Structural and functional responses of coffee trees to elevated [CO₂]

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 2^nd 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.