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dc.contributor.advisorStevenson, J. Courten_US
dc.contributor.authorStaver, Lorie Winchellen_US
dc.date.accessioned2016-02-06T06:39:06Z
dc.date.available2016-02-06T06:39:06Z
dc.date.issued2015en_US
dc.identifierhttps://doi.org/10.13016/M2K121
dc.identifier.urihttp://hdl.handle.net/1903/17272
dc.description.abstractAn ecological study was undertaken of the tidal marshes at Poplar Island, a restoration project utilizing fine grained dredged material from the shipping channels in upper Chesapeake Bay. The goals of the study were to examine the effect of a nutrient rich substrate on vegetation development, elevation change, and nutrient cycling in the constructed tidal marshes. Specifically, I examined macrophyte production, nitrogen (N), carbon (C) and silicon (Si) budgets, as well as the success of a silica amendment in enriching plant tissue concentrations. Establishment of Spartina alterniflora and S. patens on fine grained dredged material was rapid, and growth peaked in the second year. Thereafter S. alterniflora dieback occurred sporadically during the growing season, but the causes remain unclear. Elevation change averaged 7.9 ±0.8 mm y-1 in the dredged material marshes (low marsh only), compared to 7.4 ±1.4 mm y-1 in a low nutrient onsite reference marsh. Elevation change was significantly correlated with biomass production suggesting that inputs of organic matter from high rates of aboveground biomass production on nutrient rich dredged material offset the reduced contribution of belowground biomass to vertical accretion. However, dieback may have a detrimental effect on vertical accretion, which is essential for keeping up with apparent sea level rise (13.6 and 11.0 mm y-1 at Baltimore and Solomon’s tide gauges, respectively) since elevation monitoring began at Poplar Island. The tidal flux study revealed that the marsh exports ~665 kg of N y-1, including 100 kg NH4+-N y-1, and 67,874 kg y-1 TSS, and imports 35 kg NO3-N y-1. Silicon is also exported on both a seasonal and annual basis, including 4,337 kg dissolved Si y-1 and 3,924 kg biogenic Si y-1, with highest exports in July, an overlooked benefit of dredged material restoration projects. Soil Si amendments increased plant tissue concentrations significantly, but this study did not show increased resistance to N related stress effects on the vegetation. Overall, this study suggests that when considering trajectories of vegetation development, nutrient exchanges and elevation change in constructed marshes, it is essential to consider the initial nitrogen content of the substrate.en_US
dc.language.isoenen_US
dc.titleEcosystem dynamics in tidal marshes constructed with fine grained, nutrient rich dredged materialen_US
dc.typeDissertationen_US
dc.contributor.publisherDigital Repository at the University of Marylanden_US
dc.contributor.publisherUniversity of Maryland (College Park, Md.)en_US
dc.contributor.departmentMarine-Estuarine-Environmental Sciencesen_US
dc.subject.pqcontrolledEcologyen_US
dc.subject.pqcontrolledEnvironmental scienceen_US
dc.subject.pqcontrolledGeochemistryen_US
dc.subject.pquncontrolledaccretionen_US
dc.subject.pquncontrolledcarbonen_US
dc.subject.pquncontrolledmarshesen_US
dc.subject.pquncontrollednitrogenen_US
dc.subject.pquncontrolledrestorationen_US
dc.subject.pquncontrolledsiliconen_US


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