Diurnal Dynamics of Solar-induced Chlorophyll Fluorescence and
Photosynthesis in a Maize Canopy
Solar-induced chlorophyll fluorescence (SIF) offers a promising method
to remotely monitor photosynthesis at the canopy and regional scale.
However, in order to interpret satellite SIF measurements in a
biological context, there needs to be a better understanding of the
diurnal dynamics of SIF and photosynthesis under variable stress
conditions. Photons absorbed by a leaf can enter photochemistry, be
actively dissipated via non-photochemical quenching (NPQ), or be
re-emitted as chlorophyll fluorescence. Therefore, having better
understanding of NPQ should improve interpretation of SIF. At the canopy
scale, we captured diurnal dynamics of SIF and GPP. We then coupled
leaf-level measurements of chlorophyll fluorescence, NPQ and
photosynthesis and plant water status with canopy-level SIF and GPP to
explore the mechanisms controlling diurnal dynamics of fluorescence vs.
photosynthesis in a rain-fed maize field situated in upstate New York.