RESUMEN
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.
Asunto(s)
Ecosistema , Suelo , Secuestro de Carbono , China , AguaRESUMEN
Rapid urbanization destroys the ecological network connectivity among habitat patches. The research on the construction of regional ecological network at the patch level is obviously insufficient. The morphological spatial pattern analysis (MSPA) and minimum cumulative resistance (MCR) were used to identify ecological sources and to extract potential ecological corridors in Qinling Mountains, respectively. The ecological network was effectively constructed. We analyzed the structural characteristics and landscape compositions of the network. Based on the gravity model, the importance of patches in the ecological network was graded and the structural characteristics and landscape composition of the network were analyzed. The results showed that there were 10 ecological sources, 45 potential ecological corridors and 38 stepping stones in the ecological network of Qinling Mountains in Shaanxi Province, with a total area of 29686.15 km2. There were good connectivity in potential ecological corridors and ecological network nodes as indicated by network closure (0.11), line point rate (1.18), network connectivity (0.42) and cost ratio (0.99). The connectivity between ecological source was low, but the cost of network reconstruction was high. The important ecological corridors were mainly composed of forest, grassland, and cultivated land. Fore-sts accounted for 89.2% of the total corridor area (571.00 km2), indicating the good landscape structure in Qinling Mountains. The protection of ecological source areas must be strengthened, and priority should be given to the establishment and protection of important ecological corridors and ecological nodes. Our results would provide the scientific reference and basis for the ecological environment protection and high-quality development in Qinling Mountains.
