In a new study published in New Phytologist, researchers at Michigan State University (MSU) have uncovered how Amazon rainforest canopy trees manage the intense sunlight they absorb—revealing resilience to hot and dry conditions in the forest canopy while also offering a way to greatly improve the monitoring of canopy health under increasing extreme conditions. 

The study, led by doctoral candidate Leonardo Ziccardi with professor Scott C Stark in the MSU Department of Forestry, shows how tropical trees act like giant solar antennas—absorbing vast quantities of light energy that must be carefully managed. When trees absorb more energy than they can use for photosynthesis, it must be safely dissipated, either as heat or re-emitted as light—a process called chlorophyll fluorescence.

“It’s been a long journey,” said Ziccardi. “Since 2019, we’ve run multiple field campaigns across seasons, climbing giant trees in the heart of the Amazon to understand how these forests respond to environmental changes. We’ve spent hundreds of hours up in the canopy doing measurements—some of the most intense and rewarding work I’ve ever done.”