Short-term effects of Hurricanes Gustav and Ike on floating freshwater marsh communities in the Mississippi Deltaic Plain
Looft JA, Battaglia LL, Minchin PR. 2010. Short-term effects of Hurricanes Gustav and Ike on floating freshwater marsh communities in the Mississippi Deltaic Plain
Floating marsh ecosystems in the Mississippi River Deltaic Plain support a diverse array of plant species, all of which are dependent upon the floating, low bulk density mat bound together by an extensive fibrous root system. These marshes are usually found in freshwater habitats, and the effects of inundation with saline storm surge as tropical storms make landfall are poorly understood. In 2008, Hurricanes Gustav and Ike impacted coastal Louisiana marshes. We compared aspects of the pre- and post- disturbance vegetation in open herbaceous marsh, sparse shrub marsh, and shrub thicket assemblages. Overall biomass and necromass did not change following the storms, but species richness decreased significantly due to loss of species that were initially low in abundance and sensitive to salinity pulses. Within each of the vegetation types, compositional shifts between years were significant, but contrary to our predictions, pre-disturbance compositional differences between vegetation types became more pronounced following the storm. This study documents short-term changes in freshwater floating marsh communities in response to the sequential disturbances of Hurricanes Gustav and Ike. Long-term data collected from these permanent plots will help to determine whether hurricane-driven changes are ephemeral or functional triggers that accelerate effects of sea level rise.
- Type
- Unpublished Report
- Authors
- Looft, Jerrod; Battaglia, Loretta; Minchin, Peter
- Date of Issue
- 2010
- Units
- GULN
- Keywords
- ANOSIM, Communities, deltaic, Effects, floating, Freshwater, gustav, Hurricane, ike, Mississippi, pairwise, Plain, Plant, Salinity, short, Storm, Surge, term