Daniel Beverly, a postdoctoral fellow at IU Bloomington, inserts needle-like sensors into a tree at Morgan-Monroe State Forest to understand how ecosystems and plants respond to different environmental stressors like the recent total solar eclipse. Photo by Teresa Mackin, Indiana UniversityFor a plant ecophysiologist like Daniel Beverly, it doesn't get much better than a total solar eclipse.
His first encounter with a total solar eclipse was as a doctoral student in 2017 at the University of Wyoming, which had a field site in the path of totality. He took what he thought was a once-in-a-lifetime opportunity to design an experiment to study plants' response to sudden, temporary darkness and temperature change. However, on April 8, he found himself yet again in the path of totality for another total solar eclipse - this time in Bloomington, Indiana, as an Indiana University researcher.
Daniel Beverly. Photo by Teresa Mackin, Indiana UniversityBeverly is a postdoctoral fellow in the labs of professors Richard P. Phillips and Kim Novick in the College of Arts and Sciences' Department of Biology and the Paul H. O'Neill School of Public and Environmental Affairs. His work aims to understand how ecosystems and plants respond to different environmental stressors, like temperature, precipitation and light.
Again in the path of totality this year, he sought to determine how an entire forest of Indiana's native sugar maple, white oak and sassafras trees would react to the environmental changes an eclipse brings. Bloomington, as well as several other heavily forested central and southern Indiana cities were included in the path of totality.
While total solar eclipses are highly anticipated phenomena, their impacts on plants remain poorly characterized, Beverly said. In 2017, near Yellowstone National Park, he set up instruments that could measure photosynthetic and water transpiration rates of sagebrush, a shrub that grows in arid conditions, to understand and document how the plant reacted the eclipse.
When the moon blocked the midday sun, the plants behaved as if it were time for rest. When the light returned just a few minutes later, they went into shock. The rapid transition from dark to light altered biochemical processes of the plant for several hours following the event, disrupting the circadian rhythm of the shrub.
Circadian rhythm is the internal timing mechanism that regulates an organism's biochemistry. The circadian rhythm of plants regulates processes like photosynthesis and flowering. The surrounding environment plays a pivotal role in keeping the sequence of a plant's biological clock.
"It's like disrupting your sleep schedule; you can feel it," Beverly said. "For example, plants maintain an ebb and flow throughout the day regarding how much carbon they need and how their enzymes respond, just like a human's hunger and thirst. There are periods of time that it's triggered by environmental queues, too."
AmeriFlux tower in Morgan-Monroe State Forest. Photo courtesy of Tyler Roman For a parallel experiment, Beverly traveled to an AmeriFlux tower in Morgan-Monroe State Forest, 30 minutes north of Bloomington. AmeriFlux is a community of scientists gathering meteorology data and hyper-local carbon dioxide, water and energy fluxes in ecosystems across North, Central and South America. There are 13 sites in Indiana and more than 500 in the country.
The Morgan-Monroe State Forest AmeriFlux tower is managed by Novick and Phillips. Beverly said the nearly 30 sites in the path of totality across the country also collected data on the surrounding ecosystem during the eclipse.
For Beverly, this experiment is part of a long-term project monitoring carbon, water and energy fluxes of the forest to see slowly evolving changes in climate and land-cover. By using resources such as the AmeriFlux tower network, researchers can collect this data at an ecosystem-wide level.
"There are hundreds of thousands of data by site and year," Beverly said. "Towers are located across all these different ecosystems, continuously measuring data of carbon, water and energy. These are valuable data sets that are funded through tax dollars."
The tower is equipped with phenology cameras that take digital images of the environment every half hour during the day and thermal cameras that measure the temperature of the forest canopy through infrared radiation. Beverly also inserted needle-like sensors into oak, sassafras, sugar maple and poplar trees to monitor the trees' water movement and pressure.
Beverly does anticipate some difference between what he observed in 2017 and on April 8. One of those is the eclipses' duration. In 2017, darkness lasted for about two minutes and 15 seconds, while the recent eclipse lasted more than four minutes. Time of year was also a differing factor.
"It was at the end of the year in August in 2017, so it was super dry," Beverly said. "The plants were already experiencing a level of end-of-year drought and stress. This time it was the exact opposite; we are just starting to develop leaves in early April."
Witnessing cosmic events like a total eclipse is rare, which is why thousands traveled to Bloomington to be in the path of totality on April 8. Some have even called the total eclipse the largest tourism event in Indiana history. Beverly wants to use these celestial occurrences to show others how engaging science can be and to showcase valuable resources like the AmeriFlux network.
"There's so many cool things like seeing an eclipse, and I think this could definitely encourage many people and children into science," Beverly said.
