Effect of vegetation cover and sediment type on 3D subsurface structure and shear strength in saltmarshes

The vulnerability of saltmarshes to lateral erosion at their margin depends on the local biogeomorphological properties substrate. In particular, 3D architecture pore and root systems is expected influence shear strength, with repercussions for wider-scale stability saltmarshes. We apply X-ray computed microtomography (?CT) visualize quantify subsurface structures in two UK Tillingham Farm, Essex (silt/clay rich substrate) Warton Sands (sand-rich substrate), four types ground cover: bare ground, Spartina spp, Salicornia spp Puccinellia spp. extracted ?CT structural parameters that characterize morphologies each station, compared them field measurements strength using a principal component analysis correlation tests. volumes show species-dependent variations structures, plant colonization events bioturbation activity control morphology macropores, while sediment cohesivity determines persistence these over time, even after vegetation has died. Areas high porosity mean thickness were correlated lower values especially where well-connected vertical macropores associated current or previous by However, may deformation threshold sediment, they also encourage drainage, promote growth reduce marsh hydrodynamic forces. highest both sites found under density mesh-like bind resist deformation. Future studies should ideally consider time series cover, silt/clay-dominated saltmarshes, order potential effect preserved buried networks water circulation, functioning cliff-face erosion.