Towards Accurate Modeling Of Aboveground Vegetation In White Dunes: Biomechanics Of Marram Grass (Ammophila Arenaria)

Abstract

Coastal dunes, shaped by natural processes, particularly aeolian sediment transport driven by onshore winds, are dynamic environments where vegetation plays a pivotal role in trapping sediments, enabling dunes to reach substantial heights. However, the biomechanical traits of aboveground dune vegetation have received limited attention, impeding precise modeling in coastal engineering. Understanding dune erosion and accretion is essential for enhancing coastal resilience and the integration as ecosystem-based coastal protection measures. Notably, prior research has primarily focused on salt marshes and seagrass (e.g. Keimer et al. 2023), neglecting more detailed modeling of dune vegetation, often employing simplified methods like live vegetation (Figlus et al. 2014; Silva et al. 2016) or wooden dowels (Kobayashi et al. 2013; Bryant et al. 2019). The hypothesis tested for the first time here is that geographic expositions and seasonal growth stages can be quantified for marram grass (Ammophila arenaria), and that in turn, these vegetation characteristics will inform laboratory studies involving the interaction of waves, flexible vegetation and eroding dunes.