Coastal sand dune stabilization in the Pacific Northwest

Abstract

Coastal dunes are stabilized in three stages: (1) The initial stage uses sand-stilling grasses established vegetatively. For this purpose, European beachgrass,Ammophila arenaria (L.) Link., is most used, followed by American beachgrass,A. breviligulata Fern., or American dunegrass,Elymus mollis Trin. Large solid plantings must be made with the spacing and number of plants per hill adjusted to the site conditions. Plantings, using Nitrogen fertilizer, are made during the dormant season. (2) Secondary permanent grasses and legumes are seeded 2 years later when sand movement slows and the initial grasses begin to lose their vigor. Most used are seaside lupine,Lupinus littoralis Dougl., purple beachpea,Lathyrus japonicus Willd., seashore bluegrass,Poa macrantha Vasey., and native red fescue,Festuca rubra L. (3) Final control is with woody plants that are well adapted to rough areas. Scotch broom,Cytisus scoparius (L.) Link. Hooker willow,Salix hookeriana Barratt, Nootka rose,Rosa nutkana Prese., and shore pine Pinus contorta Dougl., have been extensively used.