The relative iron (II) tolerance of a range of wetland plants was determined and compared with some species characteristic of well drained soils. A wide range of tolerance occurred amongst the wetland species but they were generally more tolerant than those from well drained soils. No correlation was found between iron (II) tolerance and the amount of air space {% v/v) (aerenchyma) in the roots of these species. There was a significant negative correlation between air space and iron uptake by roots. This may have been caused by iron (II) oxidation in the rhizosphere resulting in decreased availability. There was evidence that differential iron (II) tolerance of excised root tips was maintained under aerobic and anaerobic conditions. It was thus suggested that iron (II) tolerance may not be dependent on iron exclusion or oxidation of iron (II) by oxygen diffusing through the aerenchyma. Levels of malic and citric acids in roots were altered by iron (II) sulphate, but the absolute levels and changes in levels had no correlation with the iron (II) tolerance, of the species. Peroxidase and catalase activities in root tips of plants gown in drained and flooded sand culture were measured and considered in relation to the oxidising power of roots. Activity was detected in all species examined but was generally I unaffected by flooding. Evidence from the literature suggested that these enzymes of peroxide metabolism are unlikely to be active in flooded roots and so could not mediate their oxidising power. The structure of root aerenchyma had great variability between species. The Cyperaceae had the most complex and well organised structure. Growth under flooded conditions increased air space in most species, but there were exceptions. In Eriophrum angustifolium and E. vaginatum air space was high under drained conditions and was not increased by flooding. In Filipendula ulmaria the small amount of air space was not increased by flooding. Low nutrient levels increased air space production in Nardus stricta. The function of aerenchyma and the influence of environmental factors on its production are discussed.

The flooding and anoxia tolerance of three barley cultivars (Hordeum vulgare L. cv. Kustaa, Hankki ja-673 and Pokko), beaked sedge (Carex rostrata Stokes), rice (Oryza sativa L. cv. FR13A) and yellow flag (Iris pseudacorus L.) have been assessed by determining the length of anoxia tolerance and the productivity of the barley cultivars under flooding. Other physiological parameters related to flooding and anoxia tolerance were also determined, and they included alcohol dehydrogenase activity and its enzyme kinetic parameters KM and Vmax (for reaction acetaldehyde to ethanol) in the barley cultivars and beaked sedge, production of ethanol, CO2 and some organic acids in seedlings of the barley cultivars under anoxia, and superoxide dismutase activity in barley, rice and yellow flag under hypoxia and anoxia. A study of the root anatomy of barley and beaked sedge was also conducted. The anoxia tolerance experiments revealed differences in the three barley cultivars and the flooding tolerance experiment gave very similar results. Thus, Kustaa proved to be the most anoxia tolerant and most productive under flooding, Hankki ja-673 being intermediate and Pokko the least anoxia tolerant and the least productive during flooded conditions. Simultaneous measurements of ethanol, carbon dioxide and organic acid production during anoxia together with determination of dry weight loss during the period of oxygen deprivation showed that the rate of ethanolic fermentation was significantly faster in the more intolerant cultivars. Also, the more anoxia intolerant cultivars lost more of their dry weight during the anoxic incubation than the most tolerant cultivar. These results were in agreement with the metabolic theory of flooding tolerance. Superoxide dismutase activity measurements in the barley cultivars as well as in rice under hypoxia did not reveal any changes in the activity with the onset of oxygen deprivation. Neither did incubation under total anoxia increase SOD activity. In yellow flag rhizomes, which are very flood and anoxia tolerant, large increases in SOD activity took place during and after oxygen deprivation indicating greater protection against subsequent oxidative damage. Injuries of this nature have been noticed earlier in flood intolerant species. The anatomical study of the roots and rhizomes of beaked sedge and roots of barley cultivars revealed the larger percentage of aerenchyma in beaked sedge.

xiv, 115 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / Over the past 25 years wetland mitigation banking has emerged as an increasingly popular market-based regulatory system designed to offset wetland losses through the use of pre-constructed, government-approved wetland mitigation banks. While research highlighting the biophysical effectiveness of this approach is prevalent, little is known about the spatial and social characteristics of mitigation sites when compared to sites of permitted wetland loss. This study used wetland mitigation banking records from four Oregon counties to determine the extent to which wetland displacement has occurred, if social characteristics differ between sites of wetland loss and bank sites and if the density of wetlands near permits differs from banks. Results suggest that banks have been located an average of 11 miles from the removal-fill site. Additionally, when compared to removal-fill sites, populations living near banks were wealthier, less densely populated and less ethnically diverse. / Committee in Charge: Marc A. Schlossberg, Chair; Scott D. Bridgham; Donald G. Holtgrieve

No description available.

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

A dissertation of submitted to the Faculty of Arts in partial fulfilment of the requirements for the Master's in Recreation and Tourism in the Department of Recreation and Tourism at the University of Zululand, 2009. / There has been turmoil between the Isimangaliso Wetland Park Authority and the Khula village community located adjacent to it. Khula village community members have been trespassing into the park and conducting illegal activities. Some of these include: killing wild animals, cutting trees for wood carving and medicinal purposes without permission from the Isimangaliso Wetland Park Authority. In addition, the number of hijacked tourist cars in the area is increasing and other serious criminal activities directed to tourists are becoming very common. All these illegal activities are progressively contributing, not only to the gradual deterioration of the status of the resources, but also to the spoiled relationship between the authorities, tourists and the community around the Isimangaliso Wetland Park. These occurrences are impacting adversely on the park as a tourist destination. What is implicit is that tourist visitation numbers at the Wetland Park will drop, and these reduced numbers of tourists that will affect the employment rate within the local community. Pursuant to these observations and problems, the researcher found it appealing and necessary to explore the relationship between the Isimangaliso Wetland Park Authority and Khula village community. This would be achieved by investigating the participation, practices, and patterns associated with the administration of the Isimangaliso Wetland Park. In an attempt to address the research question or problem, the following research objectives were set up: • To reveal the extent to which the local community is aware of the importance of tourism in the study area • To establish whether the communities do participate in the reserve activities that bring in income • To determine the existing type of relationship between the local communities and the park authorities • To explore whether the communities are given a platform to express their preferences about the park • To investigate whether there are any development initiatives the reserve is offering to the local community. The research methodology used to execute the objectives of the research study involved collecting information from the local community of Khula Village, Isimangaliso Wetland Park Authority and KwaZulu-Natal Ezemvelo Wildlife. Data was collected by means of sets of questionnaires. The data collected was analysed using the SPSS computer statistical package, which led to getting the research findings. There were various findings that emerged and were deduced from the research data analysed. The findings showed that a dual relationship between the local community and Park Authorities. On the one side it was good because of the social involvement of local communities in the activities of the Park, whereas, on the other side, the lack of economic participation affected the relationship negatively. The findings showed that, among the respondents from the study area, a limited number of people had had access to tertiary education. It is believed that the lack of tertian7 education influenced the availability of skills that resulted in a small number of people participating in activities that would bring economic benefit as opposed to social benefits. Social benefits were enjoyed by a larger number of the respondents whereas economic benefits were only experienced by few. Furthermore, these economic benefits were experienced through activities, which brought income to the local communities such as harvesting wood for carving and craft making. Some benefits involved the performance of cultural activities to tourists, whereby community participants were paid money for the services. The cited benefits reflect some of the important solutions to the research problem of this study.

The U.S. Environmental Protection Agency has mandated that states must include the use of biological assessments in their water quality laws to assess the biological integrity of aquatic systems. The Floristic Quality Assessment Index (FQAI), which uses wetland vegetation to assess the biological integrity of an ecosystem, has not been tested in Mississippi. The purpose of this study was to test the efficiency of the FQAI in wetlands along a gradient of human influence. Coefficients of conservatism (CC) were assigned to plant species based on their tolerance to disturbance and fidelity to habitat. A negative correlation was found between the FQAI and level of human disturbance for 53 sites surveyed in the summer of 2004. Based on the results of this study, the FQAI and the average CC could be effective tools for monitoring wetland management and restoration and for identifying areas of high conservation value in Mississippi.

No description available.

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.

Transitional areas between upland and aquatic habitats, commonly known as wetland, were once viewed as unproductive areas and were drained for farming or pasture. Wetlands are now accepted as significant ecological resources, and their protection is a mandate of federal, state, and local land managers. Due to the diversity of wetland areas, the appropriate assessment of wetland resources cannot be accomplished without long term monitoring of wetland functions. Knowledge of the duration of saturation and associated anaerobic conditions of soils in wetlands is critical to correctly classify and assess wetland areas. Soil, hydrological, and biogeochemical characteristics of the soils of the Jackson-Frazier wetland were observed from October 1992 through March 1994. Weekly observations of water levels and redox potential at depths of 25, 50, and 100 cm were made in order to characterize the degree and duration of saturation and the anaerobic conditions in the soil over time. Permanently installed piezometers measured free water in the soil and indicated the presence of two separated water tables from the onset of the rainy season in October until February when the entire soil profile became saturated with free water. Platinum electrodes measured redox potential in the soil and indicated anaerobic conditions for ten months during the first season of observation and through March of the second season. Anaerobic conditions were considered to be achieved when Fe����� was reduced to Fe����� at a potential of 200 millivolts. The highly reducing conditions correspond to periods of soil saturation indicated by piezometers. Concentrations of iron and manganese observed in soil profiles correspond to conditions of prolonged saturation and reduction confirmed by monitoring. A soil stratigraphic study done with auger holes revealed a recent alluvial deposit of montmorrillonitic clay overlying lacustrine silts identified as the Irish Bend Member of the Willamette Formation. The clay deposit overlying the surface of the wetland acts as an aquitard and creates extensive surface ponding, which maintains the saturated habitat required for wetland vegetation. The subsurface hydrology is controlled by water flowing through the Irish Bend silts which results in saturation of the soils from below. Biogeochemical transformations of iron and manganese due to suboxic and anaerobic conditions are controlled by this type of soil saturation in the Jackson-Frazier wetland. / Graduation date: 1995