title: Salt marsh recovery and oil spill remediation after in-situ burning: effects of water depth and burn duration.
abstract: Effects of water depth, burn duration, and diesel fuel concentration on the relationship between recovery of marsh vegetation, soil temperature, and oil remediation during in-situ burning of oiled mesocosms were investigated. The water depth over the soil surface during in-situ burning was a major factor controlling recovery of the salt marsh grass, Spartina alterniflora. Ten centimeters of water overlying the soil surface was sufficient to protect the marsh soil from burn impacts with soil temperatures <37 degrees C and high plant survival rate. In contrast, a water table 10 cm below the soil surface resulted in mean soil temperatures > 100 degrees C at the 2-cm soil depth, which completely inhibited the post-burn recovery of S. alterniflora. Although poor plant recovery was also apparent in the treatments with 0 and 2 cm of water over the soil surface, this result was likely due to the chemical stress of the diesel fuel used to create the fire rather than the heat, per se, which never reached the estimated lethal temperature of 60 degrees C. In-situ burning effectively removed more than 95% of floating oil from the water surface. Thus, in-situ burning prevented the oil from potentially contaminating adjacent habitats. However, in-situ burning did not effectively remediate the oil that had penetrated the soil.
authors.affiliation: Wetland Biogeochemistry Institute and Institute for Environmental Studies, Louisiana State University, Baton Rouge 70803, USA. comlin@lsu.edu
authors.forename: Qianxin
authors.initials: Q
authors.lastname: Lin
authors.forename: Irving A
authors.initials: IA
authors.lastname: Mendelssohn
authors.forename: Kenneth
authors.initials: K
authors.lastname: Carney
authors.forename: Nelson P
authors.initials: NP
authors.lastname: Bryner
authors.forename: William D
authors.initials: WD
authors.lastname: Walton
mesh_terms: D003247:Conservation of Natural Resources; D017753:Ecosystem; D004785:Environmental Pollutants; D005390:Fires; D005742:Gasoline; D006109:Poaceae / Q000254:growth & development; D011157:Population Dynamics; D012987:Soil; D013696:Temperature
chemical_list: D004785:Environmental Pollutants; D005742:Gasoline; D012987:Soil