Vegetative Response of Sagittaria Lancifolia to Burning of Applied Crude Oil

Field studies were conducted to evaluate Sagittarialancifolia sensitivity to in-situ burning of appliedcrude oil. Twenty-four plots were constructed (2.4 × 2.4× 0.6 m) in a fresh marsh and experimental treatmentswere: 1) control (no oiling and/or burning); 2) oiling (naturalremediation); and 3) oiling plus burning. South Louisiana Crudewas applied at 2 L m^-2, with a garden sprayer, on Sagittaria lancifolia stems and leaves of the oiling andoiling/burning treatment plots. Two marsh burns were conducted,one in August (Site A) and a second on separate plotsthe following April (Site B) to compare seasonal effects ofoiling and burning. Burning was initiated three days after oilapplication when the marsh was flooded to a 15–25 cm depth andwinds were calm. Live stem count, plant height growth and carbonfixation were measured up to 9 times over 52 weeks after thefirst burn (August) and 6 times over 19 weeks after the secondin-situ burn (April). Aboveground biomass was measured atthe conclusion of each study. Oil application and oil burninghad short term effects on Sagittaria lancifoliavegetation. Five to six weeks after each burn, measured Sagittaria lancifolia vegetative parameters in control, oiledand oiled/burned plots were not significantly different. Onlybiomass clipped 20 weeks after the April burn showed significanttreatment differences. Under our experimental conditions, datasuggests leaving oil to degrade and the marsh to recovernaturally may be an option to consider. Plant recovery inoiled/burned plots was as rapid as oiled plant recovery. Thissuggests burning may be a viable remediation method if a rapidresponse is needed to remove oil and control oil migration tosensitive areas.