Abstract
Forest ecological connectedness is defined as the spatial continuity of forested patches and landscapes that facilitate the exchange of materials, biodiversity, and ecosystem services; it has become an important criterion for environmental quality and economic productivity in China. Although forest cover in China has been rapidly increasing since the 1990s, forest ecosystems remain fragmented across administrative regions, resulting in complex environmental effects. This study develops a robust provincial-level Forest Ecological Connectivity Index (FECI) by merging forest cover, fragmentation, functional corridor density, and carbon stock data for 30 Chinese provinces (excluding Tibet, Hong Kong, Macao, and Taiwan) between 2013 and 2023, using data from national forest inventory records, satellite-based forest-cover products, and published databases. We use panel data econometrics (fixed-effects models, spatial Durbin models (SDMs), mediation analysis) to analyze the effects of within-province FECI improvements and ecological spillovers across provinces on (i) air quality (PM2.5 concentrations), (ii) hydrological regulation (annual surface runoff variability), (iii) regional GDP growth and green total factor productivity (GTFP), and (iv) carbon sequestration in neighboring provinces. Results indicate that a one-standard-deviation increase in FECI is associated with a 4.7 μg/m3 reduction in PM2.5 in the same province (p < 0.01) and an 23.4% reduction in annual runoff variability (relative to sample mean) in the same province (p < 0.05), with a statistically significant positive impact within a spatial bandwidth of 300–500 km. Provinces with higher forest connectivity have lower per-unit-GDP carbon emissions and higher GTFP growth (β = 0.18, p < 0.01). Mediation analysis shows that forest connectivity’s overall economic impacts are driven by ecosystem services, with carbon sequestration and water-yield regulation as the main ones, accounting for about 42%. These empirical, data-driven insights are expected to strengthen spatial governance and carbon-neutrality policy frameworks in China by incorporating ecological connectivity planning.