Recovery of a Louisiana Barrier Island Marsh Plant Community Following Extensive Hurricane-Induced Overwash

The Isles Dernieres barrier island chain provides the front line of protection for the Lower Terrebonne Estuary, Louisiana. Landfall of Hurricane Andrew on August 26, 1992 resulted in overwash of most of this island chain, thereby accelerating the erosional processes and altering the plant communities of the islands. Four zones were identified by the depth of overwash sands received (from > 50 cm to < 10 cm) to examine the factors affecting the colonization of vegetation following overwash. Within each zone a permanent transect and thirty permanent plots were established and sampled four times over two years for biotic and abiotic variables. A total of 32 plant species was identified, 30 of which were located in the zone with the highest loadings of sand. Over time this zone also had the greatest increases in species richness. The most important survivor and early colonizer of the high zone overwash was Spartina alterniflora . However, over time Spartina patens became dominant. The other zones, receiving moderate to no sand deposits, differed greatly. The few species present in these zones (<7) were indicative of high salt marsh and salt pan habitats and were dominated by Spartina alterniflora throughout the study. Using multivariate analyses, biotic and abiotic variables were correlated. The soil variables representative of topographical elevation and soil salinity influenced plant community zonations on the Isles Dernieres. Soil fertility and herbivory were not dominant factors affecting vegetation establishment. Backbarrier mars h areas that received the greatest san d loadings are now characterized by dune and swale plant species, while areas that received low sand loadings are returning to a marsh community .

[1]  M. Bertness,et al.  Effects of biomass removal and elevation on species richness in a New England salt marsh , 1997 .

[2]  M. Bertness,et al.  Disturbance and intraspecific variation in the clonal morphology of salt marsh perennials , 1996 .

[3]  U. Seeliger,et al.  Shore disturbance and dune plant distribution , 1996 .

[4]  James B. Grace,et al.  The relationship between species richness and community biomass: the importance of environmental variables. , 1994 .

[5]  J. Leeuw,et al.  Does zonation reflect the succession of salt-marsh vegetation? A comparison of an estuarine and a coastal bar island marsh in The Netherlands , 1993 .

[6]  Jef Huisman,et al.  Species dynamics and nutrient accumulation during early primary succession in coastal sand dunes , 1993 .

[7]  I. Mendelssohn,et al.  Growth and Survival of Avicennia germinans Seedlings in a Mangal/Salt Marsh Community in Louisiana, U.S.A. , 1993 .

[8]  L. Fahrig,et al.  Distribution of Barrier Island Plants in Relation to Overwash Disturbance: A Test of Life History Theory , 1993 .

[9]  U. Seeliger,et al.  Zoned Habitats of Southern Brazilian Coastal Foredunes , 1993 .

[10]  B. Wilsey,et al.  Effects of increased elevation and macro- and micronutrient additions onSpartina alterniflora transplant success in salt-marsh dieback areas in Louisiana , 1992 .

[11]  M. Bertness.  The Ecology of a New England Salt Marsh , 1992 .

[12]  I. Mendelssohn,et al.  Expansion Patterns and Soil Physicochemical Characterization of Three Louisiana Populations of Uniola paniculata (Sea Oats) , 1991 .

[13]  M. Bertness.  Zonation of Spartina Patens and Spartina Alterniflora in New England Salt Marsh , 1991 .

[14]  I. Mendelssohn,et al.  Effect of Nitrogen, Phosphorus and Potassium Additions on Plant Biomass and Soil Nutrient Content of a Swale Barrier Strand Community in Louisiana , 1990 .

[15]  M. Barbour,et al.  Beach vegetation and plant distribution patterns along the northern Gulf of Mexico , 1987 .

[16]  Aaron M. Ellison,et al.  Determinants of Pattern in a New England Salt Marsh Plant Community , 1987 .

[17]  E. Meijden,et al.  The Population Ecology of Senecio Jacobaea in a Sand Dune System: I. Reproductive Strategy and the Biennial Habit , 1979 .

[18]  A. Watkinson.  The Demography of a Sand Dune Annual: Vulpia Fasciculata: III. The Dispersal of Seeds , 1978 .

[19]  P. Godfrey.  Climate, plant response and development of dunes on barrier beaches along the U.S. east coast , 1977 .

[20]  A. G. Valk.  The floristic composition and structure of foredune plant communities of cape hatteras national seashore , 1975 .

[21]  P. Greig-Smith,et al.  A Quantitative Description of the Distribution of Annuals in the Dune System at Aberffraw, Anglesey , 1974 .

[22]  J. Olson,et al.  Rates of Succession and Soil Changes on Southern Lake Michigan Sand Dunes , 1958, Botanical Gazette.

[23]  W. D. Billings,et al.  Factors Effecting Vegetational Zonation on Coastal Dunes , 1942 .

[24]  B. Wilsey,et al.  Grazing of Panicum amarum in a Louisiana barrier Island dune plant community: management implications for dune restoration projects , 1994 .

[25]  M. Barbour,et al.  Marine beach and dune plant communities , 1985 .

[26]  H. Caswell,et al.  Effects of wrack accumulation on salt marsh vegetation , 1983 .

[27]  W. C. Banta,et al.  Origins and Effects of Spartina Wrack in a Virginia Salt Marsh , 1980 .