As a result of widespread urban development over the past two decades, global wetlands are disappearing at an alarming rate. This thesis develops a series of strategies for protecting wetland ecosystems from the ecological consequences that cascade through an ecosystem as a result of such development. This thesis is based on the paired assumptions that ecosystems represent networks of linked processes that operate across both local and global scales, and that the ecological integrity of any ecosystem can be maintained (a) only if the physical integrity of an ecosystem’s constituent processes is maintained, and (b) only if damage occurring at one ecological scale is prevented from affecting processes occurring at another. Thus, the strategies proposed here are multi-scalar and implemented at both the scale of the site and at the broader watershed scale. The strategies developed in this thesis focus on maintaining the physical integrity of the local wetlands as a means of protecting the processes that occur within the broader wetland ecosystem. The thesis proposes that wetland sites might be best protected from the effects of urban development by implementing a series of landscape interventions that provide the ecosystem with the means to reorient itself in new ecological relationships. Instead of attempting to recreate and control a complex set of conditions by imposing a deterministic architectural solution on the site, this strategy seeds new processes and new structural relationships such that the ecosystem reorganizes itself according to its own structural logic and grows into new stable relationships according to conditions that arise out of those processes. Because this approach generates a series of self-sustaining processes, human intervention is minimized beyond the initial stages. The stategies proposed here will be explored in the context of proposals recently announced by oil companies to develop ecologically sensitive wetland sites located on the Athabasca River in north-eastern Alberta.

Like life-history theory, wildlife management decisions are typically predicated on trade-offs between benefits associated with investing resources to achieve higher reproductive or survival rates versus costs or risks of achieving those goals. On the Canadian prairies, most waterfowl conservation resources are directed to policies and programs that seek to increase duck nesting success. Limited attention has focused on post-hatching life-cycle stages, yet, despite considerable recent work on duckling survival rates, many uncertainties remain concerning how abiotic and biotic factors affect duckling survival rates. The role of upland habitat characteristics may be important but has received limited attention. I evaluated hypothesized sources of variation in duckling survival for 617 mallard (Anas platyrhynchos) broods on 27 Canadian prairie-parkland sites, with emphasis on assessing effects of managed and remnant natural upland habitats. I contrasted suites of a priori and post hoc exploratory models that incorporated effects of landscape, weather, female and brood-related variables to explain variation in duckling survival rates. Survival was lower for ducklings that used areas with high proportions of semi-permanent wetlands, as well as for broods that travelled farther overland. Exploratory analyses revealed further that survival of ducklings was negatively related to the amount of managed hayland. In contrast, duckling survival was positively associated with the amount managed grassland. There was no evidence of trade-offs between benefits of managing habitat to enhance duck nesting success versus costs in terms of lower subsequent duckling survival.<p> I also addressed unresolved questions about how birds balance costs and benefits of selecting habitats by determining the survival consequences of habitat choices made during brood-rearing. In theory, fitness should be higher in preferred habitats, but this assumption is rarely tested. Fitness consequences (i.e., duckling survival) of habitat selection patterns were determined at landscape and local scales using logistic regression and information-theoretic model selection techniques. Best-approximating landscape-level models indicated that mallard females selected brood-rearing areas with a high proportion of wetland and perennial upland habitats, but duckling survival was not related to habitat selection patterns at this scale. At finer spatial scales, females selected brood-rearing areas with high proportions of wetland habitats, but, contrary to expectation, duckling survival was lower when females raised their broods in these areas. Females avoided areas with abundant perennial cover and wetlands with little vegetative cover and, consistent with prediction, duckling survival was higher when females selected areas with low perennial cover. Thus, females did not consistently select brood-rearing habitats that conferred the highest fitness benefits. Rather, the relationship between habitat selection and duckling survival depended on spatial scale and habitats considered.

Plants in constructed wetlands serve as carriers for attached microbial growth. They mainly transfer oxygen and release exudates into the root zone. As a result, an area exists around the roots (rhizosphere) in which bacteria are stimulated by root growth. Our goals were to ascertain whether stimulating the microbial community only has a local effect on the rhizoplane, and to establish the importance of this stimulation for wastewater purification in the root zone. Observations were carried out in a planted and an unplanted laboratory batch reactor incubated with an artificial wastewater with a high concentration of ammonia. Samples were taken at intervals of 10 mm away from the roots. The chemical and physical conditions and enzyme activities in soil sections at various distances from the roots affecting the efficiency of microbial nitrogen removal were characterized. An influence on the nitrification and denitrification process was detected via several parameters up to a range of different root distances: microbial parameters such as the total bacterial number, respiratory activity, protein and DNA amount seem to be affected by roots up to a distance of 50 mm from the roots, whereas the oxygen concentration, DOC and redox potential are unaffected at a distance exceeding 20-30 mm. This indicates that improved nitrogen removal is also possible in the wider root surroundings. Given the average root-to-root distance of 35 mm, the root-influenced area could therefore be expanded to the whole rooted zone in a constructed wetland.

No description available.

In 2011 Manitoba experienced an extreme flood. The operation of the Assiniboine River Diversion resulted in the addition of approximately 1.72 million cubic decameters of water to Lake Manitoba and an increase in water levels to 1.5 m above normal. Although this event resulted damage to farmland and many local homes, it also provided me the unique opportunity to utilize previously impractical methods of bathymetric and substrata distribution analysis in the adjoining Delta Marsh. Combined with satellite imagery taken in 2011 I was able to classify the vegetation classes within the study area and explore the relationship between vegetation distributions and water depth as well as those between water depth and substrata distribution. A seed bank study was carried out to explore the diversity of viable seeds in the area. In addition, satellite imagery taken in 2009 was used to evaluate the effects of the flood event experienced in 2011. / October 2015

French vertical-flow constructed wetlands (VFCW) directly treating raw wastewater are known to perform well on for SS, COD and nitrification. They are also known to robustly cope with hydraulic overloads during rainfall events. Although numerous systems have been installed in areas equipped with a combined sewer, the limits of stormwater acceptance remain ill-defined and need to be improved. Looking at the various VFCW designs and usages reported in the literature, it is difficult to draw any consensus on their hydraulic limits. Consequently, designing VFCW to accept hydraulic overloads is a complex task, as local context strongly impacts inlet flows produced during rainfall events. Dynamic models appear a requisite for filter design in such cases. Numerical CW models have essentially focused on horizontal flow, with few attempting to study VFCW dynamics which are more commonly tackled via mechanistic models. Although mechanistic models are powerful tools for describing processes within the VFCW, they are generally too complicated to be readily used by designers. The choice between detailed description and easy handling will depend on the modelling aims. If the aim is a global design tool, simplified models offer a good alternative. However, the simplified models geared to studying VFCW dynamics are extremely reduced. They are easy-handling for design and well-adapted to specific purposes (combined sewer overflow -CSO- treatment) but not necessarily to VFCW treating combined sewer wastewater, where long-term infiltration rates vary significantly. Consequently, this PhD thesis work focused on developing a simplified hydraulic model of VFCW to guide designers through the process of adapting VFCW systems to treat domestic wastewater in both dry and rain events. The simplified model makes it possible to link (i) hydraulics, by simulation of ponding time variations, (ii) biological performances, by establishing "dysfunction alerts" based on treatment performance assessment and variations in online N forms effluent from the young VFCW. These "dysfunction alerts" plot the maximal hydraulic load that a filter can accept without compromising its biological activity. The simplified model was used to model long-term hydraulics in the VFCW (i) to analyze the impact of local context and filter design on hydraulic overload acceptance (using "dysfunction alerts" and bypass discharges) and (ii) to propose VFCW designs for accepting hydraulic overload in different contexts. The modelling demonstrates that VFCW can limit days with bypass discharges to less than 20 times per year without jeopardizing filter performances. Moreover, the most problematic scenario on stormwater treatment remains a watershed with high imperviousness coefficient and low slope under a Bretagne-type climate, demonstrating that the filter is more sensitive to periodicity and duration than to intensity of rainfall events.

1. For the first time detailed phytosociological measurements, using objective methods have been made in a large number of lowland successional stands throughout eastern Canada. 2. Soil and soil surface organic matter samples were collected on a volume-weight basis for all stands studied. An increased use of bulk-density sampling methods is advocated as they allow the conversion of all nutrient percentage and parts per million analyses to actual weights par unit area profile depth, as was done in the present work. [...]

As a result of widespread urban development over the past two decades, global wetlands are disappearing at an alarming rate. This thesis develops a series of strategies for protecting wetland ecosystems from the ecological consequences that cascade through an ecosystem as a result of such development. This thesis is based on the paired assumptions that ecosystems represent networks of linked processes that operate across both local and global scales, and that the ecological integrity of any ecosystem can be maintained (a) only if the physical integrity of an ecosystem’s constituent processes is maintained, and (b) only if damage occurring at one ecological scale is prevented from affecting processes occurring at another. Thus, the strategies proposed here are multi-scalar and implemented at both the scale of the site and at the broader watershed scale. The strategies developed in this thesis focus on maintaining the physical integrity of the local wetlands as a means of protecting the processes that occur within the broader wetland ecosystem. The thesis proposes that wetland sites might be best protected from the effects of urban development by implementing a series of landscape interventions that provide the ecosystem with the means to reorient itself in new ecological relationships. Instead of attempting to recreate and control a complex set of conditions by imposing a deterministic architectural solution on the site, this strategy seeds new processes and new structural relationships such that the ecosystem reorganizes itself according to its own structural logic and grows into new stable relationships according to conditions that arise out of those processes. Because this approach generates a series of self-sustaining processes, human intervention is minimized beyond the initial stages. The stategies proposed here will be explored in the context of proposals recently announced by oil companies to develop ecologically sensitive wetland sites located on the Athabasca River in north-eastern Alberta.

A varied literature has emerged assessing the history and principles of the SDI programme and its individual initiatives. Within the literature, a widespread critique has developed that views the SDIs as falling short in two crucial areas. First, the SDIs have, in general, had limited developmental impacts . Second, many of the initiatives failed to develop adequate institutional responses to the specific conditions they faced in their various localities. The study describes the Lubombo SDI and its anchor project, the Greater St Lucia Wetland Park. It argues that the Lubombo SDI, from the outset, took institutions seriously with a long view of development. It did not seek to deliver large-scale investment in a short period. Rather, it focused on shifting the development fundamentals - including key aspects of the Lubombo region's institutional arrangements - and concentrating its resources on facilitating a major project capable of pulling the various agencies with a stake in the region's development onto a common platform. This concentration of effort, and the creation of a dedicated authority with a clear statutory mandate to promote development and conservation, has brought advances to an area where development was effectively blocked for many years. But the dynamic nature of the institutional environment remains a key challenge affecting the GSLWP and the execution of the Authority's mandate. The ability of the Authority to continue mediating the multiple tensions and complexities affecting the GSLWP will be crucial if the agenda first set by the Lubombo is to be carried forward in the coming years. / Thesis (M.T.R.P.)-University of KwaZulu-Natal, Durban, 2005

Wetlands serve many purposes in the landscape and are under increasing threat as a consequence of urbanisation despite their importance directly and indirectly to humans. Through an evaluation of the suitability of the WET-Health and WET-EcoServices tools in determining wetland functionality and the provision of goods and services of the wetlands, it was decided that these tools were particularly appropriate for fulfilling the purpose of this research. WET-Health, used in combination with WET-EcoServices, is effective in determining the overall health of wetlands and provides possible reasons for degradation which reduces the ability of wetlands to supply the benefits associated with the particular hydrogeomorphic type. A feedback and questionnaire survey was conducted with eThekwini municipality to determine if the WET-Health and WET-EcoServices tools satisfied their needs and to ascertain whether these tools would be suitable for management of their wetlands. This research, in collaboration with eThekwini municipality’s Planning Department, seeks to contribute to the management and maintenance of wetlands within the uMdloti Catchment so that more informed wetland management decisions regarding wetland sustainability can be made. A level 1 and 2 WET-Health and WET-EcoServices assessments were applied to three sites namely; the Robert Armstrong, Le Mercy and Lake Victoria Barn swallow roosting wetlands. A WET-Health Level 1 assessment can be considered more feasible than a Level 2 which provides similar results yet is more time consuming, however, expert knowledge and experience with the tool may be necessary. A Level 2 WET-EcoServices assessment is recommended as it not only highlights what benefits are being provided but the extent of each benefit thereof also determining whether a wetland has a greater chance to provide a particular benefit but may not being effective in doing so. This in turn allows for efforts and resources to be directed towards improving wetland management and land-use planning and decision making for which the tools are particularly suitable. The tools were considered appropriate and necessary for wetland management and can be adapted into eThekwini municipality’s work situation. The tools provide a holistic approach for wetland assessment as catchment activities are considered. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.