length (and therefore costs of establishment and maintenance). Trade-offs existed with other objectives, since this change would involve replacing hedgerows currently positioned in the longitudinal direction (L) of the fields by hedgerows in the transversal direction (T). This change would compromise cultural heritage value as expressed in the L/T ratio, and it would require removal of mature hedgerows in some places and adding of new hedgerows elsewhere in the landscape, thereby increasing implementation costs. The approach was evaluated positively in terms of design validity, output validity and end-user validity. The role of the Landscape IMAGES framework in setting a research agenda to enhance the role of agronomy in multifunctional land use planning is discussed.