Thanks to Cool Green Science:
Dominick Solazzo likes to say the healthy dunes at Midway Beach and South Seaside Park on the Jersey Shore have a “secret ingredient.” Of course, it’s a secret that gives itself away pretty readily when the wind blows.
“It’s Christmas trees,” Solazzo says with a smile. Discarded (natural) Christmas trees donated by the city of Secaucus, New Jersey and given a second life – so to speak – as sand dunes. And, yes, according to him and a few of his neighbors, you can smell the sharp, familiar scent of fir through late winter and part of the spring.
But why Christmas trees? In a word: structure.
“They’re like re-bar in concrete,” explains Solazzo. “They help hold the sand and the dune in place, and give it structure. And good structure matters for dunes. It matters a lot.”
Sandy and the Dunes
Solazzo knows all about dune structure. He’s the President of the Midway Beach Condo Association and dune beach administrator, and has been helping build and maintain the dunes in this community and neighboring South Seaside Park for decades.
Over the years, he and volunteers from the community – and across the Jersey Shore — have spent countless hours planting seagrass and putting up mile after mile of dune fencing, all for the sake of making the dunes strong.
When Hurricane Sandy roared ashore in October 2012, Midway Beach was one of the only communities without water damage. “Our dunes protected us,” notes Solazzo. But the dunes themselves took a beating in the process and lost a lot of their volume. Undaunted, the community, says Solazzo, “got the dune fencing up immediately after Sandy and started getting our sand back from day one.”
How to Build a Sand Dune (Christmas Trees Not Suitable for All Locations)
Despite what they may look like, healthy sand dunes are not just big piles of sand. To over simplify a bit, they are complex systems built from four key ingredients: wind, beach grasses, sand and air. (Since sand is not what anyone would call “nutrient-rich,” air provides the nitrogen beach grasses need to survive so it gets a kind of double mention here).
Dunes are also one of nature’s beautiful dichotomies – like a spider web – simultaneously strong and fragile. They can stand up to storms like Sandy and still be damaged by a footstep, which is where the need for human help to rebuild the dunes and maintain their structure (and the occasional load of used Christmas trees from Secaucus) comes in.
In the natural order of things, dunes form when enough sand is present to provide a toe hold for beach grasses to grow. As the grasses grow, they catch blowing sand and their root systems help hold the dune in place as more and more sand piles up. Over time, detritus from the grasses makes it possible for plants like beach goldenrod and bayberry to take root and begin to grow and provide more structure for the dune – the thing is, that cycle can take a very long time…
Read the whole story here.