The study provides novel findings about plant strategies under very high CO2 atmospheric conditions, such as on Mars. The authors show a large increase in fruit tree water use efficiency, an indicator for how efficiently plants photosynthesize for a given amount of water supply, when the CO2 concentrations are about an order of magnitude higher than that experienced on Earth. Therefore, these fruit trees potentially can survive and grow with less water in these conditions.
The study provides novel findings about plant strategies under very high CO2 atmospheric...
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 the 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.
As atmospheric CO2 increases globally, plants increase the rate of photosynthesis. Still,...