HOLLYWOOD, Fla. – One of nature’s best defense systems for parts of the U.S. coast under threat from hurricanes each year is a group of gnarly trees called mangroves.

These trees only grow in tropical and subtropical climates since they cannot withstand freezing temperatures. They make up dense forests in saltwater areas along parts of the Gulf Coast that feature intricately intertwined root systems, which give the appearance that the trees are walking on the water.

Those interlocking roots help protect coastlines from flooding when hurricanes hit.

"They break down that wave energy," said Laura Geselbracht, senior marine scientist at The Nature Conservancy’s Florida chapter. "In doing so, they reduce how far the floodwaters penetrate inland."

The trees also help stabilize coastlines and guard against erosion.

"These mangroves produce a lot of leaves, and that leaf litter eventually accumulates," Geselbracht said.

The dense forests also serve as home to a variety of animals, such as crabs, birds, fish and iguanas.