We drive to the shore, park the car, then (often) climb over the low grassy knoll to get to the beach.
That low grassy knoll is the foredune. Of the many dune habitats on the Oregon Coast, the foredune is closest the beach and is the most encountered on foot.
The foredune is built of sand that has blown off the beach and slowed down by the plants that can survive this harsh environment. Salty, low in nutrients, very dry in summer, and scoured by windblown sand, the foredune is a challenging place to live.
The plants of the foredune are tough: many are leathery (such as beach silvertop); some are rather succulent (such as sand verbena); some have fine hairs or sticky surfaces for protection (such as seashore lupine); many vine or trail along the sand (such as beach morning glory or beach strawberry); some combine one or more of these strategies.
Although you might not see them in daytime, there are animals here, too. Stroll along the foredune in early morning before the wind picks up and you’ll find the sand decorated with the traces of night visitors: tracks of small mammals -- squirrels, chipmunks, and mice -- string between clumps of vegetation; bird tracks indicate landings, hopping, and walking; and the fine trails of many different insects curl and loop across the sand. Larger mammals, such as raccoon and deer, may visit the foredune and leave their marks, as well.
A hundred years ago the foredunes on the Oregon Coast looked quite different than they do now.
Beginning shortly before the turn of the last century, European beachgrass was planted throughout the dunes to tame the sand and keep it from clogging our waterways and from burying our roads and buildings.
We have a similar native grass of beach and dune: American dune grass. While the blades of the European beachgrass are narrow (about ¼ of an inch) and rolled; those of the American dune grass are wide (at least ½ an inch) and flat, and they are a slightly bluer green.
European beachgrass was introduced because it thrives best in moving sand; it’s more tolerant of wind-blown sand than our native dune grass. The long, sturdy blades of European beachgrass stall the wind a bit, capturing the sand; the extensive roots hold the sand in place as the plant’s wiry runners pierce the accumulating dune.
The European beachgrass does so well here that it is taking over the dunes -- including the foredunes at the edge of the beach.
Prehistorically, the “foredunes” grew to a few feet above the top of the beach and were mostly open sand with scattered individual plants and hummocks. Those foredunes were very mobile, covering and exposing plants, and being washed over periodically by storm waves. According to several sources, in fact, true foredunes did not exist before the early 1900s.
Today, our European beachgrass foredunes can tower up to forty feet -- high enough to keep the beach sand from blowing inland and replenishing the higher dunes. Further, the extensive root systems of the European beachgrass help the dune to withstand some of the force of the rough winter surf, allowing the land to creep seaward in some places.
Far different environment than the native grassland, this thick cover of European beachgrass makes the sand shadier, cooler, and damper, as well as less mobile and therefore less abrasive. Next time you’re visiting the foredune, push your fingers into the open dry sand on the trail or on the upper edge of the beach to feel its temperature and humidity, then do the same to the sand under the beachgrass. Do you notice the difference too?
The changes to the environment caused by the beachgrass improves the habitat for many other plants. However, some of the native plants that are well adapted to the open sand are out-competed by those other plants in this now less-harsh environment and are on the decline (pink sand verbena, for example).
Some animals adapted to the open beach and sparsely vegetated foredune, such as the snowy plover, are also displaced by this altered foredune community. From egg to adult, snowy plovers are well camouflaged for open sand. For eons they have nested at the upper edge of the sandy beach, near the foredune. The dense vegetation of today’s European beachgrass foredune shelters plover predators while it overruns the plovers’ open sand habitat.
That sand knoll at the edge of the land is a dynamic, vibrant, and fascinating part of the shore.
When you go to the beach this summer, slow down and explore while you walk between car and strand. Step over the plants and watch out for the wildlife, and you may discover a new favorite place.