Sand supply and dune grass species density affect foredune shape along the <scp>US</scp> Central Atlantic Coast

Coastal foredunes form via biophysical feedbacks between sand accretion and burial-tolerant vegetation can protect coastlines from hazards such as extreme storms sea level rise. Predicting how coastal dunes, the services they provide, will change in future requires an understanding of relative roles physical ecological processes that shape their structure function. Here we assess supply, beach morphology, determining foredune its change, along a 300-km stretch US Central Atlantic coast. In particular, used spatial variability inherent beaches dunes this region to determine importance shoreline rate (SCR; proxy for supply beach), grass density four widespread dune grasses (Uniola paniculata, Ammophila breviligulata, Panicum amarum, Spartina patens) morphology metrics (height, width, aspect ratio) North Carolina Outer Banks barrier islands. Foredune are correlated with three main factors: multidecadal SCR (1997–2016), slope, species identity. Multidecadal width explained most variation in, were positively with, height negatively ratio (height divided by width). addition, changes contributed significantly change. We found positive relationship A. breviligulata which aligns previous studies on Pacific Northwest coasts. Our results demonstrate interactive functional building highly vulnerable coastlines.