Protect Marram Grass, aka Beach Grass
(Ammophila breviligulata Fernald)
Within Cobmoosa Shores we are fortunate to have beach and sand dune areas available for us to enjoy.
The dunes, in particular, are fragile ecosystems subject to erosion by wind and water. The critical “sand-binder” in Michigan’s active, coastal dune areas is a grass called marram or beach grass. As a pioneer species, it is exquisitely adapted to survive in areas characterized by high winds, low moisture, low nutrient levels, and moving sand.
Marram grass slows blowing sand by impeding it with above ground shoots, after which the sand falls down to the base of these plants and begins to pile up. The grass eventually gets buried, but then sends up more above ground parts while an extensive system of underground stems (rhizomes) and associated roots form a dense mat which binds up the loose sand and helps prevent dune erosion.
As the sand becomes somewhat stabilized, other plant species with similar adaptations to a dune environment are able to take root and promote further stabilization. Some of these are other grass species such as sand reedgrass (Calamovilfa longifolia (Hook.) Scribn.) and little bluestem (Schizachyrium scoparium (Michx.) Nash).
Especially during high-water periods, when dune and shoreline bluff erosion can be quite rapid, we need to do all we can to protect marram grass and its associates that act to stabilize the moving sand. If we damage or kill these all-important sand-binders, the sand particles will no longer be held in place, other species of vegetation will not be able to gain a foothold, and the animals that would find homes in vegetated, more stable dunes will not be able to live there.
Marram grass has a stem that can be damaged when walked on, and we all know that covering plants with opaque objects can kill them, so leaving boats on the dunes or other objects that block marram grass from the sun is not a good idea. In addition, root systems can become exposed or damaged by dragging chairs, boats, and toys across the dunes. Children digging in the dunes and sliding down dune banks can also damage the grasses. For these reasons, practice “dune diligence” and stay off these fragile areas as much as possible so as not to harm these stabilizing grasses.
Prepared by Barbara L. Rafaill, PhD
12 September 2020