摘要
在区域和植被类型尺度上定量厘定气候因子对长江中下游地区生长季植被GPP(GPP_(GS))的直接、间接和综合影响,可为全球气候变化背景下区域植被资源管理与恢复提供科学依据.利用MODIS GPP数据、气象数据和植被类型数据,结合Theil-Sen Median趋势分析和Mann-Kendall显著性检验探究长江中下游地区植被GPP_(GS)时空变化特征,并通过通径分析揭示气候因子对长江中下游地区整体和不同类型植被GPP_(GS)变化的直接影响、间接影响和综合影响.结果表明:(1)2000~2021年长江中下游地区植被GPP_(GS)呈波动上升趋势,上升速率(以C计,下同)为2.70 g·(m^(2)·a)^(-1)(P<0.01).不同类型植被GPP_(GS)均呈极显著上升趋势(P<0.01),其中,灌丛上升速率最高,为3.31 g·(m^(2)·a)^(-1),栽培植被上升速率最低,为2.54 g·(m^(2)·a)^(-1).(2)长江中下游地区GPP_(GS)呈上升趋势的面积占比为88.11%.不同类型植被GPP_(GS)呈上升趋势的面积占比均大于84%.(3)通径分析结果表明,降水和最高气温对植被GPP_(GS)的直接影响呈显著正向影响(P<0.05),而太阳辐射呈不显著正向影响(P≥0.05).最高气温、降水和太阳辐射对植被GPP_(GS)的间接影响均呈非显著负向影响(P≥0.05).在直接影响和间接影响的综合作用下,降水和最高气温对植被GPP_(GS)呈不显著正向影响(P≥0.05),而太阳辐射对植被GPP_(GS)呈不显著负向影响(P≥0.05);不同植被类型上,降水是影响栽培植被GPP_(GS)变化的主要气候因子,最高气温是影响针叶林、阔叶林、灌丛和草丛GPP_(GS)变化的主要气候因子.(4)长江中下游地区植被GPP_(GS)变化主要受最高气温、降水和太阳辐射的直接影响,降水的直接影响对植被GPP_(GS)变化的主导区域占56.72%.研究结果可为量化长江中下游地区植被固碳潜力和全球气候变化背景下制定因地制宜的生态恢复治理政策提供参考.
Quantitatively determining the direct,indirect,and comprehensive effects of climatic factors on the growing season of the vegetation GPP(GPP_(GS))in the middle and lower reaches of the Yangtze River at the regional and vegetation type scales can provide a scientific basis for the management and restoration of regional vegetation resources under the background of global climate change.Using MODIS GPP data,meteorological data,and vegetation type data,combined with Theil-Sen Median trend analysis and the Mann-Kendall significance test,the spatiotemporal characteristics of the GPP_(GS) in the middle and lower reaches of the Yangtze River were investigated at different temporal and spatial scales.Path analysis was used to further reveal the direct,indirect,and comprehensive effects of climate factors on GPP_(GS) variation in different vegetation types.The results showed that:①from 2000 to 2021,the vegetation GPP_(GS) in the middle and lower reaches of the Yangtze River showed a fluctuating upward trend,with a rising rate(in terms of C,same below)of 2.70 g·(m^(2)·a)^(-1)(P<0.01).The GPP_(GS) of different vegetation types all showed a significant upward trend(P<0.01),with shrubs having the highest upward rate of 3.31 g·(m^(2)·a)^(-1) and cultivated vegetation having the lowest upward rate of 2.54 g·(m^(2)·a)^(-1).②The proportion of the area with an upward trend in GPP_(GS) in the middle and lower reaches of the Yangtze River was 88.11%.The proportion of the area with an upward trend in GPP_(GS) was greater than 84%for all different vegetation types,with shrubs(49.76%)and cultivated vegetation(44.36%)having significantly higher proportions of the area with an upward trend than that in other vegetation types.③The path analysis results showed that precipitation and the maximum temperature had a significant positive direct effect on vegetation GPP_(GS)(P<0.05),whereas solar radiation had a non-significant positive effect(P≥0.05).The indirect effects of maximum temperature,precipitation,and solar radiation on v
作者
徐勇
盘钰春
邹滨
郑志威
郭振东
XU Yong;PAN Yu-chun;ZOU Bin;ZHENG Zhi-wei;GUO Zhen-dong(College of Geomatics and Geoinformation,Guilin University of Technology,Guilin 541006,China;School of Geosciences and Info-physics,Central South University,Changsha 410083,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第3期1615-1628,共14页
Environmental Science
基金
广西科技基地和人才专项(桂科AD21220133)
广西自然科学基金项目(2020GXNSFBA297160)。
