Detection of drought effects on photosynthetic stability of vegetation on the Loess Plateau based on solar-induced chlorophyll fluorescence

AimsThe Loess Plateau stands as one of China's most susceptible regions to meteorological drought, a vulnerability exacerbated in recent years by the backdrop of climate warming.As meteorological droughts show a rising trend, investigating the capacity of vegetation to withstand and recover from drought stress becomes paramount.Understanding the resilience and resistance of vegetation's photosynthetic physiological processes to drought is crucial for comprehending how vegetation responds to environmental shifts and for forecasting the future trajectory of vegetation development in the area.Methods Utilizing the solar-induced chlorophyll fluorescence Global SIF dataset based on OCO-2 (GOSIF) products alongside temperature and standardized precipitation evapotranspiration index (SPEI) data, this study aims to investigate the impact of drought on the spatial and temporal stability of photosynthesis across various vegetation types and climate zones on the Loess Plateau employing the multiple linear autoregressive model. Important findingsThe study revealed a linear relationship between vegetation photosynthetic resilience and the severity of drought experienced on the Loess Plateau.Vegetation photosynthetic resilience weakens in the order of mild, moderate, and severe drought.The relationship between vegetation photosynthetic resistance and drought severity exhibited a nonlinear pattern, with resistance declining from severe to mild and moderate drought.Vegetation photosynthesis on the Loess Plateau displayed insensitivity to temperature variations.Comparison across climatic zones highlighted that in arid regions, vegetation photosynthetic resilience declined