The Dirt on Climate Change
Burrowing critters shed light on environmental trends
September 10, 2009
The small creatures known as terrestrial arthropods—grubs, scorpions, millipedes, and spiders—have disproportionately big jobs. The critters are responsible for churning and developing soil. If arthropods can’t survive in a certain climate, the soil quality suffers.
“These animals are closely tied to soil formation and are pretty important for plants and our productivity. The food that we eat depends on the soil animal,” says Dan Hembree, an Ohio University assistant professor of geological sciences.
Hembree studies the burrows, tracks, and trails of the arthropods to shed light on how climate change impacts organisms. In his lab, he places arthropods such as emperor scorpions, six-inch African millipedes, grubs, and tarantulas into tanks filled with sediment, and then observes them dig and excavate new burrows. The arthropods churn sediment and bring organic matter from the surface down into the soil, where it can decompose and nourish plants and other burrowers.
Once the creatures have dug, Hembree removes them from the tank and creates a plaster cast of their burrow. He compares these modern-day castings to fossil burrows from the Pennsylvanian Period, about 300 million years ago. This period featured organisms and a climate similar to today’s environment.
Scientists have been comparing trace fossils to the burrows of modern animals for about 80 years, but they’ve primarily focused on marine animals. And while they can easily identify a trace fossil as the burrow of a former soil-dwelling organism, researchers struggle to identify specific creatures. Hembree hopes to solve the problem by comparing more of these fossils to modern burrows of known organisms.
“Trying to interpret those trace fossils has often been about storytelling,” he says. “You look at the form and you devise some possible explanation as to why it was made and what made it.”
By comparing burrows from his lab to fossil burrows, Hembree and other scientists may be able to make predictions about the future of our environment and the fate of the creatures that inhabit it.
By Jessica Patterson
Editor's Note: This story will appear in the Autumn/Winter 2009 issue of Perspectives magazine.
For more information about Hembree and his research, visit http://www.ohio.edu/geology/hembree/.