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Dealing with the issue of spring flood events is primarily based on their causes. It is therefore important to study the processes of snow accumulation and snowmelt especially in mountain areas where the development of snow water equivalent (SWE) is primarily observed. The snow water equivalent indicates amount of the water in the snow and thus represents a runoff volume during the spring melting period and demonstrates the flood risk potential. In this thesis the lumped modelling approach of the rainfall-runoff model HEC- HMS was used. The model was applied in the Bystřice River basin in the Ore Mountains where the field measurements of the snow cover and SWE is carried out. Applied temperature-index method is the well-developed method because it takes into account both the melting during precipitation and melting in the period without any precipitation and aims to capture snow energy balance by means of air temperature. Three winter periods (2006, 2008 and 2009) were simulated. The evolution of the snow water equivalent was observed and the agreement between observed and simulated hydrographs was assessed in the closure profile Ostrov. Published results show the influence of winter course and character on the model capability to simulate the snow water equivalent and runoff. The observed and...

Freshwater ice (river and lake ice), a key component of the cryosphere, plays a dominant role in the hydrology of northern climates. Although freshwater ice has been modelled at small geographic scales, it remains the only major unquantified component of the cryosphere. Therefore, the goal of this thesis is to quantify peak freshwater ice across the Northern Hemisphere using a regionally defined degree-day ice-growth model. To address this the ecological and climatic importance of freshwater ice are reviewed, as well as the physical processes that govern freshwater-ice growth, the existing approaches to modelling freshwater ice, and the major climate classification methods. Using a degree-day ice-growth model, ice-growth coefficients are defined by hydro-climatic region, and validated using maximum observed seasonal ice thickness values from across the Northern Hemisphere. The maximum seasonal extent of freshwater ice is then estimated over a 44-year temporal period and the areal extent and volume of freshwater ice quantified. / Graduate

My research addressed pheromone lure design and the activity of the grape berry moth, Paralobesia viteana, flight and infestation across three years of study. In my lure evaluations, I found all commercial lures contained impurities and inconsistencies that have implications for management. First, sex pheromone concentration in lures affected both target and non-target attraction to traps, while the blend of sex pheromones impacted attraction to P. viteana. Second, over the duration of study, 54 vineyard blocks were sampled for the pest in and around cultivated wine grape in Virginia. The trapping studies indicated earliest and sustained emergence of the spring generation in sex pheromone traps placed in a wooded periphery. Later, moths were detected most often in the vineyard, which indicated that P. viteana emerged and aggregated in woods prior to flying and egg-laying in vineyards. My research supports use of woods and vineyard trap monitoring at both the height of 2 meters and in the periphery of respective environments. These conditions should improve grower efficiency when using trapping as a tool. Cluster infestation was assessed relative to vineyard growth stage and location in the vineyard. My results are in agreement with historical studies that suggest infestation is highest in the periphery of vineyards. However, I found that infestation peaked at veraison before falling somewhat around pre-harvest. This indicated that growers should manage this pest prior to veraison, perhaps as early as budbreak, to prevent the insect from reaching damaging levels when the crop is more susceptible to loss. Lastly, by combining field-based data collection with remote climate and landscape monitoring, growers can achieve a greater level of surveillance of P. viteana. A mash up of remote and vineyard-based data can provide substantive pertinent information for management at both local and regional scales. If one grower identifies moth emergence, then growers nearby potentially can use that same information to initiate models to monitor development of the moth population in their own vineyard. This research complements the notion that the more a community shares information, the broader its applicability becomes to neighbors. / Ph. D.

Bean leaf beetle, Cerotoma trifurcata (Forster) (Coleoptera: Chrysomelidae), is an economic pest of soybean in Ontario. Field cage studies were conducted in 2010-2011 to determine voltinism in southern Ontario and the effect of C. trifurcata feeding during soybean reproductive stages on soybean yield and quality. Thermal requirements for C. trifurcata development were determined in a laboratory study. Results of field and laboratory studies support the occurrence of one generation of C. trifurcata in southern Ontario. Pod-feeding increased with both number of beetles and soybean reproductive stage. An increase in defoliation and a reduction in seed quality were observed with increasing number of beetles. Monitoring programs for late-season pod-feeding should begin when degree days approach 500 (base 9.31°C). Economic thresholds for C. trifurcata during soybean reproductive stages range from 0.27 to 2.00 beetles per plant or 8 to 60 beetles per m of row. / Ontario Ministry of Agriculture and Food – University of Guelph Sustainable Production (Plants) Program and Grain Farmers of Ontario through the Farm Innovation Program.

This study examined the differences in decomposition rates and the resulting postmortem submergence interval (PMSI) of stillborn pigs and decapitated adult pig heads enclosed in plastic trash bags. Sixteen neonate pigs were divided into two variable categories: exposed and submerged in water, enclosed in a plastic trash bag and submerged in water. Upon recovery, each sample was assigned a Total Body Score. Eighteen decapitated adult pig heads were divided into two variable categories: nine heads were enclosed in plastic trash bags, and nine heads left exposed in the water. Twelve decapitated pig heads were divided into two terrestrial variable categories: six heads were enclosed in plastic trash bags and allowed to decompose on land, and six heads were left exposed on land. Accumulated degree-days (ADD) were calculated following the scoring guides provided in Moffatt et al. (2016), Megyesi et al. (2005) and Heaton et al. (2010). These guides were used to create a baseline decomposition rate established from the control groups decay rate. This baseline in the decomposition rate was then used to establish a measurable difference between exposed and enclosed samples. It was hypothesized that head samples submerged (enclosed/exposed) would decompose slower than the terrestrial samples (enclosed/exposed). It was further hypothesized that all enclosed/submerged samples would decompose slower than the exposed/terrestrial remains. A univariate analysis of variance (ANOVA) test found no statistically significant interactions between submerged, enclosed or exposed remains, indicating that the enclosure of remains in a plastic trash bag, and subsequent submergence or not did not affect the decomposition rate of either sample. An additional ANOVA found statistically significant differences between the rate of neonate sample decomposition and adult head sample decomposition. Paired sample t-tests produced statistically significant results that indicate the inaccuracy of the ADD calculation methods developed by Megyesi et al. (2005) and Heaton et al. (2010) to neonate-sized remains, decapitated heads, submerged enclosed/exposed samples or terrestrial enclosed/exposed samples.

Tendo em vista a importância de se conhecer as exigências climáticas da videira nas condições de cultivo, o objetivo deste trabalho foi determinar os índices biometeorológicos: graus-dia (GD), índice biometeorológico de Primault (IB), índice heliotérmico de Huglin (IH) e índice heliotérmico de Geslin (IHG) para a cultivar Niagara Rosada podada em diferentes épocas e fases do ciclo vegetativo. A poda seca foi realizada no final do inverno (fase de mobilização de reservas) e a poda verde foi realizada no verão (fase de acúmulo de reservas). O delineamento experimental utilizado foi o de blocos ao acaso, constituídos os tratamentos de 9 datas de poda: 20/07, 04/08, 19/08, 03/09, 18/09, 01/02, 15/02, 02/03 e 16/03 em dois anos agrícolas (2005/2006 e 2006/2007). A parcela experimental foi composta de 12 plantas sendo duas bordaduras (dez plantas úteis) com treze anos de idade, no espaçamento de 2,0 m x 1,0 m, conduzidas no sistema de espaldeira sob irrigação. As variáveis analisadas foram os períodos e subperíodos, em dias, poda-colheita, brotação-colheita, podabrotação, brotação-florescimento, florescimento-"veraison" e "veraison"-colheita. Para a análise de variância dos índices biometeorológicos foi utilizado o teste de Tukey para comparar as médias das datas de poda, duas a duas, e o teste F para contrastes ortogonais comparando a média da poda seca versus poda verde. Na análise do índice GD e IH verificou-se que plantas podadas em épocas distintas apresentaram valores diferentes para completar o período poda-colheita. Para IB e IHG verificou-se a mesma tendência em plantas podadas em épocas distintas, apresentando valores diferentes para completar o período brotação-colheita. Os subperíodos que não diferiram estatisticamente entre as épocas de poda foram respectivamente: florescimento- "veraison" para o IB e brotação-florescimento para o IH e IHG. Os demais subperíodos apresentaram diferenças pelo teste F para contraste ortogonal para as épocas de poda. / The goal of this work was to determine four biometeorological indexes: degreedays (DD), Primault's biometeorological index (BI), Huglin's heliothermal index (HI) and Geslin's heliothermal index (GHI) for grape 'Niagara Rosada' (Vitis labrusca L.) pruned at different seasons and physiological phases. The dry pruning was done at the end of winter (carbohydrate mobilization phase) and green pruning (carbohydrate stock phase) was done during summer. The experiment was carried out in a randomized block design consisting of 9 treatments, pruning dates 20th July, 04th August, 19th August, 03rd September, 18th September, 01st February, 15th February, 02nd March and 16th March during two years (2005/2006 and 2006/2007). Twelve plants were used as experimental plot, being two border plants. The grapevine was 13 years old grown under trellis system with a 2.0 x 1.0 meter spacing under irrigation. The grape phenology was evaluated considering numbers of days for each one of the following period and sub-periods: pruning - harvest, sprout - harvest, pruning - sprout, sprout - flowering, flowering - early ripening and early ripening - harvest. To analyze those indexes, the Tukey test was used comparing pruning dates and F test for orthogonal contrast comparing plants pruned at different seasons (dry pruning versus green pruning). It was observed that plants pruned at different seasons do not require the same amount of energy to complete pruning - harvest period when using DD and HI. The same tendency was observed when using BI and GHI for those plants to complete its period sprout - harvest. Some sub-periods that did not differ statistically between dry pruning and green pruning: flowering - early ripening for BI and sprout - flowering for HI and GHI. Other sub-periods differ statistically when using F test for orthogonal contrast.

Tendo em vista a importância de se conhecer as exigências climáticas da videira nas condições de cultivo, o objetivo deste trabalho foi determinar os índices biometeorológicos: graus-dia (GD), índice biometeorológico de Primault (IB), índice heliotérmico de Huglin (IH) e índice heliotérmico de Geslin (IHG) para a cultivar Niagara Rosada podada em diferentes épocas e fases do ciclo vegetativo. A poda seca foi realizada no final do inverno (fase de mobilização de reservas) e a poda verde foi realizada no verão (fase de acúmulo de reservas). O delineamento experimental utilizado foi o de blocos ao acaso, constituídos os tratamentos de 9 datas de poda: 20/07, 04/08, 19/08, 03/09, 18/09, 01/02, 15/02, 02/03 e 16/03 em dois anos agrícolas (2005/2006 e 2006/2007). A parcela experimental foi composta de 12 plantas sendo duas bordaduras (dez plantas úteis) com treze anos de idade, no espaçamento de 2,0 m x 1,0 m, conduzidas no sistema de espaldeira sob irrigação. As variáveis analisadas foram os períodos e subperíodos, em dias, poda-colheita, brotação-colheita, podabrotação, brotação-florescimento, florescimento-"veraison" e "veraison"-colheita. Para a análise de variância dos índices biometeorológicos foi utilizado o teste de Tukey para comparar as médias das datas de poda, duas a duas, e o teste F para contrastes ortogonais comparando a média da poda seca versus poda verde. Na análise do índice GD e IH verificou-se que plantas podadas em épocas distintas apresentaram valores diferentes para completar o período poda-colheita. Para IB e IHG verificou-se a mesma tendência em plantas podadas em épocas distintas, apresentando valores diferentes para completar o período brotação-colheita. Os subperíodos que não diferiram estatisticamente entre as épocas de poda foram respectivamente: florescimento- "veraison" para o IB e brotação-florescimento para o IH e IHG. Os demais subperíodos apresentaram diferenças pelo teste F para contraste ortogonal para as épocas de poda. / The goal of this work was to determine four biometeorological indexes: degreedays (DD), Primault's biometeorological index (BI), Huglin's heliothermal index (HI) and Geslin's heliothermal index (GHI) for grape 'Niagara Rosada' (Vitis labrusca L.) pruned at different seasons and physiological phases. The dry pruning was done at the end of winter (carbohydrate mobilization phase) and green pruning (carbohydrate stock phase) was done during summer. The experiment was carried out in a randomized block design consisting of 9 treatments, pruning dates 20th July, 04th August, 19th August, 03rd September, 18th September, 01st February, 15th February, 02nd March and 16th March during two years (2005/2006 and 2006/2007). Twelve plants were used as experimental plot, being two border plants. The grapevine was 13 years old grown under trellis system with a 2.0 x 1.0 meter spacing under irrigation. The grape phenology was evaluated considering numbers of days for each one of the following period and sub-periods: pruning - harvest, sprout - harvest, pruning - sprout, sprout - flowering, flowering - early ripening and early ripening - harvest. To analyze those indexes, the Tukey test was used comparing pruning dates and F test for orthogonal contrast comparing plants pruned at different seasons (dry pruning versus green pruning). It was observed that plants pruned at different seasons do not require the same amount of energy to complete pruning - harvest period when using DD and HI. The same tendency was observed when using BI and GHI for those plants to complete its period sprout - harvest. Some sub-periods that did not differ statistically between dry pruning and green pruning: flowering - early ripening for BI and sprout - flowering for HI and GHI. Other sub-periods differ statistically when using F test for orthogonal contrast.

Les ressources en eau de l'Himalaya, vitales pour 800 millions de personnes, proviennent majoritairement de la mousson et de la fonte de la cryosphère. L'impact du changement climatique sur ces ressources, particulièrement important dans cette région selon le GIEC (2007), est un questionnement majeur à l'échelle de la chaîne himalayenne. Dans ce contexte, la quantification des composantes pluviales, nivales et glaciaires du bilan hydrologique est primordiale. A cet effet, un modèle hydrologique conceptuel distribué (HDSM) a été développé pour estimer la répartition de ces composantes dans les écoulements de la rivière Dudh Koshi de 2001 à 2005. Son bassin versant (3 700 km²), dont le point culminant est le Mont Everest, est situé à l'est du Népal. Les surfaces enneigées, calées à partir de données satellitaires, ainsi que les débits, sont correctement simulés par le modèle. Toutefois, le facteur de fonte glaciaire est surestimé, entrainant une composante glaciaire d'environ 60% des débits annuels, contre 5% selon la littérature. Cette surestimation compense une sous-estimation significative des précipitations, notamment solides. Après une correction des précipitations, les composantes pluviale, nivale et glaciaire expliquent respectivement, 63%, 9% et 29% des débits annuels de la Dudh Koshi sur la période 20012005. Pour compléter cette modélisation, les perceptions de la population sur les variations hydro-climatiques, obtenues à partir d'enquêtes dans les villages, ont été comparées aux données quantitatives utilisées et simulées par le modèle HDSM de 1977 à 2007. Cette comparaison la sous-estimation des précipitations solides. Les résultats mettent aussi en évidence une diminution significative des précipitations (totales, liquides et solides) en décembre, et une augmentation significative, non perçue par la population, des températures annuelles mesurées sur les 30 dernières années. Les deux approches, par modélisation et par enquêtes, soulignent les incertitudes importantes des données hydro-climatiques du bassin versant de la Dudh Koshi. Ces incertitudes limitent la compréhension des processus hydro-nivoglaciaires et l'estimation des impacts du changement climatique sur la ressource en eau de ce bassin. Les perceptions, bien qu'elles soient également associées à des incertitudes, apportent des informations complémentaires cruciales pour améliorer ces connaissances et la critique des données quantitatives de ce milieu de haute montagne himalayenne. / The Himalayan water resources, vital for 800 millions of people, come mainly from the monsoon and from the melting of the cryosphere. The impact of the climate change on these resources, especially significant in the area, is a major issue in the Himalayan range. In this context, the assessment of the rainfall, snowmelt and icemelt components of the water balance is crucial. Consequently, a distributed conceptual hydrological model (HDSM) was developed to estimate the contribution of each component to the Dudh Koshi River flows from 2001 to 2005. The Dudh Koshi River basin (3 700 km²), with the Mount Everest as highest peak, is located in Eastern Nepal. The snow cover areas, calibrated with satellite data, and as well as the runoff are correctly simulated by the model. Nevertheless, the ice degree-day factor is overestimated, leading to an icemelt contribution around 60% of annual discharge, against 5% in the literature. This overestimation offsets a significant underestimation of precipitation, especially solid precipitation. After a correction of the precipitation, the contributions of rainfall, snowmelt and icemelt represent respectively 63%, 9%, and 29% of the Dudh Koshi annual discharge from 2001 to 2005. To complete this modeling, perceptions of the population on the hydro-climatic variability, obtained by interviews in the villages, were compared to the quantitative data used and simulated by the model HDSM from 1977 to 2007. This comparison confirms the underestimation of precipitation, especially solid. These results also show a significant decrease of precipitation in December and a significant increase, not perceived by population, of the measured annual temperature on the last thirty years. Both approaches by modeling and interviews highlight large uncertainties on the hydro-climatic data of the Dudh Koshi River basin. These uncertainties limit the understanding of hydrological and cryospheric processes and the assessment of climate change impacts on the water resources of this basin. Although they are also uncertain, the perceptions bring crucial complementary information to improve this knowledge and the analysis of the quantitative data of this high mountain Himalayan area.

Discovery of a new host-parasite relationship, <i>Parelaphostrongylus odocoilei</i> in Dalls sheep (<i>Ovis dalli dalli</i>) in the Canadian North, prompted the first investigation of the geographic distribution, pathogenesis, ecology and epidemiology of this parasite, as well as the related protostrongylid <i>Protostrongylus stilesi</i>, at Subarctic latitudes (60-65ºN). All protostrongylid parasites have an indirect life-cycle, where first-stage larvae are shed in the feces of a mammalian definitive host, penetrate the foot of a gastropod intermediate host, and develop to infective third-stage larvae. <p> Protostrongylid larvae were recovered from over 2000 fecal samples from thinhorn sheep (<i>Ovis dalli</i>) and other hosts for <i>P. odocoilei</i> and <i>P. stilesi</i> across northwestern North America (38-69 ºN). Through novel application of molecular techniques to identify morphologically indistinguishable first-stage larvae, new records for <i>P. odocoilei</i> were established at 20 locations. This provided insight into the historical origins and biogeography of this new host-parasite relationship, and greatly expanded the known geographic range of both protostrongylids. <p> Clinical effects, including a neurological syndrome, were described in five thinhorn sheep experimentally infected with <i>P. odocoilei</i>. Neural and respiratory pathology in these five sheep were compared with over 50 wild Dalls sheep from a population naturally infected with <i>P. odocoilei</i> and <i>P. stilesi</i>. In the end stages, diffuse verminous interstitial pneumonia associated with P. odocoilei led to respiratory failure, and may have acted as a predisposing factor for bacterial pneumonia, which caused sporadic mortalities in this wild population. <p> At Subarctic latitudes, seasonal patterns in host and parasite availability, including larval shedding by Dalls sheep and larval development in experimentally infected gastropods, suggested that lambs become infected with <i>P. odocoilei</i> in a narrow seasonal window in their first fall on winter range. In combination with laboratory experiments, a degree day model for temperature-dependent larval development was developed, validated, and applied to describe and predict the effects of climate warming on protostrongylid parasites of thinhorn sheep in northern North America. In a future of climate warming, the narrow seasonal window for parasite development and transmission would be significantly extended, leading to amplification of populations of <i>P. odocoilei</i> and <i>P. stilesi</i> in endemic regions, and possibly range expansion of <i>P. odocoilei</i>. This may have consequences for the health of thinhorn sheep, as well as other wildlife that are important resources in the Canadian North.