Fri May 23, 2014
Summer Season Fires a Threat to the Great Dismal Swamp
Summer is just about here, and in many of the nation’s national parks, that means forest fires. Here in Virginia, it may also bring a different kind of blaze - one that threatens a vast wetland and wildlife refuge near Norfolk.
After losing thousands of acres in years past, experts have come up with a plan for saving the Great Dismal Swamp.
As the sun sets over 200 square miles of woodland and wetland, green tree frogs begin their enchanting symphony – serenading the animals that make their home in the Great Dismal Swamp --more than 300 kinds of birds and butterflies, black bears and bobcats, snakes and snapping turtles, minks, weasels, eagles and owls.
Some settlers coming to America in the early 1600’s believed the swamp was haunted.
"In fact the leader of that survey crew said, ‘I’ll meet you on the other side. I’m not going through that!"
Refuge Manager Chris Lowie says others saw opportunity in what was then about a million acres of uncultivated land. "The first ditch was finished in about 1763. It was the Dismal Swamp Land Company, established by George Washington himself and other entrepreneurs of that era. They saw dark, rich soil for farming. But that dark rich soil isn’t very fertile, so the farming didn’t work out as they thought."
So they turned to logging -- built more ditches to drain the swamp and put in rail lines and roads to haul the trees away. Today, hurricanes are taking down more trees -- eliminating shade that used to keep the swamp cool. Climate change is warming and drying the land even further, putting it at greater risk for massive fires started by lightning strikes or people.
Brian van Eerden is with the Nature Conservancy, which has helped to preserve and protect the swamp.
"There are peat forests extending from Virginia down to Florida, over to Texas, the Okefenokee Swamp – those are peat-based systems. Peat is accumulated plant material, and here at the dismal swamp we know that peat began forming about 8,000 years ago, and so we have 8,000 years of carbon accumulation. When those peats burn – when they dry out and they burn – the carbon that’s contained in that peat is released into the atmosphere.
That’s what happened three years ago. Again, preserve manager Lowie.
"People were smelling the smoke as far north as Cambridge, Maryland, Philadelphia, Washington, DC. Two and a half weeks after the fire started in 2011 we had 12 inches of rain. Hurricane Irene dumped 12 inches of rain in 24 hours. It did not put the fire out. The fire burned for 2 and a half months after Hurricane Irene."
And even when it appeared to be out, Lowie and his team feared the fire was smoldering under ground.
"We really only get a few weeks of surface fire, where it just rips through the landscape, burns the above ground vegetation, and then you’ve got that smoldering for months. It’ll follow the logs, the woody vegetation buried under the peat. It’ll catch those on fire under ground, and then whenever that log peeks its head up above the soil, it’ll pop right up there."
Now, the Nature Conservancy and the U.S. Fish and Wildlife Service are working to prevent future destruction.
Today, for example, hydrologist Fred Wurster uses a chain and pulley to lower a heavy steel plate into place, completing one of 21 small dams planned or already installed to control water flowing from ditches and the Great Dismal Swamp canal.
"Y’know all these ditches were dug in the 1950’s, 60’s and earlier, and they still effectively drain the swamp, and unless we put in dams like this they will – well there we go – unless we put in dams like this, it will continue to drain. "
But as water levels rise again in the Great Dismal Swamp, experts predict fewer problems with wildfires this summer, and techniques used here may prove valuable in other places. Only three percent of the Earth’s surface is covered with peat, but it stores twice the carbon found in the world’s forests.
U.S. Energy Policy