提示
基于光合与蒸散耦合/解耦特征的植被水分利用效率季节动态研究
首发时间：2025-03-03
摘要：本研究旨在通过生态系统中光合速率(以总初级生产力gpp表征)与蒸散发(et)的耦合与解耦特征，探讨生态系统尺度水分利用效率(wue)的估算方法及季节变化。研究假设gpp与et的耦合主要来自gpp与蒸腾过程之间的协同变化，解耦则主要来自非生物性的蒸发过程的相对独立变化，基于gpp与et的回归分析定义植被wue(vwue)指标，并与三种传统的wue指标开展对比。利用fluxnet2015数据集，选取落叶阔叶林(dbf)和常绿阔叶林(ebf)站点，分析四种wue指标季节变化的异同。研究发现，dbf生态系统的wue随季节变化呈现显著波动，vwue在春秋过渡季节高于夏季，该趋势与传统wue指标有显著差异，甚至呈现相反趋势；ebf生态系统的wue总体相对dbf稳定，但vwue呈现出干季与湿季有显著不同。不同wue指标间的差异表明拆分生物和非生物过程对wue估算方法及季节变化的显著影响，也为进一步理解生态系统的水分利用动态及对气候变化的响应提供有价值的参考。
关键词：
for information in english, please click here
seasonal dynamics of vegetation water use efficiency inferred from the coupling/decoupling characteristics between photosynthesis and evapotranspiration
abstract：this study aims to explore the estimation methods and seasonal variations of ecosystem-scale water use efficiency (wue) by examining the coupling and decoupling characteristics between photosynthetic rate represented by gross primary production (gpp) and evapotranspiration (et) in ecosystems. the study hypothesizes that the coupling between gpp and et mainly arises from the coordinated variations between gpp and the transpiration process, whereas the decoupling is primarily due to the relatively independent variations of non-biological evaporation. based on regression analysis between gpp and et, a vegetation water use efficiency (vwue) index is defined and compared with three traditional wue indices. utilizing the fluxnet2015 dataset, sites in deciduous broadleaf forests (dbf) and evergreen broadleaf forests (ebf) are selected to analyze the similarities and differences in the seasonal variations of the four wue indices. the findings reveal that the wue of dbf ecosystems exhibits significant seasonal fluctuations, with vwue being higher during the spring and autumn transition periods than in summer- a trend that markedly differs from, and in some cases even opposes, the patterns shown by traditional wue indices. in contrast, while the overall wue of ebf ecosystems is relatively more stable compared to dbf, vwue in ebf displays significant differences between the dry and wet seasons. these discrepancies among the various wue indices indicate that disentangling biological and non-biological processes has a significant impact on the estimation and seasonal dynamics of wue, providing valuable insights for further understanding the dynamics of ecosystem water use and their responses to climate change.
keywords：
论文图表：
引用
导出参考文献
no.****
同行评议
勘误表
基于光合与蒸散耦合/解耦特征的植被水分利用效率季节动态研究
评论
全部评论