If a tree farts in the forest, does it make a sound? No, but it does add a smidge of greenhouse gas to the atmosphere.
Gases released by dead trees — dubbed “tree farts” — account for roughly one-fifth of the greenhouse gases emitted by skeletal, marshy forests along the coast of North Carolina, researchers report online May 10 in Biogeochemistry. While these emissions pale in comparison with other sources, an accurate accounting is necessary to get a full picture of where climate-warming gases come from.
A team of ecologists went sniffing for tree farts in ghost forests, which form when saltwater from rising sea levels poisons a woodland, leaving behind a marsh full of standing dead trees. These phantom ecosystems are expected to expand with climate change, but it’s unclear exactly how they contribute to the world’s carbon budget.
“The emergence of ghost forests is one of the biggest changes happening in response to sea level rise,” says Keryn Gedan, a coastal ecologist at George Washington University in Washington, D.C., who was not involved in the work. “As forests convert to wetlands, we expect over long timescales that’s going to represent a substantial carbon sink,” she says, since wetlands store more carbon than forests. But in the short term, dead trees decay and stop taking up carbon dioxide through photosynthesis, “so that’s going to be a major greenhouse gas source.”