Range Point © DJ Zemenick
Range Point © DJ Zemenick
Moving inland from the Gulf of Mexico beachfront and across the island, there are several distinct plant zones. These include the primary dune, interdunal swales, secondary dune, and scrub.
First are the low-lying groundcover plants closest to the Gulf such as beach morning glory, coastal plain honeycombhead, beach sunflower, and bitter panic grass. Several species have eye-catching flowers that make them easy to identify. These tend to be very tolerant of both wind and salt spray. Behind these plants is the primary dune field, populated by Gulf bluestem and sea oats. These grasses form massive underground root systems that act like nets and trap moving sand. In many cases, the numerous sea oats you see on a single dune may all be the same plant. They produce seeds that are released into the wind or are carried by birds to new locations so that the plants disperse across the island.
On the backside of the primary dune are compact, woody shrubs that typically have a round shape for wind resistance. Examples include prickly pear cactus, false rosemary and Florida rosemary. Some of these have a unique smell that people associate with the dunes on Pensacola Beach. At the bottom of the dune slope are low areas where rainwater can collect. When refilled with freshwater, the salty nature of the barrier island often creates conditions to form a salt marsh. These wet areas are known as interdunal swales and have their own unique plant communities. Here grows salt marsh hay, black needlerush, and even the carnivorous sundew. Just to the west in Walton County, these swales have developed into much larger dune lakes, a unique ecosystem that can only be found in a few places around the world.
Beyond the shrubs of the secondary dune and swales is scrub territory. Protected by the primary and secondary dunes and some distance from the daily onslaught of sea breezes and the devastating effects of hurricanes, tall shrubs and trees can take root here. Time and leaf drop form a more complex, nutrient-rich soil, and larger species take root. In these areas, one may find sand pine, myrtle oak, palmetto, yaupon holly, and sand live oak. The sand live oak, a subspecies of the beloved mainland live oaks, is a dense, slow grower.
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Scrub Territory © UF/IFAS – Carrie Stevenson
Sand live oaks are salt-pruned by the constant wind and salt spray, tapering away from the Gulf. They are typically low-growing and gangly, spreading their branches wide instead of up to avoid the wind and salt. Many of these trees are actually 20 to 50 feet high but appear shorter because they have been partially covered by sand. In the pines, particularly those damaged by storms and without large canopies, are often large osprey nests. Local beaches have a high concentration of natural nesting areas, making those stable “back” dunes an important wildlife habitat.