Competition effects on plastic and genotypic responses to [CO₂]

Plant–plant interactions could mediate vegetation responses to rising atmospheric CO₂ concentration ([CO₂]), because some plants benefit more from [CO2] elevation than others. Van Loon et al. investigated how changes in performance due to elevated [CO2] are modified by aboveground plant–plant interactions.

They grew Plantago asiatica seeds originating from natural [CO₂] springs and from ambient [CO₂] in mono-stands of both origins as well as mixtures of both origins in climate rooms under different [CO₂] levels. Their results showed that plant performance to elevated [CO₂] was mainly determined by plastic responses and not by genotypic responses. However, this pattern was highly modified by plant–plant interactions.