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Mechanisms Controlling Distribution of Cosmopolitan Submerged Aquatic Vegetation: A Model Study of Ruppia maritima L. (widgeongrass) at the Everglades-Florida Bay Ecotone

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Date Issued:
2015
Summary:
Aquatic plants and submerged aquatic vegetation (SAV) are some of the most wide-ranging species and create important habitat for fish and wildlife in many ecosystems, including highly variable coastal ecotones. Mechanistically understanding factors controlling current distributions of these species is critical to project future distribution and abundance under increasing variability and climate change. I used a population-based approach to quantify the effects of spatial and temporal variability on life history transitions of the SAV Ruppia maritima L. (widgeongrass) in the highly dynamic Everglades-Florida Bay ecotone as a model to (1) examine which life history stages were most constrained by these conditions and (2) determine how management can promote life history development to enhance its distribution, an Everglades restoration target. Ruppia maritima life history transitions were quantified in a series of laboratory and field experiments encompassing a ra nge of abiotic and biotic factors known to affect seagrass and SAV (salinity, salinity variability, temperature, light and nutrients and seed bank recruitment and competition). These studies revealed that R. maritima life history varied east to west across the Everglades ecotone, driven by multiple gradients in abiotic factors that constrained different life history transitions in distinct ways. Based on this examination, persistence of SAV populations from dynamic coastal environments is highly dependent on large reproductive events that produce high propagule densities for recruitment. Large productive meadows of SAV also depend on high rates of clonal reproduction where vegetation completely regenerates in a short amount of time. Therefore, in hydrologically variable systems, maintenance or increases in SAV reproduction is required for population persistence through recruitment. However, SAV communities that do not experience high rates of sexual reproduction are dependent on successful seed germination, seedling and adult survival and clonal reproduction for biomass production and maintenance. Seedling survival and to a lesser extent, adult survival, are bottlenecks that can limit life history transitions under highly variable hydrological conditions. To ensure long-term survival in these communities, management activities that increase survival and successful life history development through these critical stages will be beneficial. If not, SAV populations may become highly reduced and ephemeral, providing less productive habitat.
Title: Mechanisms Controlling Distribution of Cosmopolitan Submerged Aquatic Vegetation: A Model Study of Ruppia maritima L. (widgeongrass) at the Everglades-Florida Bay Ecotone.
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Name(s): Strazisar, Theresa, author
Koch, Marguerite, Thesis advisor
Florida Atlantic University, Degree grantor
Charles E. Schmidt College of Science
Department of Biological Sciences
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2015
Date Issued: 2015
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 204 p.
Language(s): English
Summary: Aquatic plants and submerged aquatic vegetation (SAV) are some of the most wide-ranging species and create important habitat for fish and wildlife in many ecosystems, including highly variable coastal ecotones. Mechanistically understanding factors controlling current distributions of these species is critical to project future distribution and abundance under increasing variability and climate change. I used a population-based approach to quantify the effects of spatial and temporal variability on life history transitions of the SAV Ruppia maritima L. (widgeongrass) in the highly dynamic Everglades-Florida Bay ecotone as a model to (1) examine which life history stages were most constrained by these conditions and (2) determine how management can promote life history development to enhance its distribution, an Everglades restoration target. Ruppia maritima life history transitions were quantified in a series of laboratory and field experiments encompassing a ra nge of abiotic and biotic factors known to affect seagrass and SAV (salinity, salinity variability, temperature, light and nutrients and seed bank recruitment and competition). These studies revealed that R. maritima life history varied east to west across the Everglades ecotone, driven by multiple gradients in abiotic factors that constrained different life history transitions in distinct ways. Based on this examination, persistence of SAV populations from dynamic coastal environments is highly dependent on large reproductive events that produce high propagule densities for recruitment. Large productive meadows of SAV also depend on high rates of clonal reproduction where vegetation completely regenerates in a short amount of time. Therefore, in hydrologically variable systems, maintenance or increases in SAV reproduction is required for population persistence through recruitment. However, SAV communities that do not experience high rates of sexual reproduction are dependent on successful seed germination, seedling and adult survival and clonal reproduction for biomass production and maintenance. Seedling survival and to a lesser extent, adult survival, are bottlenecks that can limit life history transitions under highly variable hydrological conditions. To ensure long-term survival in these communities, management activities that increase survival and successful life history development through these critical stages will be beneficial. If not, SAV populations may become highly reduced and ephemeral, providing less productive habitat.
Identifier: FA00004549 (IID)
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2015.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Subject(s): Coastal zone management
Ruppia maritima -- Ecology -- Everglades National Park (Fla.)
Ruppia maritima -- Ecology -- Florida Bay (Fla.)
Seagrasses -- Everglades National Park (Fla.)
Seagrasses -- Florida Bay (Fla.)
Wetland ecology -- Everglades National Park (Fla.)
Wetland ecology -- Florida Bay (Fla.)
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Links: http://purl.flvc.org/fau/fd/FA00004549
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00004549
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Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.