[Characteristics of Spatial and Temporal Evolution of Vegetation Cover and Analysis of Driving Factors in Different Climate Zones in China from 1982 to 2022].

Abstract

In order to maintain the ecological environment and prevent soil erosion， it is of great significance to investigate the spatiotemporal dynamics of vegetation cover across different regions of China as well as the topographical effects of such dynamics. This study calculates vegetation cover from 1982 to 2022 across China by using AVHRR GIMMS-3G+ NDVI. Utilizing such methods as the Theil-Sen-Mann-Kendall test， Hurst index， CV test， and geographic detector， this study assesses the spatiotemporal evolution patterns of FVC in China's four climate regions， as well as the driving mechanisms of such patterns. It was found that： ① From 1982 to 2022， China's annual average FVC exhibited a spatial distribution pattern of "high in the southeast and low in the northwest." With a multi-year average FVC value of 0.317 7， an overall fluctuating upward trend was shown， and the temperate monsoon climate zone made the most contribution. ② From 1982 to 2022， FVC across China generally maintained high stability， with an average CV value of 0.061 2. Areas with high vegetation coverage typically exhibited higher stability. The Hurst index indicated that the vegetation coverage in China is expected to manifest an overall positive trend in the future， but the areas undergoing continuous degradation will still account for 8.88%. ③ The primary single factors driving the spatial distribution patterns of FVC across China included precipitation， soil moisture， and temperature， with significance coefficients of 0.769 2， 0.558 1， and 0.436 4， respectively. Ecological engineering has reversed land degradation to some extent； nevertheless， extreme climate cycles may still overtake the ecosystem's recovery threshold. ④ The coupled effects between precipitation and soil moisture versus other factors were the primary drivers of vegetation growth in China. In the temperate monsoon climate zone of China， as the primary regions for such ecological engineering projects as the Three-North Shelterbelt Forest and the Beijing-Tianjin-Hebei Sandstorm Source Control Project， it has been demonstrated that human intervention could significantly enhance vegetation coverage. In the high-altitude and frigid Qinghai-Tibet Plateau climate zone， human activities have disrupted the regional microclimate water cycle structure along major rivers， particularly in ecologically fragile areas such as the Yarlung Tsangpo River Basin， thus further hindering the ecological recovery capacity. This study provides theoretical support for formulating regionally differentiated ecological recovery strategies.