scholarly journals Relationship of variable chlorophyll fluorescence indices to photosynthetic rates in microphytobenthos

2007 ◽  
Vol 49 ◽  
pp. 71-85 ◽  
Author(s):  
J Serôdio ◽  
S Vieira ◽  
F Barroso
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosynthetic Rates ◽  
Variable Chlorophyll Fluorescence ◽  
Relationship Of

scholarly journals The Impacts of Growth and Environmental Parameters on Solar-Induced Chlorophyll Fluorescence at Seasonal and Diurnal Scales

2019 ◽  
Vol 11 (17) ◽  
pp. 2002
Author(s):  
Leizhen Liu ◽  
Wenhui Zhao ◽  
Jianjun Wu ◽  
Shasha Liu ◽  
Yanguo Teng ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Growth Parameters ◽  
Pearson Correlation ◽  
Canopy Structure ◽  
Principal Component ◽  
Environmental Parameters ◽  
Area Index ◽  
Relationship Of ◽  
The Impact

Solar-induced chlorophyll fluorescence (SIF) is considered to be a potential indicator of photosynthesis. However, the impact of growth and environmental parameters on SIF at different time-scales remains unclear, which has greatly restricted the application of SIF in detecting photosynthesis variations. Thus, in this study, the impact of growth and environmental parameters on SIF was thoroughly clarified. Here, continuous time series of canopy SIF (760 nm, F760) over wheat and maize was measured based on an automated spectroscopy system. Meanwhile, field measurements of growth and environmental parameters were also collected using commercial-grade devices. Relationships of these parameters with F760, apparent SIF (F760/solar radiance, AF760), and SIF yield (F760/canopy radiance of 685 nm, Fy760) were analyzed using principal component analysis (PCA) and Pearson correlation to reveal their impacts on SIF. Results showed that F760 at seasonal and diurnal scales were mainly driven by solar radiation (SWR), leaf area index (LAI), chlorophyll content (Chl), mean leaf inclination angle (MTA), and relative water content (RWC). Other environmental parameters, including air temperature (Ta), relative humidity (Rh), vapor pressure deficit (VPD), and soil moisture (SM), contribute less to the variation of seasonal or diurnal F760. AF760 and Fy760 are likely to be less dependent on Ta, Rh, and VPD due to the removal of the impact from SWR, but an enhanced relationship of AF760 (and Fy760) with SM was observed, particularly under water stress. Compared with F760, wheat AF760 was better correlated to LAI and RWC as expected, while maize AF760 did not show an enhanced relationship with all growth parameters, probably due to its complicated canopy structure. The relationship of wheat Fy760 with canopy structure parameters was further reduced, except for maize measurements. Furthermore, SM-induced water stress and phenological stages should be taken into consideration when we interpret the seasonal and diurnal patterns of SIF since they were closely related to photosynthesis and plant growth (e.g., LAI in our study). To our knowledge, this is the first exploration of the impacts of growth and environmental parameters on SIF based on continuous ground measurements, not only at a seasonal scale but also at a diurnal scale. Our results could provide deep insight into the variation of SIF signals and also promote the further application of SIF in the health assessments of terrestrial ecosystems.

A possible relation between the function of photosystem II in oxygen evolution and the variable chlorophyll fluorescence

1989 ◽  
Vol 238 (1291) ◽  
pp. 127-136
Keyword(s):  
Chlorophyll Fluorescence ◽  
Photosystem Ii ◽  
Reaction Centre ◽  
Redox Potentials ◽  
Donor Side ◽  
Hypothetical Model ◽  
Surplus Energy ◽  
Variable Chlorophyll Fluorescence ◽  
And Function ◽  
Energy Dependent

A hypothetical model for the structure and function of photosystem II is proposed that attempts to incorporate different phenomena related to the variable chlorophyll fluorescence inherent in this photosystem. The involvement of pheophytin redox chemistry on both the acceptor and donor side of photosystem II is postulated to achieve redox potentials high enough to oxidize water. The presence of this symmetry would be the cause of inefficient photochemistry in photosystem II when, under unbalanced carbon metabolism, a surplus charge remains on the reaction centre. In addition, such a scheme would enable an efficient dissipation of surplus energy in the reaction centre itself, and would be the origin ofthe ‘energy-dependent’ quenching of chlorophyll fluorescence, q ( E ).

Relationship of intertidal surface sediment chlorophyll concentration to hyperspectral reflectance and chlorophyll fluorescence

2006 ◽  
Vol 29 (2) ◽  
pp. 183-196 ◽  
Author(s):  
Jacco C. Kromkamp ◽  
Edward P. Morris ◽  
Rodney M. Forster ◽  
Claire Honeywill ◽  
Scott Hagerthey ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Surface Sediment ◽  
Chlorophyll Concentration ◽  
Hyperspectral Reflectance ◽  
Relationship Of ◽  
Intertidal Surface
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