The Life of a Barrier Island Barrier islands are special places. They appear permanant and static but in fact are continually changing, moving parallel to the mainland and toward or away from it. They buffer the mainland from storms, but storms may cause a particular island to disappear or split in two. Or storms may push a dune line clear across an island as Hurricane Fredric did in 1979 on parts of Santa Rosa Island. Despite all these transitory qualities, life grabs hold on these islands as if it meant to hang on forever.
Salt is one of several factors determining the kind and abundance of plant life.
Near the gulf, plants, such as the sea oats, which are tolerant of high salt levels can grow. Behind the primary dune, shrubs and some trees can be found, but they never grow much higher than the dunes that protect them from the salt spray. Farther back, freshwater collects in marshes among old dunes and supplies trees with water. Animal life on these barrier islands, too, is limited by the plant life, which provides food and protection. This is a special little world extraordinarily affected by the whims of nature.