Grantee Research Project Results
2012 Progress Report: Beach Grass Invasions and Coastal Flood Protection: Forecasting the Effects of Climate Change on Coastal Vulnerability
EPA Grant Number: R833836Title: Beach Grass Invasions and Coastal Flood Protection: Forecasting the Effects of Climate Change on Coastal Vulnerability
Investigators: Hacker, Sally , Seabloom, Eric , Ruggiero, Peter
Current Investigators: Seabloom, Eric , Ruggiero, Peter , Hacker, Sally
Institution: Oregon State University
EPA Project Officer: Packard, Benjamin H
Project Period: July 1, 2008 through June 30, 2012 (Extended to June 30, 2013)
Project Period Covered by this Report: July 1, 2011 through June 30,2012
Project Amount: $599,980
RFA: Ecological Impacts from the Interactions of Climate Change, Land Use Change and Invasive Species: A Joint Research Solicitation - EPA, USDA (2007) RFA Text | Recipients Lists
Research Category: Climate Change , Aquatic Ecosystems
Objective:
Increased storm severity and sea-level-rise resulting from climate change have greatly elevated the risk of coastal communities. These risks have been exacerbated by alterations to coastal ecosystems and the introduction of non-native species. In the Pacific Northwest of the United States, coastal dunes protect about half of the coastline, and our initial results suggest that increases in wave height and sea level rise could increase the frequency with which waves overtop and erode dunes. Intentional planting of non-native grasses (Ammophila spp.) may have initially increased coastal protection from flooding by building tall foredunes parallel to the shoreline. However, an unintentional second invasion appears to be decreasing foredune height, thereby increasing risk exposure. In addition, many agencies are removing beach grasses to restore habitat for imperiled species. The effects of these conservation actions on flooding risk are unknown. Managers of west coast dune systems are faced with an apparent conundrum. Climate change is increasing the need for the protection services of grass-dominated coastal dunes, but conservation mandates the removal of these invasive grasses to favor recovery of threatened and endangered species. Furthermore, the uncontrolled invasion by the second grass, A. breviligulata, is associated with declines in dune height and biodiversity. Despite the conflicting values of coastal protection and conservation, neither invasive species dynamics nor coastal protective values have been quantified under future invasion and climate change scenarios. Here, we proposed research to address three fundamental objectives (1) determine the relationship between climate change and beach grass invasion, (2) determine the effects of non-native beach grass invasion on coastal vulnerability, and (3) determine if conservation management alters coastal vulnerability to flooding under a range of climate change, invasion and management scenarios.
Progress Summary:
We have assembled a large data set that includes shoreline change, dune geomorphology, and vegetation data necessary to understand the interaction between sand supply, dune grass invader, and the effects on foredune geomorphology from Grays Harbor, Washington, to Bandon, Oregon (Objective 1). Analysis shows that dune geomorphology is the result of both sand supply and dune grass species—sites with high sand supply and A. breviligulata as the dominant invader feature shorter and wider dunes compared to sites that have low sand supply and A. arenaria as the dominant invader. We have concluded experiments to look at the mechanisms of this interaction. To assess vulnerability to storm waves and sea level, we have applied total water level (TWL) models developed by Ruggiero to our dune geomorphology measurements (Objective 2). Our calculations show that shorter dunes dominated by A. breviligulata are more vulnerable to overtopping than taller dunes dominated by A. arenaria. Finally, to assess vulnerability of dunes to various climate change, invasion and management scenarios, we developed a number of realistic climate change scenarios relevant to foredune flooding risk (Objective 3). These include sea level rise and increases and decreases in waves. We have applied these scenarios to current grass invasion dynamics, but in addition, to projected invasion scenarios including one that has A. breviligulata dominate along the Oregon coast. In our models, altered storm intensity was the largest driver of overtopping; however, the invasion by A. breviligulata tripled the number of areas vulnerable to overtopping and posed a four-fold larger exposure than sea-level rise over multi-decadal time scales. Finally, one of us (Hacker) has worked as part of a collaborative group that is considering the functions and services provided by estuarine and coastal ecosystems. The knowledge of dunes gained from this grant has contributed substantially to this broader, international research and we have a number of papers published from this group.
Future Activities:
We will continue to analyze and apply our data, write papers and make presentations at meetings.
Journal Articles on this Report : 9 Displayed | Download in RIS Format
Other project views: | All 55 publications | 19 publications in selected types | All 17 journal articles |
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Barbier EB, Koch EW, Silliman BR, Hacker SD, Wolanski E, Primavera JH, Granek EF, Polasky S, Aswani S, Cramer LA, Stoms DM, Kennedy CJ, Bael D, Kappel C, Perillo GME, Reed DJ. Vegetation's role in coastal protection:response. Science 2008;320:176-177. |
R833836 (2010) R833836 (2011) R833836 (2012) R833836 (Final) |
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Barbier EB, Koch EW, Silliman BR, Hacker SD, Wolanski E, Primavera J, Granek EF, Polasky S, Aswani S, Cramer LA, Stoms DM, Kennedy CJ, Bael D, Kappel CV, Perillo GME, Reed DJ. Coastal ecosystem-based management with nonlinear ecological functions and values. Science 2008;319(5861):321-323. |
R833836 (2010) R833836 (2011) R833836 (2012) R833836 (Final) |
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Barbier EB, Hacker SD, Kennedy C, Koch EW, Stier AC, Silliman BR. The value of estuarine and coastal ecosystem services. Ecological Monographs 2011;81(2):169-193. |
R833836 (2010) R833836 (2011) R833836 (2012) R833836 (Final) |
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Hacker SD, Zarnetske P, Seabloom E, Ruggiero P, Mull J, Gerrity S, Jones C. Subtle differences in two non-native congeneric beach grasses significantly affect their colonization, spread, and impact. Oikos 2012;121(1):138-148. |
R833836 (2010) R833836 (2011) R833836 (2012) R833836 (Final) |
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Koch EW, Barbier EB, Silliman BR, Reed DJ, Perillo GME, Hacker SD, Granek EF, Primavera JH, Muthiga N, Polasky S, Halpern BS, Kennedy CJ, Kappel CV, Wolanski E. Non-linearity in ecosystem services: temporal and spatial variability in coastal protection. Frontiers in Ecology and the Environment 2009;7(1):29-37. |
R833836 (2010) R833836 (2011) R833836 (2012) R833836 (Final) |
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Seabloom EW, Ruggiero P, Hacker SD, Mull J, Zarnetske P. Invasive grasses, climate change, and exposure to storm-wave overtopping in coastal dune ecosystems. Global Change Biology 2013;19(3):824-832. |
R833836 (2012) R833836 (Final) |
Exit Exit |
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Zarnetske PL, Seabloom EW, Hacker SD. Non-target effects of invasive species management:beach grass, birds, and bulldozers in coastal dunes. Ecosphere 2010;1(5):1-20. |
R833836 (2010) R833836 (2011) R833836 (2012) R833836 (Final) |
Exit Exit Exit |
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Zarnetske PL, Hacker SD, Seabloom EW, Ruggiero P, Killian JR, Maddux TB, Cox D. Biophysical feedback mediates effects of invasive grasses on coastal dune shape. Ecology 2012;93(6):1439-1450. |
R833836 (2011) R833836 (2012) R833836 (Final) |
Exit |
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Zarnetske PL, Gouhier TC, Hacker SD, Seabloom EW, Bokil VA. Indirect effects and facilitation among native and non-native species promote invasion success along an environmental stress gradient. Journal of Ecology 2013;101(4):905-915. |
R833836 (2012) R833836 (Final) |
Exit Exit Exit |
Supplemental Keywords:
Global climate, invasion, dune geomorphology, foredune, coastal protection, risk assessment, beach grasses, Ammophila arenaria, Ammophila breviligulata, community structure, shoreline change, ecosystem services, climate models, total water level models, management, RFA, Scientific Discipline, Air, climate change, Air Pollution Effects, Environmental Monitoring, Ecological Risk Assessment, Atmosphere, anthropogenic stress, biodiversity, ecosystem impacts, environmental stressors, coastal ecosystems, landscape characterization, climate variability, Global Climate ChangeRelevant Websites:
Peter Ruggiero | College of Earth, Ocean, and Atmospheric Sciences | Oregon State University ExitThe Seabloom Lab | University of Minnesota Exit
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.