Unraveling the complex interconnections between food-energy-water nexus sustainability and the supply-demand of related ecosystem services

Matching the supply and demand of related ecosystem services can be an effective way to realize long-term sustainable management of the food-energy-water nexus (FEW Nexus) in drylands. However, few studies have focused on the matching of supply and demand for ecosystem services associated with advancing the sustainability of FEW-Nexus, there is limited research in this domain, which lacks systematic and quantitative analysis of the relationship between them and FEW Nexus sustainability. Here, this research takes the West Liaohe River Basin in the arid region of China as a case study. Based on a localized FEW Nexus sustainability evaluation index system, the FEW Nexus sustainability and the supply-demand matching characteristics of the corresponding ecosystem services in the West Liaohe River Basin from 2005 to 2015 were assessed. The relationship between them was analyzed quantitatively through the methods of coupling coordination degree and geographical detector. The results showed a synergistic improvement in both FEW Nexus sustainability and the supply-demand situation of combined ecosystem services. The supply of food production and water yield were able to meet their demands adequately from 2005 to 2015, with a strengthening surplus, leading to an overall surplus and gradual improvement in the integrated ecosystem services. This surplus synergistically promoted the process of FEW Nexus sustainability. The results of the geographical detector indicate that the supply-demand ratio of carbon sequestration was the main factor influencing FEW Nexus sustainability. Areas with higher FEW Nexus sustainability tended to have larger deficits in carbon sequestration, which was more evident in areas with high levels of urbanization. Therefore, the key to enhancing FEW Nexus sustainability in the basin is to balance the supply of and demand for carbon sequestration services. Overall, the present study not only provides a basis for strengthening the management of the supply-demand of ecosystem services associated with FEW to achieve regional sustainable development, but also offers insights into how the growing demand for the FEW Nexus is exerting pressure on the balance between supply and demand of related ecosystem services.