Ecosystem Services-Based Foodshed Assessment for Spatial Planning: The Istanbul Metropolitan Area

Supply chain disruptions and climate shocks have exposed the fragility of food systems, highlighting the urgency of reconnecting urban areas with local food production through spatial planning. This study develops a regional-scale ecosystem service (ES)-based foodshed assessment framework, integrating agricultural capacity, ecological functionality, and infrastructure, specifically roads, food industries, and markets. The framework combines the Metropolitan Foodshed and Self-Sufficiency Scenario (MFSS) model with stakeholder-prioritized integrated ES mapping and Geographic Information System (GIS)-based multi-criteria suitability analysis. Applied to Istanbul and the Marmara Region, the assessment focuses on cereals/legumes, vegetables, and fruits/spices under four scenarios projected to 2033. Results show that integrating ESs increases the area classified as suitable by 26%, while infrastructure constraints reduce it to 9%, reflecting the spatial trade-offs between ecological potential and accessibility. Istanbul, with limited agricultural land, achieves self-sufficiency levels below 10% in all scenarios, highlighting its structural dependency. Eliminating food loss and waste reduces regional land demand by 23%. The framework offers policy-relevant insights for conservation, ecological restoration, and decentralized food system development. It remains open to further enhancement through the inclusion of livestock-based systems, updated land cover data, and climate projections, factors essential for assessing long-term resilience. Overall, the ES-based assessment can support food- and ecosystem-sensitive spatial planning in metropolitan regions.