Peat Soil, The Great Dismal Swamp, And An Attempt To Slow Climate Change

Oct 11, 2017

The U.S. Fish and Wildlife Service is trying to reverse more than two centuries of damage to sensitive peat soil in the Great Dismal Swamp.

In the 1760s, George Washington ordered slaves to drain the swamp - which straddles the border between North Carolina and Virginia - in an attempt to harvest cedar and cypress trees.  More than 200 years of logging since then shrunk the swamp to about 113,000 acres, and perhaps just as environmentally alarming, has left behind dry peat soil.

Peat is made of fallen twigs, leaves and other woody material that does not fully decompose in wet environments. It traps large amounts of carbon and methane.

"That soil supports our trees (and) it reduces wildfire risk," says Great Dismal Swamp manager Chris Lowie. "But when the water table is really low, that wildfire burns down into the ground because, again, it's woody material. That alters our habitat because it burns a hole in the ground."

It also releases those climate-changing gasses. The U.S. Geological Survey says the last two big fires at the Great Dismal Swamp released an estimated 6.2 million metric tons of carbon dioxide, more than the annual output of 1 million cars.

Now, the refuge is slowly raising the water table through a series of dams in an attempt to re-saturate the peat. But Lowie says he has to balance those efforts with the forest's modern ecosystem, which has changed significantly since Washington's time.

"With all the draining that occurred, we don't have a wet forest community anymore.  We have a dry forest community," Lowie says. "So we're gradually - very conservatively and very gradually - trying to re-wet the swamp so we don't negatively affect the habitats that we're responsible for."

Lowie says it could take years to figure out the best way to restore the soil, but so far the peat is healthy in places where the refuge has re-saturated it.

The Associated Press contributed to this report.