Life Sciences Commons^™

Stimulated Growth Response To Sand Burial Of A Coastal Shrub, D. Nicole Keller

Theses and Dissertations

Drivers of vegetation zonation on barrier islands are complex and interconnected. Sand burial is a strong driver in dynamic coastal systems, especially in the foredune community. However, it is not well understood how burial impacts the interdunal swales communities and it is especially difficult to separate the effects of burial from salinity. Climate change is altering the frequency of overwash events as well as expanding the range of the native shrub, Morella cerifera, on the Virginia barrier islands. To accurately forecast island response to climate change it is important to understand how the shrub responds to sand burial. Juvenile …

Modern Fair-Weather And Storm Sediment Transport Around Ship Island, Mississippi: Implications For Coastal Habitats And Restoration Efforts, Eve Rettew Eisemann

Master's Theses

The Mississippi – Alabama barrier island chain is experiencing accelerated sea level rise, decreased sediment supply, and frequent hurricane impacts. These three factors drive unprecedented rates of morphology change and ecosystem reduction. All islands in the chain have experienced land loss on the order of hectares per year since records began in the 1840s. In 1969, Hurricane Camille impacted as a Category 5, breaching Ship Island, and significantly reduced viable seagrass habitat. Hurricane Katrina impacted as a Category 3 in 2005, further widening Camille Cut. To better understand the sustainability of these important islands and the ecosystems they support, sediment …

Emergent Interactions Influence Functional Traits And Success Of Dune Building Ecosystem Engineers, Joseph K. Brown

Theses and Dissertations

Stability of coastal systems are threatened by oceanic and atmospheric drivers of climate change. Sea-level rise compounded with increased frequency and intensity of storms emphasizes need for protection of inner island systems by dune formations. Dune building processes are affected by interactions between growth of ecosystem engineering dune grasses and environmental factors associated with disturbance such as sand burial and salt spray. Climate change may also cause latitudinal expansion of some species, resulting in emergence of competitive interactions that were previously absent. Topographic structure of coastlines, traditionally influenced by sand burial, could change as a result of competition emergence. My …

Blue Carbon In Freshwater / Brackish Marshes On The Barrier Islands Of Virginia Aboveground Net Primary Productivity And Carbon Pools, Emily Caitlin Adams

Biological Sciences Theses & Dissertations

"Blue carbon" is a relatively new concept describing carbon distributed tidally and sequestered via net production within coastal ecosystems, including seagrass beds, mangrove forests, and salt-water marshes. These systems sequester carbon at least 10 times faster than terrestrial systems. Fresh to brackish wetlands that receive irregular tidal influence due to overwash and storm events have not been typically studied as blue carbon systems. My objective was to quantify carbon pools within four interdunal fresh to brackish marshes on Hog Island, Virginia to determine their blue carbon potential. Marshes 1 and 2 were farthest from the ocean, below and above a …

Marine Fungi Of U.S. Gulf Of Mexico Barrier Island Beaches: Biodiversity And Sampling Strategy, Allison Kathleen Walker

Dissertations

Marine fungi are an important but often overlooked component of marine ecosystems. Primarily saprotrophic, they are vital to coastal nutrient cycling processes and food webs. However, basic marine fungal distribution data are lacking in many parts of the world, as is knowledge of the sampling intensity required to characterize the biodiversity of these communities. The roles of substrate, season and latitude in shaping intertidal ascomycete community structure were examined for the U.S. Gulf of Mexico, and the role of sampling frequency on species richness estimates was also addressed. Best sampling practices were developed and 750 collections of beach detritus, sand …

Thresholds Of Change In Decomposition Rate Along A Dune/Swale Transect On A Virginia Barrier Island, Dominic J. Graziani

Biological Sciences Theses & Dissertations

Aboveground and belowground decomposition rates were determined along a barrier island dune/swale transect located on the Virginia Coast Reserve-Long Term Ecological Research Site using litterbags and wooden dowels. The objective was to determine the influence of fine scale changes in the environment on decomposition to identify any potential thresholds affecting decomposition rate. Wax myrtle (Morella cerifera L. Small) leaves and dowels of southern yellow pine wood were used as standard substrates to evaluate environmental influences on decay. Aboveground (F=6.494, p < 0.0001) and belowground (F=5.705, p < 0.0001) decay rates (yr^-1) showed significant variation among litterbag/dowel locations. Aboveground decay rates (yr^-1) ranged from 0.339 (Upper Dune station) …

Interisland Variability Of Dune Plant Community Structure On Virginia's Barrier Islands, Justin K. Shafer

Biological Sciences Theses & Dissertations

The barrier islands of the Virginia Coast Reserve LTER site provide an opportunity to study interisland variability of dune plant communities. My research focused on the variation in biomass and diversity of communities among islands and dune positions. Grassy dunes of young, intermediate and old age were sampled on Smith, Hog, and Parramore Islands. Aboveground biomass was obtained from harvest plots, and roots were extracted from cores. Data were collected on depth to groundwater and total soil nitrogen. Variation in mean aboveground biomass was evident among the islands with the highest values on Hog Island, followed by Smith, then Parramore …

Evaluating Vascular Plant Composition And Species Richness On Horn Island, Mississippi, Using Passive And Active Remote Sensing In Conjunction With Ground Based Measurements, Kelly Lynn Lucas

Dissertations

Barrier island vegetation is subjected to chronic abiotic stressors combined with periodic storm events that favor species adapted to harsh environments. These islands are the first landforms to be affected by changes in coastal subsidence and sea-level rise. Evaluating changes in vegetation is important for understanding the impact of global climate change on coastal environments.

This study assesses vegetation composition and plant species richness on Horn Island, Mississippi using ground data in conjunction with remotely sensed spectral and LIDAR data. The goals of this research are to: 1) classify and map vegetation composition on Horn Island using hyperspectral and LIDAR …