This study was conducted in burned and harvested areas of Catalonia. It was evaluated the effect of the granivorous in predispersive fruit removal of Smilax aspera and Quercus coccifera and postdispersive seed removal. Nuts removal by rodents was nil in the burned area while for S. aspera only occurred in 2008. The minimum distance to any unburned margin and the distance to the fire perimeter explained patterns of seed removal for rodents and ants, respectively. Seed removal was also lower at unlogged sites vs. logged ones but it was only significative for ants. Rodents removed more seeds under piles of branches because logging while ants did so in areas of bare soil. It should consider the impact of granivorous in the management of burned habitats. / Este estudio fue desarrollado en áreas quemadas y taladas de Cataluña. Se evaluó el efecto de los granívoros en la remoción predispersiva de frutos de Smilax aspera y Quercus coccifera así como la remoción postdispersiva de semillas. La remoción de Quercus por parte de roedores fue nula en el área quemada mientras que para S. aspera solo ocurrió en el 2008. La distancia minima a cualquier margen no quemado y la distancia al perímetro del incendio explicaron los patrones de remoción de semillas para roedores y hormigas, respectivamente. La remoción de semillas también fue menor en las estaciones taladas vs. las no taladas, pero solo de forma significativa para hormigas. Los roedores removieron más semillas bajo amontonamientos de ramas producto de la gestión forestal mientras que las hormigas lo hicieron en áreas de suelo desnudo. Se debería contemplar el efecto de los granívoros en la gestión de los hábitats quemados.

Bushfires are an integral part of the Australian environment, and consequently Australian fire fighters are regularly confronted with the challenge of bushfire fighting activities. Bushfires can be extensive and long-lasting, and as a result fire fighters can be exposed to bushfire smoke for long periods without respite. Anecdotal evidence suggests that bushfire smoke exposure can lead to respiratory symptoms such as coughing, wheezing, and shortness of breath. In an optimal environment, fire fighters are equipped with respirators and protective filters to prevent the inhalation of the air toxics in bushfire smoke. Yet, reports from the fire ground indicate that the protective filters are not effective in preventing the inhalation of bushfire smoke. As a result, fire fighters have increasingly expressed concern about the ineffective equipment and the resultant respiratory symptoms during and after bushfire fighting. This research aims to establish a scientific data base to support the anecdotal evidence. The objectives of the research were: (1) to identify and quantify the air toxics in Western Australian bushfire smoke; (2) to profile the acute respiratory health effects associated with bushfire smoke exposure; (3) to assess the effectiveness of three different types of filters under controlled conditions in a smoke chamber, and in the field during fuel reduction burn-off; (4) to formulate recommendations for reducing fire fighters' exposure to bushfire smoke; and (5) to inform policy decision makers about the most effective form of respiratory protective equipment for bushfire fighting. Exposure trials were conducted in an experimental setting utilising bushfire smoke conditions in a smoke chamber and during prescribed burn-offs. Repeated measurements of respiratory symptoms, pulmonary function and oximetry were undertaken before and after bushfire smoke exposure. In addition, personal air sampling inside the respirators was undertaken to quantify and compare the levels of filtered air toxics. The analysis of the collected data demonstrated that, of those compared, the particulate/organic vapour formaldehyde filter was most effective in protecting fire fighters' respiratory health during the smoke exposure period of maximally 120 minutes. Further research would be useful to determine the v effectiveness of the filters under more realistic conditions during bushfire fighting activities. The findings of this research have resulted in a policy review in Western Australia. In 2006, the Fire and Emergency Services Authority of Western Australia (FESA) reviewed its Bush Fire Smoke Exposure Standard Operational Procedures 51, and now issues the recommended particulate/organic vapour/formaldehyde filters to the 1,000 FESA career fire fighters. The use of protective equipment for bushfire fighters is inadequately regulated worldwide and the recommendation implemented by FESA can be seen as proactive and in advance of national and international best practice. In conclusion, this project was instrumental in the translation of public health research into best practice that protects occupational health, without the need for the lengthy process of legislative reform. Fire fighter organisations in other countries with high frequencies of bushfires could learn from this example, and move to review their policies and introduce adequate personal protection for fire fighters.

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Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-11-07T16:12:29Z No. of bitstreams: 1 Tese - Contribuição das queimadas na América do Sul para o derretimento das geleiras Andinas.pdf: 12013598 bytes, checksum: b9ec5b579fb35328075809a39c2dbffb (MD5) / Made available in DSpace on 2017-11-07T16:12:29Z (GMT). No. of bitstreams: 1 Tese - Contribuição das queimadas na América do Sul para o derretimento das geleiras Andinas.pdf: 12013598 bytes, checksum: b9ec5b579fb35328075809a39c2dbffb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / O período de maior ocorrência das queimadas na América do Sul, de agosto à outubro, coincide com mudanças sazonais na circulação atmosférica que tornam favoráveis o transporte e a deposição de black carbon sobre as geleiras Andinas. Com o intuito de avaliar o potencial impacto do black carbon emitido pelas queimadas na bacia Amazônica sobre a massa de gelo dessas geleiras, foram modeladas a emissão de BC, o seu transporte e deposição sobre a geleira Zongo, as mudanças no albedo e a perda de massa de gelo/neve em 2 anos críticos, 2007 e 2010. Os valores de emissão para estes anos na bacia Amazônica foram de 34 e 26 Gg para os picos em setembro, e 51 e 76 Gg anuais. Estes valores foram utilizados para a modelagem da emissão, transporte, deposição e perda de massa de gelo devido ao black carbon. A redução no albedo devido as queimadas foi de 2,5-5%, o que resultou em uma perda de massa de gelo/neve de 3,0-6,5 kg/m² ao ano, equivalente a um incremento de 2-4,5% na perda de massa de gelo/neve anual. Esta perda de massa de gelo devido as queimadas pode ser observada na descarga da geleira nos meses de agosto e setembro. O recuo da frente da geleira apresentou uma relação direta com o desmatamento e o número de queimadas na América do sul. Períodos com maiores taxas de recuo coincidiram com os anos de maiores eventos de queimada e desmatamento. / The period of greatest occurrence of fires in South America, from August to October, coincides with seasonal changes in atmospheric circulation that favor the transportation and deposition of black carbon on the Andean glaciers. In order to evaluate the potential impact of the black carbon emitted by the fires in the Amazon over these glaciers, we modeled the emission of BC, its transport and deposition on the Zongo glacier, the change in glacier albedo and the resulting Ice / snow mass loss, during 2 critical years, 2007 and 2010. The emission values for these years in the Amazon basin were 34 and 26 Gg for the peaks in September, and 51 and 76 Gg annual. These values were used for modeling the emission, transport, deposition and loss of ice/snow due to black carbon. The estimated albedo reduction were 2.5-5%, which resulted in a loss of ice / snow mass of 3.0-6.5 kg / m² per year, equivalent to an increase of 2-4,5% annual ice / snow mass loss. The estimated ice/snow loss due to Amazon fire emission can be observed in the Zongo's discharge during august and september. The retreat of the front of the glacier presented a direct relation with the deforestation and the number of fires events in South America. Periods with the highest retreat rates coincided with the years of major events of burning and deforestation.

An investigation into using attention mechanisms for better feature extraction in wildfire spread prediction models. This research examines the U-net architecture to achieve image segmentation, a process that partitions images by classifying pixels into one of two classes. The deep learning models explored in this research integrate modern deep learning architectures, and techniques used to optimize them. The models are trained on 12 distinct observational variables derived from the Google Earth Engine catalog. Evaluation is conducted with accuracy, Dice coefficient score, ROC-AUC, and F1-score. This research concludes that when augmenting U-net with attention mechanisms, the attention component improves feature suppression and recognition, improving overall performance. Furthermore, employing ensemble modeling reduces bias and variation, leading to more consistent and accurate predictions. When inferencing on wildfire propagation at 30-minute intervals, the architecture presented in this research achieved a ROC-AUC score of 86.2% and an accuracy of 82.1%.

This diploma thesis covers the individual citizens' perception of suburban events in order to discuss the point of view of the early modern Czech citizen and their ability to gain information of the world around through the analysis of such suburban events that were registered in the chosen chronicles, originating between the years 1575-1600, a period that is considered "a golden age of the Czech cities". First, the background of the chroniclers is outlined, because it might have influenced the choice of events they decided to include in their works, i.e. the position of the concrete city, the level of education in the said period or the author's personal life. Second, the general knowledge of the authors is described in the thesis through the means of analysis of the type of recorded information (e.g. Turkish wars, the deaths of famous persons, wildfires, councils and the like). In other words, the thesis is to point out what type of information was considered to be the most interesting or extraordinary to the wider public, and which circles were usually covered by the chroniclers. Therefore, the reader is to discover the world of thought of the early modern citizen, which has been restricted to us because of the lack of other than administrative materials, and the impulses that influenced and...

Heathlands typically experience regimes consisting of frequent and intense fires. These fire regimes play important roles in the lifecycles and population dynamics of all species in these communities. Prescribed fire is commonly applied to heathlands to minimise the risk of wildfires as well as to promote biodiversity. Ignitions in heathlands tend to either be unsustainable, or quickly develop into rapidly spreading intense fires. This presents a major problem for the application of prescribed fire and is the primary focus of this thesis. Heathland ignition has been investigated in three sections; litter ignition; vertical development of fire into the shrub layer; and horizontal spread through the shrub layer. These were studied in laboratory experiments using miniature versions of field fuels. Ignition success in litter layers was related to the dead fuel moisture content. Litter type, ignition source, and presence of wind were found to affect the range of ignitable fuel moisture contents of a litter bed. The effect of litter type was best explained by density. Dense litter beds required drier conditions for ignition than low density litter beds. The vertical development of fire into shrubs was mostly dependent on live fuel moisture content, but crown base height, presence of wind, ignition source, shrub height and the percentage of dead elevated fuel were also important. Horizontal spread of fires through shrub layers was most affected by the presence of a litter layer, with nearly all ignitions successful when there was an underlying litter fire. Fire spread would only occur in shrubs without a litter layer when the shrub layer was dense and dry, or had a substantial dead fuel component. Spread was more likely to be sustained when there was wind. Models predicting the moisture content of dead fuels were tested in heathlands, and as would be expected those that can be calibrated for different fuel types were found to have the best performance. Fuel moisture content and fuel load models were reviewed for heathlands, and a number of recommendations for future research were made.

Forested watersheds in western North America are subject to significant change from natural and anthropogenic disturbance, including wildfire. Forest canopy changes have subsequent impacts on sub-canopy snow processes. A simple, process-based point energy balance model was developed to quantify differences in energy balance characteristics between a burned and a healthy forest stand. Potential model uncertainties were identified using sensitivity analyses. Simulated snowmelt accurately recreated measured snowmelt, providing confidence in the model’s ability to simulate energy balance processes in subcanopy environments where wind redistribution and sublimation are not major drivers of the local snowmelt energy balance. In the burned stand, sub-canopy snow accumulation was greater but melted more rapidly than in the healthy stand. The removal of forest canopy resulted in more energy available for snowmelt, including higher short-wave and lower long-wave radiation, and increased turbulent fluxes. Burned stands should be considered a separate land cover type in larger scale watershed models. / xii, 129 leaves : ill,, map ; 29 cm

With natural disasters occurring with more frequency and severity, understanding how to facilitate survivors’ resilience and recovery is becoming increasingly important. The Camp Fire in California, which started on November 8, 2018, was one of the most destructive wildfires in recorded history in terms of loss of life and damage to property. Aid from many types of entities (e.g., non-profits, governments, and for-profits) at various levels (e.g., local, state, and federal) was available to survivors, but perhaps the most influential source of support was Disaster Facebook Groups. In the month after the Camp Fire, around 50 Camp Fire Facebook Groups (CFFGs) were created, with over 100 CFFGs existing over the course of recovery. CFFGs are Facebook Groups with the goal of helping Camp Fire survivors. The support exchanged in CFFGs was immense and ranged from financial assistance to emotional support to community building. <br><br>This dissertation offers a mixed-method, event-specific case study of the use and utility of Disaster Facebook Groups after the Camp Fire. I examined how CFFGs offered unique and valuable spaces for connection that allowed members to engage in resilience organizing and disaster response and recovery. To conduct this case study, after engaging in observations of the Groups for over two years, I interviewed 25 administrators of CFFGs and distributed a survey in the Groups that was completed by survivors of the Camp Fire who were members of at least one CFFG during their recovery. I used network perspectives and the Communication Theory of Resilience (Buzzanell, 2010, 2019) as lenses through which administrators’ and survivors’ experiences with CFFGs was understood. I also analyzed the two datasets using multiple and mixed methods but primarily thematic analysis and path modeling. <br><br>The analyses for this case study are presented in four studies. The first two studies provide an understanding of the spaces for connection offered by CFFGs (i.e., characterizing the CFFGs and describing the spaces for connection as both helpful and hurtful), while the last two studies examine the use and utility of CFFGs (i.e., explaining the evolution of activity in CFFGs and investigating the connectivity and social support in CFFGs). <br><br>Across the four studies, I explored three central arguments, which are the primary contributions of this dissertation. First, I advocated for incorporating network thinking into resilience theorizing. With the findings of this dissertation, I extend the Communication Theory of Resilience by offering “managing communication networks” as a refinement of its fourth process of resilience (i.e., using and maintaining communication networks). Managing communication networks addresses the active strategies people use to manage their communication networks, including expanding, contracting, maintaining, and using their communication networks, as they endure and overcome hardship. I also forward the argument that people’s resilience is encompassed by their social networks, meaning their social network can be passively implicated by their resilience or actively involved in their resilience, but can also initiate resilience on their behalf.<br><br>Second, I contended Disaster Facebook Groups offer unique and valuable spaces for connection that facilitate resilience organizing and disaster response for at least five reasons. I argued that Disaster Facebook Groups empower emergent organizing; privilege local knowledge; are convenient; lack anonymity which adds authenticity; and allow for individualization. The findings of this dissertation provide evidence of how these reasons converged in CFFGs to enable members to exchange support that was not, and could not be, available elsewhere.<br><br>Third, I hypothesized that the use of Disaster Facebook Groups would predict the utility of Disaster Facebook Groups, resilience, and recovery for survivors. I tested two models that use different variables to represent the use and utility of CFFGs and recovery from the Camp Fire. The first model investigated how activity in CFFGs influenced the perceived helpfulness of CFFGs and how both the activity in and perceived helpfulness of CFFGs influenced the extent of recovery for survivors. I used retrospective data about five time points across survivors’ first two years of recovery and found the model was most explanative up to one month after the Fire. The second model assessed how various indicators of connectivity in CFFGs impacted received social support (i.e., informational, emotional, and tangible support), resilience, and satisfaction with recovery for survivors. The intensity of survivors’ connections to CFFGs, when they joined their first CFFG, and how many Facebook Friends they gained from their participation in CFFGs were the most predictive indicators of connectivity. From the Groups, survivors reported receiving informational support more than emotional support and emotional support more than tangible support.<br><br>I put the findings of the four studies, as well as the three central arguments, in conversation with each other in the discussion section, focusing on theory, practice, and methodology. Regarding theory, I contribute network thinking to resilience theorizing: I underscore resilience as an inherently networked process; I acknowledge expanding and contracting communication networks as sub-processes of resilience that complement but are distinctly different from using and maintaining communication networks; and I forward “managing communication networks” as a refinement and extension of the Communication Theory of Resilience’s fourth process of resilience (i.e., using and maintaining communication networks). Related to practice, I call for the continuation of conversations around Disaster Facebook Groups as unique and valuable spaces for connection, particularly regarding the five reasons I established. I also give suggestions for practice related to the use and utility of Disaster Facebook Groups for disaster response and recovery. For methodological considerations, I discuss the importance of forming relationships with participants when engaging in research about online communities and natural disasters and call to question the translation of findings about social media across platforms and the role of neoliberalism in resilience and disaster research and practice. Despite its limitations, this dissertation makes meaningful contributions to theory, practice, and methodology, while offering fruitful directions for future research. This mixed-method, event-specific case study brings attention to the influential citizen-driven disaster response in Facebook Groups after the Camp Fire. <br>