Some critical thinking on the integrative assessment of ecosystem service supply and demand relationships

In the past decade, research on the relationships between the supply and demand of ecosystem services has been flourishing. To address issues such as the misuse of supply and demand concepts, methods, and results in current research, we proposed five key aspects that need to be considered to enhance the scientific rigor and practical value in assessing relationships between ecosystem service supply and demand. Firstly, it is essential to clarify the distinctions and connections between the concepts related to ecosystem service supply and demand, which are crucial prerequisites and starting points for assessing their relationships. Secondly, it is necessary to integrate relevant environmental standards or policy objectives to develop reliable methods for assessing the demand for ecosystem regulating services. Furthermore, it is important to properly address the modifiable areal unit problem by determining the most appropriate spatial scale and unit for evaluating relationships between ecosystem service supply and demand. Additionally, it is crucial to differentiate between quantitative and qualitative methods for characterizing (im)balances or (mis)matches between ecosystem service supply and demand, particularly avoiding the use of qualitative methods to represent quantitative relationships between supply and demand. Lastly, it is imperative to integrate ecosystem service flows into the assessment of supply and demand relationships, and evaluate the dynamic supply and demand relationships of regional ecosystem services from a coupled "supply-flow-demand" perspective.