The mighty wind whirled. Waves crashed and pounded the beach. Sand was swept up into the air, where it spun around and blew away. But nothing could topple the science project that Tony Pontari's 4th-grade class had begun. Their hand-built sand dune held tough through winter storms, helping protect the beach and town of Margate, New Jersey. Inside the sand dune: used Christmas trees that the kids had "planted" to help nature create a new dune! "My class wanted to do something to help the town," says Pontari.

In many beachfront towns, sand dunes provide protection against wind and wave erosion. Dunes work as a windbreak that helps stop the wind from blowing beach sand away and the ocean water from spilling past the beach. However, many dunes are not strong enough to survive big storms. For years, people tried to strengthen Margate's dunes by laying trees sideways on the sand. But those trees were usually swept out to sea by rising tides and strong coastal winds.

A Recycled Forest Fights Erosion

Last year the Union Avenue School class decided to try a new strategy. They buried trees standing up. The class planted Christmas trees in three trenches, each 100 feet long. By using Christmas trees, the students found a use for dead trees that are usually thrown away after every Christmas season. The recycled trees kept the new dune in place through last winter. While big storms called northeasters washed away other sand dunes, the trees helped hold the beach together. "I thought the trees were done for," says Pontari. "But it worked."

It worked so well that this year's 4th-grade class decided to continue the project. This time they had partners. Teacher Kevin Burns from nearby Brigantine Middle School had heard about the kid-made dune in Margate and wanted his students to build one too.

The kids got a little help from town officials. After Christmas, workers for the towns of Margate and Brigantine collected used trees and brought them down to the two towns' beaches. The workers dug three-foot-deep trenches, but it was up to the students to drag and plant the trees. "The trees were heavy, and some were bigger than me," says 4th grader Jim Abbott. But the kids had fun too. "You sometimes found Christmas lights!" says 4th grader Kara Weiner.

The kids buried only the lower half of each tree in the sand. The upper half acted as a sand catcher, trapping windblown sand until the tree was completely buried. The students tied red ribbons that hung down from the treetops. They check the buildup of sand by measuring the distance between the end of each ribbon and the top of the growing dune. The two schools communicate by e-mail to compare results.

Later this spring, when the dunes have collected enough sand, the classes will plant dune grass on top of them. The roots of the grass grow down and anchor the dunes. Town workers will then place wooden fences around the sand to help pack the sand together and protect the dunes.

A Home for Native Species

Sand dunes help protect the shoreline ecosystem too. The dunes provide habitats for such marine species as the least tern, piping plover and sea turtle. "The dunes will give the animals a home," says Abbott. The new dunes will also protect the homes of human residents from flooding, and keep the sand where it belongs: on the beach!