Attributing differences of solar-induced chlorophyll fluorescence (SIF)-gross primary production (GPP) relationships between two C4 crops: corn and miscanthus

Authors

• Genghong Wu, University of Illinois Urbana-Champaign
• Kaiyu Guan, University of Illinois Urbana-Champaign
• Chongya Jiang, University of Illinois Urbana-Champaign
• Hyungsuk Kimm, University of Illinois Urbana-Champaign
• Guofang Miao, University of Illinois Urbana-Champaign
• Carl J. Bernacchi, USDA ARS
• Caitlin E. Moore, University of Illinois Urbana-Champaign
• Elizabeth A. Ainsworth, University of Illinois Urbana-Champaign
• Xi Yang, University of Virginia
• Joseph A. Berry, Carnegie Institution of Washington
• Christian Frankenberg, Division of Geological and Planetary Sciences
• Min Chen, University of Wisconsin-Madison

Document Type

Article

Date of this Version

8-15-2022

Citation

Agricultural and Forest Meteorology 323 (2022) 109046

doi:10.1016/j.agrformet.2022.109046

Comments

U.S. government work

Abstract

There remains limited information to characterize the solar-induced chlorophyll fluorescence (SIF)-gross primary production (GPP) relationship in C4 cropping systems. 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.