Advancing Integrated Transboundary Watershed Management Through Recreational Services Assessment: A Supply and Demand Framework Analysis

Neglecting integrated management may exacerbate the imbalance between the supply and demand of ecosystem services (ESs) in transboundary watersheds. Although management strategies such as payments for watershed services (PWS) have been implemented to mitigate the externalities and imbalance of ESs, the complexity of transboundary watersheds is often underestimated, diminishing their effectiveness. This study proposed a comprehensive transboundary framework to assess the dynamics of recreational service supply and demand in China's Xin'an River, identifying the driving factors. Results showed that: (1) the supply growth rate of recreational services in upstream (50.5%) was higher than that in downstream (8.4%) during the study period; (2) demand in the upstream was lower than that in the downstream. This observation was corroborated through choice experiments; (3) recreational services exhibited a significant supply-demand imbalance with 74.5% oversupplied. These results suggest that environmental externalities are not fully internalized, especially in upstream areas; (4) the study identified road accessibility, land degradation, and demand preferences as key driving factors. These insights offer a new perspective on the internalization of PWS and can inform the development of policies for transboundary region-integrated management.