Influence of Depositional Patterns of Dredged Material on Soil Properties of a Restored Coastal Louisiana Salt Marsh.

Soil physical, chemical and bio-geochemical properties of a restored coastal marsh were monitored and analyzed from 2005 to 2009. Total area of 109 ha reconstructed marsh located at Port Fourchon, Louisiana, was divided into five habitats based on elevation. The habitats were classified as high (knoll), flat (swale), upper intertidal, intertidal, and water. The higher habitats were located where the dredged materials were deposited. The composition of dredged material at the highest elevation was mainly sand and shells. Higher clay and silt content were found in the habitats located with distance from the dredge source. Macronutrient and micronutrient were relatively low in all habitats except for Na and Ca. All elements were statistically significant difference among habitats except for NO₃-N and NH₄-N.  The depth of 0-15 and 15-30 cm had no influence on elemental content. Soil redox potential was significant difference among habitats. Higher elevations had higher redox potential values. Marsh vegetation was greatest at the highest elevation.