北京林业大学学报2025，Vol.47Issue(10)：19-31,13.DOI:10.12171/j.1000-1522.20250147
贺兰山植被GPP对干旱的非线性响应
Nonlinear response of vegetation GPP to drought in the Helan Mountains of northwestern China
摘要
Abstract
[Objective]This study aims to elucidate the response mechanisms of vegetation productivity to drought events across multiple time scales in arid and semi-arid regions,reveal their spatiotemporal patterns,and provide a scientific basis for regional carbon cycle regulation and climate adaptation management.[Method]Taking the Helan Mountains of northwestern China as the study area,we applied the Denitrification-Decomposition(DNDC)and Forest-DNDC models to simulate the spatiotemporal dynamics of gross primary productivity(GPP)from 2001 to 2021.Drought conditions were characterized using the Standardized Precipitation Evapotranspiration Index(SPEI)at four time scales:SPEI-1(monthly),SPEI-6(semi-annual),SPEI-12(annual),and SPEI-24(multi-year).Linear correlation analysis and generalized additive models(GAMs)were used to quantitatively evaluate the effects of drought characteristics(duration,severity,intensity,and frequency)on GPP.[Result](1)During 2001-2021,GPP in the Helan Mountains showed a significant increasing trend,with an average annual growth rate of 0.20 g/(m2·year)(expressed as carbon),and showed a spatial gradient decreasing from the center to the surrounding areas;(2)GPP responses to drought were strongly time-scale-dependent and nonlinear.At the short-term timescale(SPEI-1),GPP was negatively correlated with drought duration,severity,and frequency,while weak drought intensity showed a slight positive effect,suggesting compensatory growth responses;(3)As the time scale extended(SPEI-6,SPEI-12,and SPEI-24),the inhibitory effect of drought on GPP progressively intensified,showing nonlinear threshold behavior;(4)Among ecosystems,grasslands were the most sensitive to medium-and long-term droughts,with GPP reductions significantly greater than those in forests and shrublands.[Conclusion]GPP responses to drought stress in the Helan Mountains exhibit pronounced time-scale dependence and nonlinear behavior,with distinct sensitivity differences among ecosystem types.This study highlights the need to integrate drought characteristics and vegetation sensitivity into multi-scale drought risk assessment and ecosystem management strategies,providing a scientific basis for enhancing carbon sequestration capacity in arid regions.关键词
贺兰山/干旱事件/总初级生产力/非线性响应/Forest-DNDC模型/DNDC模型Key words
Helan Mountains/drought events/gross primary productivity(GPP)/nonlinear response/Forest-DNDC model/DNDC model分类
农业科技引用本文复制引用
王新云,何杰,潘佩佩,刘兴社,王兆一..贺兰山植被GPP对干旱的非线性响应[J].北京林业大学学报,2025,47(10):19-31,13.基金项目
宁夏自然科学基金项目(2022AAC03097、2024AAC03079),国家自然科学基金项目(42471336). （2022AAC03097、2024AAC03079）
