CS17 Invasive Species
Date: Thursday, June 13, 2002
Time: 4:45:00 PM
Location: Sidney
 
FeistBE, National Marine Fisheries Service, Seattle, USA, blake.feist@noaa.gov
Hilborn, R, , University of Washington, Seattle, USA, rayh@u.washington.edu
Simenstad, C, A, University of Washington, Seattle, USA, simenstd@fish.washington.edu
 
A SIMPLE MODEL FOR PREDICTING RECRUITMENT AND EXPANSION OF NON-INDIGENOUS SMOOTH CORDGRASS, SPARTINA ALTERNIFLORA (LOISEL)
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We modeled recruitment and subsequent expansion of non-indigenous Atlantic smooth cordgrass (Spartina alterniflora) patches in Willapa Bay, Washington. Data inputs included lateral expansion rates of established patches and sea surface temperature anomaly data. We assumed that the production of potential seeds and propagules was proportional to the total area occupied by S. alterniflora, and that the probability of successful germination/establishment into new areas was proportional to the total available uncolonized area, modified by sea surface temperature. We estimated the parameters of the model using estimated year of birth for individual patches based on mean lateral growth rates. We found that recruitment was not entirely explained by the total uncolonized area available, and that ocean conditions, influenced by the Pacific Decadel Oscillation (PDO), explained some of the recruitment trends. Our model could be used to test alternative control strategies for S. alterniflora expansion. In addition, our findings suggest that global climate change may accelerate the invasion of this non-indigenous estuarine emergent marsh plant in the Pacific Northwest of the United States.