Jim LaCarrubba, Long Beach's director of public works, said the city has placed thousands of Christmas trees along the beach to catch sand blown by the wind, allowing the dunes to gradually reform, The New York Times reported Monday.
LaCarrubba said the dunes protected the city from storms.
"Some areas lost three to five feet in elevation on the beach," LaCarrubba said. "We've become that much more vulnerable to storms."
Some of the trees were donated by Home Depot while others formerly stood in the living rooms of residents.
The trees were arranged on the shore by about 100 volunteers last week.
"It was a very nice healing thing for residents to do to contribute to our protection," City Manager Jack Schnirman said.