Backshore and Dunes1

When sand that has been washed high up on a beach dries out, it may be blown landward by winds. This leads to the formation of a sandy "backshore" above the level reached by the highest tides. Under certain conditions, an extensive area of sand dunes may develop. In these cases, there is likely to be a moderately stabilized foredune close to the shoreline, then a region of rolling dunes in which bare sand predominates.

The stability of the backshore depends on a number of factors, including the extent to which it is colonized by vegetation, the type of vegetation, the amount of clay and organic matter in the soil, and wind velocity. Dunes are especially prone to disturbances. If the vegetation on a dune is uprooted by a strong wind, the sand of that dune may be blown away and may menace plants growing on other dunes.

The following account deals with most of the flowering plants characteristic of backshores and dunes of our region. It does not cover components of the coastal forest that have colonized ancient dunes, or species that grow in freshwater ponds or bogs that may be nestled among the dunes. Not all of the plants mentioned are strictly limited to backshores and dunes, by the way; some of them grow on sandy bluffs high above the shore, and a few occur in inland situations.

Landward from the Salt Marsh

The relatively dry land that borders a salt marsh generally has a characteristic assemblage of flowering plants, not all of which are necessarily limited to this habitat. Most of the ones that will be mentioned may also be found on bluffs that overlook the protected shores of bays, and certain of them are successful in suitable habitats some distance from the sea.

Reference Cited

1. Kozloff, Eugene N. 1973. Seashore Life of the Northern Pacific Coast. University of Washington Press. Seattle, WA.