Measuring Leaf Photosynthesis (IMAGE) University of Wyoming Caption Smithsonian Tropical Research Institute interns Laura Lyon (left) and Catalina Guerra measure leaf level photosynthesis to better understand how tropical trees use soil moisture at the Agua Salud project site in the Panama Canal Watershed. (Mario Bretfeld Photo) Credit Mario Bretfeld Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.