Physical characteristics of salt marsh sediments: ecological implications

Publisher Website
Google Scholar
Abstract
We measured the physical characteristics of 4 sediment types commonly found in southeastern (USA) salt marshes and thier relationship to sediment drainage and compressibility. Compressibility was found to be positively correlated with total silt-clay content (r2 = 0.953) and negatively correlated with total sand content (r2 = 0.942). A linear relationship (r2 = 0.832) was found between the square root of sediment percolation velocity and bulk density. Calculations of the rate of air entry and porewater turnover based on our measurements of drainage and compressibility are consistent with the supply of SO42- necessary to support the rate of SO42- reduction found at North Inlet, South Carolina, USA, by previous researchers and indicate that compressibility may regulate the turnover of reduced end products such as pyrite. For incompressible sediments, it was demonstrated that the entry of air into sediments following water loss by evapotranspiration is quantitatively important in oxidizing reduced sulfur compounds, while drainage of compressible creek bank sediments is apparently sufficient to replace SO42- utilized by dissimilatory SO42- reducers.
Keywords