Analysis of vegetation ecological quality change and its driving forces in Guangxi from 2000 to 2020

In order to grasp the spatiotemporal variation characteristics and driving mechanism of vegetation ecological quality in Guangxi, based on multi-source data such as meteorology, terrain, soil and remote sensing, and using the ecological quality index (EQI) as an evaluation indicator, linear trend analysis, correlation analysis and geographical detector method were used to analyze the spatiotemporal variation and driving mechanisms from 2000 to 2020. The results were as follows: (1) Since 2000, the vegetation EQI of Guangxi had significantly increased, and the regional vegetation ecology had improved significantly. The development of vegetation ecological quality had experienced stages of slow growth, rapid growth and significant improvement. In terms of space, the vegetation EQI in Guangxi showed a characteristic of high in four directions and low in the middle, with the high-value areas gradually expanding from the east to the west and north. (2) The influencing factors of spatiotemporal evolution of vegetation ecological quality in Guangxi were significantly different. The overall change of vegetation ecological quality at different altitudes showed a trend of ‘increase-decrease-stability-fluctuation’. The vegetation ecological quality in different soil types was high in loam soil and low in sandy soil. The ecological quality of forest and shrub-grass was high, and the ecological quality of farmland vegetation was low. There was a significant positive correlation between vegetation ecological quality and climate driving factors, which was affected by both temperature and precipitation. The area mainly driven by temperature (T) was the widest, followed by the area mainly driven by precipitation (P). The areas driven strongly (［T+P］+) and weakly (［T+P］-) by temperature and precipitation were smaller.(3) The driving force of changes in vegetation ecological quality change of Guangxi was affected by terrain, soil, vegetation, climate, natural disasters and human activities. The order of explanatory power of natural influencing factors was vegetation > terrain > soil > climate, in which the vegetation net primary productivity and vegetation coverage were the most important factors affecting the spatiotemporal variation of vegetation ecological quality. The effects of natural factors on vegetation ecological quality in Guangxi was interactive, showing a nonlinear enhancement and two-factor enhancement relationship, and the interaction between terrain and vegetation, soil and vegetation, and climate and vegetation were the most obvious. Natural disasters and human activities aggravated the impact of vegetation ecological quality change. Among them, meteorological disasters such as drought and low temperature damage inhibited the improvement of vegetation ecological quality, while human activities such as forestry ecological engineering promoted the improvement of vegetation ecological quality. The research results provide a scientific theoretical reference and technical support for making reasonable measures of vegetation ecological protection and restoration in Guangxi.