Eco-fiscal sustainability of plain afforestation: From ecological value creation to value realization

Afforestation projects can enhance ecosystem services (ESs) but may leave persistent fiscal commitments for land leasing and forest maintenance after project construction. Existing ES and Gross Ecosystem Product (GEP) assessments have largely focused on ecological value creation, with limited attention to whether and under what conditions this value can be converted into funding for long-term operation. This study develops an eco-fiscal sustainability framework integrating spatial restructuring, GEP accounting, life-cycle cost analysis, future projection, ecological value realization (EVR), and uncertainty analysis, using the Plain Afforestation Project in Xiji Town, Beijing, as a case study. From 2010 to 2023, afforestation transformed the landscape from cropland dominance to a forest–cropland mosaic, while GEP increased by 26.6% to CNY 839.5 million and regulating services accounted for 92.02% of total GEP. Assuming no further afforestation, total GEP is projected to increase to CNY 916.2–939.8 million by 2080, mainly through forest development within the afforestation area, whereas annual fiscal costs generally decline as construction expenditure ends and maintenance requirements decrease. However, cumulative cost coverage depends strongly on EVR: under the 2030 baseline activation scenario, and given the specified cost pathway and GEP uncertainty, the 10% and 20% EVR scenarios do not achieve cumulative cost coverage by 2080, whereas all 3000 simulations under the 30% scenario reach non-negative cumulative net cash flow before 2080. These findings show that eco-fiscal sustainability depends not only on ecological value creation but, more critically, on the capacity to convert realizable ecological value into stable funding, providing a framework for the long-term management of post-construction peri-urban plain afforestation.