Air [CO2] tends to increase due to climate changes, affecting plant growth. Field-grown Coffea arabica trees were grown under actual and elevated [CO2] for four years. Rakocevic et al. find that elevated [CO2] stimulated stomatal conductance and whole-plant photosynthesis, increasing water-use efficiency during the fourth dry period.
Elevated [CO2] reduced leaf area and carbon investment in 2nd order branches, but also changed plant carbon partitioning by elevated [CO2], with plants showing structure rejuvenation. Data also suggest carbon allocation to root system under elevated [CO2]. After long-term exposure to elevated [CO2], structural and functional responses balanced each other and must be considered when studying impacts of elevated [CO2] in perennial species.