Saving the Rainforest
One dendrometer at a time
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By Jennifer Anderson
David DeFilippis has always been a handy guy to have around. Before college, he worked as a diesel mechanic, a welder and a woodwind instrument repairer, always enjoying the mental challenge of solving mechanical problems. When a freshwater sciences professor during his undergraduate years at the University of Wisconsin–Milwaukee complained about having to take water samples by hand, DeFilippis built him a machine that did it automatically.
So it’s not too surprising that DeFilippis has turned inventor again, now that he’s studying for his doctorate in biological sciences at Marquette and engaged in an ambitious research effort studying competition between woody vines, or lianas, and indigenous trees in Panamanian rain forests. His latest invention — an electronic dendrometer — automates another laborious task: handmeasuring daily changes in the growth of these vines and trees, much to the appreciation of his team members.
Supported by the Graduate Research Fellowships Program of the National Science Foundation, DeFilippis focuses on the research project he’s conducting in collaboration with Dr. Stefan Schnitzer, Mellon Distinguished Professor of Biological Sciences, who has led research in Panama for decades. Vines are integral to maintaining a diverse community of wildlife in the rain forest, says DeFilippis, acting as interwoven highways for insects and animals to move between trees. But the lianas are often detrimental to the trees, stealing sunlight and water while simultaneously crowding them out for space. As tree cover thins, forests suffer in their capacity to act as “carbon sinks” that offset emissions caused by burning fossil fuels.
Wrapping around tree trunks and vine stems like a rubber band, DeFilippis’ devices measure daily changes in circumference, as influenced by water supply, a process known as diurnal fluctuation. Equipped with the inexpensive wireless technology found in garage door openers, they upload measurement data to a cloud server. As he’s worked on welding and gluing dozens of dendrometers for deployment this spring, DeFilippis has also developed a program that will synthesize the data and convert it into graphs. These visualizations will improve his team’s ability to envision what’s in store for the rain forest, comparing how trees and vines tolerate extended dry seasons and understanding the broader environmental impact of vines spreading at the expense of trees.
“Marquette has been extremely supportive about accommodating my research,” says DeFilippis. “This project has been an amazing combination of technology development, environmental studies and biology. I can’t imagine being able to do this anywhere else.”
This story is part of a three-part series on grad student research at Marquette University. Read more here.
