The spatial variation of forest aboveground carbon sequestration (ACS) is crucial for assessing the carbon storage and time of carbon-emission peaking. Unfortunately, a systematic assessment of accurate ACS and its change has not yet been developed, especially at a large scale. Here, we evaluate the spatiotemporal ACS trend based on LANDIS PRO and PnET-II models from 2000 to 2020 in Western Sichuan, China, coupled with multi-source remote sensing datasets (e.g., MODIS and Lansat) and in situ forest inventory to obtain the landscape information. The Mann-Kendall trend test is used to examine the ACS trend. The total ACS increased from 344.62 to 466.99 Tg due to large-scale reforestation programs from 2000 to 2020. The evergreen coniferous forest contributed the most ACS (85.28%) in Western Sichuan compared with other species. The developed methodology can be applied to analyzing the ACS at the watershed and regional levels promptly and helping decision-makers and managers develop effective forest management measures.

The Zagunao, as a typical alpine forested watershed in the upper Yangtze River Basin, China, plays an important role in providing valuable forest ecosystem services such as water purification, water supply, climate regulation, and carbon sequestration for downstream cities in the Chengdu plain. However, alpine forests in the Zagunao watershed are confronted with growing disturbances including climate changes and anthropogenic disturbances. These disturbances can impact ecological patterns and processes, resulting in degraded forest ecosystem functions and services. Thus, detecting degraded forests and associated driving factors in the Zagunao watershed is urgently needed. In this study, we combined the meteorological data and multiple remote sensing datasets to investigate the spatial distribution of forest degradation and its driving factors in the Zagunao watershed. The key findings are: (1) from 2001 to 2017, degraded forests accounted for 9.71% of the forested area in the Zagunao watershed, and the natural coniferous broadleaved mixed forest was the main degraded vegetation type; (2) 95% of the degradation was driven by anthropogenic activities while only 5% of it was caused by climate drivers. This study is beneficial for forestry sectors to effectively detect forest degradation and provides scientific guidance for future forest restorations and management in alpine forested watersheds.

Understanding the temporal variations of terrestrial water storage (TWS) in large river basins is crucial for water resource management and ecosystem protection. Yet, the variations of TWS in large river basins are often been assessed in term of temporal trends with limited studies on the stationarity of TWS. In this study, we investigated the temporal trends and stability of TWS in then large river basins in China from 2004 to 2014 using the corrected Gravity Recovery and Climate Experiment (GRACE) gravity satellite data. Key findings are: (1) the average TWS in China showed a significant downward trend during the study period; and (2) the TWS in ten large river basins was non-stationary across China. Water surpluses were observed in the Northeast and the Southeast, while water deficits were found in the Northwest and the Southwest. This study provides policy-makers with critical information to design adaptive strategies and plans for basin-scale water resources management.

Southwest China is an ecologically fragile area in China. Understanding temporal and spatial variations of vegetation degradation can help to formulate measures of ecosystem protection and ecological function restoration. In this study, we evaluated vegetation dynamics and identified vegetation degradation and its spatial patterns in Southwest China, based on land cover, DEM, and GLASS LAI datasets from 2001 to 2017. The key results are: (1) Though the average LAI in Southwest China showed an insignificant trend during the study period, based on grid-scale analysis, significant declines in LAI indicating vegetation degradation were identified in some areas such as western Sichuan, western and central Yunnan, and western Tibet; (2) about 10.75% of the vegetation experienced significant degradation during the study period in Southwest China; (3) degraded vegetation was mostly distributed in high elevation areas, and about 43% degraded vegetation was located in areas with the elevation between 3500m and 5000m; (4) the dominant degraded vegetation types included grassland, alpine vegetation, shrubland, and coniferous forest. Our findings can provide valuable management implications for vegetation restoration and ecological protection in Southwest China.

The upper Minjiang River watershed provides critical ecological services to sustain downstream populated cities in the Chengdu plain of China. Understanding its environmental quality dynamics and associated response to vegetation change can help with vegetation restoration program designs for better protection of watershed ecosystems. In this study, five environmental quality indices were first calculated to evaluate environmental quality dynamics by use of MODIS MCD12Q1 and SPOT NDVI products. Then, responses of environment quality to vegetation change from 2001 to 2017 were assessed. Key findings were: (1) there was a slight decline in the integrated ecological index (EI), indicating a relatively stable environment quality in the study watershed; (2) EI had significant positive correlations with forest land or grassland area, while its relationship with the sparse woodland area was significantly negative; and (3) environmental quality changes were mainly driven by soil erosion, earthquake, landslides, vegetation change, and human activities. This study has important implications for the protection of environmental quality by vegetation restoration.