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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.
201

Effects of enclosure on home range and resource selection: a comparison of two African elephant herds (Loxodonta Africana Africana)

Leonard, Armand 12 June 2014 (has links)
Enclosed game reserves are at risk of local vegetation over-utilization and homogenization by elephant. Understanding how the elephant spatial distribution is coupled to their seasonal resources use can aid future management given the threat of climate change. A comparison of home ranges and core area sizes across seasons and years was made between an elephant herd outside in an open system, compared to the elephant inside Limpopo Lipadi Game and Wilderness Reserve (LLGWR). Location data, obtained by GPS-GSM technology, was used to determine seasonal home ranges and core areas by local convex hull (LoCoH) methods and to generate seasonal General Estimating Equations (GEE). Remote sensing data was used to determine habitat variables. The home ranges of the elephant herd outside as expected, was twice as large during summers and a third larger during winters than the elephant herd inside the fenced reserve. The influence of seasonal rainfall on home range size was reflected at home range scale for the outside herd and for the core area scale for the herd inside the reserve. Increased rainfall overcomes the ‗magnet effect‘ of artificial waterholes on elephant distribution in the landscape only in the open system. Inside the reserve, contrary to expectation the winter home ranges were non-significantly larger than summer home ranges due to space limitation induced by fencing and permanent artificial waterhole density. Resource use was evaluated by using GEE models at a scale larger than established home ranges and therefore would reflect as home range determinants. The study confirms that elephant do not use resources randomly. A scale in resource selection of elephant cows exists, with distance to drainage lines at small scale preferred during winter, with aspect, slope, elevation, and NDVI at larger scales. Fencing furthermore, affects the scale at which selection occurs by limiting resource availability, especially during resource restrictive periods and limits range expansion during resource abundant periods. Elephant cows prefer gentle terrain, close to permanent water [<1.77km (SD inside the reserve, and <2.33km ( outside the reserve], moderately high NDVI, riparian vegetation during late winter and early summer if available. Generally, during lower rainfall periods lower elevations are preferred along the elevation gradient, and during higher rainfall periods, higher elevations. The elephant herd outside the reserve, furthermore prefer aspects in the landscape during hot summers that are cooling and cool winter aspects that are warming to facilitate energy saving and thermoregulation. Key words: Elephant home range, core areas, fencing, seasonal, artificial waterholes, open system, NDVI, elevation gradient, distance to water, seasonal GEE modelling.
202

Movement ecology of gemsbok in the central Kalahari in response to vegetation greenness as assessed by satellite imagery

Relton, Claire E 22 January 2016 (has links)
Centre of African Ecology Animal, Plants and the Environmental Sciences University of the Witwatersrand, Johannesburg. / Arid African savannas experience seasonal, variable rainfall, resulting in unpredictable patterns in vegetation distribution. Understanding the spatio-temporal variability in primary productivity and the resulting behavioural responses of native herbivores is essential for the analysis of the vulnerability of savanna ecosystems to climatic and human-induced threats. The Central Kalahari Game Reserve (CKGR), Botswana, is open to free-ranging wildlife to its south and west. The mostly homogeneous dune landscape is interspersed with valley and pan systems, which deviate considerably from dune regions in their soil and vegetation structures. I assessed the phenology of green vegetation across the pan-valley and dune habitats of the northern CKGR, using Normalized Difference Vegetation Index (NDVI) imagery, and related variations in greenness to the ecology of gemsbok (Oryx gazella), a herbivore species that is highly adapted to arid conditions. Eight female gemsbok were collared in the northern CKGR, and their patterns of habitat selection and responses to three greenness measures (NDVI, ΔNDVI and Relative Greenness) were assessed using logistic regression models. Gemsbok 12-hour displacement distances for each herd were compared seasonally to assess whether gemsbok in the northern CKGR differ in their movement strategies depending on the prevailing environmental conditions at that point in time and space. The northern CKGR experiences high inter-annual variability in NDVI greenness and phenology. Pan-valley and dune habitats did not have significantly different rates of green-up or green season durations, but dune habitats had higher NDVI levels. Patches with the highest greenness levels showed little spatial persistence from year to year. Gemsbok did not select for higher NDVI or ΔNDVI, but they selected for categories of relative greenness that were higher than the lowest relative greenness level. Gemsbok selected pan-valleys over dunes during the green season, but were not selective during the brown season, probably as a result of the loss of green grasses in pan-valley habitats during this period. Finally, gemsbok had no specific general trend in seasonal displacement distances. Gemsbok in the CKGR are likely to be opportunistic feeders, and herds probably made varying behavioural decisions based on their immediate environmental conditions.
203

The Euro as an International Currency: An Evaluation of the Challenge to the Dollar Based on Currency Reserves and the Exchange Rate

Kouznetsova, Ekaterina January 2007 (has links)
Thesis advisor: Matteo Iacoviello / Since its launch, the euro has successfully achieved the status of an international currency, and the prospect of its ability to challenge the dollar is increasingly credible. This paper supplements the ongoing academic discussion by reevaluating the characteristics necessary for such a position in light of the most recent information available on the euro area, and then providing econometric evidence as support. I regress the lags of shares of dollar and euro reserves on the current shares and predict steady state values for each currency. I then regress the same lags, as well as the exchange rate lag, on the change in the euro/dollar exchange rate. I find, first, that the share of euro reserves, while still not as high as the share of dollars, is nonetheless significant: about 26%. Second, the euro/dollar exchange rate is only slightly affected by changes in the share of either currency's reserves. I conclude that confidence in the euro as an alternative international currency is growing, and that the euro has become a real challenge to the dollar. / Thesis (BA) — Boston College, 2007. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Economics. / Discipline: College Honors Program.
204

Zlatá rezerva Centrální banky a cenová stabilita / Gold in Central Bank Reserves and Price Stability

Melnychuk, Olena January 2019 (has links)
There is a traditional view that central banks should hold enough gold in their reserves to be considered financially secure and keep low inflation. However, after the fall of the Bretton-Woods system, many central banks have been decreasing its gold reserves by converting gold into other assets and still they do not experience high inflation. This thesis aims to answer the question if gold reserves of central banks indeed positively affect price stability. We use the panel data for 110 countries for the period from 2000 to 2016. We find that there is a significant negative effect of central banks' gold reserves on inflation but only if we control the proxy variables for the financial strength of central banks. Furthermore, the significance holds only for the inflation-targeting countries, there are no significant effects for the whole data sample. JEL Classification: E31, E52, E58, F41, G11, G21 Keywords: Gold reserves, Central Banks, Inflation rate, Price Stability Author's e-mail: 73099909@fsv.cuni.cz Supervisor's e-mail: tomas.havranek@fsv.cuni.cz
205

Marine Reserves: Do they bring net Benefits to Economies? / Přináší mořské rezervace čistí užitek národním ekonomikám?

Tyl, Michal January 2007 (has links)
Although more than 1300 marine reserves have already been established around the world, they still present a relatively new tool for environmental conservation and fisheries management. In accordance with this new approach towards marine protection, conservationists currently call for rapid establishment of a reserve network, which would encompass 10% to 30% of the oceans. Representative habitats from coastal areas as well as high seas would be included. Such a network should serve as a haven for marine species, ensuring their sustainability and aiding them to recover from fishery pressure. Furthermore, reserves are expected to enhance yields to the fishing industry through spillover and larval export. The paper attempts to determine, whether and under which conditions do marine reserves bring net benefits to economies.
206

The contribution of Multi-tenure reserve networks to biodiversity conservation.

Fitzsimons, James Andrew, mikewood@deakin.edu.au January 2004 (has links)
A consistent and integrated approach to nature conservation across the landscape and regardless of tenure is widely recognised as essential in ensuring the effective conservation of biodiversity. 'Multi-tenure reserve networks', which incorporate public and private lands managed for conservation, are considered a means of achieving landscape scale conservation. Biosphere Reserves (BR) and Conservation Management Networks (CMN) are characteristic models in Australia. This thesis aims to evaluate the role of such networks in protecting biodiversity, specifically by: (1) analysing the spatial configuration (size, shape, connectivity) of networks and their individual components; (2) evaluating the contribution of networks (in real terms and in reporting procedures) to biodiversity conservation objectives; (3) analysing the influence of the attitudes and perceptions of land managers on the functionality of networks; and (4) evaluating the influence of coordinating bodies on network functionality. In order to account for deficiencies in existing classifications of conservation lands, a new classification system was developed for this thesis - the Conservation Lands Classification. This classification incorporates conservation mechanisms on public and private lands and forms the basis for comparing network components in three Australian case studies - the Bookmark BR located in the Murray Mallee of South Australia, the Gippsland Plains CMN on the eastern Gippsland Plains of Victoria and the Grassy Box Woodlands CMN across the inland slopes of New South Wales. The spatial configuration of individual components within networks was measured using spatial analysis techniques within a geographic information system (GIS). GIS was also used to measure the contribution that networks made to a comprehensive, adequate and representative reserve system through the ecosystems they protected. The attitudes and perceptions of landowners and managers within the networks were obtained using questionnaires. Questionnaires were also sent to network coordinators. Statistical and descriptive analysis was conducted on the results. The sizes of individual components varied markedly between the three networks, however within each network public reserves were on average larger than private conservation lands. Although levels of physical connectivity varied between networks, Bookmark BR and Gippsland Plains CMN showed greater similarity to each other than to the Grassy Box Woodlands CMN. The findings raise important questions about the real and perceived differences in the BR and CMN models. All networks, and particularly those components outside the public protected area estate, contributed to enhancing the protection of ecosystems unrepresented or under-represented in the reserve system, although the extent of this contribution varied between networks. Trade-offs between reserve design efficiency and a contribution to a comprehensive, adequate and representative reserve system were evident between networks. Bookmark BR was characterised by high connectivity, strong reserve design integrity but a lower contribution to protecting under-reserved ecosystems, whereas the opposite was evident in the Grassy Box Woodlands CMN. Over 88% of managers considered their involvement in multi-tenure reserve networks to be a positive or very positive experience. A lack of resources and time for management were considered major limitations of these networks. The majority (80%) of private land managers within networks were willing to be included in a national reserve system of conservation lands. This has important implications for the Australian National Reserve System, which currently incorporates mostly public land. The changing nature of the network coordination arrangements suggests an organic fluid evolution of network structures is likely, contrasting with the desire for legalistic and administrative rigidity promoted by government agencies. The thesis concludes that all the networks studied contribute in varying degrees to biodiversity conservation. The key factors influencing the current and potential contribution that such networks make are: (1) the aims, directions and restrictions set by or imposed upon the coordinating body; and (2) the biophysical nature of the surrounding bioregion and resultant historical land use and tenure pattern. Although the successful operation of such 'multi-tenure' networks ultimately relies on the willing participation of private landholders, ongoing institutional support is likely to be required for maintaining networks in the longer term. Considering networks are increasingly formed outside of the influence of government institutions, this presents a significant challenge for effective coordinated conservation.
207

A bioeconomic analysis of marine reserves for Paua (Abalone) management at Stewart Island, New Zealand

Schneider, Viktoria, n/a January 2006 (has links)
Marine reserves have increasingly been recognised for their potential to address the pervasive problem of unsustainable harvest of fisheries worldwide. Biologists advocate the benefits of increased spawning biomass, larger modal sizes and greater densities of fish within marine reserves, and the possibility of spillover to adjacent fishable areas. Bioeconomic studies, however, find that pay-offs from stand-alone marine reserves rarely compete with sustainable yield management schemes, but that they can be beneficial when stocks are heavily exploited. Most of these bioeconomic models are analytical and deterministic in nature, and therefore ignore the redistribution of effort in response to closure and the inherent uncertainty of the marine environment. We present a bioeconomic analysis of a network of no-take areas around Stewart Island in New Zealand applied to the shellfish species paua (abalone) that incorporates both predicted redistribution and reduction in effort, as well as stochastic recruitment. A nested logit model is applied to spatially recorded catch and effort data by the Ministry of Fisheries between 1998 and 2003 to capture the two level decision-making process of divers. On any given day, divers decide whether to go diving at all, and if so, which of the 16 statistical areas around Stewart Island to visit. Weather conditions, spatially varying levels of catch per unit of effort and distance are used as explanatory variables to select areas for closure according to the �least economic impact� in terms of loss of diving trips. An age-structured biological model is developed with parameters specifically applied to paua stocks around Stewart Island. Virgin paua biomass as of 1974 is estimated on the basis of growth, survival, post-larval recruitment and egg production in the absence of fishing. Historic catch rates are then applied to find overall and area-specific levels of exploitation rates, spawning biomass, egg production, legal biomass and numbers of paua. In a final step, the economic model is linked to the biological model to simulate the imposition of no-take areas when taking account of the initial disproportional shift of harvest to fished areas in the first year, and the increase in overall pressure on legal biomass in the years thereafter. We contribute to the marine reserve debate by showing that in the very long run, the overall yield under closure of a relatively small area approaches and even slightly surpasses the yield under no closure for an assumed spillover gradient of 40% despite the redistribution of effort. The most important benefits of marine reserves emerge when stochastic recruitment is included in the recruitment function. In practice, predictions about the stock status and the impact of different harvest levels become much more difficult when acknowledging the inherent variability of the marine environment. The likelihood of stock collapse depends on the assumed value of two recruitment parameters, which highlights the effects of parameter uncertainty and emphasizes the role of marine reserves for population persistence. We also show that under uncertainty average yields under a management regime of a network of no-take areas in addition to the quota system can equal yields under no closure for an assumed spillover gradient of 40%, despite the increased pressure on areas adjacent to the closed areas. Our findings have significant implications for the management of the paua fishery at Stewart Island. For a heterogeneously abundant species, such as paua, spatial management in addition to quota limits could be vital in ensuring the long-term sustainability of the fishery given the inherent variability of the marine environment.
208

Struggle over land and lines mapping and counter-mapping Utah's San Rafael swell /

Durrant, Jeffrey O., January 2001 (has links)
Thesis (Ph. D.)--University of Hawaii at Manoa, 2001. / Includes bibliographical references (leaves 334-348). Also available on microfiche.
209

Multi-Scale Patch Dynamics of Coral Communities: A Cross-Caribbean Investigation Using a Landscape Ecology Approach

Huntington, Brittany 12 October 2011 (has links)
The overarching objective of this dissertation was to improve our knowledge of the relationship between seascape heterogeneity and diversity of stony coral assemblages across spatial scales. Coral communities on patch reefs in three regions of the Caribbean were used as a model system to investigating this relationship because patch reef heterogeneity could be readily quantified within the seascape using remote sensing and image analysis techniques. I began with a theoretical approach, exploring the origins of observed species diversity among coral communities at increasing spatial scales. Hierarchical sampling and null models revealed that coral diversity was governed by non-random processes at local- (10s of meters) and meso- (100s of m) scales. Spatial autocorrelation and reef heterogeneity were then investigated as potential mechanistic drivers of these non-random diversity patterns. I found limited support for spatial drivers. However, beta diversity was significantly correlated to metrics of reef heterogeneity (measured as reef size, spatial configuration, and complexity), indicating that differences in reef heterogeneity were making a disproportionate contribution to the overall coral community diversity. The relationship between corals and reef heterogeneity was found to be both scale-dependent and region dependent. This theoretical approach was followed by a manipulative approach using an existing artificial patch reef array to experimentally test the influence of reef spatial configuration and topographical complexity on local diversity. Corals were most sensitive to reef size and secondarily reef configuration within the seascape. Unlike reef fishes, reef complexity did not emerge as a strong predictor of the coral community composition in either the observational data or the experimental manipulation. These observational and experimental explorations of the relationship between corals and habitat reveal that intra-habitat variability (i.e. differences between patch reefs) can influence the diversity and abundance of corals. I then focused on applying this improved theoretical understanding towards improving coral management efforts. I present a new methodology to assess the efficacy of marine reserve effects by controlling for natural seascape variation within and beyond the reserve boundary, and I quantified the bias of underestimating coral diversity by using conventional reef monitoring protocols that ignore differences in reef size. In conclusion, I demonstrate empirically that seascape attributes of reef heterogeneity can contribute to coral diversity at relatively small spatial scales (<1km) and can affect corals with different life history traits in different ways. Hence, management and conservation efforts must consider the role of these meso-scale spatial metrics to influence the structure of the coral assemblage at the local scale.
210

Evaluating ecotourism in Mexico’s biosphere reserves – whale watching activities in the World Heritage Site of Laguna San Ignacio, Baja California Sur, Mexico, 1994-2002

Rossing, Peter 11 1900 (has links)
A descriptive case study approach and 34 indicators was used to examine the socio-economic impacts of whale watching tourism in the Laguna San Ignacio (LSI) World Heritage Site - located within the El Vizcaino Biosphere Reserve in Baja California Sur, Mexico. The framework measured both the socio-economic changes, and the economic viability of the local and regional operators. This approach led to a detailed understanding of the underlying, and often complex, inter-related factors that shaped the ecotourism development in LSI between 1994 and 2002. It identified strengths and weaknesses of current ecotourism development making it a valid tool for evaluating and improving these activities in any biosphere reserve. More specifically the objectives were to examine: 1. How existing ecotourism operations and their activities in the LSI have changed since 1994; 2. Whether these changes have made ecotourism a more viable socio-economic development alternative for the local communities; and 3. Which strategies may be useful in overcoming identified barriers to further socio-economic benefits both from existing and future ecotourism activities. The results strongly suggested that the benefits from ecotourism improved significantly between 1994 and 2002. Economically this was reflected in growth of visitor numbers (50%), employment (100%) and local and regional revenue approximately 70% (or 55% in real terms adjusting for inflation). Social benefits were seen in more cooperation among previous antagonistic stakeholders; a wider distribution of ecotourism benefits; some improvement in living standards and increasing local support for the Reserve. Politically, local stakeholders became more empowered through involvement in tourism related management activities. The viability of the local and regional operators also improved significantly as they became more sophisticated in their product offerings, enhanced their facilities and gained a market share of ecotourism relative to the foreign operators. These improvements were particular true for the operators that sold package tours. However, the analyses also revealed a number of barriers with the most important ones being: • Unresolved historic land use conflicts over rights to land with ecotourism possibilities; • Lack of activities diversification possibilities outside the tourism season; • Stagnating visitor numbers; • Uneven business skills among operators; • Poor marketing and promotional efforts; • Insufficient ecotourism infrastructure; • A proposed ecotourism tax; • Low profit margin of the ecotourism operators; and • Lack of funding for further investments To alleviate these threats and barriers 13 general strategies were identified. An elaboration of these resulted in 39 concrete operational strategies on how potentially to implement them.

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