There is increasing policy interest in valuing a broader range of ecosystem services in environmental management. Engagement of local people in ecosystem management is fundamental to making operational approaches viable. Development of decision support systems capable of operating in complex, data sparse non-linear multi-component systems is challenging. This thesis explores approaches for spatially explicit support of negotiation of land use change to manage ecosystem service provision across a range of ecosystem services. Initial research on the impacts of farmer interventions on ecosystem service provision in the Pontbren Catchment in mid Wales were used to identify operational requirements and knowledge gaps. Initial findings highlighted the importance of taking a spatially explicit approach and revealed significant gaps in data to inform decision making at local levels. Research revealed that local stakeholder's ecological knowledge suggested significant complementarities with scientific understanding of ecosystem function in the catchment that was useful for addressing data gaps and for validation of high resolution spatial datasets. Existing approaches for mapping ecosystem services were then reviewed to explore the extent to which they could be used to inform on the ground decision making. This revealed significant gaps in relation to mapping flows of ecosystem services and for informing decision making at finer scales. An iterative process was used to develop specifications for spatial tools
focused at field, farm and immediate landscape scales connecting field level
decisions about land use change (e.g. addition or removal of tree cover) with impacts on landscape scale processes (e.g. flood risk and habitat networks). The approach was then tested and adjusted following a scoping study in the Elwy catchment. The specifications resulted in Polyscape, a participatory methodology and geographic information system (GIS) mapping tool which integrates the knowledge of local and technical experts with readily available spatial environmental data to facilitate negotiation of land use change to manage ecosystem service provision. Polyscape offers a means for prioritising existing features and identification of opportunities for land use change to improve ecosystem service provision. It meets a key need for models and visualisations that it can be widely applied as it uses readily available data for parameterisation. Deficiencies in the data can be reduced by incorporating
local stakeholder knowledge (which, in tum, increases stakeholder participation in the negotiation process). The Polyscape approach was applied in the Cambrian
Mountains where output was evaluated by a range of local stakeholders (including farmers and ecologists). The feedback suggested that the approach delivered credible results at local landscape scales and provided a reasonable basis for the negotiation of ecosystem service provision. Requirements for implementing policy at local scales for effective ecosystem management were identified. Achieving this would require decentralised and integrated governance structures amongst agencies and training in participatory methodology. Polyscape provides a tangible framework for doing this.