New perspectives for spatial planning in Switzerland: the role of ecosystem services

Spatial planning deals with the spatial expression of human activities in an integrated way to minimize their negative impacts on the natural and land systems. Rapid land use and land cover changes are important drivers of change of the benefits people derive from biodiversity and ecosystem functions, known as ecosystem services (ES). The concept of ES has the potential to frame the systematic integration of a comprehensive ecological understanding in spatial planning. In Switzerland, ES may have been affected to different degrees by past and current land management strategies. Better integration of ES into spatial planning requires an understanding of: (i) the relationships between land management strategies and the supply of ES, (ii) the degree of uptake of the ES concept in current planning documents, (iii) the spatio-temporal patterns of ES supply and their drivers of change, and (iv) place-based knowledge to develop planning policies with multiple objectives. The aim of this thesis is to understand the role of ES for spatial planning in Switzerland. Four hypotheses are tested in individual articles published in international peer-reviewed journals. The first article seeks to understand the historical dynamics of ES and analyses regional diversity of ES changes in Swiss cantons. It shows the limited impact of current land management policies to preserve ES supply, and their application at the cantonal level develops long lasting "regionalities" in the supply of ES. The second article includes qualitative aspects to understand the uptake of ES in cantonal structural plans. It shows the strong discrepancies in the level of representation of ES across cantons, the little emphasis put on some ES across all plans, notably in binding parts, and the lack of coordination between cantons. The third paper explores the spatial patterns and drivers of temporal variations of ES supply at the municipal level in the canton of Vaud. It demonstrates that ES trade-offs and synergies vary across space and time and respond to different drivers of change. The last article puts emphasis on stakeholders' preferences and perceptions of ES to better consider ES in planning. It demonstrates the importance of considering different viewpoints of key stakeholders to develop integrated planning measures for ES. Overall, the findings highlight empirically clear territorial clustering of ES at the cantonal and municipal scale. It suggests five areas for intervention: coordination between sectors at the federal and cantonal level; stricter implementation of the Federal Act on Spatial Planning and interdisciplinarity; incentives to assist farmers in changing their ways; revision of the Sectorial Plan on land crop rotation areas; and strengthening the legal framework around the integration, and protection of protected areas and biodiversity in planning. Finally, we discuss two planning alternatives with the use of land sparing and land sharing strategies in Switzerland. We conclude that such dichotomy is not suitable and that both principles could be used to guide spatial planning in hilly and mountainous regions and in the Plateau area, respectively. Altogether, this work contributes to closing the gap between research on ES and the integration of this knowledge in spatial planning. It calls for a paradigm change in spatial planning based on an in-depth understanding of making human benefits from ecosystems explicit, and dealing with trade-offs.