Data from: C4 photosynthesis boosts growth by altering physiology, allocation and size

C4 photosynthesis is a complex set of leaf anatomical and biochemical
adaptations that have evolved more than 60 times to boost carbon uptake
compared with the ancestral C3 photosynthetic type1,​2,​3. Although C4
photosynthesis has the potential to drive faster growth rates4,5,
experiments directly comparing C3 and C4 plants have not shown consistent
effects1,6,7. This is problematic because differential growth is a crucial
element of ecological theory8,9 explaining C4 savannah responses to global
change10,11, and research to increase C3 crop productivity by introducing
C4 photosynthesis12. Here, we resolve this long-standing issue by
comparing growth across 382 grass species, accounting for ecological
diversity and evolutionary history. C4 photosynthesis causes a 19–88%
daily growth enhancement. Unexpectedly, during the critical seedling
establishment stage, this enhancement is driven largely by a high ratio of
leaf area to mass, rather than fast growth per unit leaf area. C4 leaves
have less dense tissues, allowing more leaves to be produced for the same
carbon cost. Consequently, C4 plants invest more in roots than C3 species.
Our data demonstrate a general suite of functional trait divergences
between C3 and C4 species, which simultaneously drive faster growth and
greater investment in water and nutrient acquisition, with important
ecological and agronomic implications.