Soil multifunctionality assessment in Grenoble Alpes metropolis using the MUSE method for soil health integration in the planning process

Soil multifunctionality reflects the capacity of the soil to provide multiple ecological functions and ecosystem services (Garland et al., 2021). It is jointly determined by biotic and abiotic factors (Y. Shi et al., 2025). Soil health is known as the continued capacity of soil to function as a vital living system within an ecosystem and land-use boundaries (Laishram et al., 2012). Recognizing this vital role, soil health has become a key parameter to assess, and several methods and tools have been developed for this purpose. The MUSE method - originally a French acronym for Method for the Evaluation of Soil Multifunctionality - is a Digital Soil Mapping (DSM) approach that assesses four soil ecological functions: carbon storage, biodiversity storage, infiltration capacity, and agronomic potential (Branchu et al., 2021) based on publicly available datasets of soil properties. These biological, chemical and physical functions are assessed individually and in combination through a scoring system that enables the spatialization of each ecological function and of soil multifunctionality.The SPADES (Spatial Planning and Design with Soil) project aims to facilitate the integration of soil in spatial planning and design. By promoting soil literacy and gathering adaptable tools, methods and instruments among the countries involved in the project, SPADES is putting soil health at the heart of planning for the benefit of current and future generations. Grenoble-Alpes Metropolis (GAM) is one of 17 SPADES research pilots involved in the co-creation process to learn, develop and test transferable results - recommendations regarding soil health integration in spatial planning and design.GAM is experiencing urban sprawl, habitat fragmentation, and soil health degradation due to construction, infrastructure development, and intensive land use. Soil sealing and compaction are common in urban and peri-urban areas, while agricultural soils face risks of erosion and land take. These trends threaten the ecological functions and ecosystems services provided by soils, like supporting biomass and biodiversity, regulating the water cycle and climate. While the region has environmental ambitions, integrating soil data and soil health into spatial planning frameworks remains a complex task. Local planning documents lack detailed information, limiting the capacity of planners to make informed, soil-sensitive decisions.Within the framework of SPADES project, the MUSE method is applied at GAM in order to (ii) assess soil multifunctionality and support soil-informed land-use planning. The original method and some adaptations are tested to showcase the possibilities offered and identify the most adapted versions for integration of the resulting maps in the planning documents and  help integrating soil health into decision-making processes. The approach seeks to guide soil management practices that preserve soil health and functions, improve soil quality, and promote sustainable land use. (ii) Within the context of modelling approaches to bridge the scale gap between point measurements and Pan-European monitoring, the study evaluates the MUSE method’s interoperability across diverse contexts, identifies and addresses barriers to its transposability, and tackles key challenges related to MUSE development and operationalization, including data availability, accuracy, reliability, practical usefulness, interpretability, and the scales “local versus global” transferability issue.