The American alligator (Alligator mississippiensis) has been frequently studied in large reservoirs and coastal marshes. Large ontogenetic shifts in their diet and morphology have been linked with changes in habitat use, with adult males using deep, open water and juveniles and nesting females relying on vegetated marsh. In certain regions of the inland portion of the alligator’s range, these different aquatic habitats are represented by seasonal wetlands and riverine systems that are separated by a terrestrial matrix. Ontogenetic habitat shifts, therefore, would require overland movements between systems, which has important implications for conservation of the species. I tested several commonly used methods of surveying alligator populations to determine the most effective method of studying alligators in seasonal wetlands. I then used systematic trapping, nest surveys and radio telemetry to determine habitat use and overland movement rates by different sex and size classes. I found that seasonal wetlands provided nesting and nursery sites for these inland alligator populations, but that both juveniles undergoing an ontogenetic shift and nesting females move between the wetlands and riverine systems. Overland movements by alligators between the wetland and riverine habitats establish a level of functional connectivity between these aquatic ecosystems. I constructed a habitat suitability index of both the wetlands and the surrounding landscape to determine which patch and landscape characteristics were important to wetland use by alligators. I found that both descriptive wetland characteristics and the spatial relationships between wetlands were important predictors of alligator use. Overland movement was related to upland landuse as well as distance between aquatic habitats. Conserving a variety of wetland sizes and types within an intact upland matrix is critical to maintaining connectivity across the landscape. Furthermore, understanding how species may act as mobile links between ecosystems, particularly those with ontogenetic niche shifts, illustrates the importance of approaching conservation from a landscape perspective.

<p>The research was driven by a need to increase the knowledge base concerning wetland ecological responses, as well as to identify and evaluate the factors driving the functioning of the Franschhoek Trust Wetland. An ecohydrological study was undertaken in which vegetation cover, depth to groundwater, water and soil chemistry were monitored at 14 sites along three transects for a 12 month period. The parameters used include temperature, pH, electrical conductivity (EC), sodium, potassium, magnesium, calcium, iron, chloride, bicarbonate, sulphate, total nitrogen, ammonia, nitrate, nitrite and phosphorus. T-tests and Principal Component Analysis (PCA) were used to analyze trends and to express the relationship between abiotic factors and vegetation.</p>

No description available.

Treatment efficiency in a constructed wetland is related in part to the amount of time that a wastewater remains in the system. Current design methods idealize the system as a plug flow reactor and use a "residence time" based solely on the volume of the cell and the flow rate. Under this assumption, every element of wastewater entering the wetland cell experiences the same residence time. It is understood that this idealization ignores the existence of longitudinal dispersion, short circuiting and stagnant regions within the wetland cell. The result of these phenomena is a distribution of residence times. In other words, portions of the effluent exit the cell earlier than predicted, resulting in undertreatment, and portions exit late, resulting in excess treatment. The average concentration of treated wastewater at the outlet is a function of this distribution and the reaction kinetics associated with the waste. The overall effect of a distribution of residence times is reflected in a reduction of treatment efficiency at the outlet. Hydraulic regimes of constructed wetland systems were investigated at a pilot project site providing tertiary treatment of a pulp mill wastewater. Two vegetation types, bulrush and cattail, were investigated and compared to nonvegetated and rock-filter cells with identical configurations. Tracer studies used a fluorescent dye and were performed over the course of a year. Dye was input as a pulse at the inlet end of the cell and sampled over time at the outlet end to obtain concentration breakthrough curves. From these curves, time to peak, actual mean detention times, degree of dispersion, and extent of dead space were calculated, as well as predicted treatment efficiency. Results indicated varying degrees of dispersion, short circuiting, and dead space in the individual cells. Analysis of the residence time distributions provided estimates of the "active" volume of the treatment cell and the degree of short circuiting in the system. Effective volume of the planted cells ranged from 15 to 25% of full volume. Early arrivals of the peaks of the distributions, indicative of short circuiting, ranged from 30% to 80% of the theoretical detention times. A first order treatment model and a kinetic coefficient, k, were assumed, and corresponding treatment efficiencies were compared to the theoretical treatment of an ideal plug flow reactor. Reduced treatment efficiencies for the planted systems ranged from 2 to 20 %, by this estimation. Many references attempt to analyze wastewater treatment systems by refering to two models: dispersed plug flow and an approximation of tank-in-series. These models were investigated as potential descriptions of the hydraulic regime present in constructed wetlands. Residence time distributions of the constructed wetlands in this study indicated flow was not exclusively dispersed plug flow. This simplified model does not account for the exchange of material with "dead" space in the wetland cell. The data suggest a combination model of dispersed plug flow with a transient storage zone component may be more appropriate. / Graduation date: 1994

Wetlands of the Prairie Pothole Region of North America provide habitat for over 50% of the continent's breeding waterfowl, but most of the region's wetlands have been lost or degraded through intensive agricultural development. Despite widespread wetland losses in much of the Canadian prairies, there is little information about trends in degradation of remaining wetlands. Using habitat data collected for ~10,500 wetlands across the Canadian prairies during annual waterfowl surveys, 1985-2005, I employed multistate models in Program MARK to estimate rates of impact and recovery of wetlands resulting from agricultural activities. Then, I characterized the incidence of agricultural degradation to these wetlands. Rates of impact to wetland margins (natural vegetation around flooded basins) declined over time, likely due to a decreasing percentage of unaffected wetlands; recovery rates for margins were always lower than impact rates, suggesting increased cumulative degradation of wetlands over time. Unlike margins, impact and recovery rates for basins fluctuated with spring pond densities. Shallow ephemeral wetlands located in agricultural fields had the highest impact and lowest recovery rates. Multistate modeling could also be used to estimate rates associated with other landscape processes.<p><p> My second objective was to determine whether physical characteristics of prairie Canada wetlands could be used to predict breeding duck abundance. First, I sought to determine how pre-existing models developed in the Dakotas (USA) performed when predicting breeding duck abundances on Canadian prairie wetlands. I related duck pair abundance to pond area, and then compared observed to predicted duck abundance. The Dakota models performed reasonably well in predicting numbers of blue-winged teal (<i>Anas discors</i>), gadwall (<i>A. strepera</i>), and northern pintail (<i>A. acuta</i>), but predicted fewer mallards (<i>A. platyrhynchos</i>) and northern shovelers (<i>A. clypeata</i>) than were observed on wetlands. Pond area was an important predictor of duck abundance in all models, but results were less biased and more consistent in models developed specifically for Canadian wetlands. Spatiotemporal variation in the relationship of breeding duck abundance and wetland characteristics was also affected by regional duck and pond densities. Overall, the new applications and models developed and validated in this study will be useful for wetland and waterfowl management in the Canadian prairies.

<p>Very little protection has been afforded to wetlands1 and estuaries within the South African legislative framework.2 These ecosystems are extremely important and valuable to mankind, the flora and fauna.3 The continued destruction of wetlands and estuaries is the most heinous act of environmental vandalism on a worldwide scale today.4 Wetland and estuarine loss has been accelerated and extended by human activities such as mining,5 urbanisation,6 drainage, river diversion,7 groundwater abstraction as well as climate change.8 Time is running out for so many critically important sites and for the world at large.9 Without wetlands and estuaries the biosphere10 cannot continue to do its essential work.11 Despite, the importance of a range of resources and services12 which wetlands and estuaries provide, these have been taken for granted by humans.13 As a result hereof, the maintenance of wetlands and estuaries has received low priority in many countries.14 This is further precipitated by the lack of interest and ignorance which result in the conversion of wetlands and estuaries into man-made structures.15 Research has shown that the lack of information and the awareness of the importance of these ecosystems has the made the conservation legislation for these ecosystems a toothless dragon.16 People are becoming increasingly aware17 of the loss of wetlands and estuaries, once in abundance and now merely shadows of their former nature.18 To investigate this lack of protection, the starting point would be the global level.</p>

This thesis proposes a way in which architecture and the built environment might work to integrate human consciousness and natural process. A theoretical design entitled Landscope is presented as a responsive, sustainable landscape that offers understanding of nature through active observation, interpretation and transformation of the environment. The design proposal is situated at the edge of Hamilton Harbour, Ontario, Canada, adjacent to the existing facilities of the National Water Research Institute. Two extended studies accompany the design proposal. The first, Water, presents a poetic exploration of cosmic, responsive, and connective qualities of water relating to nature and technology. The second study, Connected Fields, focuses on the visionary American engineer Buckminster Fuller and his ‘Geoscope’ project, a geodesic dome designed to act as a monitoring and control centre for global material and resource flows. This section also includes a discussion of general conceptions of the world, focusing on key twentieth-century conceptions of the Biosphere, Gaia, and the Noösphere. Historical theories of environmental perception are discussed including Gestalt psychology and technical systems of observation. Drawing upon this cultural material, the thesis attempts to open boundaries that separate nature and technology, encouraging a complex, mutually dependent relationship between these traditionally separate realms. The general pursuit is a cybernetic and virtual model for environmental and ontological hybridity, involving an evolution of consciousness at both individual and global scales.

Treatment wetlands been showed efficient for reducing pollutant in waste water. In Lajeado – RS, Brazil the landfill has poor leachate water treatment. It is necessary to supplement the treatment plant because they need to reduce BOD, COD and nitrate of the water going to recipient. A subsurface flow wetland (SSF) can be a good choice.  In order to be able to design an efficient SSF it is important to understand how the grain sizes of a substrate affect the reducing of pollutants in waste water. This study focus on two substrate, sand with grain size of 0 - 3 mm and gravel with the grain size of 10 - 20 mm. To see the grain size reduces BOD, COD and nitrate best, the experiment used eight pilot scales SSF for leachate water treatment, four filled with sand and four filled with gravel. Two different flows, four with batch and four used continuous flow; two of each was planted with Thypa angustifolia L. Samples were taken from each wetland every week during a four week period. The results showed that the wetlands with the fine- grained substrate; sand gave the better reduction of BOD, COD and TKN (total kjeldahl kväve). It also showed great reduction in color. Important to notice in this study is the lack of time; more samples are required to be able to establish a pattern.

The aim of this study was to examine what impact restored and constructed pounds and wetlands have on waterfowls in the area of Linköping. The birdlife in five constructed wetlands werechosen to investigate if specific factors like age, size and vegetation affected the avian diversity in wetlands. Also, extra focus has been given to the threatened Horned Grebe (Podiceps Auritus), breeding in the studied area. The results showed that the number of species as well as individuals of waterfowl and Horned Grebe changed over time in what might be a result of succession in the wetlands. Comparing the number of birds to the size of the wetlands showed a clear correlation. Larger areas inhabited greater numbers of species and individuals. However, the Horned Grebe showed a reverse result, as they seem to prefer smaller wetlands. Finally, a correlation between the numbers of observed Black-headed gulls and Horned Grebes could be found. When there was a greater number of Horned Grebes observed there was also a greater numbers of gulls present. Possibly the Horned Grebe takes advantage of the Black-headed gull-colony for protection against predators.

This thesis proposes a way in which architecture and the built environment might work to integrate human consciousness and natural process. A theoretical design entitled Landscope is presented as a responsive, sustainable landscape that offers understanding of nature through active observation, interpretation and transformation of the environment. The design proposal is situated at the edge of Hamilton Harbour, Ontario, Canada, adjacent to the existing facilities of the National Water Research Institute. Two extended studies accompany the design proposal. The first, Water, presents a poetic exploration of cosmic, responsive, and connective qualities of water relating to nature and technology. The second study, Connected Fields, focuses on the visionary American engineer Buckminster Fuller and his ‘Geoscope’ project, a geodesic dome designed to act as a monitoring and control centre for global material and resource flows. This section also includes a discussion of general conceptions of the world, focusing on key twentieth-century conceptions of the Biosphere, Gaia, and the Noösphere. Historical theories of environmental perception are discussed including Gestalt psychology and technical systems of observation. Drawing upon this cultural material, the thesis attempts to open boundaries that separate nature and technology, encouraging a complex, mutually dependent relationship between these traditionally separate realms. The general pursuit is a cybernetic and virtual model for environmental and ontological hybridity, involving an evolution of consciousness at both individual and global scales.