Data for the paper: Physiological responses to ultra-high CO2 levels in an evergreen tree species

As atmospheric CO2 increases globally, plants increase the rate of photosynthesis. Still, leaf gas exchange can be downregulated by the plant. Here we tested the limits of these plant responses in a fruit tree species under very high CO2 levels relevant to future Earth and to contemporary Mars. Plant water use decreased at 1600 ppm CO2 and remained low at 6000 ppm. Photosynthesis significantly increased at 6000 ppm. In summary, ultra-high CO2 may partly compensate for limited water availability.