Attributing Differences of Solar-Induced Chlorophyll Fluorescence (SIF)-Gross Primary Production (GPP) Relationships between Two C4 Crops: Corn and Miscanthus

Themes: Feedstock Production, Sustainability

Keywords: Field Data


Wu, G.Guan, K.Jiang, C., Kimm, H., Miao, G., Bernacchi, C.J.Moore, C.E.Ainsworth, E.A., Yang, X., Berry, J.A., Frankenberg, C., Chen, M. June 21, 2022. “Attributing Differences of Solar-Induced Chlorophyll Fluorescence (SIF)-Gross Primary Production (GPP) Relationships Between Two C4 Crops: Corn and Miscanthus.” Agricultural and Forest Meteorology 323:109046. DOI: 10.1016/j.agrformet.2022.109046.


Relationships between canopy SIF760 and GPP at half-hourly and daily scales in (a and d) 2018 corn, (b and e) 2019 miscanthus and (c and f) 2020 miscanthus. Half-hourly SIF760-GPP relationships were colored by APAR, and the colored triangles with black edge color were sunny days and the colored circles were cloudy days. Daily SIF760-GPP relationships were separated into sunny days (white circles) and cloudy days (black triangles). “ns” indicated that SIF760 and GPP were not significantly correlated. Other r values were statistically significant. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

Information to characterize the solar-induced chlorophyll fluorescence (SIF)-gross primary production (GPP) relationship in C4 cropping systems remains limited. The annual C4 crop corn and perennial C4 crop miscanthus differ in phenology, canopy structure and leaf physiology. Investigating the SIF-GPP relationships in these species could deepen our understanding of SIF-GPP relationships within C4 crops. Using in situ canopy SIF and GPP measurements for both species along with leaf-level measurements, we found considerable differences in the SIF-GPP relationships between corn and miscanthus, with a stronger SIF-GPP relationship and higher slope of SIF-GPP observed in corn compared to miscanthus. These differences were mainly caused by leaf physiology. For miscanthus, high non-photochemical quenching (NPQ) under high light, temperature and water vapor deficit (VPD) conditions caused a large decline of fluorescence yield (ΦF), which further led to a SIF midday depression and weakened the SIF-GPP relationship. The larger slope in corn than miscanthus was mainly due to its higher GPP in mid-summer, largely attributed to the higher leaf photosynthesis and less NPQ. Our results demonstrated variation of the SIF-GPP relationship within C4 crops and highlighted the importance of leaf physiology in determining canopy SIF behaviors and SIF-GPP relationships.


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  • GPP and APAR relationships
  • Leaf assimilation rate responses to intracellular CO2 concentrations

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