Plant productivity and diversity in coastal wetlands in Mississippi – impact of hydrological extremes

<p>Wetlands are highly productive ecosystems that provide important ecosystem services and are threatened by extreme hydrological events. I evaluated how diversion of freshwater like Bonnet Carré Spillway openings in Louisiana, US, affected vegetation productivity and diversity in salt marshes on the neighboring Mississippi Gulf Coast, US. My study area is two estuarine systems that differ in their proximity to the Bonnet Carré Spillway, elevation, and salinity including Hancock County Marshes on the west, and Grand Bay National Estuarine Research Reserve (NERR) on the east in Mississippi. I collected above- and belowground biomass samples in 2020 and 2021, developed linear mixed-effects models to predict how the plant productivity and diversity changed with elevation and soil porewater salinity, and linked vegetation productivity to spectral information of Landsat and Sentinel satellite images. I applied the models to hindcast vegetation productivity based on historical satellite images approximately during May and August of years with and without Bonnet Carré Spillway openings to assess the openings’ impact on vegetation productivity. While elevation was included in most of the models to predict above- or belowground biomass in Hancock County marshes, soil porewater salinity was the more prevalent driver in the Grand Bay NERR. Additionally, vegetation biodiversity decreased with salinity in both salt marshes. As the frequency and duration of the Bonnet Carré Spillway openings increased, the peak green aboveground biomass decreased in both estuaries in the year when the spillway opened and was concentrated in the region that is closer in proximity to the Bonnet Carré Spillway.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2022

Author dc:creator

• Feldpausch, Kodi

Contributors dc:contributor

• Wei Wu
• Chet Rakocinski
• Tracy Quirk

• Wetlands
• Mississippi Sound
• Bonnet Carré Spillway
• Aboveground Biomass
• Vegetation Indices
• Bayesian modeling
• Ecology and Evolutionary Biology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/945

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-2016