Divergent impacts of drought on autumn phenology in China

Abstract

Drought events occur frequently, but the impact of drought on plant autumn phenology, i.e., End of growing Season (EOS), has not been thoroughly studied. Considering that drought has cumulative and lagged effects on plants. In this study, we quantified two effects of drought on EOS in China. Our results indicated that cumulative and lagged affected 39.5% and 70.1% of plants EOS in China over the past two decades. Two effects of drought on short timescales (2- to 4-accumulated month and 1- to 5-lagged month) largely affected EOS of plants. Drought in the first two months of EOS advanced EOS, while drought in the fifth month before EOS caused plants to overcompensate for growth and delayed plant senescence. At the biome level, forests were more resistant to drought than grasslands and shrublands. From the perspective of the water balance gradient, drought was more significant in humid regions, and it was found that increased water loss exacerbated the effects of drought and shortened plant response time. Our study reveals the impact of drought on plant autumn phenology and provides insights into predicting future vegetation growth patterns under global change.

Keywords

• Autumn phenology
• Drought
• Cumulative effect
• Lagged effect
• SPEI