Bibliography: leaves 105-121. / viii, 133, [28] leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis tests the hypothesis that plant strategies to respond to seasonal flooding can be used to predict their tolerance to variation in water regime. The studies illustrate contrasting strategies for survival in seasonally fluctuation water levels. These are tested in the field against similar species. Plants are surveyed at four stages of flooding at Bool Lagoon. The morphologically plastic species, V. reniformis and Triglochin procerum, respond to flooding with taller shoots and increased investment in photosynthetic tissue. It is concluded that the reproductive effort is much lower in the field than in the pond experiments, and changes in the population density of both species are not related to water regime. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1997?

Mémoire (M.P.Aquat.) -- Université du Québec à Chicoutimi, 1992. / Document électronique également accessible en format PDF. CaQCU

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Dry bean breeding programs have made significant advances in combating both abiotic and biotic stresses as well as improving plant architectural traits via selective breeding. Flooding can cause complete crop loss in dry bean. On the other hand, breeding for an upright architecture in dry bean has been a breeding target in several programs. However, the stem cell wall components underlying this change have yet to be studied. This research focused on analyzing the cell wall components that might be involved in dry bean architecture as well as pre-germination flooding tolerance in dry bean. For the plant architecture study, two significant genomic regions were identified on Pv07 and Pv08 associated with lignin accumulation in dry bean. For the pre-germination flooding study, one unpigmented seed coat genotype (Verano) and three pigmented seed coat genotypes (Indeterminate Jamaica Red, Durango, and Midnight) had germination rates similar to that of the tolerant check.

Over the past century, sea level has risen nearly eight inches along the California coast and climate scientists suggest substantial increases in sea level as a significant impact of climate change over the coming century. This project explores the concept of creating a sustainable living environment for seaside residents in Redwood City as an alternative to permanent construction on land in the event of a substantial rise in sea level. This project will generate a flood-resilient design solution that is capable of rising and falling with the water. In order to ensure the well-being of the inhabitants, I will analyze a number of case studies, notably the Netherland’s water dwellings, New Orleans’s amphibious residences and Sausalito’s floating communities, for the purpose of identifying key themes that will facilitate the construction of a single-family amphibious residence in Redwood City. This project is a response to environmental design challenges raised by ongoing atmospheric events such as the gradual rise in sea level and disastrous events such as Hurricane Katrina in 2005 where extreme flooding due to failed coastal defenses exhibited catastrophic effects on coastal residences, its inhabitants, and the surrounding ecosystem.

The primary motivation of this study is to analyze the 1D-2DH hydrodynamic model of the San Francisco Bay and Sacramento-San Joaquin Delta (SFBD) outlined in Nederhoff et al. (2021). I compared model water level data to 70 tidal records from the National Oceanic and Atmospheric Association (NOAA), the United States Geological Survey (USGS), the California Data Exchange Center (CDEC), and from local municipalities throughout the Bay Area to investigate how the model captures water levels and tidal constituent amplitudes. While the Nederhoff et al (2017) model analyzed an extended time period from 1950-2019, I analyzed M2 amplitude and tidal water levels for the water year of 2017 (WY2017) with a larger dataset that extended into the Sacramento-San Joaquin Delta. Because WY2017 was a high river flow year for the Sacramento Delta, the model was able to be evaluated throughout a large range of flow regimes. I used harmonic analysis through the MATLAB package UTide (Codiga et al. 2011) to assess the model’s ability to replicate M2 amplitudes. I assessed the error for these M2 values as well as for tidal water levels. The average RMSE for M2 amplitude is 0.111 m across the entire model domain during WY2017, performing fairly consistent throughout the model. The one exception being the shallow and complex Grizzly Bay, which performed significantly worse, with RMSE values around 0.5 m. The model better replicated water levels in the 2DH grid representation of the San Francisco Bay ( Attempts to improve the model were mostly unsuccessful. I tried to increase the grid resolution at the Carquinez Strait to improve tidal propagation upstream, but altering the grid caused the coupling between the 2DH grid and 1D network to detach. This prevented the propagation of water flow in either direction at the coupling near Collinsville. The software required to fix this coupling was non-standard and unavailable for my usage, so I was unable to resolve the issue. I also attempted to create a new wind forcing file using in-situ data rather than the ERA5 reanalysis. This new wind forcing made negligible difference in water level and M2 model skill. An experiment in removing river flow showed that riverine impacts on elevating extreme water levels only have effects (>0.05 m) east of the Carquinez Strait. Extreme water levels west of this point in the San Pablo, Central, and South Bays are dominated by tides, storm surge, and to a lesser extent local wind. A decrease in tidal amplitude by river flow potentially decreases flood risk in some parts of the Bay during times of high outflow from the Sacramento-San Joaquin Delta. I also investigated maximum equilibrium effects of constant wind in the two prevailing wind directions (southerly and westerly) of the San Francisco Bay. The wind setup effect become more prominent (>0.05 m) at and above a steady 10 m/s in both directions. This study also showed that wind likely exerts a small influence on tidal properties, especially for winds greater than 10 m/s.

<p>Aquatic vegetation in the pristine coastal marshes of eastern Georgian Bay (GB) provides critical spawning and foraging habitat for fish species, with complex habitat supporting the greatest diversity. These wetlands are threatened by a changing water level regime and forecasted lower water levels. To monitor and conserve these wetlands, we must understand how they function and respond to this stressor. The overall goals of this thesis are to determine the impact of declining water levels on both wetland fish habitat and the fish community as well as identify the spatial scale of habitat utilization by fishes.</p> <p>We first delineate all coastal wetlands in eastern GB, identifying 3771 wetlands that provide habitat for Great Lakes fishes. Using satellite imagery, we develop an object-based classification method to classify four types of wetland vegetation. Since submerged aquatic vegetation (SAV) is not visible from satellite imagery in GB, we develop a model to predict potential area of this important habitat. The model suggests that the response of SAV to declining water levels depends on wetland geomorphology, but generally, the area of SAV decreases. To assess the response of fish habitat coverage and structure to sustained low-water levels, we classify vegetation in images collected in 2002 and 2008. The result is increasingly homogeneous habitat, a net loss of fish habitat and a decrease in fish species richness. Finally, mark-recapture and radio-tracking are used to evaluate fish movement among closely situated wetlands. Results suggest that the current distance used to group and protect small wetlands provincially (750 m), likely protects most resident fish species, but does not cover movement patterns of a top predator. This research will advance our scientific understanding of freshwater coastal ecosystems and aid in the creation of conservation strategies to mitigate future threats from declining water levels.</p> / Doctor of Philosophy (PhD)

<p>Coastal wetlands are hydrologically connected to their watershed and the lake. Water levels in Georgian Bay have been at a sustained low for thirteen years and thus connectivity of wetlands to the lake is being threatened as water levels decline. Decreased connectivity has likely caused changes in ecological and chemical characteristics. Future climate change models predict further water declines and potentially increasing the number of wetlands that will be hydrologically disconnected. The over-arching goal of this thesis is to investigate the role of connectivity between the lake and coastal marshes in eastern Georgian Bay on the amount of potential fish habitat, water chemistry and larval amphibian habitat.</p> <p>Bathymetric information is needed in order to estimate fish habitat and two approaches were utilized in order to collect these data. A site-specific method completed in 2009 used an intensive field survey in seven wetlands to create a digital elevation model and calculated the amount of fish habitat at 10 cm increments. A second, regional method, selected 103 sites by using a stratified random sample in 18 quaternary watersheds. In both methods, changes in water levels between 173 and 176 m asl resulted in the most drastic loss of habitat. Approximately 24% of the current fish habitat has already been lost due to low water levels.</p> <p>Water chemistry in coastal marshes is influenced by hydrologic connection. In the summers of 2010 and 2011, 35 coastal marshes were sampled, 17 of which had been impounded and disconnected by a beaver dam. Beaver-impounded marshes resulted in significantly lower pH, conductivity, dissolved oxygen and sulphate concentrations, but had significantly higher soluble reactive phosphors concentrations. These conditions are indicative of the lack of connection and reduced mixing with lake water. This altered habitat was shown to support breeding area for 7 species of amphibians, the most common being green frogs and the least common being American Toads and chorus frogs.</p> / Master of Science (MSc)

Chlorella vulgaris and Chlorella pyrenoidosa were compared relative to their abilities to grow at osmotic potentials of -0.1, -0.5, -1.0, -1.5, -2.0 MPa, [polyethylene glycol(PEG)-induced], and for osmotically-induced changes in lipid composition. C. vulgaris growth was inhibited as osmotic potentials decreased, while C. pyrenoidosa growth was moderately inhibited at -2.0 hPa. C. vulgaris produced increasing concentrations of triglycerides and sterol esters and decreasing levels of polar lipids and sterols as osmotic concentrations increased. Polar lipids, triglycerides, and sterols declined in C. pyrenoidosa while steryl esters remained constant. Ratios of free sterols to polar lipids were 10-fold greater in C. pyrenoidosa and were unaffected by reduced osmotic potentials. In C. vulgaris the sterol to polar lipid ratio declined. Decreasing osmotic potentials in a continuous culture of C. vulgaris, lowered cell lipid concentration, and had no effect on chlorophyll concentrations. The greatest decrease occurred as the osmotic potential decreased from -0.1 to -0.5 HPa. Decreasing osmotic potential caused the phospholipid concentrations to decline. Saturation of triglycerides and free fatty acids increased and decreased, respectively, while polar lipids remained fairly constant. However, the sterol to phospholipid ratio increased as the osmotic potential was lowered. BAS 13-338 (4-chloro-5-(dimethylamino)-2-phenyl-5- 3(2H)pyridazinone) had no effect on C. vulgaris resistance to osmotic stress, but caused growth inhibition as concentrations increased. However, BAS 13-338 was effective in decreasing growth inhibition of C. vulgaris grown in inhibitory levels of ethanol. BAS 13-338 had differing effects on the lipid composition of C. vulgaris when grown in PEG at an osmotic potential of -1.5 MPa compared to -0.1 MPa with 0.33% ethanol. The greatest effects were observed in the ethanol treatments where the qualitative composition of precursor sterols increased as the level of BAS 13-338 increased. This investigation confirmed the important role of lipids in responding to environmental stress through observations of lipid responses to osmotic stress and by manipulation of lipid concentrations using BAS 13-338. Resistance to ethanol inhibition but not osmotic inhibition was achieved in the investigation. / Ph. D.

Studies were conducted to evaluate the effect of pre-irrigation media moisture deficit, irrigation application rate, and intermittent irrigation on irrigation efficiency [(amount applied - amount leached) amount applied' 100] of spray stake-irrigated, container-grown plants. In the first experiment, pine bark-filled containers were irrigated to replace moisture deficits of 600, 1200, or 1800 ml. Deficits were returned in single, continuous applications at application rates of 148, 220, and 270 ml/min. Application rate did not affect irrigation efficiency. Efficiency decreased with increased medium moisture deficit. In the second experiment, containers, at 600 ml media moisture deficits, were irrigated with 400 or 600 ml (65% and 100% water replacement, respectively). Irrigation volumes were returned in a single, continuous application or in 100ml applications with 30 min intervals between irrigations (intermittent). Irrigation efficiency was greater with intermittent irrigation, 95 % and 84 % for 400 and 600 ml replacement, respectively, than with continuous irrigation, 84% and 67% for 400 and 600 ml replacement, respectively. When applied intermittently, most water loss from containers occurred after 400 ml were applied. In the third experiment, containers were irrigated with 600 ml (100% water replacement) in 50, 100, or 150 ml applications with 20, 40, or 60 min intelVals between applications. A control was included in which 600 ml was applied in a single, continuous application. Irrigation efficiency increased with decreasing application volume and increasing length of interval between applications. The greatest efficiency (86%) was produced with an irrigation regimen of 50 ml applications with at least 40 min between applications. The control treatment (continuous) produced an irrigation efficiency of 62%. When applied intermittently, most water loss from containers occurred after a total of 300 ml were applied. / Master of Science