A quantificação de recursos florestais é usada para fins diversos nas ciências naturais, e depende da obtenção de dados de campo de forma precisa e rápida, e o inventário florestal tem se valido principalmente de trabalho humano manual para este fim. A tecnologia LiDAR, baseada em sistemas a laser, permite a coleta desses dados por meio da representação tridimensional do ambiente e a geração de informações espacialmente precisas dos objetos que o compõe. O sistema de varredura laser terrestre (terrestrial laser scanning - TLS) aplica essa tecnologia sob abordagem terrestre, e assim pode ser usada na representação 3D de florestas e ambientes naturais. Devido a crescente número de estudos nesse tópico atualmente o sistema TLS é capaz de fornecer métricas florestais básicas com elevada exatidão, como densidade de plantio e diâmetro à altura do peito, além de informações não obtidas pelo inventário florestal padrão, como estimativa da biomassa e índice de área foliar, entre outros. Este trabalho tem por objetivo a avalição da capacidade do sistema TLS em fornecer com exatidão métricas de árvores individuais selecionadas em dois povoamentos florestais localizados no sudeste do Brasil. Árvores de Eucalyptus sp. (n = 6) e Pinus elliottii var. elliottii (n = 5) foram submetidas à varredura e os valores obtidos pelo mapeamento 3D foram comparados com dados medidos em campo manualmente. Os resultados encontrados mostram que o algoritmo empregado na filtragem dos troncos foi eficiente no isolamento dos fustes de árvores individuais até a altura total das árvores amostradas, enquanto que o algoritmo para modelagem do tronco filtrado foi capaz de fornecer medidas de diâmetro até 50% da altura total das amostras. A exatidão das medidas de DAP pelos dados TLS foi de 0,91 cm e 2,77 cm (REQM) para Eucalyptus e Pinus, respectivamente. Os diâmetros ao longo do fuste tiveram mais exatidão no Eucalyptus (REQM = 2,75 cm e r = 0,77) do que no Pinus (REQM = 3,62 cm e r = 0,86), resultados condizentes com os encontrados em literatura. A exatidão da estimativa dos diâmetros diminuiu ao longo do fuste. O autor sugere que a influência de vento forte no momento da varredura pode ter interferido na qualidade das nuvens de pontos em relação a ruídos e na exatidão dos modelos de obtenção de diâmetros. A partir destes resultados conclui-se que, para as características ambientais e parâmetros de varreduras apresentados, o sistema TLS foi capaz de fornecer dados com exatidão aceitável, e mais estudos devem ser conduzidos buscando o entendimento e mitigação de efeitos que podem dificultar a obtenção de dados precisos nos estratos superiores do dossel florestal. / Forest resources assessment is used for diverse purposes on natural sciences, and relies on field data acquisition in fast and precise ways, and forest inventory has been relying mainly on manual human labor for that. LiDAR technology, which is based on a laser system, allows for these data acquisition through 3D representation of surroundings and the generation of espacially precise information about the objetcs within. Terrestrial laser scanning - TLS - applies this technology in a land approach, thus it can be used on the 3D representation of forests and natural scenes. Due to increasing number of studies on this subject nowadays TLS system is capable of giving basic forest metrics with high precision, as for plant density and diameter at breast height, besides information not obtained by standard inventory procedures, as biomass estimation and leaf área index, among others. This work aims the assessment of TLS capability on giving precise metrics of individual trees located at two forest stands in southeastern Brazil. Trees of Eucalyptus sp. (n = 6) and Pinus elliottii var. elliottii (n = 5) were scanned and the numbers obtained by 3D mapping were compared to manually measured field data. The results found show that the algorithms used on trunk filtration were efficient on individual trees stem isolation until total height of measured trees, while the trunk modelling algorithm was capable of giving diameters until 50% of samples total height. The precision of DBH measurements by TLS data was 0,91 cm and 2,77 cm (RMSE) for Eucalyptus and Pinus, respectivelly. Diameters along the stem were more preciselly estimated for Eucalytus trees (RMSE = 2,75 cm and r = 0,77) than for Pinus trees (RMSE = 3,62 cm and r = 0,86), results consistente with literature. The precision of diameters estimation diminished along the stem. The author suggests that the influence of intense wind by the time of scanning can have interfered on cloud point quality in the terms of noises and thus on the precision of diameter estimation modelling. From these results one can conclude that, considering the environmental aspects and scanning parameters presented, TLS system was capable on giving data with acceptable precision, and more studies must be carried searching for understanding and mitigation of effects that can difficult precise data acquisition on upper forest strata.

Accelerated soil erosion and the subsequent decline in soil depth has negative environmental, and consequently financial, impacts that have implications across all land cover classifications and scales of land management. Ironically, although attempts to quantify soil erosion nationally have illustrated that soil erosion can occur in the UK, understanding whether or not the UK has a soil erosion problem still remains a question to be answered. Accurately quantifying rates of soil erosion requires capturing both the volumetric nature of the visible, fluvial pathways and the subtle nature of the less-visible, diffuse pathways, across varying spatial and temporal scales. Accordingly, as we move towards a national-scale understanding of soil erosion in the UK, this thesis aims to explore some of the multiple techniques available for developing an understanding of soil erosion in the UK. The thesis first explored the information content of existing UK-based soil erosion studies, ascertaining the extent to which these existing data and methodological approaches can be used to develop an empirically derived understanding of soil erosion in the UK. The second research chapter then assessed which of two proximal sensing technologies, Terrestrial Laser Scanning and Structure-from-Motion Multi-view Stereo (SfM-MVS), is best suited to a cost-effective, replicable and robust assessment of soil erosion within a laboratory environment. The final research chapter built on these findings, using both Rare Earth Oxide tracers and SfM-MVS to elucidate retrospective information about sediment sources under changing soil erosion conditions, also within a laboratory environment Given the biased nature of the soil erosion story presented within the existing soil erosion research in the UK, it is impossible to ascertain if the frequency and magnitude of soil erosion events in the UK are problematic. However, this study has also identified that without ‘true’ observations of soil loss i.e. collection of sediment leaving known plot areas, proxies, such as the novel techniques presented in the experimental work herein and the methods used in the existing landscape scale assessments of soil erosion as included in the database chapter, are not capable of providing a complete assessment of soil erosion rates. However, this work has indicated that despite this limitation, each technique can present valuable information on the complex and spatially variable nature of soil erosion and associated processes, across different observational environments and scales.

A common platform for both disaster risk reduction (DRR) and climate change adaptation (CCA) has been sought around the world to reduce human vulnerability, enhance adaptive capacity and achieve other contemporary global targets. This policy framework at global and national level creates a challenge for local level implementation: climate change is a global risk predicted by scientists whereas disaster vulnerability is experienced by local people. To consider these circumstances, the thesis examines how DRR and CCA can be integrated at local level and what kind of governance and institutions are needed to ensure community participation in the whole process of local development. In order to address the research question, the thesis focuses on four inter-related themes: (i) redefining social vulnerability in a changing environment; (ii) understanding local knowledge, experiences and practices in terms of coping with climate induced disasters; (iii) investigating the DRR and CCA conundrum of implementing national policies at local level; and (iv) exploring the transformation of socio-cultural landscape of rural Bangladesh through external interventions at local level in a DRR–CCA context. The study has gone through an in-depth empirical data analysis of DRR and CCA processes both in flood prone Jamuna river basin and cyclone prone coastal areas in Bangladesh. Fieldwork involved qualitative approaches and methods, and some use of quantitative survey method; including 29 semi-structured in-depth interviews, varied participatory rural appraisal (PRA) tools applied in nine focus group discussions (FGDs) and a questionnaire survey conducted in three selected study villages. Respondents included local people, particularly disaster survivors, local level practitioners, national level professionals formally linked to disaster and climate issues and academics. The findings of the thesis show that local knowledge and practice, particularly through recent experiences of environmental crisis help communities to adapt to climate related disaster risks and that the survivors of floods have more distinct coping and adaptive capacity than those of cyclones. The research found that disaster management in Bangladesh is strong up to local level and that recent government and nongovernmental initiatives for DRR and CCA assist communities coping with extreme events. However, the whole system often fails to identify and understand localised disaster and climatic risks due to a lack of effective community inclusiveness in decision-making processes. The study argues that a ‘whole-of-society’ approach should be a pervasive aspect of internal and external interventions aiming to implement more integrated DRR–CCA at local level.

To address the growing frequency and intensity of disasters a global effort is underway to change the dominant approach to disaster policy from disaster response to integrating disaster risk reduction (DRR) throughout development activities. Research into how DRR policy progresses in a government context is lacking. Using a qualitative case-study approach this research examines how the global policy prescription of mainstreaming disaster risk reduction (DRR) is unfolding within the Government of Nepal. In particular, this research a) challenges the rhetoric of substantive policy change that underpins the concept of mainstreaming and b) questions its efficacy as a neoliberal post-New Public Management policy tool given that the disaster vulnerability literature implicates neoliberalism as a driver of disaster risk. Finding change to be the dominant theme throughout the research, it applies theories and frameworks from the policy paradigm change literatures (e.g. Advocacy Coalition Framework, social learning and paradigm policy change) to explain what was found in the Nepal case-study. Eight months of fieldwork took place throughout 2014-2016. In total, eighty-eight in-depth interviews were conducted with bureaucrats and political party members at the central, district, and local levels. This research advances the disaster vulnerability scholarship through its critique of neoliberal policy discourse and its application of policy change literature. It is argued that the concept of mainstreaming fits the criteria of a neoliberal buzzword; the findings of this research demonstrate why this is problematic. The lead ministry responsible for disaster management appropriated the global policy rhetoric of mainstreaming DRR in order to minimize any substantive policy change that the DRR agenda promotes. Despite this, evidence is also found of a growing awareness and advocacy of DRR within the Government of Nepal. This is suggestive of an advocacy coalition starting to develop, which is being built through social learning. The role of individual bureaucrats and political party members, rather than a centralised legalistic approach, is found to be fundamental to changing the disaster response policy paradigm. This research calls attention to the need to critically analyse how top-down global DRR policy prescriptions are interpreted by nation-states. Empty and hollow global policy buzzwords are easily translated into a rhetoric that does not match with the reality of the governing and the policy environment.

Disasters, both natural and human-made can have severe impacts on communities and infrastructure. The approach to minimising the impact of such events is Disaster Risk Reduction. This research looks at weather related disasters in the Kingdom of Saudi Arabia and methods used to reduce risk. The research was undertaken using a mixed methods approach. Some 200 people, both male and female, were sampled using questionnaires in four different provinces of the kingdom. The purpose was to gain an understanding of their knowledge of hazards and preparedness. Interviews were held with a number of key stakeholders in disaster management. Focus groups were conducted with religious leaders in order to gain an understanding of the role of Islam in risk reduction. The results showed that the majority of questionnaire respondents lacked knowledge and information about disasters in their places of residence. Further, they are not well prepared to face the risks of natural disasters and lacked knowledge of how to mitigate their risks. However, the majority of participants strongly believed they can minimize the risk of disasters and they were enthusiastic to participate in any efforts of disaster risk reduction in the kingdom. The Saudi government is building a disaster management system. However, it needs a greater focus on raising community awareness and preparedness. The research finds that the mosques has the opportunity to play an important role of in raising community awareness and preparedness. The Holy Quran teaches that protecting the environment and all creatures is part of Islamic worship. An extreme version of the fatalistic view of natural disasters is not fully supported in this study, which argues that natural disasters might have many other interpretations, such as a test from God, a natural process and a result of humankind’s negative intervention in nature. The role of the mosque, which has a special sacred place in the life of every Muslim, has been researched. The research shows that the mosque has a central role in the life of Muslims but this role seems to have declined recently. The strategic position of the mosque and its special status in the life of every Muslim make it a very important place for effective natural disaster risk reduction. This study suggested possible roles for the mosque to raise awareness and to help with preparedness. Some practical steps are suggested to integrate Islamic teachings into the policies and strategies of natural disaster risk reduction in the Kingdom of Saudi Arabia. These steps are based on previous research about the role of religion in disaster risk reduction and the findings of this research.

Microorganisms are known to tolerate a variety of extreme environments, such as high and low pH, desiccation and a wide range of temperatures that would prove uninhabitable for most eukaryotic cells. However, extreme radiation exposure is a ubiquitous hazard to pro- and eukaryotic viability. Ionising and non-ionising radiation, and their associated high energies, cause damage to a cell in the form of DNA double-strand breaks, membrane deterioration, and lethal mutations. Radiation also induces secondary effects such as the production of reactive oxygen species, which attack and degrade organic compounds. It is therefore not surprising that radiation is considered by the scientific community to be one of the main influencing factors when regarding habitability on the early Earth, as well as other planets, such as present-day Mars. This thesis explores the response of select microbes that have been exposed to extreme radiation environments, i.e. both high and ultra-low radiation. Understanding how radiation affects the geochemical environment is key to the assessment of its potential to support life and to harbour molecules associated with life. The effect of radiation-induced photochemistry on the early terrestrial and present-day Martian surface is explored in conjunction with Fenton chemistry. Iron oxides are abundant on both Earth and Mars and act as catalysts in Photo-Fenton reactions, enabling the production of free radicals. The resulting consequences for habitability are shown to be antagonistic, with iron oxide enabling both the protection or destruction of cells, depending on the local geochemistry. In addition, the photo-reactivity of perchlorate is investigated. The UV-induced activation of the strong oxidant, and recently confirmed Martian surface constituent, is demonstrated, revealing its severe bacteriocidal effect on microbes. It is also shown to significantly reduce microbial viability when combined with further Martian soil constituents and components required for Photo-Fenton chemistry. In order to accurately analyse the effects of low earth orbit radiation on prokaryotic life, cyanobacterial samples were attached to the outside of the International Space Station as part of the EXPOSE-R2 mission for 1.5 years. The samples were subjected to various conditions, including exposure to a minimally filtered space radiation environment and simulated Mars conditions. The experiment is designed to test the protection that biogenic and non-biogenic substances may provide to cells. The results in this work present the post-flight analysis of the samples and demonstrate the ability of these substances to maintain cyanobacteria viability. They also show that the cyanobacterial cells themselves can effectively act as a shield for a secondary, co-cultured bacteria species. On the other end of the radiation dose scale, this work addresses the gaps in knowledge with regard to the little-understood effects of low, sub-background radiation on prokaryotes. Using the Boulby Underground Lab in the functioning Boulby Mine, Cleveland UK, microbes are cultivated under regulated, extremely low radiation environments to test multiple dose-response models. The results show no change in cell's growth rates or gradients in low radiation exposure when compared to surface-dose controls. They also fail to exhibit any enhanced susceptibility to stress factors, such as UV irradiation, as suggested by previous work in the field. These experiments mark the first extensive and tightly controlled research into microbial responses in the near-absence of radiation. This work illustrates the importance of understanding both primary and secondary effects of radiation on microbes and begins to bridge the knowledge gap from both ends of the dose axis. These approaches show the far-reaching influence radiation has on astrobiologically relevant topics, such as habitat geochemistry and life detection, and demonstrate the capacity of life to survive in extreme radiation environments.

This thesis examines the emergence of Community Radio in the United Kingdom. It places the sector within an historical context dominated by the BBC and strongly influenced by the subsequent arrival of commercial radio broadcasting. Understanding this historical context, which includes consideration of the role played by unlicensed 'pirate' radio operators, is, in the opinion of the author, a critical prerequisite necessary for assessing how and why current Community Radio practice has developed in the way it has. Primary research for this thesis includes a variety of semi-structured interviews with campaigners, practitioners and regulators and, whilst primarily focused on the emergence of the Community Radio sector within the British context, it does not ignore wider international perspectives. Recognising that, well before Community Radio began to emerge in the UK, much of the early conceptual development of the sector took place in other jurisdictions, the author also draws upon a number of international sources, including some primary research in the Republic of Ireland, Norway and the United States of America. The influence of two key factors, those of regulation and technology, are central to this research, the author arguing that these in particular have helped define (and constrain) the current position and future opportunities available to Community Radio within the United Kingdom. Legislation and regulation may have defined clear, and in some instances unique, operational objectives for British Community Radio, but when defining such objectives they have also had to take into account limited broadcast spectrum availability, constraining the scope and scale of the sector as a result. Beyond a consideration of the historical and of present day practice, this thesis also looks towards the future, examining current developments in digital broadcasting which offer the potential to counter such current capacity constraints and provide opportunities for additional community-based services in future.

Studies were conducted on a population of tiger salamanders, Ambystoma tigrinum, at Henderson Island Wildlife Management Area in Jefferson County, TN. Tests were conducted to locate the nonbreeding habitat of the salamanders and to detect any difference in fluctuating asymmetry (FA) between larval populations in a large, permanent pond and an ephemeral wetland. Drift fences were installed with pitfall traps at selected locations around each pond to determine nonbreeding habitat use by adults. Most adult salamanders were found using a blackberry (Rubus sp.) dominated old-field, a grassy field, and a shrub-grass mix field, which were all adjacent to the ponds. No statistical difference in FA between the 2 ponds.

The Asian clam, Corbicula fluminea, is an invasive bivalve species that now occurs through most of the lower 48 United States. While a significant degree of salinity tolerance has been observed in C. fluminea, owing to its estuarine lineage, the physiological and behavioral responses to changes in salinity by these organisms are not completely understood. It was hypothesized that Corbicula would initially avoid elevated salinity levels (>1 g/L) behaviorally through valve closure, but would eventually have to open to dispel anaerobic waste products and deal with the salinity. To explore this, Corbicula were collected and put through a series of experiments at salinity exposures of 0, 2.5, and 5.0 g/L, with tissue water content and hemolymph osmolality being measured. After an initial 96-hour exposure, it was observed that the percent tissue water content of clams in 2.5 g/L and 5.0 g/L water dropped 3.29% and 4.18%, respectively, below that of the control groups in 0 g/L. After a 24-hour time-course experiment, this change in tissue water was found to largely occur within the first eight hours of exposure for the 2.5 g/L and 5.0 g/L groups. It was also noted that the hemolymph osmolality of both the 2.5 g/L and 5.0 g/L groups rose to approximately 78 mOsm/kg and 148 mOsm/kg, respectively, matching the osmolality of their exposure water in roughly the same time span and indicating that little behavioral avoidance of the elevated salinity was occurring. The osmolality of the control group did not match the osmolality of the 0 g/L water at 0.5 mOsm/kg, but was held at a constant level around 50 mOsm/kg. In a later experiment measuring the same variables for clams in 10.0 g/L, it was found that the tissue water and osmolality did not begin to change significantly until after 12 hours, indicating behavioral avoidance at this salinity level. A context study was also conducted comparing oxygen consumption and percent tissue water between various salinities in a light and dark exposure to determine if ambient light influenced siphoning of the clams and exposure to the salt. In this experiment, it was observed that clams held in salinities of 5.0 g/L for 24 hours consumed roughly 1.90 mg O2/L/g/h, whereas clams held in the control only consumed roughly 0.73 mg O2/L/g/h. These findings suggest that Corbicula osmoregulate in freshwater but osmoconform at salinities of 2.5 g/L and 5.0 g/L. The data from the context study also suggests that this conformation comes at a significant metabolic cost. Furthermore, and in contrast to the results of some previous studies, a significant level of behavioral avoidance of elevated salinity does not appear to commence until the clams are at a salinity above 5 g/L.

Large scale ecosystem restoration is an important societal issue because significant risks, costs, and benefits can accrue on large landscapes. It is important to understand baseline ecosystem conditions, existing condition, and to the extent possible estimate ecosystem response to alternative management scenarios. Incorporating ecosystem process and function into restoration planning and implementation will make ecosystem restoration projects sustainable. The Upper Mississippi River System is an excellent case study for such issues because it is an important, multiple-use ecosystem with significant ongoing investment in ecosystem, agri-system, and navigation system management. Large-scale geomorphology, hydrology, and land cover information was compared among presettlement, contemporary, and potential future reference conditions to examine ecosystem state and evaluate mechanisms responsible for ecosystem condition. The UMRS was scaled by physiographically similar characteristics into large floodplain reaches several hundred river miles in length, geomorphic reaches 50 to several hundred miles, and a mile-by-mile segmentation of the river floodplain extent. Ecologically relevant geomorphic classes were devised from existing data and evaluated by river reach to characterize presettlement geomorphology, and dams and levees were superimposed to reflect the altered hydrogeomorphology of the contemporary ecosystem. A pre- and post-impact Indicators of Hydrologic Alteration river stage analysis evaluated dam impacts, and pre-dam and post-dam aquatic habitat class distribution was compared. A floodplain inundation simulation analysis provided new information on the potential spatial distribution of frequent floods. Land cover data available for presettlement and modern reference periods were compared at several spatial scales. Multivariate analyses evaluated land cover characteristics among geomorphic reaches, as well as to assess the influence of hydrogeomorphic drivers on land cover for presettlement and contemporary reference periods. The objective of this research was to clearly delineate the divergence of environmental conditions among reference periods to evaluate which drivers need to be, and can be, altered to change ecosystem state. Hydrogeomorphic response to development indicates several restoration objectives that are appropriate system-wide and others that are best suited to specific river reaches. Similar data sources are available for much of the rest of the United States through the Public Land Survey and engineering surveys of any significant civil works projects.