Abstract: As the core region of the “Grain to Green” Program, the Loess Plateau of Northern Shaanxi became an example with the most dramatic changes in earth surface pattern and vegetation cover. Evaluating the effectiveness of vegetation restoration is important for promoting regional ecological environment. In this study, the fractional vegetation coverage (FVC) was used as the index to analyze the changes in vegetation coverage in this area. Soil conservation service, carbon sequestration service, habitat quality, and water yield were used to characterize the regional ecosystem services (ESs). The effects of FVC on ESs were analyzed based on the bivariate spatial autocorrelation model. The trade-off synergies and spatio-temporal variations of different scales of those indices were discussed. The results showed that the FVC of the study area presented a fluctuating upward trend from 2000 to 2020, with the annual average value increasing from 31.7% to 47.1%. Carbon sequestration service and soil conservation service were increased, habitat quality was stable. Water yield increased firstly and then decreased, with an overall upward trend. The ESs changes were scale-dependent. There was an obvious synergistic relationship among ESs. There was a significant spatial dependence between FVC and ESs, with some differences in the degree of correlation. FVC had the strongest impact on soil conservation, followed by carbon sequestration service. However, the increase of vegetation coverage and water consumption of forest and grass led to the negative effect of water yield reduction. In gene-ral, FVC in the Loess Plateau of Northern Shaanxi had achieved remarkable success, and the ecological environment had been significantly improved.

Key words: vegetation coverage, ecosystem service, spatiotemporal change, bivariate spatial autocorrelation