Environmental Controls on the Growth of Dune-Building Grasses and the Effect of Plant Morphology on Coastal Foredune Formation

Vegetated coastal foredunes protect habitats and infrastructure from storm-driven flooding. To improve understanding of foredune formation and morphology by quantifying the relationship between plant growth and position (cross-shore and elevation), I planted and monitored 180 individuals (Ammophila breviligulata, Spartina patens, Uniola paniculata) on Hog Island, Virginia. Growth in all species was correlated with change in elevation, and varied with position in S. patens and U. paniculata. Relationships were most predictive in A. breviligulata and U. paniculata. Transplant basal area and lateral spreading was greater at low elevations (340 cm2, 48%) than at intermediate (95, 17%) or high elevations (107, 20%). I derived allometric scaling relationships relating longest visible leaf length to basal and frontal area and found that the empirical ratio of basal-to-frontal area (~0.8, all species) maximized dune height in a morphodynamic foredune growth model. Model results suggest that plant morphology exerts a nonlinear control on dune morphology.Master of Scienc