Proceedings of the Third International Conference on Invasive ...

<strong>Proceedings</strong> <strong>of</strong> <strong>the</strong> <strong>Third</strong> <strong>International</strong> <strong>Conference</strong> on Invasive SpartinaChapter 3: Ecosystem Effects <strong>of</strong> Invasive SpartinaInundation Time vs. Tidal Height0.80Inundation Time (%)0.750.700.650.600.550.500.450.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2Tidal Height (m)Fig. 4. Plot <strong>of</strong> inundation time (%) calculated from continuous tidalheight data relative to estimated elevation from LIDAR data.Fig. 3. LIDAR image <strong>of</strong> Robert’s Landing showing lower extent <strong>of</strong> hybridSpartina distribution (grey) and invertebrate sampling points along transects(dots).y = -0.0006x² + 0.3889x + 56.787, R² = 0.1713 (2)The high abundances at intermediate tidal elevationswere due to high numbers <strong>of</strong> small juvenile clams (> 1 mm)that did not contribute very significant biomass. When weanalyzed <strong>the</strong> data by phyla, we found that annelids, mollusksand crustaceans generally showed similar patterns. Annelidsalso showed a substantial decline in biomass with tidalelevation:y = -0.0165x + 13.624, R 2 =0.12 (3)Molluscs and crustaceans showed a similar but morevariable decline (R 2