The Real Grass We Should Be Talking About
This issue is all about local heroes. At first, I thought we would be talking about sandwiches, because I know a place you all need to try. But then I realized it was the other kind of hero, one that is courageous, protects us all, and achieves great things. I have a few that come to mind easily, but none of them are of the human persuasion. However, you can certainly find them roaming the wetlands nearby or dotting the beaches up and down the coastline.
These local heroes help protect our dunes, shorelines, and tidal wetlands, in other words, pretty much all along our coastal edges. They stand bravely against raging acts of nature. They have specifically evolved over time and are specialized for their purposes. They are the native grasses of the Delaware Bay and Mid-Atlantic shores and they all seem pretty great to me.
Three grasses stand out the most to me for dune protection and tidal wetland marshes: American Beachgrass, Smooth Cordgrass, and Saltmeadow Cordgrass. Specifically designed for their locations, they are essential in a resilient seaside landscape.
You may be hearing more and more about coastal resiliency as we progress deeper into an environmental crisis. Thanks to data-driven evidence, we all know that climate change is happening. The scary part is that it’s happening at a faster rate than previously suggested. The hopeful part is that there are many countries and organizations already on board and coming up with innovative ways to mitigate this problem.
American Beachgrass (Ammophila breviligulata) can be found on our dune systems up and down the coast. The primary dune, meaning the first dune evident walking from the surf, is literally our first defense against coastal storms and surges.
When dunes are rebuilt, they are planted heavily with beachgrass. This beachgrass is essential in dune establishment and longevity. The roots of this grass can extend far into the sandy soil, even greater than six feet in length. Not only do the roots grow down, but they also grow into each other creating a web inside the dune. This root-web helps hold the dune in place during storms and coastal flooding.
Beachgrass spreads by rhizomes, and its leaves and stems can get to be two to three feet tall. Its seed heads can be up to 10 inches in length and appear as spikes at the end of the stem. A mass of beachgrass can also have visual impact, with its graceful stems, leaves, and seed heads nodding in the wind for a picturesque day at the beach.
Even though American Beachgrass is tough as nails and survives stressful conditions at the beach, that doesn’t mean it’s indestructible. It can be impacted by trash and debris humans leave behind at the beach, and by humans who climb on the dune or explore it with their pets in tow. Dune walkers tend to trample the grasses and other vegetation living there. So please stay off the dunes and help protect the grasses that protect us.
Smooth Cordgrass (Spartina alterniflora) lives on the edges of saltwater marshes from the high-water line to the upland area around the marsh. It grows typically from one foot tall up to three feet tall and provides food for wildlife such as snow geese, ducks, and sparrows to name a few. The Smooth Cordgrass spreads by rhizomes which helps mitigate erosion and can even tolerate drought. Its stems and leaves tend to lean over in large stands providing a charming landscape when the marsh is viewed from a distance.
Smooth cordgrass can withstand periodic flooding in brackish conditions. That is why it is so important to have this layer of protection around tidal wetlands. When a significant storm event occurs, and the tidal surge raises the water level above high tide, the grasses and the entire marsh act like a sponge to take in the barrage of flood waters.
Saltmeadow Cordgrass (Spartina patens) thrives in the upper tidal zone where it tends to stay saturated in the brackish tidal waters. It can grow up to seven feet tall and provides food for geese, duck, sparrows, muskrat, and others. It spreads rapidly by rhizomes and can grow over one foot per year. This cordgrass also helps to mitigate erosion and stabilize soils.
American Beachgrass, Smooth Cordgrass, and Saltmeadow Cordgrass are some of the first buffers to help protect our coastal area. In addition, marshes are huge carbon sinks (areas that hold onto carbon) due to their large quantities of biomass. Other types of carbon sinks are forests, soils, oceans, and other types of wetlands. They act like lungs for our planet. Without them, Earth would appear very differently than it does today. So thank these local heroes next time you pass by their natural habitat. ▼
Eric W. Wahl, RLA is a landscape architect at Element Design Group and president of the Delaware Native Plant Society.