The study looked at how temperate forests might respond to higher levels of CO2 in the air. They did experiments with different tree species in various conditions to see how they would grow. The researchers found that the size and shape of pots, as well as the amount of light and nutrients, affected how trees responded to increased CO2. Birch and maple seedlings reacted differently to changes in moisture levels when exposed to elevated CO2. The study also looked at how changes in tree communities could impact overall forest productivity.