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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
161

Nutrition and habitat driven foraging of wild dolphins in the Bahamas: a recipe for prey

Unknown Date (has links)
Two sympatric dolphin species, Stenella frontalis and Tursiops truncatus, resident to Little Bahama Bank, Bahamas were found to mostly forage independent of one another, but occasionally foraged in mixed groups. Analysis of over 20 years of data revealed the degree of overlap to be minimal with spatially distinct regions identified for both species, environmental segregation based on depth, bottom type, temperature, and time of day. Results based on observational data indicated significant differences in group size and selected prey. For S. frontalis, lactating females had the most distinct diet, which differed from that of non-reproductively active (NRA) females. Pregnant females had ambiguous prey use results, but diet differences were revealed through nutritional analysis. Lactating females had a higher intake of all nutrients (% moisture, % lipid, % protein, and calories) than pregnant females but lower than NRA females. Mother and calf pairs selected prey for caloric and moisture values. The influence of calves on foraging groups was reflected through discrete differences in all nutrients. Males and females appeared to select the same major prey, but female prey use was much more diverse. / by Christopher R. Malinowski. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
162

Using a Groundwater Influenced Sea Level Rise Model to Assess the Costs Due to Sea-Level Rise on a Coastal Community’s Stormwater Infrastructure Using Limited Groundwater Data

Unknown Date (has links)
A confounding factor for sea level rise (SLR) is that it has a slow, steady creep, which provides a false sense for coastal communities. Stresses caused by SLR at today’s rate are more pronounced in southeastern Florida and as the rate of SLR accelerates, the exposure areas will increase to a point where nearly all the state’s coastal infrastructure will be challenged. The research was conducted to develop a method for measuring the impact of SLR on the City of West Palm Beach (City), assess its impact on the stormwater system, identify vulnerable areas in the City, provide an estimate of long-term costs of improvements, and provide a toolbox or strategies to employ at the appropriate time. The assessment was conducted by importing tidal, groundwater, topographic LiDAR and infrastructure improvements into geographic modeling software and performing analysis based on current data. The data revealed that over $400 million in current dollars might be needed to address stormwater issues arising from SLR before 2100. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
163

Testing the Floristic Quality Assessment Index in natural and created wetlands in Mississippi, USA

Herman, Brook Danielle. January 2005 (has links)
Thesis (M.S.) -- Mississippi State University. Department of Biological Sciences. / Title from title screen. Includes bibliographical references.
164

Upholding the coral loop : Resilience, alternative stable states and feedbacks in coral reefs

Norström, Albert January 2010 (has links)
Coral reefs are suffering unprecedented declines in coral cover and species diversity. These changes are often associated with  substantial shifts in community structure to new dominant organisms. Ultimately, these “phase shifts” can be persistent and very difficult to return from. Building insurance against degradation and decreasing the likelihood of reefs undergoing shifts to undesirable states will require sustainable management practices that uphold coral reef resilience. This thesis consists of five papers that contribute new knowledge useful for managing the resilience of coral reefs, and other marine ecosystems. Paper I shows how the morphology of natural substrate (dead coral colonies) can significantly influence coral recruitment patterns. Paper II focuses on larval lipid levels, a key determinant of coral dispersal potential, in a common Caribbean coral (Favia fragum). It shows that i) lipid levels exhibit a significant, non-linear reduction throughout the larval release period of F. fragum and ii) exposure to a common pollutant (copper) could potentially lead to a more rapid lipid consumption in the larvae. Paper III presents a broader analysis of the different undesirable states a coral reef can shift to as a consequence of reef degradation. It concludes that different states are caused by different driving factors and that management must explicitly acknowledge this. Paper IV proposes a suite of resilience indicators that can help managers assess when a coral-dominated reef might be moving towards a shift to an undesirable state. These indicators capture key-processes occuring on different temporal and spatial scales and signal resilience loss early enough for managers to take appropriate measures. Finally, Paper V reviews the feedback loops that reinforce the undesirable states of five important marine ecosystems and suggests certain strategies that can ease the restoration back to healthier conditions. Managing these critical feedbacks will recquire monitoring the processes underpinning these feedbacks, breaking already established feedbacks loops through large-scale management trials and acknowledging transdisciplinary solutions that move management beyond the discipline of ecology / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 5: In progress.
165

Recreational ecosystem service benefits from the Chestermere Lake Reservoir : value for day use non-resident visitors

Bewer, Robert January 2012 (has links)
Irrigation infrastructure provides many ecosystem service (ES) benefits that enhance the well-being of Albertans and is central to economic activity in southern Alberta. Management of irrigation infrastructure and water resources is becoming increasingly challenging as Alberta’s population and economy grows. Past water allocation decisions have not generally considered the need of ecosystems leading to declining ecosystem health, and changes to provision of ES benefits in Alberta. The goals of current Alberta government policy include changing how water and land is managed to ensure that ecosystem health and ES provision is maintained. The research in this thesis concentrates on establishing the value of recreational ES benefits provided by the Chestermere Lake Reservoir, and obtaining information on the spatial aspects and visitor characteristics. A mixed method approach is used combining a qualitative discussion with a quantitative analysis using a geographic information system (GIS) and the travel cost method (TCM). The selection of the mixed method and combined GIS-TCM approach was based on past success in previous studies. The findings reveal a substantial value for recreational ES benefits provided by the Chestermere Lake Reservoir occurring within a limited area similar to other studies of recreational benefits from reservoirs. The findings of this research provide information for decisions makers, water infrastructure managers, and water transfer participants when assessing the impact of planned actions. Further research is recommended to build upon the findings of this study and further expand the available information on ES benefits to include all ES provided by southern Alberta. / x, 125 leaves : col. ill. ; 29 cm
166

Cross-shelf coral reef biodiversity : does data and ecological theory fit with habitat-based species conservation models?

Radford, Benedict January 2007 (has links)
[Truncated abstract] Selection of priority areas for Marine Park conservation is often compromised by the lack of comprehensive biodiversity data and the resources and expertise necessary to gain this information directly by sampling. One cost effective alternative is the use of species groups or indicator species as surrogates for total biodiversity. However use of these surrogates requires an ecological understanding of how they reflect biodiversity gradients. A framework for unravelling these relationships has been suggested that involves relating species biodiversity to different and competing ecological models using appropriate statistical analysis. I use this framework to explore coral species biodiversity over a range of environmental gradients encompassing the North West Shelf of Australia and the Great Barrier Reef in North East Australia. ... I assessed physiological responses of corals to physical factors to corroborate crossshelf patterns in species biodiversity. Finally, I investigated to what extent coral cooccurrence based species groups (or guilds) can be used as surrogates for total coral biodiversity. The major findings of this thesis were: i) coral biodiversity along cross-shelf environments was highly correlated to specific gradients of abiotic reef conditions; ii) larval modelling indicates the potential for significant connectivity across continentalshelf environments such that differences in species distribution are not simply as a result of self seeding. iii) similar correlative patterns were demonstrated for coral species that occur along comparable abiotic gradients in reef areas of both Eastern and Western Australia, suggesting a causal relationship between the physical environment and coral biodiversity; iv) coral physiological parameters measured using lipid fractions independently corroborated the hypothesis that there is a biological basis for observed coral distributions; v) reef coral communities are not highly structured across abiotic physical gradients and biodiversity across the shelf increases as conditions become suitable for a wider range of species; vi) total coral biodiversity can be estimated very accurately (within r2 values ranging from 0.75 to 0.90) using a small number (15-30) of optimally chosen indictor species using the randomForest statistical method. These results suggest coral biodiversity over cross-shelf environments conforms most closely to the
167

Wildfire under a changing climate in the Bolivian Chiquitania : a social-ecological systems analysis

Devisscher, Tahia January 2015 (has links)
With the same force that human activities accelerate and amplify change in the biosphere, human agency can play a critical role in influencing future trajectories. However, managing increasingly complex problems is becoming ever more challenging. Among other things, it requires a systemic thinking about the future to anticipate how intertwined drivers may respond to rapid change. This thesis addresses such challenge in the context of contemporary wildfires, which are becoming increasingly complex to manage and a growing global concern. The study adopted a novel approach (Chapter 3) to study wildfire as a complex social-ecological system. The overarching aim is to generate insights into wildfire causes, effects and feedbacks to anticipate future wildfire risk and inform management strategies that can prevent potential impacts. I combine different disciplinary lenses, multiple spatial scales of analysis and participatory methods to analyse wildfire dynamics in the Chiquitania region, located in the Department of Santa Cruz, Bolivia, at the southern edge of Amazonia. This region has a unique tropical dry forest that is susceptible to changes in climate and fire regimes, and a rapidly expanding agricultural frontier. During the recent 2010 drought, large wildfires affected this region intensifying public concern about potential 'mega-fires', particularly given predictions of more extreme seasonality in the future. The first research paper of this thesis (Chapter 4) evaluates the effects of wildfire recurrence on the forests of the Chiquitania using ecological surveys. In addition to significant biomass loss, the observed patterns in species abundance and dominance suggest that the forests respond to recurrent fires through a shift in tree species composition, with fire-tolerant species becoming more dominant. The second research paper (Chapter 5) analyses future wildfire risk in the Chiquitania region using fuzzy cognitive mapping. This conceptual modelling approach engaged different actor groups in the region to integrate their perspectives of the regional wildfire dynamics. Semi-structured interviews informed the scenario assumptions which considered failure to respond in time to wildfire risk, as well as implementation of alternative management strategies. Unexpectedly, the fire management strategy showed less trade-offs between wildfire risk reduction and production compared to the fire suppression strategy. The high vulnerability of the agricultural production to wildfire risk has implications for local communities that largely depend on agriculture for subsistence if future climatic conditions become drier. The third research chapter (Chapter 6) uses interviews and focus group discussions to analyse how different forms of knowledge and perceptions of fire relate to prevalent wildfire risk strategies in the Chiquitania. The analysis reveals that strategies are in tension between two conflicting narratives and understandings of fire. On this basis, a deliberation process is proposed with the potential to integrate opposing views into more inclusive and collective solutions to manage wildfire risk within a reflexive governance framework. The fourth research paper (Chapter 7) complements the above ground-based studies with a regional assessment of wildfire risk based on remotely sensed land cover, anthropogenic and climatic data. Maximum entropy was used as a probabilistic modelling approach to simulate future wildfire risk scenarios driven by different development trajectories, and assuming changing climatic conditions. Important determinants of wildfire risk were climate, road development, deforestation and density of human settlements. Positive feedbacks between rapid frontier expansion and drought conditions almost doubled potential biomass loss compared to estimates in the 2010 drought. Land used for agriculture and cattle ranching showed particularly high levels of wildfire risk, with serious implications for the subsistence and economy in the Chiquitania if the agricultural frontier is expanded at an accelerated rate. The combination of new findings and modelling tools developed in this thesis are relevant to inform wildfire risk management decisions in the Chiquitania. The timing is fitting as the regional government of Santa Cruz is developing a ten-year programme to address increased wildfire risk at the time of thesis submission, and the recently launched Regional Fire Platform promotes dialogue about possible solutions. More broadly, the approach to study wildfire as a social-ecological system has proven extremely useful to generate insights into different facets of a complex problem that is becoming a major concern in most of Amazonia and globally. This thesis generates important theoretical and practical contributions to the study of social-ecological systems, and provides a concrete example of how increasingly complex problems can be anticipated and managed under climate change and rapidly changing conditions with a more integrated and socially inclusive approach that can inform adaptation decisions for more sustainable futures.
168

Tourism policy, biodiversity conservation and management: a case study of the Kruger National Park, South Africa

Zhou, Leocadia January 2009 (has links)
The Kruger National Park (KNP) management has recently made considerable progress in enacting new policies to address biodiversity conservation and management challenges. However, the interlinkages among the new policies to support biodiversity conservation and management have not been evaluated, particularly the principles and approaches, and how these interact in terms of policy decision-making at the economic and political levels. This study seeks to evaluate the interlinkages among the new policies and how they affect one another, as an avenue to promote a more integrated and comprehensive policy implementation. These policies include the tourism policy, the elephant management policy, and the water provision policy. At policy-making level, the integration of these three policies enhances the possibilities for balancing and controlling the pressures exerted on environmental resources. At the implementation level, it offers a framework for the coordination of the interventions of the policies in space so as to recognise and capitalize on their synergies. Given the inevitably multifarious and departmentalized nature of policy formulation in the KNP, there is a need for the analysis of interlinkages amongst policies. The conceptual framework underpinning this study derives much from Briassoulis’ (2004) policy integration. The research utilizes both qualitative and quantitative research methods, and focuses on selected camp sites within the Park. The findings indicate that current procedures for tourism policy-making and implementation are weak, and little is done by way of impact assessment. This has been attributed to the lack of capacity at the KNP. The findings also reconfirm that policy-making is too fragmented. As a result, policy coordination and cooperation among park managers is weak. This study suggests that an environmental policy integration approach can lead to improved policy-making and implementation. Informed by the data collected from interviews, questionnaires and document analyses, a management framework has been developed to demonstrate how an integrated approach to Environmental Policy Integration (EPI) or management can help sustain the practice of wildlife tourism and support biodiversity conservation. It is concluded that greater realisation of integrated policy-making and implementation in the KNP can be achieved by establishing a formal coordinating office. However, a special feature of KNP policy-making is its widespread consultation system that can provide a fertile ground for enhancing EPI.
169

Současný výskyt světlíků ( Euphrasia ) v Krkonoších a zhodnocení vlivu doby seče na jejich početnost / Current occurrence of eyebright (Euphrasia) in the Krkonoše (Giant) Mountains and the evaluation of the effect of the time of mowing

Blahník, Jan January 2012 (has links)
At the time the Black and Red List of the Vascular Plants of the Krkonoše (Giant) Mountains was being compiled it was found that no information was available about the distribution of eyebright (Euphrasia) or other facts concerning this hemiparasite growing in the Krkonoše. The aim of this work was to fill the gap. This was to be done by creating a GIS layer with the current distribution of eyebright in the mountains, by analysing the soils taken in places of eyebright occurrence, in neighbouring places and those closely resembling them but without eyebright. The soils were taken each time from five places in the particular locality and were analysed as a mixed sample. In all, 107 mixed soil samples were taken, of which 53 in places where eyebright occurred and in 54 similar places where eyebright was absent. Eyebright grows in places with a higher pH and it performs better in lower available phosphorus concentration. Management test was used to test the earlier time of mowing meadows containing eyebright, when a larger number of flowering eyebright occurs among the plants in comparison with the number of flowering eyebright on surfaces mown at a later time.; Management testing was carried out from June to July 2011 in six localities, with five plots in each locality, in the Eastern and Western...
170

Understanding lək̓ʷəŋən soils: The foundation of environmental stewardship in coastal anthropogenic prairies

Lowther, Emma 20 July 2022 (has links)
Long-term human habitation introduces morphological and chemical changes to soil as a result of cultural, economic, and stewardship practices. These cultural soils, or Anthrosols, are recognized globally. On the Northwest Coast of North America, Indigenous marine and terrestrial land stewardship practices are recognized on present-day landscapes. Increased awareness of these stewardship practices is informed by Indigenous knowledge, ecological legacies, ethnographic studies, and archaeological evidence. This research was undertaken to better understand how lək̓ʷəŋən (Straits Salish) stewardship of a cultural landscape affected the development of soil across a village-garden gradient. On Vancouver Island, British Columbia, Indigenous cultivation of culturally important root foods was interrupted by colonization and its pervasive effects, so an additional research aim was to investigate how cultural soils remain after being disconnected from traditional stewardship. There is a growing global understanding that Indigenous management of ecosystems plays a key role in ecological health. At the regional scale, Songhees First Nation are interested in learning about their soils to inform future restoration efforts and connect youth with their land and culture. The lək̓ʷəŋən Ethnoecology and Archaeology Project (LEAP) is a collaborative research project with the Songhees First Nation to learn more about the physical remains of lək̓ʷəŋən stewardship: soils are a key part of the project. Community knowledge, ethnographic sources, and ecological legacies informed the archaeological excavation and soil sampling in this research. Archaeological excavation was utilized to understand the pedologic and archaeological setting of the site. Soil samples were analyzed for physical and chemical properties to see if a statistical difference between on and off-site samples could be detected. Data from the archaeological excavation were recorded and interpreted. A gradient of influence does exist across the village-garden; the village has a strong physical and chemical signature that can be seen through archaeological excavation, macroscopic remains in the soil, and elevated levels of phosphorous, calcium, and soil pH. Results from the garden are less clear, previous ecological studies and archaeological surveys show evidence of lək̓ʷəŋən stewardship—culturally important plant species and burial cairns are present. However, within the soil, the macroscopic remains and soil chemistry signatures are not as strong as the village which indicates that the health of lək̓ʷəŋən gardens facilitates their continued ecological functioning which ultimately may obscure earlier soil signatures of stewardship. Archaeological investigation alone does not always show the full scope of Indigenous terrestrial management practices. Incorporating present-day community knowledge, ecological legacies of plant cultivation, and utilizing soil chemical data are important to understanding the interconnections between people and their environments across cultural landscapes. Current work on the ecological legacies of plant cultivation can be assisted by investigating the soil as a site that also undergoes co-development with Indigenous stewardship. / Graduate

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