Managing ecosystem service deficits through ecological-social prioritization.

Arid and semi-arid regions face extensive challenges in sustaining ecosystem services due to increasing environmental and socio-economic pressures. Understanding the complex interactions between social and ecological systems in these regions is essential for achieving spatial sustainability. This study introduces a comprehensive framework integrating spatial analysis, statistical modeling, and Bayesian networks to assess the supply and demand of eight key ecosystem services across Iran, including forage, water yield, medicinal plants, mushroom, carbon sequestration, pollination, recreation, and aesthetic value. The results revealed that at least 60% of the country's area is deficient in one or more ecosystem services. The greatest deficiencies were observed in forage (78%), pollination (75%), and mushroom (26%), primarily concentrated in downstream areas. Principal component analysis (PCA) indicated that, from an ecological perspective, water services and carbon sequestration play the most critical roles, whereas, from a social perspective, water services, pollination, and forage hold the highest priority. Statistically significant differences were identified in service demand among stakeholder groups (p < 0.05). Furthermore, the relationships between services showed that synergistic interactions prevailed at the supply level (p < 0.01), while trade-off relationships dominated at the demand level (p < 0.05). Bayesian network modeling identified population, land-use change and management as the most influential socio-economic drivers of the supply-demand mismatch in ecosystem services. Spatially, the highest sensitivity to threatening factors was observed in medical plant services (78%) and aesthetic values (74%). By integrating ecological and social dimensions, this approach offers a practical tool for informed decision-making, sustainable resource management, and effective environmental planning in arid and semi-arid ecosystems.