Silent But Deadly

By Eleanor Spicer Rice ’03, ’12 PHD

The salt water that creeps inward from North Carolina’s coast reduces thousands of acres of trees each year to sticklike trunks called snags, leaving behind what scientists call “ghost forests.”

Melinda Martinez ’21, a Ph.D. student in the Department of Forestry and Natural Resources, explains that sea-level rise due to climate change accounts for the creation of the ghost forests. As this forest death continues across the coastal United States, Martinez has studied a curious impact of them — tree farts.

Living forests act as “carbon sinks,” places that filter greenhouse gases from the atmosphere, essentially locking them into the earth. At the same time, their vegetation produces oxygen and releases it into the atmosphere. When trees die, the remaining snags act as filtered smokestacks, funneling the greenhouse gas methane from the soil. Microbes living in the snag convert the methane to carbon dioxide and release it back into the atmosphere. These “tree farts,” Martinez found, can increase the total carbon dioxide in the local ecosystem by 25 percent.

. . . “tree farts” can increase the total carbon dioxide in the local ecosystem by 25 percent.

Sea level in the Southeastern U.S. will continue to rise, wiping out hundreds of thousands of forest acres. Eventually, the ghost forests will run out of gas and will give way to a new type of habitat.

“We expect that ghost forests will continue to expand, but it’s important to know these are transient areas,” says Martinez. “They will eventually become marshes and, in some cases, open water, where most of the ecosystem services are lost.”

Over time, the greenhouse gas emissions in ghost forests will stabilize, and these areas may return to their role as carbon sinks. Until then, the tree ghosts will keep farting greenhouse gases into the atmosphere. Pardon.