Key stress indicators from chlorophyll fluorescence in five desert plant species

作者：Chuan Jin, Tianshan Zha, Charles P.‐A. Bourque, Peng Liu, Xin Jia, Yun Tian, Xinhao Li, Xinyue Liu, Xiaonan Guo, Mingze Xu, Xiaoyu Kang, Zifan Guo, Ning Wang · 发表于：Ecological Indicators · 年份：2022 · DOI：10.1016/j.ecolind.2022.109679 · 被引用次数：14 · 研究领域：Plant Water Relations and Carbon Dynamics、Plant responses to elevated CO2、Remote Sensing in Agriculture

Pulse-amplitude modulated chlorophyll fluorescence (ChlF) is widely used to measure environmental stress in plants. Yet, its continuous, long-term usage in situ is challenged due to the lack of appropriate daytime indicators. We investigated the prospect of creating new daytime indicators based on an application of linear regression on daily measurements of photochemical efficiency (ФPSII) and photosynthetically active radiation acquired in situ at 30-minute intervals. Daily regression parameters, thus generated, were subsequently used in a broader context of desert-plant response to environmental change. Here, we compared parametric and non-parametric methods to test the feasibility of daytime-based regression parameters, i.e., maximal quantum yield of photosystem II photochemistry (Fv/Fm) and daily mean ФPSII, in gauging physiological response in three shrub and two herb species as influenced by eight environmental variables. Results demonstrated that: (i) Random Forest (RF; a non-parametric method) provided the best assessment of interaction between ChlF-based parameters and environmental variables, compared with multiple linear regression (MLR; a conventional parametric method); (ii) variable importance and partial dependence plots indicated that the daily regression parameters of the ФPSII-to- photosynthetic photon flux density relationship (y-intercept and slope) were superior to those of ФPSII and Fv/Fm; and (iii) compared with Fv/Fm, the y-intercept and slope improved...