As a critical component of the geographical divide between the northern and southern regions of China, the ecological stability of the Qinling region has profound implications for ecological balance within China and across East Asia. However, the degradation risk areas of the Qinling region remain unclear, and there are gaps in the delineation of key ecological protection areas. This study examines the improvement and decline in the Qinling region from 2000 to 2023 in terms of ecosystem patterns, quality, and functions. Moreover, key ecological function and degradation risk zones were identified, and future development paths were proposed for the Qinling region. The findings indicate that: (1) Urban area expansion was the most rapid, increasing by about 1800 km², with an average yearly growth rate of 2.43%. Ecosystem quality increased in 48.07% of the Qinling region. The degradation risk zones of ecosystem quality and function were primarily located in the Sanjiangyuan, the Minshan-Qinghai-Tibet Plateau, and the Loess Plateau in Shaanxi, Henan, and Gansu. The core areas for water and soil conservation only accounted for 17.92% and 10.47%, respectively, mainly distributed across the Qinling-Daba Mountains. Based on ecological patterns, quality, functions, and ecological protection and restoration projects, the Qinling region has been divided into two majority categories and 16 subcategories: 7 ecologically key functional areas and 9 degradation risk areas. This study offers recommendations for formulating ecological protection and restoration policies, thereby promoting the sustainable development of the region’s ecology and economy.
Central Asia is one of the most sensitive regions to climate changes in the world and the grassland degradation of this region has attracted considerable concern. Quantifying the driving force of grassland degradation is important for understanding the effects of climate variation and human activities on grassland. In this study, net primary productivity (NPP) was selected as an indicator to quantitatively evaluate the relative role of climate variation and human activities in Central Asia from 2000 to 2020. This study used the global NPP product MOD17A3 as actual NPP and estimated the potential NPP using the Thornthwaite memorial model. The potential NPP and the difference between the potential NPP and actual NPP were used to represent the influence of climate variation and human activities. The grassland degradation or restoration can be demonstrated by the slope of actual NPP (SA). A positive slope value (SA) suggested that restoration occurs, whereas a negative slope value suggested that degradation occurred. The results showed that 23.08% of the total grassland area experienced grassland degradation, whereas 2.51% of the whole grassland underwent grassland restoration. Furthermore, 53.8% of the degraded grassland areas were influenced by climate variation, and 14.5% were caused by human activities. By contrast, the relative roles of climate variation and human activities in grassland restoration were 25% and 47.9%, respectively. The NPP variation also could be calculated by assessing the effects of these factors and the results showed that 55.7% of the NPP decrease was caused by climate variation, whereas 9.6% was a result of human activities. On the contrary, climate variation and human activities resulted in 19.8% and 37.3% of grassland restoration, respectively. Therefore, climate variation was the dominant factor of grassland degradation, and human activities were the main driver of grassland restoration in Central Asia.
Southwest China (SWC) holds the distinction of being the world’s largest rock desertification area. Nevertheless, the impacts of climate change and ecological restoration projects on the carbon sinks in the karst area of Southwest China have not been systematically evaluated. In this study, we calculated carbon sinks by utilizing the Carnegie–Ames–Stanford Approach (CASA) model, and the actual measurements, including the net primary productivity (NPP) data and soil respiration (Rs,) were calculated to obtain carbon sink data. Our findings suggest that the carbon sinks in the karst areas are displaying increasing trends or positive reversals, accounting for 58.47% of the area, which is larger than the overall average of 45.08% for Southwest China. This suggests that the karst areas have a greater carbon sequestration potential. However, approximately 10.42% of carbon sinks experience negative reversals. The regions with increasing and positive reversals are primarily located in the western parts of Guizhou and Guangxi, while negative reversals are observed in the eastern parts of Chongqing, Guangxi, and Guizhou. Ecological restoration projects are the main driving factors for the carbon sinks with increasing trends. Increased humidity and ecological restoration management are the main reasons for the positive reversals of carbon sinks. However, warming and drought shift the carbon sinks from increasing to decreasing in Chongqing, east of Guangxi and Guizhou. The findings of this study highlight the significant role of ecological restoration projects and reexamine the impact of climate change on carbon sequestration.