Since the beginning of the 21st century in Shaanxi Province, China, ecological restoration has increased fractional vegetation cover (FVC) and decreased soil and water erosion. The climate and topography will be critical factors for maintaining vegetation coverage in the future. Based on the moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) data, we monitored FVC variations in Shaanxi Province, China, as well as in three subregions of the Loess Plateau (LOP), Qinling–Bashan Mountain (QBM), and Guanzhong Plain (GZP). Using Sen+Mann–Kendall, correlation analysis, and geodetector methods, we detected trends and responses to climate change and topographical characteristics in Shaanxi Province from 2000 to 2018. The results indicated that 73.86% of the area in Shaanxi Province exhibited an increasing FVC with a growth rate of 0.0026 year⁻¹ from 2000 to 2018. The FVC in the three subregions varied, as QBM (87.24–91.47%) > GZP (47.45–66.93%) > LOP (36.33–49.74%), which displayed a significant increase, slight increase, and slight decrease, respectively. The variation of FVC was significantly positively correlated with climate factors (precipitation, temperature, sunshine duration) at monthly and seasonal scales. The time-lag duration between FVC and climate factors was 1–3 months except for the conjunctional areas of GZP with the LOP and QBM, which exhibited a time-lag of 5–6 months. Topographically, the landform of hills had the highest FVC increase at an altitude of 500–1500 m and a slope of 2°–6°. The dominant driving factors affecting FVC variation in Shaanxi Province and LOP area were climatic factors. In the QBM area, the dominant factors were related to topography (relief, elevation, slope), whereas in the GZP area, they were relief and sunshine duration. We can conclude that local topography characteristics are important in implementing revegetation projects because they strongly influence water, temperature, and sunshine redistribution.

There are disagreements regarding the accuracy of estimation and spatial distribution of carbon emissions in China. It is of great significance to estimate a more detailed carbon emission inventory for China and analyze the carbon emission characteristics of different regions. This study comprehensively estimated carbon dioxide and methane emissions (and their spatial distributions) across eight carbon-emitting sectors in 360 prefecture-level cities in China in 2020. The results indicated that total carbon emissions in China amounted to 146.00 × 10⁸ t, with carbon dioxide and methane accounting for 95.87% and 4.13%, respectively. The industrial sector was the main source of carbon emissions, accounting for 75.42% of the total. The North China Plain, the Northeast Plain, and the Sichuan Basin were identified as the carbon emission hotspot areas with the most intensive carbon emission densities. Among the clustered four carbon emission zones based on carbon emission density and economic carbon intensity, the High Carbon Emission Density and High Economic Carbon Intensity zones accounted for 41.73% of total carbon emissions. To achieve carbon neutrality, it is essential to devise emission reduction strategies for specific areas by thoroughly considering spatially explicit variation at the prefecture level, with a focus on primary carbon-emitting cities and sectors.

Arid regions face multiple challenges such as population expansion, water scarcity, land degradation, and biodiversity reduction. Understanding temporal and spatial patterns of ecosystem service trade-offs and synergies is critical for sustainable development and effective ecosystem service management in arid regions under environmental stress. Taking the Tarim River Basin in China as an example, five ecosystem services (carbon sequestration, water yield, sediment delivery ratio, habitat quality, and food production) were studied at different scales in 1990, 2000, 2010, and 2020 in the inland arid region. Spearman correlation, geographical weighted regression, and self-organizing mapping were used to analyze the ecosystem service trade-offs and synergies. The results showed that the ecosystem services in the basin increased gradually; in particular, the water yield increased from 15.38 × 10⁹ m³ to 29.8 × 10 m³, and the food production increased from 11.03 × 10⁶ t to 29.26 × 10⁶ t. There was a significant positive correlation between carbon sequestration, water yield, and habitat quality, but a negative correlation between sediment delivery ratio and food production. The spatial distribution of trade-offs and synergies of ecosystem services varies in different years and on different scales. The area change in ecosystem service bundles at the pixel scale is relatively small, while the area change at the sub-basin scale is relatively large. This paper provides policy suggestions for the ecological management and sustainable development of the Tarim River Basin through the analysis of ecosystem service trade-offs and synergies.

Alpine ecosystems, as one of the most representative terrestrial ecosystems, have garnered significant attention due to their susceptibility to human activities and climate change. However, the distribution patterns and driving factors of alpine soil bacterial communities remain to be further explored, especially for different dominant phyla. This study investigated the soil bacterial community composition, elevational patterns, and relationships between bacterial diversity and environmental factors at four elevation gradients (2406–3204 m) on Mt. Taibai, Qinling Mountains, China, using 16S rRNA sequencing. The results showed that the dominant bacterial phyla were Acidobacteria, Actinobacteria, Proteobacteria, and Chloroflexi, accounting for over 69% of the bacterial sequences in soil samples. Dominant bacterial communities exhibit distinct elevation gradient patterns in diversity and community structure. The α-diversity of Actinobacteria and Chloroflexi decreases with increasing elevation, whereas that of Proteobacteria and Acidobacteria increases. Moreover, the community structure of Actinobacteria shows greater variation across elevations than the other three dominant bacterial groups, with significant differences observed among elevations. Redundancy analysis and distance decay analysis revealed that elevation was significantly correlated with the soil bacterial community structure (p < 0.01). Different dominant bacterial communities were regulated by distinct environmental factors, providing strong evidence for understanding microbial community assembly. Therefore, the α- and β-diversity of soil bacteria on Mt. Taibai exhibit distinct elevational variations, and elevation-driven plant diversity and pH may be key factors shaping the spatial distribution of soil bacteria.