Apparent photosynthetic capacity exhibits substantial diurnal
variation
There is substantial diurnal variation in apparent photosynthetic
capacity (apparent Vcmax andJmax ) (ranging from 0% change to over 50%
decline). This variation has been ignored by TBMs, which typically use
fixed estimates of apparent Vcmax and by leaf
level physiologists who previously lacked an approach to collect high
temporal resolution data in vivo . While we found interspecific
differences in the diurnal response, the decline in apparentVcmax and apparent Jmaxhas important implications for modelling photosynthetic carbon uptake
and should not be ignored.