Multiple studies demonstrate that increased atmospheric carbon dioxide levels directly impact forests and vegetative growth by stimulating photosynthesis and plant productivity, though these effects can be modulated by nutrient limitations and physiological changes.
The retrieved papers consistently show that elevated carbon dioxide levels directly affect forest productivity, photosynthesis, stomatal conductance, biomass, and nutrient allocation, supporting the claim. None of the papers refute the core premise that CO2 directly affects vegetative growth, though some discuss interacting constraints such as nitrogen limitation or warming.