Linking Value Chains and Ecosystem Services in the semi-humid area of North Africa: Frameworks for Sustainable Development of Landscape Chains in the Medjerda Watershed, Northern Tunisia

Abstract

In subhumid North Africa, and particularly in northern Tunisia, agriculture-based livelihoods are increasingly threatened by natural resource overuse, climate change–driven water stress, environmental degradation, and growing socio-economic pressures. The Medjerda watershed, a region of strategic ecological and agricultural importance, supports diverse farming systems that are tightly interlinked with local ecosystems and livelihoods. However, escalating pressures from resource overexploitation, pollution, climate variability, and plant and animal disease outbreaks are undermining both ecosystem functioning and economic resilience. Addressing these interrelated challenges requires analytical approaches that explicitly capture the interactions between value chains and ecosystem services. This guideline presents an integrated framework that combines a descriptive and an analytical component to support sustainability-oriented planning and decision-making in the Medjerda watershed. The descriptive component establishes the regional context and identifies key ecosystem-dependent agricultural value chains. Building on this foundation, the analytical component introduces two complementary methods: value chain mapping combined with the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) to prioritize value chains with high ecosystem service potential, and Ecosystem Service Value Chain Analysis (ESVCA) to examine value chains through a systems-based ecological and economic lens. Together, these methods enable the identification of critical dependencies, synergies, trade-offs, and vulnerabilities between economic activities and ecosystem services. By clarifying how these methodologies can be operationalized and the types of insights they can generate, the guideline provides practical tools for stakeholders to promote inclusive economic growth while ensuring sustainable natural resource management. Targeted at policymakers, researchers, development practitioners, and local actors, the guideline lays the groundwork for subsequent applied analyses and supports the design of resilient, ecosystem-aligned agricultural value chains in the Medjerda watershed.