Response intensity and sensitivity of gross primary productivity to drought stress in the middle reaches of the Yangtze River
ZHENG Liang1，2， WU Hao1，2， LIN Anqi1，2， SHEN Fang1，2， JIANG Ting1，2
(1. School of Urban and Environmental Sciences, Central China Normal University, Wuhan 430079, China;2. Hubei Key Laboratory of Geographic Processes Analysis and Simulation, Wuhan 430079, China)
Abstract：Drought， as a typical extreme climatic event， has shown increasing frequency and intensity under global warming， posing serious threats to regional ecosystem stability and terrestrial carbon cycle functioning. Gross primary productivity （GPP）， a key indicator of vegetation carbon sequestration capacity， is critical for understanding the sensitivity of the carbon cycle to climate change. This study focuses on the middle reaches of the Yangtze River and systematically assesses the response intensity and sensitivity of GPP to cumulative drought stress， based on MODIS GPP products and multi-timescale standardized precipitation evapotranspiration index （SPEI）. The results indicate that during the study period， regional GPP exhibited a significant upward trend， while SPEI showed a slight recovery but generally remained in a state of moisture deficit with frequent drought events. GPP responded differently to droughts of varying timescales. Short-term drought （SPEI_01） exhibited a slight promotion effect on GPP， but with prolonged drought duration， the responses in some cropland and grassland areas shifted from promotion to suppression， suggesting that cumulative drought has a persistent negative effect on carbon uptake.GPP responses of grassland， forest， and cropland ecosystems to drought stress exhibited marked differences. Grasslands exhibit the highest sensitivity to drought. Forests demonstrated stronger water regulation and buffering capacities， with more delayed but smaller fluctuations. Croplands， influenced by both natural conditions and human management， showed pronounced spatial heterogeneity and complex response patterns. By analyzing multi-time-scale drought indices and the corresponding responses of GPP， this study elucidates the divergent mechanisms underlying the cumulative drought responses among different ecosystem types. These findings enhance the understanding of drought response mechanisms across different ecosystems and provide a scientific basis for improving regional carbon sink capacities and formulating targeted climate adaptation strategies.
郑粮,吴浩,林安琪,申芳,姜婷,. 长江中游总初级生产力对干旱胁迫的响应程度及敏感性研究[J]. 华中师范大学学报(自然科学版), 2025, 59(5): 647-657.
ZHENG Liang,WU Hao,LIN Anqi,SHEN Fang,JIANG Ting,. Response intensity and sensitivity of gross primary productivity to drought stress in the middle reaches of the Yangtze River. journal1, 2025, 59(5): 647-657.
2025, Vol. 59 
