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Controls and modification of large-scale climate–hydrology–ecology associationsLaize, Cedric Louis Raymond January 2015 (has links)
The study aimed to disentangle the climate–hydrology–ecology chain of processes at large spatial and temporal scales. River ecology was considered in terms of some of the main controls of physical habitat (environmental flows, hydraulics, and water temperature). The research included four complementing studies investigating associations between: (1) climate (atmospheric circulation and regional climate) and river flows; (2) river flows and river hydraulics; (3) regional climate and river water temperature; (4) regional climate and environmental flows. The first three studies focused on current conditions, had a national (mainland UK, or England and Wales) geographical scope and a seasonal temporal scale, and used only near-natural sites. In each study, the main drivers were identified, as well as the rivers or regions most/least sensitive. UK-focussed findings were then put into the wider context of future climate- and human-induced river flow change at the pan-European scale: a novel method to assess ecological risk due to flow alteration was developed and applied to flow scenarios for the 2050s. The role of basin properties in modifying those associations was also assessed. Two key aspects emerged: (i) importance of seasonal patterns; and (ii) strong basin property patterns. The study addressed the lack of studies with extensive geographical coverage, high site density, and long periods of records. Spatial patterns could only be found for studies involving climate and flow (historical or future projections); for hydraulics and temperature, spatial patterns were related to basin properties. For all studies, a small set of basin properties were found to have a significant influence: elevation, permeability (except for hydraulics), size (hydraulics and temperature only).
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The role of food availability in determining the energetic and life history costs of reproduction in short-lived birdsWebber, Simone Leigh January 2012 (has links)
Food availability strongly affects avian breeding success. Conflicting results from food supplementation studies have obscured the role of food availability in shaping the life history trajectories of birds. With the popularity of providing food for wild birds increasing, the effects of this resource for breeding birds need to be clarified. In this study Blue Tits (\(Cyanistes\) \(caeruleus\)) and Great Tits (\(Parus\) \(major\)) were provided with supplementary food to investigate whether food availability reduced the costs of breeding for adults, and affected life history traits. Food supplementation with peanut cake disrupted the timing of Great Tit breeding and reduced fecundity. There was no effect of food supplementation on Great Tit adult or juvenile survival, except in 2010 when females traded off fecundity against future survival. Blue Tit fecundity was largely unaffected by food supplementation, but the provision of mealworms improved adult female survival. Food supplementation reduced female Daily Energy Expenditure (DEE) for both species during egg laying and for Great Tits feeding nestlings, revealing unexpectedly complex life history strategies. Through the integration of physiological techniques and life history frameworks we can understand the interaction between organisms and their environment and the effects of anthropogenic actions such as food supplementation of birds.
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Impacts of microbial activity on trace metal behavior during the bioremediation of phenanthrene-contaminated soilsAmezcua Allieri, Myriam Adela January 2003 (has links)
A novel method for the bioremediation of phenanthrene using the fungus Penicillium frequentans was utilised to remove phenanthrene (200 mg kg\(^{-1}\)) from soil containing both metals and phenanthrene, over 29 days. Bioremediation of phenanthrene and its effects on trace metal behaviour has been investigated. Metal behaviour studied includes metal speciation and the kinetics of exchange between solution and solid phase and plant uptake of the more labile and mobile, and potentially more bioavailable metal species. Phenanthrene removal by P. frequentans was optimised in terms of both soil water and nutrient composition. Slightly lower removal rates were obtained using P. frequentans alone (73%) and plants alone (67%). However, the highest phenanthrene removal (77%) was obtained using both fungus and plant. Assessment of the metal behaviour before and after phenanthrene biodegradation showed that the removal of phenanthrene by either fungal or mixed fungal and native microflora resulted in an increased flux of metal from solid to solution, an increased pool of potentially bioavailable and toxic metal species and increased plant uptake to both Echinochloa polystachia and Triticum aestivum, by factors of 4-13. In the presence of plants alone, metal mobilisation and uptake increased by smaller factors. In some cases, there was no increase in metal mobilisation and a maximal increase of 2 was found in Ni and Pb. These results highlight the impact of bioremediation process on metal behaviour. In addition, it is suggested that phytoremediation and not bioaugmentation using P. frequentans is the best overall option to obtain a considerable phenanthrene removal, reducing the increased pool of potentially bioavailable and toxic metal species
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Salmon population in watersheds of different complexities following ice recession in Glacier Bay as determined by the physical habitat templateSønderland, Svein Harald January 2017 (has links)
The diets of sympatric stream dwelling juvenile coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) were analyzed in five streams of different age and watershed complexity since glacial retreat in Glacier Bay, southeast Alaska. Interferometric synthetic aperture radar (IFSAR) data were analyzed with geographic information systems (GRASS GIS) to understand watershed change since deglaciation. Spatiotemporal variations of watershed characteristics from GIS were then used to develop a four-dimensional physical habitat template (PHT) and a directional model of stream development. Juvenile coho salmon and Dolly Varden coexisted in all streams with a strong overlap in diet while using different foraging zones. Diet niche breadth for both species increased with the amount of terrestrial insects in the diet as a result of resource depression, as mean fork length (FL) of juvenile fish increased when aquatic insects were a greater part of the diet, but decreased with greater terrestrial input. Using the stable isotopes of δ15N and δ13C, the contribution of marine derived nutrients (MDN) to stream biota was found to be determined by salmon spawner abundance and watershed retention, and an increase in δ15N and δ13C dispersion (SD) was found with stream age, likely causing a difference in the fractioning of δ15N and δ13C. The most significant change with stream age was denudation of watersheds and the development of stream networks. Dietary overlap was linked to fish resource depression, and controlled by stream geomorphology. Juvenile salmonids were found to consume sea lice (Lepeophtheirus salmonis) in the older streams.
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Comparative study of methods for quantifying wood smoke in the UK atmosphereHu, Lihua January 2012 (has links)
The thesis investigates the inorganic aerosol concentrations and wood smoke tracer potassium and levoglucosan concentrations in Birmingham, UK. Also a multi-wavelength aethalometer was utilized as a carbonaceous aerosol detector to directly measure the local wood smoke PM mass and traffic PM mass. To achieve this, daily PM2.5 inorganic ions sodium, ammonium, potassium, magnesium, calcium, chloride, nitrate, sulphate, and organic compound levoglucosan were measured over a period of more than one and half years at four sampling locations. There were: (1) Elms road, University of Birmingham; (2) North Kilworth Mill Observatory Site; (3) Churchill Pumping Station Site; and (4) Budbrooke, Warwick Sampling Site. Correlation analysis, regression analysis, and seasonal variation were examined for those inorganic and organic elements and compounds. The results were used to provide comprehensive spatial and temporal distributions, intra-site and inter-site comparison differentiations. Wood smoke potassium and levoglucosan were used as wood smoke tracer to determine the local resident wood smoke PM mass concentrations in this thesis. Budbrooke, Warwick Sampling Site for example, a mean value of 62ng m-3 wood smoke potassium was measured at winter periods but the mean value of only 17ng m-3 was measured during summer periods. This significant difference demonstrated a frequent wood smoke activity in this area during winter periods. Also a multi-wavelength aethalometer was used as wood smoke mass detector to measure the local resident wood smoke PM mass and local traffic PM mass concentrations. These three methods have their unique processes of acquiring the wood smoke mass concentrations, thus the results from these method have considerable variations. Therefore these three methods have inter-compared with each other to achieve better wood smoke concentrations results in order to obtain the best method of measuring local wood smoke mass.
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Bacterial acid phosphatase and its application to waste remediation and metal recoveryMennan, Claire January 2011 (has links)
PhoN-type acid phosphatase from an atypical Serratia sp. was applied to the removal of radionuclides from aqueous flows. In the presence of metal ions the phosphatase produces metal phosphate at the cell surface via the liberation of inorganic phosphate from a phosphate donor (glycerol-2-phosphate). Previous studies using biogenic hydrogen uranyl phosphate (HUP) on Serratia sp. removed \(^{60}\)Co, \(^{137}\)Cs and \(^�\)Sr via intercalative ion exchange into the HUP crystal lattice. Due to their non toxic and non radioactive nature, zirconium phosphates offer an alternative to HUP for the decontamination of potable water. Zirconium was successfully biomineralised by Serratia sp. forming gel-like deposits with little or no crystalline phases, as shown by XRD. This biogenic zirconium phosphate removed 100 % Co\(^{2+}\) and Sr\(^{2+}\) from solutions. Increased capacity can be achieved by co-crystallisation with Zr(IV) supplement assuming phosphatase radioresistance. The Serratia sp. phosphatase exists in two distinct isoforms (SP1 (radioresistant) and SP2 (radiosensitive)) which were purified and further characterised in this study. Both isoforms were found to have redox capability and were able to potentiate free radical damage to deoxyribose in a Fenton-type reaction. Analysis using highly sensitive Micro-Proton Induced X-ray Emission (PIXE) analysis found no metallic components in SP1 or SP2. Database interrogation using partial sequences of the phosphatase and the Basic Local Alignment Search Tool (BLAST) confirmed homology with PhoC and PhoN of several pathogenic bacterial species and also similarities with the vanadium haloperoxidases, indicating these phosphatases and peroxidases could have a common ancestor. The relatedness of the Serratia sp. PhoN to pathogenic species producing PhoN is discussed along with the possible role of phosphatase as both a scavenger of phosphate and in providing a defense mechanism for the pathogenic bacterial cell against the free radical-mediated immune response of the host.
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Botanical processes in urban derelict spacesAustin, Kevin Charles January 2003 (has links)
This thesis set out to investigate the processes that determine the richness and composition of plant communities on derelict land in the West Midlands. Experimental work included vegetation surveys, soil seed bank investigation, field mapping and seed rain trapping methods. Interpretation of the data involved a range of approaches including vegetation classification and ordination, comparative analysis of plant functional attributes and the development of regression models incorporating landscape and habitat variables. Derelict habitats were identified as holding a diverse array of communities at the early stages of succession which are poorly represented by current vegetation classifications, functional diversity is however much lower in pioneer communities. The majority of these species employing the expected strategies of early succession notably high reproductive capacity and seeds which are small, highly dispersive and form persistent seed banks. Dense seed banks were typically formed on sites and were dominated by a small set of consistently occurring species. Changes in seed bank density and composition were consistent with time represented both by the chronosequence of sites and increasing soil depth. Little evidence was found to suggest that diversity or species composition is linked to site connectivity related to either patch density or the presence of linear features. These findings have considerable implications for application of principles of metapopulation and island biogeography principles to urban conservation. In particular the trend for planners to designate urban wildlife corridors is questioned as being probably of no benefit to native diversity and indeed these features are identified as being instead potentially significant pathways for invasive alien species. The most important factors influencing the composition of sites were seen to be those linked closely with past and present human activity. Particularly significant are the nature of dereliction substrates and haphazard disturbances such as fire and tipping which influence vegetation succession temporally and spatially.
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New materials for strontium removal from nuclear waste streamsSavva, Savvaki N. January 2016 (has links)
The primary aim of this project is to investigate potential new materials for application in ion exchange processes to remove \(^9\)\(^0\)Sr from nuclear waste streams. This work can be broadly split in to two sections, work on attempts to synthesise new materials and work to investigate ion exchange properties of two recently prepared materials AV-7, a synthetic analogue of tin-kostylvite and AV-3, a synthetic analogue of petarasite. Synthesis on new materials was focused on metal silicate materials, in particular titanium, zirconium and tin silicates containing exchangeable group I and II cations. These synthesis attempts initially were focus on targeted mineral phases such as noonkanbahite, BaKNaTi\(_2\)(Si\(_4\)O\(_1\)\(_2\))O\(_2\), followed by a series of brief surveys examining the effects of various changes to precursor gels such as concentration of bases such as NaOH, metal to silicon ratios and the presence of mineralizing agents such as sodium fluoride. The synthesis of two synthetic mineral phases potentially interesting for ion exchange is also reported here, titanite and fresnoite. Ion exchange studies focused mainly on AV-7 and AV-3 but also included well known ion exchange materials for comparison such as clinoptilolite and Nb-doped crystalline silicotitanate and brief investigations in to the ion exchange of fresnoite and titanite. Ion exchange was followed using X-Ray fluorescence, ion chromatography and radioactive \(^8\)\(^5\)Sr exchanges measured using scintillation counters.
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Brominated micropollutants within the integrated steel-making process and their fate in the EnvironmentDrage, Daniel January 2013 (has links)
PBDEs were found in the raw sinter mix (RSM) used in iron ore sintering. Mass balance calculations after measurement of output samples (ESP dust, sinter product and stack emissions) revealed net reduction of PBDEs during sintering. After PBDD/Fs were detected in stack emissions, PBDEs and PBDD/Fs were investigated using a sinter pot (SP) - a laboratory scale version of the sintering process - under various conditions. Results suggested de novo synthesis of PBDD/Fs occurs within the process, but this was not caused by the PBDE content of RSM. The results from the SP ruled out PBDE formation within the sintering process. Measurement of PBDEs in UK air and soil demonstrated that whilst PBDEs appeared to have decreased since legislative use restrictions, their persistence is highlighted by their continued detection. PBDEs decreased in air and soil with distance from Birmingham City Centre, highlighting the higher density of PBDE sources in urban areas. Australian soils were less contaminated with PBDEs than the UK. Similar spatial patterns were found in both countries, with industry and urbanisation causing increased likelihood of elevated ∑PBDE concentrations primarily from Penta-BDE. Agricultural soil showed an influence of OctaBDE congeners. Sediment cores from Port Jackson, Australia demonstrated that PBDEs were still rising at the end of the 20th Century. Industry was highlighted as a source as cores from the industrialised western side of the harbour were more contaminated than that from the urban north-east.
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The hydroecological response of Greenlandic streams to a changing climateDocherty, Catherine Louise January 2018 (has links)
Arctic streams are vulnerable to climate change due to the strong linkage between cryosphere, hydrology, physicochemical habitat and ecology. Our knowledge on how stream hydroecological dynamics will respond to climate change is largely based on the impact of the reduction in glacial extent in a warmer Arctic, however our knowledge of the response of Arctic streams with low glacial input are poorly understood. To address this knowledge gap, three field campaigns to Zackenberg (northeast Greenland) were carried out (2013 – 2015) to investigate snowmelt stream hydroecological patterns and processes. Streams were chosen that were sourced from both small and large snowpacks, representing low and high snowfall conditions. Streams with large snowpacks were found to have low channel stability and high suspended sediment concentration compared to streams with small snowpacks. Channel stability, rather than water temperature, was the most important factor influencing macroinvertebrate community dynamics, where streams with low channel stability had reduced macroinvertebrate density and taxa richness. The results of this research recommend new classifications to Arctic and alpine stream habitat types, and suggest that, as snowfall is predicted to increase in the Arctic, snowmelt-fed streams may experience decreased channel stability, and as such, a decline in macroinvertebrate density and diversity.
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