(1) in the absence of conductance acclimation,
the relative increase in photosynthesis at high CO2 is much larger
in species with lower, than in species with higher, conductances,
as already reported by [56]; (2) such an increase may be reduced
if the species has lower rates, or downregulates photosynthetic
capacity (Vc,max and Jmax); (3) the reduction in the potential benefit
of high CO2 on AN will be approximately doubled, if in addition
to acclimation of gs (as expected), there is also down regulation
of gm under high CO2. (4) acclimation of gs and gm has a higher
impactin low conductance species regardless oftheir biochemistry,
resulting in an overall percentage increase of AN at high CO2 which
is only marginally higher than that shown by high conductance
species; and (5) both the benefits in the absence of acclimation
and the partial cancelation of such benefits by acclimation
are more evident as temperatures increase, for which differences
among species are expected to be larger in high-temperature
climates.