Divergent trends in vegetation greenness and resilience across China's forestry ecological engineering regions

Significant greening has occurred in China's Forestry Ecological Engineering (FEE) regions in recent decades, driven by carbon dioxide fertilization and ecological restoration efforts. However, whether widespread greening enhances resilience and what factors drive its changes remain uncertain. To address these issues, we used long-term remote sensing vegetation indices from 1982 to 2022 to evaluate theoretical resilience based on lag-1 autocorrelation, variance, and skewness. We then examined the spatiotemporal coherence between greenness and resilience and conducted an attribution analysis of resilience changes in greening regions. The findings reveal that most regions in FEE areas exhibited a significant greening trend over the past 41 years. However, the substantial increase in vegetation greenness did not result in a corresponding improvement in resilience. Climate variability and long-term trends emerge as the primary drivers of resilience changes in greening areas. Notably, although vegetation greening may not be the primary factor driving changes in resilience, it could potentially mitigate or amplify the influence of climate on resilience. This work underscores the limitation of assessments predicated solely on superficial ecological conditions and advocates for integrating ecological resilience metrics into the appraisal of ecological engineering efficacy. Moreover, in ecological restoration, it is essential to consider regional climate conditions and vegetation scale to prevent competition for resources crucial to existing flora.