Aug 25, 2023 09:02 PM
https://www.sciencealert.com/photosynthe...tures-soar
INTRO: Forests, it's often said, are the lungs of Earth. Tall trees stretch skyward to find sunlight, sucking water up from their roots and carbon dioxide in through their leaves to photosynthesize. Like any chemical reaction, this elemental exchange works best within an optimal temperature range, outside of which a tree's photosynthetic machinery can break down.
With global temperatures rising, a new study combining tree canopy measurements and global satellite data has found a small fraction of canopy leaves in tropical forests might be reaching their upper limit. "This study shows that there are times and places where tropical forest leaves are surpassing their critical temperature thresholds," says senior author and tropical ecologist Gregory Goldsmith of Chapman University in California.
Research shows tropical trees can keep photosynthesizing up to 46.7 °C (116 °F) on average. But the world doesn't warm evenly, and neither do forest canopies. Heat tolerance varies among species and populations, and possibly even within leaves of the same tree, Goldsmith says.
To understand if some leaves are nearing temperatures that are too hot for photosynthesis, a team led by Northern Arizona University ecoinformastician Christopher Doughty pulled data from NASA's ECOSTRESS sensor, which measures land surface temperatures as it whizzes around Earth aboard the International Space Station... (MORE - details)
INTRO: Forests, it's often said, are the lungs of Earth. Tall trees stretch skyward to find sunlight, sucking water up from their roots and carbon dioxide in through their leaves to photosynthesize. Like any chemical reaction, this elemental exchange works best within an optimal temperature range, outside of which a tree's photosynthetic machinery can break down.
With global temperatures rising, a new study combining tree canopy measurements and global satellite data has found a small fraction of canopy leaves in tropical forests might be reaching their upper limit. "This study shows that there are times and places where tropical forest leaves are surpassing their critical temperature thresholds," says senior author and tropical ecologist Gregory Goldsmith of Chapman University in California.
Research shows tropical trees can keep photosynthesizing up to 46.7 °C (116 °F) on average. But the world doesn't warm evenly, and neither do forest canopies. Heat tolerance varies among species and populations, and possibly even within leaves of the same tree, Goldsmith says.
To understand if some leaves are nearing temperatures that are too hot for photosynthesis, a team led by Northern Arizona University ecoinformastician Christopher Doughty pulled data from NASA's ECOSTRESS sensor, which measures land surface temperatures as it whizzes around Earth aboard the International Space Station... (MORE - details)
