You are here:
A SPATIO-TEMPEROL ANALYSIS OF THE ENVIRONMENTAL AND CLIMATIC FACTORS CONTROLLING THE EXPANSION OF SPARTINA ALTERNIFLORA IN WILLAPA BAY, WASHINGTON
Citation:
Feist, E. F. A SPATIO-TEMPEROL ANALYSIS OF THE ENVIRONMENTAL AND CLIMATIC FACTORS CONTROLLING THE EXPANSION OF SPARTINA ALTERNIFLORA IN WILLAPA BAY, WASHINGTON. 1999.
Description:
Circa 1890, smooth cordgrass, Spartina alterniflora, was unintentionally introduced to Willapa Bay, Washington, presumably as discarded packing material for eastern oysters, Crassostrea virginica. At present, S. alterniflora covers over 2,000 ha of the littoral flats in Willapa Bay, and it may pose a threat to wildlife. The spatial distributions of S. alterniflora are patchy, suggesting that littoral flats are heterogeneous over space and time. My overall objective was to determine which environmental variables account for the patchiness of S. alterniflora in Willapa Bay. I used spatial analysis and simulation modeling to evaluate the influence of environmental and climatic variables on the spatial and temporal distributions of S. alterniflora. First, I estimated lateral growth rates of S. alterniflora patches between 1970 and 1990, based on aerial photograph interpretations. From this I reconstructed recruitment periodicity from 1890 to 1990. Lateral growth rates of individual S. alterniflora patches were 79.3 (plus/minus 1.67 SE) cm yr-1. Recruitment has been episodic and increasing in frequency since 1890. Climatic factors associated with El Ni?o-Southern Oscillation (ENSO) events, especially sea surface temperature, may account for some of this recruitment variability.