A new study led by Oregon State University suggests leaves in forest canopies are not able to cool themselves below the surrounding air temperature, likely meaning trees’ ability to avoid damaging temperature increases, and to pull carbon from the atmosphere, will be compromised in a warmer, drier climate. The findings contrast with a prevailing theory in the scientific community that canopy leaves can keep their temperature within an optimal range for photosynthesis. Published in the Proceedings of the National Academy of Sciences, the research… showed that canopy leaves warm faster than air, are warmer than air during most of the day and only cool below air temperature in mid- to late-afternoon. Future climate warming is likely to lead to even greater canopy leaf temperatures, which would negatively impact forest carbon cycling and enhance forest mortality risk, the scientists say. [also see further coverage in Florida State University News]