Ecophysiology of coffee growth and production in a context of climate changes

The global coffee market is circumscribed to two species, Coffea arabica (aka. Arabica coffee) and C. canephora (aka. Robusta coffee), which account for ca. 99% of coffee production. Both species exhibit some fragility to the perils of ongoing climate changes, with exacerbation of these conditions expected over the years to come. Supra-optimal temperatures and drought are the major environmental stresses impacting coffee growth and production, especially under full sunlight conditions. By contrast, growing evidence suggests that elevated atmospheric [CO₂] partly mitigate the impacts and damages caused to coffee plants by warming and droughts. Moreover, the positive effects of enhanced [CO₂] on coffee photosynthesis and yields are suggested to be greater under moderate to high solar irradiances. Here, we explore (i) the role of photosynthetic gas exchanges as a key physiological driver on coffee production; (ii) the ecophysiological responses of shaded and unshaded coffee plantations to compare and contrast shade benefits and drawbacks in the coming years (highlighting the use of agroforestry and particle films as agronomic management strategies to reduce solar energy loads); (iii) the present and forthcoming aspects associated with the coffee production, emphasising the positive role of rising atmospheric [CO₂] in boosting coffee yields; (iv) some morpho-physiological aspects linked to the overall superior yield performance of Robusta to that of Arabica coffee; and finally (v) provide some guidance on the optimum temperature range for coffee production.