The quantitative and spatial–temporal variations in the characteristics of ecosystem value can be helpful to improve environmental protection and climate adaptation measures and adjust the balance between economic development and the ecological environment. The arid and semi-arid regions of China are undergoing the effects of climate change across the entire northern hemisphere. Their ecological environments are fragile and in conflict with anthropogenic activities, which significantly altered more ecosystems services in these regions. Therefore, estimating the effects of anthropogenic activities on ecosystem services is important for formulating ecological policy and regional environmental mitigation plans of these regions. This study employed the model of ecosystem service value (ESV) assessment and the bivariate spatial autocorrelation method to reveal the spatiotemporal variations in the characteristics of ecosystem value in the arid and semi-arid ecological regions of China and its interaction with human activities. Results showed that (1) the total value of ES of the study area increased from USD 487,807 billion in 2000 to USD 67,831,150 billion 2020; (2) the ES value provided by forest land first increased by 5.60% from 2000 to 2020; (3) the ESV provided by grassland showed an overall decline over the 20 years. Food and raw material production showed the lowest ES value, and climate regulation and soil conservation decreased from 2000 to 2020; (4) the index of human footprint patches decreased from 45.80% in 2000 to 17.63% in 2020, while the high and very high human footprint index areas increased significantly, mainly due to the rapid urbanization and improvement of railway networks in these areas. Spatially, the regions with high human footprint were mostly dispersed in the northeastern of China such as Shanxi and Gansu, whereas the regions with a low human footprint remained mainly located in the central and southwestern parts of China; (5) significant spatial dependencies between changes in ESV and the human footprint index were recorded. Our study could provide a scientific basis for ecosystem functions regulation and land development security in arid and semi-arid ecological regions.

Ecological protection and the restoration of full-array ecosystems is an important part of ecological civilization construction, which is a powerful measure to implement the concept of green development and help bridge the gap between the respective inevitable requirements of the current ecological environment and economic development. To solve this problem, a multi-scale index system was constructed to identify ecological sources comprehensively. The minimum-cost path method, the circuit theory, and the cyclic window search method were adopted to quantitatively identify the important ecological sources and corridors in scale nesting and pinch points and barrier points that affect multi-level connectivity. Furthermore, the specific optimization layout strategy of the ecological network structure of the Hefei metropolitan area was proposed. According to the results, if ecological sources and corridors at two scales are overlaid, the coincident area of ecological sources at two scales is 1719.95 km². As important ecological sources, Chaohu Lake Basin, Niuwangzhai, and Wuding Mountain, which are important areas to maintain the ecological network, need to be protected. Ten overlapping ecological corridors, which are mainly distributed in Changfeng County, are easily damaged long term. As a result, ecological nodes should be set up as temporary habitats for species transfer. In addition, based on the circuit theory and the cyclic window search method, calculating areas of pinch points at two scales yields 1637.75 km² and 434.22 km², respectively, and for areas of barrier points yields 2182.75 km² and 126.97 km², respectively. The ecological pinch points at two overlapping scales among them are important areas for future protection. Due to the small and fragmented spatial distribution in the urban area, pinch points with an average size of 0.58 km² are easy to be restored and will greatly improve the connectivity of the ecological network after restoration. Furthermore, through the quantitative identification of ecological network elements of two scales, the paper puts forward an optimization strategy for an ecological network in the Hefei metropolitan area from three aspects of “point-line-polygon.” The research results can reference decision-making concerning the delineation of urban growth boundary, regional ecological security pattern, land space renovation, and ecosystem restoration.