关键词: 日光诱导叶绿素荧光, 植被光合, 黄土高原, 干旱, 复原力, 抵抗力

Abstract: The Loess Plateau is one of the most frequent areas of meteorological drought in China, and in recent years, under the background of climate warming, meteorological drought has an increasing trend. Exploring the resistance and resilience of vegetation photosynthetic physiological activities to droughts is important for understanding the response of vegetation growth to environmental changes and predicting the future development of vegetation in the region. Based on the solar-induced chlorophyll fluorescence GOSIF products, temperature and SPEI data, the multiple linear autoregressive model, this study aimed to analyze the effects of drought on the spatial and temporal stability of photosynthesis in vegetation among different vegetation types and climate zones on the Loess Plateau.The results showed that there was a linear relationship between vegetation photosynthetic resilience and the degree of drought on the Loess Plateau. Vegetation photosynthetic resilience weakens in the order of mild, moderate, and severe drought. The relationship between vegetation photosynthetic resistance and the degree of drought was nonlinear. Vegetation photosynthetic resistance decreased from severe to mild and to moderate drought. Vegetation photosynthesis on the Loess Plateau is insensitive to temperature changes. We compared vegetation in different climatic zones and found that the vegetation photosynthetic resilience in arid climatic zones decreased with increasing drought intensity, By contrast, vegetation photosynthetic resilience was more stable in semi-arid climatic zones and decreased in the order of severe, mild, and moderate drought in semi-humid zones. Among the vegetation types, forests demonstrated the highest vegetation photosynthetic resilience and resistance. The results of this study will advance our understanding of the regional characteristics of vegetation stability in the Loess Plateau under the background of climate change and thus lay the scientific foundation for the ecological restoration and management of the Loess Plateau.

Key words: solar-induced chlorophyll fluorescence, photosynthesis, Loess Plateau, meteorological drought, resilience, resistance