RurbanSoilFunctions: Synergies and trade-offs in soil functions of rurban spaces

• Applicants: Professorin Dr. Carola Paul; Professorin Dr. Christine Wachendorf
• Subject Area: Soil Sciences ; Forestry
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 548312187

Project A02 addresses the role of tree-based land use diversification in enhancing, or mitigating trade-offs between soil functions in rurban social-ecological systems. Rurban transformation processes are closely linked to changes in land use and soil management, influencing the level and stability of soil functions. Intensification and extensification of agriculture, as well as land use homogenization and diversification, occur side by side as a rurban assemblage, affecting, among others, primary productivity, cycling of nutrients, water, and carbon. A critical challenge is reconciling trade-offs between soil functions valued by private beneficiaries (e.g., farmers prioritizing production) and public beneficiaries (e.g., carbon sequestration and nutrient retention) under climate and socio-economic perturbations. Tree-based systems could play a pivotal role in addressing these trade-offs as has been demonstrated for temperate and semi-arid regions. However, empirical evidence on how such systems enhance or exacerbate trade-offs remains limited, especially under the diverse social-ecological conditions of rurban farms. The central hypothesis of this project is that heterogeneity inherent to rurbanity enhances soil multifunctionality at the landscape scale. By combining empirical soil data and enhanced process understanding with a risk-sensitive ecological-economic farm and landscape model, we aim to better understand the interplay between tree-based systems, performance of soil functions and farm resilience in rurban transformation processes. Our empirical work will initially be conducted in Morocco in Phase 1, while the farm and landscape model will also be applied to available data for India. We will specifically focus on the prominent effect of soil organic matter on many soil functions by spatial analyses of organic carbon-related soil quality indicators, affected by management and tree-based agriculture. For example, we will analyse the effect of organic matter on soil water retention potential, and its contribution towards a more resilient agriculture. By bringing soil functions and socio-economic farm functions together in the robust, multicriteria land use allocation model optimLanduse, we will investigate how heterogeneity of farm endowments, lifestyles and perceptions in rurban settings affect the suitability of tree-based systems to simultaneously provide various soil functions and enhance farm resilience. The resulting in-silica rurban landscapes will improve our understanding on how rurban social-ecological heterogeneity is linked to land-use composition and the provision of soil functions. Combining empirical soil research with mechanistic social-ecological modelling and a co-learning process will contribute to a comprehensive understanding of sustainable rurbanity.

• DFG Programme: Research Units
• Subproject of: FOR 5903: Sustainable Rurbanity - Resources, Society, and Regulatory Systems
• International Connection: India, Morocco
• Co-Investigator: Professor Dr. Tobias Karl David Weber
• Cooperation Partners: Professor Dr. Sathish Ayyappa; Professor Dr. Ngonidzashe Chirinda; Professorin Dr. Fatiha Hakimi; Professor Dr. Nassreddine Maatala