The inhibition of leaf respiration in the light has long been reported at a leaf scale, but recent isotopic evidence suggests that inhibition also occurs at the ecosystem scale. This is important, as inhibition at the ecosystem scale would imply a significant bias in current estimates of ecosystem photosynthesis and respiration, but it is not known how widespread inhibition is across different ecosystems, nor to what extent inhibition affects ecosystem photosynthesis and respiration estimates.
In this paper (Keenan et al., 2019, Nature Ecology and Evolution), we develop novel techniques based on globally distributed eddy-covariance observations to allow for the estimation of inhibition of ecosystem respiration during the day. Our results show that the inhibition of respiration is a pervasive and significant phenomenon across ecosystems, that varies in dependence of ecosystem functional characteristics. We use our results to develop new methods to estimate ecosystem photosynthesis and respiration from eddy-covariance flux observations, and show that previous estimates were appreciably biased and gave incorrect diurnal cycles. Eddy-covariance based estimates of ecosystem photosynthesis and respiration are widely used to test models and satellite based observations, which suggests that the current understanding derived from those approaches will need to be updated.