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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

EFFECTS OF WET SEASON HYDRO-PATTERN ON CRAYFISH (PROCAMBARUS FALLAX) POPULATION DENSITY AND JUVENILE MORTALITY RISK

Unknown Date (has links)
Distribution and abundance of water impacts population dynamics and habitat structure within a wetland ecosystem. It is known that drought can interfere with trophic dynamics and temporarily free crayfish from the threat of predation by population limiting fish predators in seasonal freshwater wetlands. Less is known about wet season water depths, and their effect on predator prey interactions. In order to address this, I conducted a two-and-a-half-year study in which I experimentally manipulated the wet season water depth in four 8 ha replicate wetlands of the central Everglades, allowing two wetlands to be flooded as natural rainfall patterns would allow (unconstrained hydro-pattern) and two wetlands to experience a constrained hydro-pattern in which the maximum depths to which they were flooded was limited. I discovered that crayfish, small marsh fish, and large bodied predatory fish populations were unaffected by the water depth difference between the hydro-pattern treatments. Unlike fauna, flora did respond to the hydro-pattern treatments with stem densities increasing in the wetlands under the constrained hydro-pattern treatment. / Includes bibliography. / Thesis (MS)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection
12

Biogenic gas dynamics in peat soil blocks using ground penetrating radar: a comparative study in the laboratory between peat soils from the Everglades and from two northern peatlands in Minnesota and Maine

Unknown Date (has links)
Peatlands cover a total area of approximately 3 million square kilometers and are one of the largest natural sources of atmospheric methane (CH4) and carbon dioxide (CO2). Most traditional methods used to estimate biogenic gas dynamics are invasive and provide little or no information about lateral distribution of gas. In contrast, Ground Penetrating Radar (GPR) is an emerging technique for non-invasive investigation of gas dynamics in peat soils. This thesis establishes a direct comparison between gas dynamics (i.e. build-up and release) of four different types of peat soil using GPR. Peat soil blocks were collected at peatlands with contrasting latitudes, including the Everglades, Maine and Minnesota. A unique two-antenna GPR setup was used to monitor biogenic gas buildup and ebullition events over a period of 4.5 months, constraining GPR data with surface deformation measurements and direct CH4 and CO2 concentration measurements. The effect of atmospheric pressure was also investigated. This study has implications for better understanding global gas dynamics and carbon cycling in peat soils and its role in climate change. / by Anastasija Cabolova. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
13

Linking the ecological and economic values of wetlands a case study of the wetlands of Moreton Bay /

Clouston, Elizabeth M. January 2002 (has links)
Thesis (Ph. D.)--Griffith University, 2002. / Title from PDF title page (viewed on May 7, 2005). Includes bibliographical references (p. 343-382).
14

Hydroperiod of wetlands and reproduction in wood frogs (rana sylvatica) and spotted salamanders (ambystoma maculatum) /

Kolozsvary, Mary Beth, January 2003 (has links) (PDF)
Thesis (Ph. D.) in Ecology and Environmental Science--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 88-96).
15

Examining the link between macrophyte diversity, bacterial diversity, and denitrification function in wetlands

Gilbert, Janice M. January 2004 (has links)
Thesis (Ph. D.)--Ohio State University, 2004. / Document formatted into pages; contains xiii, 234 p. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2005 June 1.
16

Diversity among plant species in an emergent wetland an initial survey of the Landingville Marsh /

Shidisky, Joseph G. January 1997 (has links)
Thesis (M. Ed.)--Kutztown University of Pennsylvania, 1997. / Source: Masters Abstracts International, Volume: 45-06, page: 3071. Typescript. Abstract precedes thesis as preliminary leaves [1-2]. Includes bibliographical references (leaves 76-79).
17

Aerial photography and the wetland resource interpretation testing and ecosystem restoration /

Homblette, Daniel J. January 1982 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 527-539).
18

The effects of urban hydrology and elevated atmospheric deposition on nitrate retention and loss in urban wetlands

Stander, Emilie. January 2007 (has links)
Thesis (Ph. D.)--Rutgers University, 2007. / "Graduate Program in Ecology and Evolution." Includes bibliographical references.
19

The effects of secondary sewage effluent on the water quality, nutrient cycles and mass balances, and accumulation of soil organic matter in cypress domes

Dierberg, Forrest Edward, January 1980 (has links)
Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 268-286).
20

Habitat, home range, diet and demography of the water vole (Arvicola amphibious) : patch-use in a complex wetland landscape

Neyland, Penelope Jane January 2011 (has links)
Water vole (Arvicola amphibius) ecology was studied at the National Wetland Centre Wales (NWCW), a National Key Site for water voles, consisting of a diversity of interconnected habitats, including ponds, ditches and reed-beds. A novel method of mapping the vegetation of the wetland landscape was devised, using patches of vegetation classified according to the dominant vegetation type (DVT). The richness and abundance of DVT patches was used as an index of diversity at the habitat level. This provided a basis for describing the matrix habitat, which underpins the study of water vole ecology at the patch-landscape scale. The practical application of the DVT mapping approach allows the stages of wetland succession to be monitored, identifies areas of high biodiversity and provides a baseline on which to monitor the distribution and movements of animal species. Implementation of this method reduces time and the need for specialist field surveyors, thereby facilitating efficient management practices if applied at a national level. An intensive four year study of a metapopulation of water voles on eight adjacent ponds in the NWCW wetland reserve revealed an important insight into the dynamics of wild populations in complex, non-linear habitats. Multi-annual fluctuations in population densities were observed, characterised by a peak density phase and a low density phase. Density dependent juvenile dispersal was characteristic of the water vole population. Female water voles in diverse pond habitats maintained intra-sexually overlapping home ranges, uncharacteristic of this species. During the breeding season, water voles selected the ponds with the highest habitat diversity (assemblage of DVTs) but were typically associated with the least diverse DVT patches within the vegetation mosaic. Temporal plasticity in niche partitioning was observed both between genders and between individual female water voles at NWCW. During the winter. Bramble (Rubus fruticosus) was the most important dominant vegetation type, providing a source of cover and protection from predation. Water voles selected 23 plant species (and 3 non-plant species) as food. Soft Rush (Juncus effusus) a species with high nitrogen and calorific content was favoured particularly. The physical effects of water vole grazing and burrowing, combined with the large amounts of nitrogen- containing faeces deposited in latrines and underground burrows, has implications for wetland nutrient cycles. The effects of large scale vegetation clearance are described and holistic management recommendations are presented.

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