Representing flexible salt marsh vegetation at the stem scale: biomechanics, modeling approaches, and research gaps

The accurate representation of flexible salt marsh vegetation at the stem scale is fundamental for improving our understanding of the fluid–vegetation interaction and its role in coastal protection and other ecosystem services. This paper critically reviews existing methodologies used to replicate flexible salt marsh vegetation in both physical experiments and numerical modeling approaches. Specifically, the review (i) assesses which biomechanical stem properties are most relevant for reproducing realistic plant behavior under hydrodynamic forcing, (ii) examines how previous studies have implemented surrogate and numerical representations of flexible stems, and (iii) synthesizes current research gaps related to the accurate replication of vegetation mechanics. Particular attention is given to parameters such as stem geometry, flexural stiffness, material density, and their scaling in experimental and computational frameworks. By identifying inconsistencies, methodological trade-offs, and unresolved challenges, this paper provides guidance for engineers and modelers in selecting appropriate representation strategies. At the same time, it informs ecologists which field-measured plant properties are most critical for supporting reliable vegetation–flow modeling efforts, thereby fostering stronger integration between ecological field campaigns and hydrodynamic modeling studies.