Stratified vertical sediment profiles increase burrowing crab effects on salt marsh edaphic conditions

Burrowing animals can profoundly affect the biological structure and ecosystem functions of their environments. For instance, burrowing crabs in soft-sediment coastal ecosystems, like salt marshes, can increase sediment deposition and facilitate sediment homogenization and turnover, with potential impacts to sediment biogeochemistry. However, the relative importance and overall impacts of burrowing crabs on sediment dynamics can vary considerably between, and within, salt marsh habitats. Past studies have suggested that sediment properties can influence how burrowing crabs will affect edaphic conditions in salt marshes, but these studies often assume homogenous sediment conditions and fail to consider how marsh sediment properties change with depth. Here, we conducted a series of field surveys in three tidal salt marshes with variable sediment properties to understand if salt marsh vertical sediment profiles can help predict the nature of burrowing crab-sediment relationships. We found ..., Site Descriptions
            To evaluate if marsh vertical sediment profile stratification informs burrowing crab effects on sediment edaphic conditions, we used a complex of two, 34-year-old constructed marshes and one natural marsh (~2,140 ± 15 - 2,290 ± 20 years old; Smyth 2020) along the West Fowl River in southern Alabama, USA (CON-1: 30°22’02.3” N, 88°09’06.8” W; CON-2: 30°22’03.5” N, 88°09’02.6” W; NAT: 30°22’02.5” N, 88°09’37.2” W). The natural marsh (hereafter, NAT) is approximately 1km from the two constructed sites (hereafter, CON-1 and CON-2), which are hydrologically connected to NAT by a dredged tidal channel. All three sites experience diurnal microtides with an amplitude of approximately 0.26 m (Smyth 2020) and range in elevation from 0.26-0.36 NAVD88 (Ledford and others 2021).
            The plant community at each marsh is dominated by Juncus roemerianus (hereafter, Juncus), with smaller patches of Spartina alterniflora and Distichlis spicata along creek banks and i..., All files are CSVs and should be compatable with excel and other basic data-base software.Â