Regional calibration of ecosystem service valuation under climate and tourism influences: a case study in subtropical Longyan, China.

Precise evaluation of ecosystem service value (ESV) under climate variability is essential for supporting regional ecological management. This study has improved the equivalent factor method. This method takes into account local factors such as temperature, precipitation, net primary productivity (NPP), and tourism revenue, and dynamically adjusts the equivalent coefficient for Longyan City (a humid subtropical area in China). The Equivalent Factor Method after Improvement (EFMAI) is evaluated against the Functional Value Method (FVM) and the baseline Equivalent Factor Method before Improvement (EFMBI), using statistical indicators such as R², RMSE, and Theil's U. Results indicate that EFMAI substantially improves the accuracy of regulation and cultural service estimations, aligning closely with FVM outputs. Specifically, ESV changes from 2010 to 2020 show that regulation services contributed 47.6% of the total increase, followed by cultural services (29.4%), while supply services remained relatively stable, reflecting stronger dependence on exogenous socio-economic factors. Despite these improvements, EFMAI does not consistently outperform EFMBI in supply services due to the limited responsiveness of biophysical models to economic and institutional variables. Moreover, cultural service discrepancies arise from differences in measurement basis: EFMAI employs tourism income, whereas FVM uses site-specific visitation data. Given these limitations, the method provides a more nuanced tool for service valuation in policy-oriented regions similar to China and contributes to methodological advancements in climate-adjusted ESV assessment.