No Respiration term in one of Rooted Aquatic Plants Formulation

In EFDC+ Theory Base about aquatic plant (this link), “Dissolved oxygen coupling” is described by the formula(7.163) in The figure below is formula(7.163).My question is: Why this formula lack the “Respiration term”? I think both photosynthesis and respiration of SAV link to DO dynamics.

The respiration and photosynthesis are included in the growth rate factor, as these are lumped values. This is the same way as it works in the WQ kinetics. Note that for the WQ kinetics the original EFDC only uses daily averages. With EFDC+ the user can obtain diurnal fluctuation for WQ with option 2 (attached), which uses solar radiation directly from the ASER file. However, we haven’t updated the RPEM sub-model to reflect the sub-daily time scales.