title: Coastal foredune evolution: the relative influence of vegetation and sand supply in the US Pacific Northwest.
abstract: Biophysical feedbacks between vegetation and sediment are important for forming and modifying landscape features and their ecosystem services. These feedbacks are especially important where landscape features differ in their provision of ecosystem services. For example, the shape of coastal foredunes, a product of both physical and biological forces, determines their ability to protect communities from rising seas and changing patterns of storminess. Here we assessed how sand supply and changes in vegetation over interannual (3 year) and decadal (21 year) scales influenced foredune shape along 100 km of coastline in the US Pacific Northwest. Across 21 years, vegetation switched from one congeneric non-native beachgrass to another (Ammophila arenaria to A. breviligulata) while sand supply rates were positive. At interannual timescales, sand supply rates explained the majority of change in foredune height (64-69%) and width (56-80%). However, at decadal scales, change in vegetation explained the majority of the change in foredune width (62-68%), whereas sand supply rates explained most of the change in foredune height (88-90%). In areas with lower shoreline change rates (±2 m yr(-1)), the change in vegetation explained the majority of decadal changes in foredune width (56-57%) and height (59-76%). Foredune shape directly impacts coastal protection, thus our findings are pertinent to coastal management given pressures of development and climate change.
authors.affiliation: Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA plz@anr.msu.edu.
authors.forename: Phoebe L
authors.identifier: http://orcid.org/0000-0001-6257-6951
authors.initials: PL
authors.lastname: Zarnetske
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, 104 CEOAS Administration Building, Corvallis, OR 97331, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Ruggiero
authors.affiliation: Department of Ecology, Evolution, and Behavior, University of Minnesota, 100 Ecology Building, 1987 Upper Buford Circle, St Paul, MN 55108, USA.
authors.forename: Eric W
authors.identifier: http://orcid.org/0000-0001-6780-9259
authors.initials: EW
authors.lastname: Seabloom
authors.affiliation: Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA.
authors.forename: Sally D
authors.initials: SD
authors.lastname: Hacker
mesh_terms: D017753:Ecosystem; D019015:Geologic Sediments / Q000032:analysis*; D058865:Introduced Species; D015205:Northwestern United States; D006109:Poaceae / Q000254:growth & development*; D012987:Soil; D013045:Species Specificity
chemical_list: D012987:Soil
keywords: Ammophila; beachgrass; coastal dune; coastal protection; ecosystem service; sand supply
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