Kent State Geography Researcher Examines Tree Growth by Looking at Air Masses

What are the main factors that either inhibit or promote growth in trees? Traditionally, scientists primarily looked at temperature and precipitation.

Dr. Cameron C. Lee

However, Cameron C. Lee, Ph.D., assistant professor of Geography at Kent State University, and the members of his ClimRISE Lab take a different approach to biometeorological research.

They believe that living organisms are not just impacted by temperature, or just by humidity, or just by wind, but rather by the combined impacts of all of these things simultaneously. To examine these relationships, they use air masses, which are atmospheric bodies thousands of kilometers in size.

Lee and his co-author, Matthew Dannenberg, Ph.D., assistant professor at the University of Iowa, in the Department of Geographical and Sustainability Sciences, recently published their results in the Journal of Geophysical Research – Biogeosciences after examining the tree rings of 130 different tree species and over 900 different locations throughout the Northern Hemisphere. They found that for the majority of species they examined, it is the air masses that impact tree growth even more-so than temperature and precipitation.

“It’s the synergistic combination of all the weather’s elements – these air masses – that are just better indicators in many instances,” Lee said. “Air masses are sort of like taking all the components of the atmosphere – like temperature, humidity, pressure, cloud cover, winds, etc. – and the near-infinite possible combinations of them, and then merging them into about a dozen typical weather “types” for a location.”

The researchers also found that a tree ring’s width was related to air mass occurrences dating all the way back to the summer prior to the year the ring grew.

“This means that these air masses have the potential to help predict things like tree health and tree death,” Lee said. “And, on the larger scale, perhaps even help forecast the potential for wildfire.“

This research was recently the focus of a spotlight feature on Eos, the science news magazine of the American Geophysical Union. To see the Eos article, visit:

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Media Contacts:
Jim Maxwell,, 330-672-8028
Dr. Cameron C. Lee,, 330-672-0360

POSTED: Monday, May 1, 2023 01:55 PM
Updated: Monday, May 1, 2023 02:12 PM
Jim Maxwell