Comprehensive evaluation of ecosystem service functions in Yunnan province based on InVEST model

Objective This study aims to evaluate the ecosystem service values in Yunnan Province and examine their spatial distribution and temporal changes.

Method Utilizing the InVEST model, we evaluated soil conservation, carbon storage, water conservation, and water purification services in Yunnan Province for the years 2010 and 2020. Quantile segmentation was employed to identify service boundaries, and fitting methods were used to determine constraints between services. Space scale, time scale were analyzed to comprehend the spatiotemporal evolution of ecosystem functions. The value of these services was estimated using cost replacement and other methods.

Result (1) Except for water purification, ecosystem services in Yunnan generally exhibit a west-high-east-low quality pattern. Most areas have low nitrogen and phosphorus outputs, with high-output zones being sporadically distributed. (2) High-quality service areas, excluding water purification, are predominantly located at altitudes between 2 400-2 800 m. (3) Compared to 2010, soil conservation and carbon storage improved in 2020, whereas water retention and purification services degraded. (4) In 2010, except for a negative linear relationship between nitrogen load and soil conservation concerning water purification, other service constraints displayed hump-shaped and double camel-hump patterns with increased sensitivity to constraint variables. The overall threshold shows a left shift trend. (5) From 2010 to 2020, the overall value of ecosystem services in Yunnan decreased, mainly due to water retention. In 2010, the total service value was 1.79 × 10¹² CNY (4.54 × 10⁶ CNY/km²), dropping to 1.71 × 10¹² CNY (4.33 × 10⁶ CNY/km²) in 2020.

Conclusion Yunnan’s ecosystem service value is substantial. Over the past decade, while soil conservation and carbon storage have improved, water retention and purification have declined.