Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-03-05T18:27:51Z No. of bitstreams: 2 Fernando_Martins2017.pdf: 3146180 bytes, checksum: a1dcde101c1559cda9b93c488d0f17e9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-05T18:27:51Z (GMT). No. of bitstreams: 2 Fernando_Martins2017.pdf: 3146180 bytes, checksum: a1dcde101c1559cda9b93c488d0f17e9 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / For species that do not exhibit parental care such as oviparous insects, choosing a favorable oviposition site is of utmost importance for brood success. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate humidity. However, at least one lab experiment with mole crickets (Orthoptera: Gryllotalpoidea) indicated a linear oviposition responses to substrate humidity. The house cricket Acheta domesticus (Orthoptera: Grylloidea) also shows a linear juvenile body growth response to substrate humidity, which suggests a positive relationship between humidity and oviposition preference. We evaluated the relationship between oviposition frequency and substrate humidity in forest litter- dwelling species, primarily composed of Ubiquepuella telytokous, using field experiments. We also tested oviposition responses of U. telytokous to substrate humidity in a laboratory experiment. We offered oviposition substrates that varied in humidity from zero percent to maximum substrate water absorption capacity. Oviposition preference was estimated using presence or absence of eggs as a binary response variable, adjusted logistic regression (GAMM) was used to test for non-linear responses, and GLMs were used to test linear responses. We found that oviposition probability increased linearly with substrate humidity for U. telytokous in both field and lab experiments. Our results demonstrate the importance of substrate humidity as an ecological niche requirement for this species. This work bolsters knowledge of litter cricket life history association with humidity, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying. / Para espécies que não apresentam cuidados parentais, tais como insetos ovíparos, a escolha de um local de oviposição favorável é de extrema importância para o sucesso da prole. A teoria do nicho prevê que a oviposição de grilos deve mostrar uma resposta em forma de sino à umidade do substrato. Entretanto, pelo menos um experimento de laboratório com paquinhas (Orthoptera: Gryllotalpoidea) indicou uma resposta de oviposição linear em relação a umidade do substrato. O grilo doméstico Acheta domesticus (Orthoptera: Grylloidea) também apresenta um crescimento corporal dos juvenis linear em relação a umidade do substrato, o que sugere uma relação positiva entre umidade e preferência de oviposição. Aqui testamos a relação entre a frequência de oviposição e a umidade do substrato, em espécies de grilos de serrapilheira florestal, primariamente compostas Ubiquepuella telytokous, utilizando experimentos de campo. Também testamos as respostas de oviposição de U. telytokous em experimentos de laboratório. Oferecemos substratos de oviposção que variaram a umidade de zero porcento até a capacidade máxima de absorção do substrato. A preferência de oviposição foi estimada utilizando presença ou ausência de ovos como uma variável resposta binária, regressão logística ajustada (GAMM) para testar respostas não lineares, e GLMs para testar respostas lineares. Verificamos que a probabilidade de oviposição aumenta linearmente com a umidade do substrato para U. telytokous, nos experimentos de campo e laboratório. Nossos resultados demonstram a importância da umidade do substrato como requisito de nicho ecológico para Ubiquepuella telytokous. Este trabalho reforça o conhecimento da associação de história de vida de grilos com a umidade, e sugere que esses organismos podem ser particularmente ameaçados por mudanças climáticas que tornam habitats áridos.

Bien que l’écologie de la truite (Salmo trutta) ait déjà été bien étudiée, les processus expliquant la dynamique spatio-temporelle des populations restent à caractériser. L’objectif de cette thèse était d’identifier les processus démographiques (ex. survie ou déplacements) et l’influence des processus biotiques (interactions entre individus) et abiotiques (conditions environnementales) qui structurent dans le temps et dans l’espace les différentes classes d’âge (alevins, juvéniles et adultes) de ces populations. J’ai étudié l’influence sur la survie apparente de (1) la densité-dépendance et (2) des conditions environnementales vécues directement par les truites (habitat hydraulique et température de l’eau). Pour évaluer la transférabilité des résultats, j’ai évalué (3) l’échelle spatiale (globale ou locale) à laquelle opéraient les processus et (4) si ces processus variaient entre populations (approche hiérarchique). J’ai considéré la dynamique de 45 populations de truites dont 22 sont situées à l’aval d’un ouvrage hydroélectrique. A large échelle, il est apparu que le recrutement de populations séparées par des distances allant jusqu’à 75km peut être synchronisé par de fortes crues lors de l’émergence des alevins ou des déplacements du substrat de ponte. Nous avons synthétisé les résultats de l’application d’un modèle déterministe de dynamique de population, calibrés localement sur neuf stations aux conditions environnementales bien caractérisées. Cette synthèse a montré que des processus locaux influençaient directement la dynamique des populations. Enfin, la construction d’un modèle hiérarchique a montré le rôle structurant de la mortalité densité-dépendante des juvéniles et des adultes, dont l’intensité augmentait en l’absence d’abris (<2% de la surface) ou variait avec la température de l’eau (diminution pour les juvéniles et augmentation pour les adultes). Ce travail fournit des bases scientifiques aux gestionnaires d’ouvrages hydro-électriques pour leur permettre de limiter leur influence sur les populations de poissons et répondre ainsi aux demandes réglementaires / Brown trout (Salmo trutta) ecology was largely studied. However, the process structuring the spatiotemporal patterns of population dynamics remains unclear. The objective of this thesis was to identify the demographic processes (e.g. survival or displacements) and the influence of biotic (between-individuals interactions) and abiotic (environmental conditions) processes structuring the age-stages (fry, juveniles and adults) of these populations in time and space.I studied (1) the role of density-dependence on survival and (2) the influence of environmental conditions experienced by trouts (hydraulics and water temperature). To assess the results’ transferability, I studied (3) the spatial scale (global or local) of influence of the processes and (4) if those processes varied among populations (hierarchical approach).I considered the dynamics of 45 trout populations, 22 being located downstream a hydropower facility. At a large scale, the recruitment of distant populations (up to 75 km apart) may be synchronized by large floods during emergence of fry or by spawning substratum displacements. We summarized the results of a determinist population dynamics models, locally calibrated on nine reaches showing well-described environmental conditions. This summary revealed the influence of various local drivers on population dynamics. Finally, a hierarchical model showed that density-dependent mortality among juveniles and adults was a key biotic process. The strength of the competition was greater in absence of shelter (<2% of the surface) and varied with water temperature (decreasing for juveniles and increasing for adults).The results of this work will provide scientific basis to hydropower facility managers. This will help them to reduce their influence on trout populations and respond to regulatory demands

Upland peat catchments are usually assumed to function as carbon sinks, however, there have been extensive studies witnessing increasing trends in concentrations and fluxes of organic carbon in UK rivers over the last few decades. A number of controls on dissolved organic carbon (DOC) release from peatlands, such as climatic changes and landuse management, have been proposed. This study examines the effects of land use and management on organic carbon exports in the Dyke catchment of the River Halladale (northern Scotland) with a nested catchment approach. This study provides insight into the processes controlling the DOC dynamics in the Dyke catchment, and the impact of disturbance caused by landuse changes such as afforestation and tree felling for restoration. The results from factor analysis, end-member mixing, absorbance (E4/E6), and hysteresis analyses on stream water chemistry from individual sub-catchments identified the major hydrological pathways during storm events, and based on these results, conceptual models were developed to explain DOC evolution during storm events. At all the sites studied, nearsurface soil water was identified as the major controlling end-member for stream DOC concentrations. The calculated annual flux of DOC from the Dyke catchment, up-scaled from the results of the individual sub-catchments, is 521.6 kg C ha-1 yr-1, which is significantly (~5 times) higher than the previously published value (103.4 kg C ha-1 yr-1) for the River Halladale catchment (Hope et al., 1997). In this study, it is shown that about 57 - 95% of the DOC export occur during 5 - 10% of the high flows, therefore, it is crucial that quantitative records of DOC export are developed using high frequency storm event measurements, as well as lower frequency low flow sampling. Climatic changes related to precipitation, temperature, coupled with water yield capacity of the sub-catchments, are identified as significant controls on DOC fluxes, rather than landuse change, as the intact site releases more organic carbon per unit area compared to the disturbed and re-wetted site undergoing restoration. In addition, the results from this study provide landowners, policy makers and organisations with the evidence they require for initiating future peatland restoration works, as felling of forestry coupled with drain-blocking is shown to be an effective restoration technique that may help a catchment to eventually return to a near-pristine state.

This study is a test of a methodology to predict changes in elevation and shoreline position of coastal wetlands in Trinity Bay, Texas, in response to projected sea level rise. The study combines numerical modeling and a geographic information system. A smoothing technique is used on a United States Geographical Survey (USGS) digital elevation model to obtain elevation profiles that more accurately represent the gently sloping wetlands surface. The numerical model estimates the expected elevation change by raster cell based on input parameters of predicted sea level rise, mineral and organic sedimentation rates, and sediment autocompaction rates. A GIS is used to display predicted elevation changes and changes in shoreline position as a result of four projected sea level rise scenarios over the next 100 years. Results demonstrate that this numerical model and methodology are promising as a technique of modeling predicted elevation change and shoreline migration in wetlands. The approach has potential utility in coastal management applications.

In this research, hyperspectral and multispectral images were utilized for vegetation studies in the greenbelt corridor near Denton. EO-1 Hyperion was the hyperspectral image and Landsat Thematic Mapper (TM) was the multispectral image used for this research. In the first part of the research, both the images were classified for land cover mapping (after necessary atmospheric correction and geometric registration) using supervised classification method with maximum likelihood algorithm and accuracy of the classification was also assessed for comparison. Hyperspectral image was preprocessed for classification through principal component analysis (PCA), segmented principal component analysis and minimum noise fraction (MNF) transform. Three different images were achieved after these pre-processing of the hyperspectral image. Therefore, a total of four images were classified and assessed the accuracy. In the second part, a more precise and improved land cover study was done on hyperspectral image using linear spectral unmixing method. Finally, several vegetation constituents like chlorophyll a, chlorophyll b, caroteoids were distinguished from the hyperspectral image using feature-oriented principal component analysis (FOPCA) method and which component dominates which type of land cover particularly vegetation were correlated.

Using ethnographic research methods, I collaborated with the organization Earthworks to conduct a community assessment on the health issues related to the air quality in Karnes County, Texas, an oil and gas community. The research consisted of in-depth interviews with residents on their experiences and knowledge on the health issues associated to air quality. This research is going to be used to inform the community and develop strategies to empower community members in improving their environmental conditions.

Canonical correspondence analysis (CCA) was used to explore relationships between measured environmental variables and in situ phytoplankton communities in a moderately eutrophic North Texas Reservoir.

L’accroissement de la population humaine mondiale a des répercussions majeures, ce n’est donc pas surprenant, compte tenu de la nécessité de nourrir une population grandissante au niveau planétaire, que la production en conchyliculture ait augmenté au cours des dernières décennies. Or, les connaissances acquises concernant les divers facteurs du déterminisme du sexe et du rapport des sexes chez les bivalves sont très limitées et cela pourrait ralentir grandement le taux de production des éleveurs et leur capacité à intervenir si les stocks venaient à diminuer de façon inquiétante. Certains travaux mentionnent que certains facteurs environnementaux, comme la température, auraient un effet sur le rapport des sexes chez une variété de bivalves, incluant la moule bleue commerciale Mytilus edulis, quoiqu’aucune étude n’ait validé cette dernière possibilité. Cela dit, il est possible que l’environnement des adultes puisse aussi affecter le phénotype de la progéniture. En effet, une transmission intergénérationnelle a déjà été identifiée chez Mytilus, mais la possibilité que les conditions des parents affectent le rapport des sexes spécifiquement n’a jamais été abordée. Il est toutefois connu qu’un facteur maternel présent dans l’œuf affecte le sexe de la progéniture et que cette espèce de bivalve a un mode de transmission des mitochondries particulier. Ce mode de transmission appelé « transmission doublement uniparentale » a rendu possible l’identification du sexe chez les embryons. De cette façon, 1938 embryons provenant de 25 croisements artificiels réalisés à trois températures et effectués lors de trois différentes années ont été analysés. Nos analyses mettent en évidence une variation significative dans la proportion de larves femelles entre les années passant de 64 % à 98 %. Dans certains cas, la proportion de femelle varie de 0 à 100 % entre les différents traitements. Même si un effet général sur le rapport des sexes n’était pas significatif, chaque croisement s’est avéré avoir une norme de réaction qui lui est propre face aux 3 différentes températures. Cette étude met en valeur l’effet important de l’environnement sur le déterminisme du sexe chez M. edulis, autant chez les parents que lors du développement des embryons. / The factors affecting sex determination still remain unknown for most bivalve species. Some studies reported that environmental factors, such as temperature, influence sex determination in certain species, and this has been hypothesized also for the blue mussel Mytilus edulis, but not experimentally validated yet. Adult exposure to different environmental conditions during gametogenesis, which occurs seasonally, may also affect offspring phenotype, including sex determination. Intergenerational carryover effects have been reported in bivalves, but the impact of parental exposures on offspring sex determination has not been examined so far. To address these questions, artificial fertilizations were performed on individuals collected in three different years and their embryos and larvae were reared at three different temperatures to specifically test if the environment influence offspring sex ratio through effects on parental developing gametes and/or on developing embryos. We took advantage of the doubly uniparental inheritance of mitochondria in bivalves to determine the sex of the larvae. The analysis of 1938 larvae from 25 crosses revealed that the overall proportion of female larvae was significantly different among years, varying from 64 % to 98 %. While the proportion of female larvae across temperature ranged from 0 to 100 % in some cases, the reaction norms were cross-specific and there were no significant effects of rearing temperature on sex ratio. Taken together, our results suggested that sex determination in M. edulis occur during the gametogenesis according to the genotype of the parents, but could also be changed during the development. More importantly, both processes are strongly affected by environmental conditions.

Palustrine wetlands in Lesotho are vulnerable to vegetation loss due to overgrazing and the nature of the topography, the latter leading to gully erosion exacerbated by a degraded soil structure. Degraded soils are not able to adsorb pollutants; neither can they support vegetation growth. The presence of degraded soils in wetlands thus contributes towards leaching of pollutants into nearby streams and groundwater resources. Khubelu wetland (which was the focus of this study) is a palustrine wetland that discharges water into the Khubelu stream in Lesotho. The water purification function of this wetland is pertinent since Khubelu River is one of the tributaries at the headwaters of the shared Orange- Senqu basin. This function is threatened by vegetation loss and soil degradation through overgrazing and environmental conditions like extreme climatic variations. Consequently, water released into adjacent streams from the wetland could be of low quality, further putting at risk the health of this ecosystem and users of these streams due to toxicity caused by the polluted water from the wetland. With predicted floods and/or droughts and intense heat, water temperatures may rise by up to 70% in the 21st century according to researchers. It is believed that floods would lead to shorter residence time of water within wetlands, washing away soil with pollutants into surrounding streams before any geochemical processes that would sequester them occurs. Droughts on the other hand would lead to failure of dilution of polluted waters. Excessive evaporation due to intense heat would also leave pollutant-concentrated water behind. Since these wetlands are the headwaters of an international river, the problem of water pollution and deteriorated water resources might be regional. The main aim of the study was to characterise the extent of soil degradation and water quality in the Khubelu wetland and assess the water purification ability in an endeavour to understand the role the wetland plays in the quality of water in rivers and streams fed by the Khubelu wetland, and also to understand how changes in climate would impact on the wetland characteristics. In situ analyses of soil and water were done followed by sampling of the same for further analysis in the laboratory using standard methods. Surface water samples were collected from two sampling points in the Khubelu stream, whereas water in the wetland was sampled from seven piezometers installed in the wetland. Three replicates of water samples were collected from each sampling point monthly over a period of one year. The water properties determined included pH, Electrical Conductivity (EC), Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), cations (magnesium, calcium, potassium and sodium), Total Dissolved Solids (TDS), nitrates, phosphates and chlorides. The data generated from these analyses were subjected to various statistical tests and the Water Quality Index (WQI) of the wetland and stream waters determined. The water quality drinking standards were preferred in this study since the major beneficiaries of the stream that emanates from the wetland are human populace. Prediction of water quality in the wetland in light of the changing climate was done using the Water Evaluation and Planning (WEAP) model. Soil samples were collected from the upper, middle and lower areas of the wetland, referred to as upstream, midstream and downstream of the wetland in the report, at the same sites where the piezometers were installed. At each site, three sampling points were identified two metres apart from each other and samples collected at depths of 15 cm, 30 cm and 45 cm at each site. The soil samples were then characterised for their texture, pH, Electrical Conductivity (EC), Cation Exchange Capacity (CEC), Total Carbon (TC), Total Nitrogen (TN), Organic Matter (OM), exchangeable calcium, magnesium, potassium and sodium, and available phosphorus, using standard procedures. The soil data generated were then subjected to data analyses and the Chemical Degradation Index (CDI) of the wetland soils determined. Determination of the wetland’s potential to purify water was done by assessing its ability to retain nutrients, pollutants and sediments. Results obtained in this study showed that the wetland and stream water had circumneutral pH with values that ranged from 6.32 -7.69. The values for Na, Ca, K, Mg, TDS, NO3, Cl and DO in the wetland and stream waters were below the WHO drinking water standards thresholds of 200 mg/l for Na and Ca, 12 mg/l for K, 150 mg/l for Mg, 50 mg/l for TDS 50 mg/l for NO3, 5 mg/l for DO and BOD, and 250 mg/l for Cl. Food and Agricultural Organisation (FAO) water standards for livestock drinking were: EC: <1.5 mS/cm (Excellent); 1.5 – 5.0 mS/cm (very satisfactory); < 250 mg/l of Mg for cows, 400 mg/l for beef cattle, and 500 mg/l for adult sheep. SA Irrigation water quality standards were also used, and it was determined that pH was within the acceptable threshold of 6.5 – 8.4, 70 mg/l for sodium and 0.4 mS/cm for EC. EC of 0.41 mS/cm to 1.12 mS/cm in the wetland and 0.67 mS/cm to 2.11 mS/cm in the stream was above the SA irrigation water quality standards. Other water properties such as PO4 (0.06-1.26 mg/l in stream and 0.17- 0.61 mg/l in wetland), and COD (10.00 to 55.00 mg/l in stream and 48-140.80 mg/l in the wetland) were above the WHO permissible limits. The water quality in the Khubelu wetland and stream ranged from very poor to unsuitable for drinking, with WQI values of 107 for the stream and 93 for the wetland. Water quality simulation along the Khubelu stream using the WEAP model shows that by the year 2025, BOD as one of the water quality parameters, would be high, with DO declining further especially if temperature increases and precipitation decreases. The wetland had sandy and acidic soils, with the TC and TN content of the soil decreasing with depth. The CDI value for the soil was 3.29. Regarding potential to reduce sediments, nutrients and organic pollutants, the wetland scored 7.09, 5.39 and 7.39 out of 10, respectively. This implies that there is moderate potential for the wetland to purify water that is discharged into the stream. The study concludes that the stream and wetland water qualities are unsuitable for human consumption and usable for livestock drinking. However, there might be some risks associated with evaporation that would leave the water saline. The wetland water presents a threat to the water quality of the receiving stream. However, the wetland has moderate potential to retain sediments, nutrients and toxic organics. This potential is threatened by a predicted decrease in precipitation and increase in temperature since oxygen-depleting contaminants and other pollutants whose behaviour in the environment are influenced by climate are highly likely to increase in concentrations in both the wetland and the stream. There is therefore a threat to the supply of water of good quality to the Senqu catchment, which supplies neighbouring countries (South Africa, Namibia and Botswana). Similar studies to this one need to be carried out for other wetlands in Lesotho on a regular basis to come up with data that would aid policy development that seeks to protect water resources. / Environmental Sciences / D. Phil. (Environmental Management)

Anthropogenic impact on the environment, mainly resource depletion and pollution, is limiting the potential for future generations to have the same resources that previous generations have enjoyed. Perhaps one of the greatest challenges of our time will be curtailing our own personal impacts on the environment. To do this, we must adopt more sustainable lifestyles at home. This research sought to understand how neighborhood identity affects sustainability at the household level. In the summer of 2012, residents of two neighborhoods in Portland, Oregon completed 314 self-report, web-based surveys. The neighborhoods selected for this research were demographically similar, but one projected a sustainable neighborhood identity and the other did not. Survey questions were designed to determine respondents: level of engagement in their neighborhood, attitudes towards the environment, and adherence to sustainable behaviors. Findings suggest that neighborhood engagement can influence household sustainability levels in Portland. This research also suggests that the city or region may have more effect on perceived household sustainability than the neighborhood does.