After Sandy, Not All Sand Dunes Are Created Equal
When Superstorm Sandy hit Island Beach State Park — one of the last remnants of New Jersey's barrier island ecosystem — it flattened the dunes, pushing all that sand hundreds of feet inland.
Three months later, the park was still officially closed, but the beach swarmed with volunteers. Members of the local Beach Buggy Association, volunteers from inland New Jersey, and a chilly but enthusiastic group of high school students dragged hundreds of old Christmas trees across the sand and laid them in a snaking line along the beach.
It seems like a bizarre strategy, but it's an effective one. The trees' needles and branches will trap windborne sand and serve as a foundation for new dunes.
Katie Barnett, a specialist with the New Jersey Department of Environmental Protection, was the project's mastermind. After Sandy, she put out a call for Christmas trees on the park service's Facebook page. The trees came pouring in from all over the state.
"We had a goal of getting 1,000 trees," Barnett says. "Just with that one Facebook post we got 4,000 trees — so we were a little overwhelmed."
The community is eager to get the dunes back. During the storm, people saw how valuable dunes can be.
"The areas that had natural stable dune systems are the areas that survived the best," Barnett says. "The areas that didn't have dune systems are the areas that really got wiped out."
But not all dunes are created equal. There are man-made dunes, and there are natural dunes. Norbert Psuty, a retired professor from Rutgers University, knows the difference better than most. He's studied dunes along the coast of New York.
"I've been working at Fire Island since 1976 and I've been through a number of storms," Psuty says. "This time I was flabbergasted. Dunes 100 feet wide, 30 feet high ... were gone."
But Psuty says replacing these dunes with man-made ones is tricky. Piles of sand — even those anchored by Christmas trees — will erode much faster than natural dunes.
That's why the dune builders at Island Beach State Park plan to plant beach grass on top of their new dunes come spring. The vegetation will add stability.
Mimicking nature's ingredients is important, but Psuty says there are still more important things to worry about.
"The real problem is the whole beach dune system is naturally migrating inland," Psuty says. "The beach is now where the houses were formerly."
A combination of sea level rise and erosion means that dunes want to form farther inland, pushing into coastal towns. If you try to push the dunes back toward the water, back where they once were, Psuty says they won't survive long. They'll erode away.
The alternative is to let dunes re-form naturally. Psuty has observed the process in the Fire Island Wilderness, where policy forbids the construction of man-made dunes.
First, beach grass catches sand thrown up by the wind. A hill of sand begins to form, anchored by an organic mesh of roots and rhizomes.
Because these plants can't survive too close to the salty waves, the dunes grow high up on the beach. An empty stretch of sand serves as a buffer between the dunes and the ocean and supplies the dunes with the sediment they need to grow.
Natural dunes are strong, but they take a long time to grow.
"I would say ... a decade," Psuty says.
You might have to wait until 2023 for your dune system to fully recover from Sandy. Island Beach State Park Manager Ray Bukowski says they don't have that kind of time.
"We can't sit and hope a dune gets re-formed here," Bukowski says. "We've got to jump-start the dune and let it start doing its thing."
He says in the short term these Christmas-tree-seeded dunes are the best way to protect the inland habitat of Island Beach from storms.
"Our hope is that it works so well that this becomes an annual process," Bukowski says. "Next year after Christmas we can open up our lot and have folks drop [their trees] off."
Dunes may rise and fall, but there will always be Christmas trees in January.
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Transcript
ROBERT SIEGEL, HOST:
In New Jersey, thousands of discarded Christmas trees have dodged the wood chipper and hit the beach instead. Communities up and down the Mid-Atlantic coast are using old Christmas Trees to help rebuild dunes that were flattened by Hurricane Sandy. But scientists warn that these manmade dunes could be less sturdy than those that form naturally. NPR's Adam Cole visited one restoration project on the New Jersey coast and sent this report.
ADAM COLE, BYLINE: Three months after Hurricane Sandy hit, Island Beach State Park was still officially closed but the beach was full of volunteers, community members, local surf fishermen and a group of high school students.
UNIDENTIFIED MAN: Okay. What school you guys from?
UNIDENTIFIED GROUP: Peddie.
UNIDENTIFIED MAN: All right. And what are you doing here?
UNIDENTIFIED GROUP: (In unison) Putting trees (unintelligible)
UNIDENTIFIED MAN: Why?
UNIDENTIFIED WOMAN: To rebuild the dunes.
COLE: All right. How is that going to work? Well, the basic idea is simple. The discarded Christmas trees will trap windborne sand and serve as a foundation for new dunes. Earlier in the morning, a special truck cut a zigzagging trench across the beach.
KATIE BARNETT: It's foolproof. All you have to do is put a tree and in the ready trench.
COLE: That's Katie Barnett, a specialist with the State Department of Environmental Protection. After Hurricane Sandy demolished Island Beach's dunes, Barnett put out a call for Christmas trees on the New Jersey Park Service's Facebook page. The trees came pouring in from all over the state.
BARNETT: We had a goal of getting 1,000 trees. And just with that one Facebook post we got 4,000 trees, so we were a little overwhelmed.
COLE: The community is eager to get their dunes back. During the storm, they saw how valuable dunes can be.
BARNETT: The areas that had natural stable dune systems are the areas that survived the best. The areas that didn't have dune systems are the areas that really got wiped out. So, again, dunes, good stuff.
COLE: But not all dunes are created equal. There are man-made ones and there are natural ones. And Norbert Psuty knows the difference better than most. He studies dunes along the coast of New York.
NORMAN PSUTY: I've been working at Fire Island since 1976 and I've sort of been through a number of storms.
COLE: Psuty is a retired professor from Rutgers University.
PSUTY: This time, I was flabbergasted. Dunes that were 100-feet wide, 30-feet high were gone.
COLE: But Psuty says replacing these dunes with man-made ones is tricky. Piles of sand, even those anchored by Christmas trees, will erode much faster than natural dunes. And the team that's building Island Beach State Park's dunes knows this. That's why they're planning to plant beach grass on top of their new dunes come spring. The vegetation will add stability.
Still, Psuty says there are other things to worry about.
PSUTY: The real problem is the whole beach dune system is naturally migrating inland.
COLE: A combination of sea level rise and erosion means that dunes want to form further inland, pushing into coastal towns. And if you try to push the dunes back toward the water, back where they once were, Psuty says they won't survive long. They'll erode away. The alternative is to let dunes re-form naturally. Here's how it works.
Grass spouting high up on the beach catches sand thrown up by the wind.
PSUTY: Roots and rhizomes and organic matter helps bind all these sand particles together.
COLE: A hill of sand forms, anchored by this organic mesh and it forms a safe distance from ocean waves. Natural dunes are strong, but they take a while to grow.
PSUTY: I would say, you know, a decade.
COLE: A decade. So you'd be waiting until 2023. Island Beach State Park manager Ray Bukowski says they don't have that kind of time.
RAY BUKOWSKI: We can't sit and hope a dune gets re-formed here. We've got to jump-start the dune and let it start doing its thing.
COLE: He says in the short term these Christmas-tree-seeded dunes are the best way to protect the inland habitat of Island Beach from storms.
BUKOWSKI: Our hope is that it works so well that this becomes an annual process. And next year, after Christmas, we can open up our lot and have folks drop them off.
COLE: Dunes may rise and fall, but there will always be plenty of Christmas trees in January. Adam Cole, NPR News. Transcript provided by NPR, Copyright NPR.
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