Oikos o18887 Hacker, S. D., Zarnetske, P., Seabloom, E., Ruggiero, P., Mull, J., Gerrity, S. and Jones, C. 2012. Subtle dif- ferences in two non-native congeneric beach grasses significantly affect their colonization, spread, and im- pact. – Oikos 121: 138–148.

Appendix A1 Photos of foredunes with (A) arenaria at South Beach, OR, and (B) Ammophila breviligulata at Cape Shoalwater, WA.

1 Appendix A2 The latitude and longitude of 57 sites used to determine the change in abundance of two non-native beach grass species, , Ammophila breviligulata, and one native species, Elymus mollis, on the coast of , USA. Sites were originally surveyed by Seabloom and Wiedemann (1994) in 1988 and re-censused in 2007. In addition, foredune elevation and width were surveyed along transects at a subset of 34 sites designated by the site identification prefix GH and LB to determine changes in foredune geomorphology over the same 19 year period.

Site ID Site name Latitude Longitude OLY01 Port Townsend 48°7´16.03˝ –122°45´22.31˝ OLY02-T1 Dungeness Spit 48°8´49.54˝ –123°11´9.78˝ OLY05-T1 Waatch 48°18´11.36˝ –124°39´51.66˝ OLY04 Seiku 48°17´4.08˝ –124°22´55.98˝ OLY03 Clallam 48°15´18.50˝ –124°15´38.47˝ OLY06 Shi Shi 48°14´49.97˝ –124°41´56.79˝ OLY07 Ozette 48°7´38.82˝ –124°42´29.58˝ OLY08 Moclips 47°14´20.15˝ –124°13´2.56˝ OLY10 Copalis 47°8´6.60˝ –124°11´8.88˝ OLY11 Griffiths-Priday State Park 47°7´45.25˝ –124°11´8.50˝ OLY09 Copalis 47°7´24.80˝ –124°11´5.96˝ OLY12-Ba Ocean City (backdune) 47°4´13.01˝ –124°10´32.30˝ OLY12-F Ocean City (foredune) 47°4´13.01˝ –124°10´32.30˝ OLY17-Ba Ocean City State Park (backdune) 47°1´56.41˝ –124°10´18.93˝ OLY17-F Ocean City State Park (foredune) 47°1´56.41˝ –124°10´18.93˝ OLY17-Be Ocean City State Park (beach) 47°1´56.41˝ –124°10´18.93˝ OLY16-Ba Ocean Shores (backdune) 46°59´40.01˝ –124°10´20.16˝ OLY16-F Ocean Shores (foredune) 46°59´40.01˝ –124°10´20.16˝ OLY15 Ocean Shores 46°59´2.69˝ –124°10´20.19˝ OLY14 Ocean Shores 46°58´21.95˝ –124°10´21.91˝ OLY18 Hoquim 46°58´24.81˝ –123°56´52.77˝ OLY13-Ba Ocean Shores (backdune) 46°55´42.53˝ –124°10´24.48˝ OLY13-F Ocean Shores (foredune) 46°55´42.53˝ –124°10´24.48˝ GH82 Cohasset 46°51´16.04˝ –124°6´50.60˝ GH18 Cohasset 46°51´8.25˝ –124°6´48.12˝ GH17 Cohasset 46°50´58.90˝ –124°6´44.15˝ GH09 Cohasset 46°50´16.98˝ –124°6´30.40˝ GH06 Grayland 46°49´46.45˝ –124°6´21.32˝ GH05 Grayland 46°47´57.18˝ –124°5´57.38˝ GH13 Grayland 46°47´52.21˝ –124°5´55.72˝ GH01 Grayland 46°47´22.47˝ –124°5´59.12˝ GH12 Heather 46°46´28.85˝ –124°5´55.86˝ GH07 Heather 46°45´54.88˝ –124°6´8.09˝ GH03 Heather 46°45´50.15˝ –124°6´7.33˝ GH11 Heather 46°45´34.80˝ –124°6´3.72˝ GH04 Cape Shoalwater 46°44´39.26˝ –124°5´44.87˝ GH20 Cape Shoalwater 46°44´29.36˝ –124°5´35.95˝ GH20A Cape Shoalwater 46°44´24.58˝ –124°5´28.50˝ LB49 Leadbetter Point 46°37´8.58˝ –124°4´11.55˝ LB08 Leadbetter Point 46°36´22.05˝ –124°4´5.14˝ LB11 Leadbetter Point 46°36´3.55˝ –124°4´2.61˝ LB15 Leadbetter Point 46°35´46.43˝ –124°4´0.35˝

2 LB1020 Long Beach 46°33´10.41˝ –124°3´41.75˝ LB06 Long Beach 46°32´16.19˝ –124°3´36.84˝ LB01 Long Beach 46°32´8.82˝ –124°3´37.68˝ LB14 Long Beach 46°30´45.03˝ –124°3´34.97˝ LB12 Long Beach 46°30´35.58˝ –124°3´34.74˝ LB05 Long Beach 46°29´21.43˝ –124°3´30.11˝ LB02 Long Beach 46°28´28.60˝ –124°3´32.28˝ LB03 Long Beach 46°27´10.49˝ –124°3´32.03˝ LB09 Long Beach 46°26´1.360˝ –124°3´33.97˝ LB07 Long Beach 46°23´34.33˝ –124°3´41.05 ˝ LB35 North Head 46°21´18˝ –124°3´50.53˝ LB36 North Head 46°20´13.03˝ –124°3´58.62˝ LB37 North Head 46°19´17.95˝ –124°4´5.69˝ LB2842 North Head 46°18´45.97˝ –124°4´13.02˝ LB32 North Head 46°18´33.50˝ –124°4´16.33˝

3 Appendix 3 The latitude and longitude of 77 transects at 19 sites used to determine aspects of foredune geomorphology and beach grass community structure along the Washington and coasts in 2006. The littoral cells on the coast include the Columbia River Littoral Cell (just north of Grays Harbor, Washington, to Tillamook Head, Oregon), the Netarts Littoral Cell (Cape Meares to Cape Lookout, Oregon), Sand Lake Littoral Cell (Cape Lookout to Cape Kiwanda, Oregon), the Neskowin Littoral Cell (Cape Kiwanda to Cascade Head, Or- egon), the Newport Littoral Cell (Yaquina Head to Cape Perpetua, Oregon), the Coos Bay Littoral Cell (Heceta Head to Cape Arago, Oregon), and the Bandon Littoral Cell (Cape Arago to Cape Blanco, Oregon). See Fig. 1 for locations.

Littoral cell Site ID Site name Latitude Longitude Columbia River GH82 Cohasset 46°51´16.04˝ –124°6´50.60˝ GH18 Cohasset 46°51´8.25˝ –124°6´48.12˝ GH17 Cohasset 46°50´58.90˝ –124°6´44.15˝ GH09 Cohasset 46°50´16.98˝ –124°6´30.40˝ GH06 Grayland 46°49´46.45˝ –124°6´21.32˝ GH05 Grayland 46°47´57.18˝ –124°5´57.38˝ GH13 Grayland 46°47´52.21˝ –124°5´55.72˝ GH01 Grayland 46°47´22.47˝ –124°5´59.12˝ GH12 Heather 46°46´28.85˝ –124°5´55.86˝ GH07 Heather 46°45´54.88˝ –124°6´8.09˝ GH03 Heather 46°45´50.15˝ –124°6´7.33˝ GH11 Heather 46°45´34.80˝ –124°6´3.72˝ GH04 Cape Shoalwater 46°44´39.26˝ –124°5´44.87˝ GH20 Cape Shoalwater 46°44´29.36˝ –124°5´35.95˝ GH20A Cape Shoalwater 46°44´24.58˝ –124°5´28.5˝ LBP-NR6 Leadbetter Point 46°37´22.89˝ –124°4´12.92˝ LBP-NR5 Leadbetter Point 46°37´12.37˝ –124°4´11.58˝ LB49 Leadbetter Point 46°37´8.58˝ –124°4´11.55˝ LBP-NR7 Leadbetter Point 46°36´47.52˝ –124°4´8.79˝ LBP-NR8 Leadbetter Point 46°36´31.31˝ –124°4´6.17˝ LB08 Leadbetter Point 46°36´22.05˝ –124°4´5.14˝ LB11 Leadbetter Point 46°36´3.55˝ –124°4´2.61˝ LB15 Leadbetter Point 46°35´46.43˝ –124°4´0.35˝ LB1020 Long Beach 46°33´10.41˝ –124°3´41.75˝ LB06 Long Beach 46°32´16.19˝ –124°3´36.84˝ LB01 Long Beach 46°32´8.82˝ –124°3´37.68˝ LB14 Long Beach 46°30´45.03˝ –124°3´34.97˝ LB12 Long Beach 46°30´35.58˝ –124°3´34.74˝ LB05 Long Beach 46°29´21.43˝ –124°3´30.11˝ LB02 Long Beach 46°28´28.60˝ –124°3´32.28˝ LB03 Long Beach 46°27´10.49˝ –124°3´32.03˝ LB09 Long Beach 46°26´1.36˝ –124°3´33.97˝ LB07 Long Beach 46°23´34.33˝ –124°3´41.05˝ LB35 North Head 46°21´18.00˝ –124°3´50.53˝ LB36 North Head 46°20´13.03˝ –124°3´58.62˝ LB37 North Head 46°19´17.95˝ –124°4´5.69˝ LB2842 North Head 46°18´45.97˝ –124°4´13.02˝ LB32 North Head 46°18´33.50˝ –124°4´16.33˝ FS02 Fort Stevens 46°12´20.65˝ –123°59´53.81˝ FS03 Fort Stevens 46°6´6.22˝ –123°56´36.12˝ FS01 Fort Stevens 46°3´8.07˝ –123°55´53.81˝ Netarts CL03 Cape Lookout 45°25´38.43˝ –123°57´37.28˝

4 CL02 Cape Lookout 45°25´18.54˝ –123°57´39.85˝ CL01 Cape Lookout 45°22´51.46˝ –123°57´59.24˝ Sand Lake SL02 Sand Lake 45°17´9.22˝ –123°57´48.70˝ SL01 Sand Lake 45°16´56.29˝ –123°57´48.43˝ SL03 Sand Lake 45°16´51.19˝ –123°57´46.51˝ Neskowin PC03 Pacific City 45°11´39.37˝ –123°58´7.42˝ PC01 Pacific City 45°11´23.58˝ –123°58´8.43˝ PC02 Pacific City 45°10´26.75˝ –123°58´14.02˝ Newport SB03 South Beach 44°36´28.06˝ –124°4´5.88˝ SB02 South Beach 44°36´16.11˝ –124°4´1.13˝ SB01 South Beach 44°35´58.71˝ –124°4´0.99˝ Coos Bay SILT01 Siltcoos River 43°52´12.46˝ –124°9´24.49˝ SILT02 Siltcoos River 43°52´3.30˝ –124°9´27.00˝ SILT03 Siltcoos River 43°51´51.57˝ –124°9´29.69˝ DO-NR5 Overlook 43°50´52.01˝ –124°9´40.54˝ DO-NR6 Dunes Overlook 43°50´46.13˝ –124°9´41.86˝ DO-NR4 Dunes Overlook 43°50´8.79˝ –124°9´48.21˝ DO01 Dunes Overlook 43°50´7.49˝ –124°9´48.41˝ DO02 Dunes Overlook 43°49´29.98˝ –124°9´56.00˝ DO03 Dunes Overlook 43°49´16.31˝ –124°9´58.74˝ TK-NR6 Tahkenitch Creek 43°48´54.45˝ –124°10´2.70˝ TK-NR5 Tahkenitch Creek 43°48´37.66˝ –124°10´6.27˝ TK-NR4 Tahkenitch Creek 43°48´24.08˝ –124°10´8.60˝ TM-NR6 Tenmile Creek 43°38´46.04˝ –124°12´38.55˝ TM-NR4 Tenmile Creek 43°36´30.19˝ –124°13´5.81˝ TM-NR5 Tenmile Creek 43°36´27.27˝ –124°13´6.91˝ UD02 Umpqua Dunes 43°35´49.07˝ –124°13´17.46˝ UD01 Umpqua Dunes 43°35´37.42˝ –124°13´21.24˝ UD03 Umpqua Dunes 43°34´56.65˝ –124°13´32.86˝ Bandon BAN-NR3 Bandon Beach 43°3´52.67˝ –124°26´17.64˝ BAN-NR2 Bandon Beach 43°3´30.23˝ –124°26´23.44˝ BAN-NR1 Bandon Beach 43°2´39.85˝ –124°26´35.87˝ MCK-NR1 Elk River 42°48´14.67˝ –124°31´51.02˝ MCK-NR2 Elk River 42°48´1.86˝ –124°31´44.28˝ MCK-NR3 Elk River 42°47´52.09˝ –124°31´40.34˝

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