New College faculty share results of carbon decay experiment

Community members gathered at Robinson Preserve to hear Assistant Professor of Biology and Environmental Studies Brad Oberle present the results of his carbon sequestration research. Oberle and students from his Forest Ecology Lab class worked on a worldwide research project last fall to study carbon sequestration in different habitats in coastal Manatee County.
All the collected data can help scientists learn how much carbon is being released into the air, which can have an effect on climate change.
They planted tea bags, which contain organic material, at various sites throughout the county and measured carbon decay by weighing the bags at the start of the experiment and again when they dug up the bags 90 days later.
“What we found is that in different restored habitats,” explained Oberle, “you see patterns that you would expect for both [carbon] withdrawals and deposits.”
Oberle and the students anticipated mangroves would have slow withdrawal rates and high rates of deposit, and the opposite for highlands. They based their hypotheses on their understanding of mangroves as “great blue carbon builders,” explained Oberle, whose slow decay rates mean “they store carbon partly because withdrawals from that carbon account are slower than they are in other systems.”
Although the habitats’ carbon consumption patterns aligned with their expectations, Oberle and his team still found unexpected results. It turns out the age of the habitat plays a role in carbon sequestration, regardless of habitat type. Older soil has a lower deposit rate than soil that was recently restored, and Oberle formulated a theory to explain the difference.
“Probably the most surprising and original thing that we found,” continued Oberle, “is that in our older soils, you actually have lower rates of deposit, and we think the reason that might be is because older soils have more diverse and more effective communities of organisms that can eat more of the tea. Basically, they can use more of the carbon that goes into the soil.”
Oberle delivered his remarks at the Mosaic Nest facility, a multi-purpose event space with 360° views of the preserve that is only open to the public during special events. Many who were in attendance, including preserve staff members, were also part of the corps of volunteers who helped the students plant tea bags at the start of the experiment. In addition to community volunteers, New College also partnered with the Sarasota Bay National Estuary Program, the Tampa Bay National Estuary Program, and Manatee County Parks and Recreation to conduct the experiment.
Liz Lebron is associate director of communications and marketing at New College of Florida.