Fluorescence spectrum measured with an LI-6800
Fluorescence spectrum measured with an LI-6800

Modification to a gas-exchange system to measure passive and active fluorescence simultaneously

Work led by recently graduated M.S. student, Eliot Meeker! 

Eliot W Meeker, Troy S Magney, Nicolas Bambach, Mina Momayyezi, Andrew J McElrone, Modification of a gas exchange system to measure active and passive chlorophyll fluorescence simultaneously under field conditions, AoB PLANTS, Volume 13, Issue 1, February 2021, plaa066, https://doi.org/10.1093/aobpla/plaa066

Summary: Solar-induced fluorescence (SIF) is a promising tool to estimate photosynthesis across scales; however, there has been limited research done at the leaf level to investigate the relationship between SIF and photosynthesis. To help bridge this gap, a LI-COR LI-6800 gas exchange instrument was modified with a visible-near-infrared (VIS-NIR) spectrometer to measure active and passive fluorescence simultaneously. The system was adapted by drilling a hole into the bottom plate of the leaf chamber and inserting a fibre-optic to measure passive steady-state fluorescence (Ft,λ, analogous to SIF) from the abaxial surface of a leaf. This new modification can concurrently measure gas exchange, passive fluorescence and active fluorescence over the same leaf area and will allow researchers to measure leaf-level Ft,λ in the field to validate tower-based and satellite measurements