Wang Mingming, Zhang Leiming
Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China.
Plants (Basel). 2023 Jun 5;12(11):2224. doi: 10.3390/plants12112224.
Using in situ near-surface observations of solar-induced chlorophyll fluorescence (SIF) and gross primary productivity (GPP) of a subtropical evergreen coniferous forest in southern China, this study analyzed the dynamics of SIF, GPP and their environmental responses, and explored the potential of SIF in characterizing the variation of GPP. The results showed that SIF and GPP have similar diurnal and seasonal variation and both reach the highest value in summer, indicating that the SIF can be applied to indicate the seasonal variation of GPP for the subtropical evergreen co-niferous. With the increase in temporal scale, the correlation between SIF and GPP becomes more linear. The diurnal variations of both SIF and GPP were characterized by photosynthetically active radiation (PAR), the seasonal variations of SIF and GPP were influenced by air temperature (Ta) and PAR. Probably due to the absent of drought stress during the study period, no significant correlation was detected between soil water content (SWC) and either SIF or GPP. With the in-crease in Ta, PAR or SWC, the linear correlation between the SIF and GPP gradually decreased, and when Ta or PAR was relatively higher, the correlation between SIF and GPP become weakly. Further research is still needed to illustrate the relationship between SIF and GPP under drought condition which occurred frequently in this region based on longer observation.
利用对中国南方亚热带常绿针叶林太阳诱导叶绿素荧光（SIF）和总初级生产力（GPP）的近地表原位观测，本研究分析了SIF、GPP的动态变化及其对环境的响应，并探讨了SIF在表征GPP变化方面的潜力。结果表明，SIF和GPP具有相似的昼夜和季节变化，且均在夏季达到最高值，这表明SIF可用于指示亚热带常绿针叶林GPP的季节变化。随着时间尺度的增加，SIF与GPP之间的相关性变得更加线性。SIF和GPP的昼夜变化均以光合有效辐射（PAR）为特征，SIF和GPP的季节变化受气温（Ta）和PAR的影响。可能由于研究期间没有干旱胁迫，土壤含水量（SWC）与SIF或GPP之间均未检测到显著相关性。随着Ta、PAR或SWC的增加，SIF与GPP之间的线性相关性逐渐降低，当Ta或PAR相对较高时，SIF与GPP之间的相关性变弱。基于更长时间的观测，仍需要进一步研究来说明该地区频繁发生干旱条件下SIF与GPP之间的关系。
