Footprints in the Sand - Eco Trail
Please leave only your footprints

Dune Vegetation

As you move from the Gulf of Mexico inland and across the island, you will cross several distinct plant zones.

First are the low-lying ground cover plants such as sea rocket and dollar weed. These tend to be very tolerant of both wind and salt spray. Behind these plants is the primary dune field, populated by grasses 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. These grasses produce seeds that are released into the wind or are carried by birds to new locations so that the plants disperse across the island.

Behind the primary dune are the plants of the secondary dune. These are small, woody shrubs that typically have a round shape for wind resistance. Examples include beach goldenrod, beach rosemary, and beach heather. Some of these have a unique smell that people associate with the dunes on Pensacola Beach. Within the secondary dune field are low areas where rainwater can collect. These wet areas are known as swells and have their own unique plant communities. Ground pine, broomsedge, cattails, and even the carnivorous sundew can be found there.

Beyond the shrubs of the secondary dune and swells are the tertiary dunes. Here you will find trees and shrubs such as live oak, yaupon holly, sand pine, saw palmetto, southern magnolia, and even cactus. The trees appear to be short and stubby on the side facing the Gulf and tapered higher on the landward side. This is known as wind sculpting and is caused by the exposure to wind and salt spray from the Gulf. Many of these trees are actually 20 to 50 feet high but appear shorter because they have been partially covered by sand.

Sea Oats © Daniel Carnley

Sea Oats

One of the most common plants you’ll see growing in our dunes is the sea oat. Sea oats are important to barrier island ecology and are often used in soil stabilization projects because their long root structure firmly holds loose soil. Sea oats also help protect the mainland against hurricanes by providing a stronger barrier against the surging tide. Picking or disturbing sea oats is punishable by fine.

Switchgrass

Switchgrass, also known as panic grass, makes its home in our dunes. It plays an important role in erosion control. In other ecosystems, it is used as feed for cattle and other grazing animals. Due to its ability to produce high yields on low-quality farmland, switchgrass has been researched as a bioenergy crop for a number of years. Some, including President George W. Bush, have suggested using switchgrass as a component of ethanol fuels in place of more expensive crops such as corn.

Cattails

Cattails are easily recognized by their hot dog shape, which is actually a collection of tiny female flowers known as a spike. Cattails are extremely resistant to flooding—even after death, cattail stalks are capable of transmitting oxygen into the rooting zone. Cattails are edible, and evidence suggests that humans regularly consumed them in Europe circa 30,000 years ago. Today, they’re mostly eaten by other mammals such as muskrats.

Sundew

Sundews form one of the largest families of carnivorous plants. They are covered by tentacles tipped with a sticky liquid called mucilage. The mucilage resembles morning dew, lending the plant its name. Mucilage gives off a smell that is attractive to insects. Upon touching the sundew’s tentacles, the insect becomes ensnared. Eventually, the prey dies by either exhaustion or asphyxiation as the mucilage envelops it and clogs its spiracles. Death usually occurs within 15 minutes. The plant, meanwhile, secretes various enzymes to both dissolve the insect and free the contained nutrients. The nutrient soup is absorbed through the leaf surfaces and can then be used to help fuel the sundew’s growth.