Photorespiration in R plantecophys

[tyeentaylor]

Hi Remko,

I'm exploring a question about photorespiration, and I'm trying to figure out how it's accounted for in plantecophys. I can see that the Ci-dependent relative reaction affinity of Rubisco for C vs. O is reflected in Km, and the compensation point with GammaStar. But I can't see any specific accounting for the CO2 released during photorespiration.

Is Ac actually the balance of Vc and photorespiration? Thus, for Vcmax limited A:

Ac = Vc - 0.5*Vo
Anet = Ac - Rd

Is that right? And does the CO2 released from photorespiration contribute to the estimate of Ci?

Thanks very much for any clarifications.

Ty

[RemkoDuursma]

Hi Ty, yes that is correct. Photorespiration is accounted for in the model implemented in Photosyn and fitaci. The model of Farquhar et al (1980) accounts for it (https://link.springer.com/article/10.1007/BF00386231).