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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.
61

Impact of fire in the taiga of southeastern Manitoba on wildlife, vegetation, and value to resource users

Martin, H.V.P. 23 October 2013 (has links)
During the summer of 1982, trapping and vegetation surveys were carried out on permanent study plots within 6 of 7 different types of plant communities within the South-eastern Manitoba Taiga, which had been subjected to fire in May of 1980. A unique feature of this study area was the existence of an 8 year pre-fire data base. A total of 129 mammals, 123 of which are typified as "small mammals" were captured in 2100 trap nights. The number captured in each plant community were as follows: Jack Pine Ridge 19, Alder Jack Pine Ecotone 30, Alder Tamarack Bog 20, Jack Pine Sand Plain 5, Black Spruce Bog 5, Aspen Upland 21, Black Spruce Tamarack Bog 29. Pre-fire small mammal data for the permanent study plots were available, and up to ten years of data were used for comparative evaluation of fire effects. The effects of the fire vary according to the severity of the burn, but small mammal population numbers and biomass estimates for most plots increased the fall immediately after the burn, and then dropped in 1981. Specifically, Clethrionomys gapperi and Peromyscus maniculatus increased with the fire, and Sorex cinereus continued to fluctuate. Three growing seasons after the fire, population numbers and biomass estimates have declined, but are equal to or above minimum pre-fire levels. The effects of fire on other local wildlife, such as ungulates, fur bearers, and birds are discussed briefly. Current vegetation data were compared with pre-fire data and some basic post-fire reproductive strategies were observed. Pioneer or fugitive species with numerous light-weight wind-disseminated seeds, or those with Long-lived seeds stored in soil seed banks, which grow and mature rapidly were present. Frugivores are also suspected to have been an agent of post-fire seed dispersal. Vegetative reproduction through root sprouting or suckering was a dominant strategy observed on some plots. Relatively slow growing, late maturing species with larger, heavier seeds were also observed, and these are expected eventually to regain their upper canopy status. In an attempt to place a dollar value on the study area, the user's willingness to pay for benefits from use of the resources of the area, was combined with the potential attainable revenue from exploitation of local resources. The combined value is calculated to be in excess of $597,208.93. Interest in timber resources 80 years hence could present a conflict for land use management. It is recommended that the Taiga Biological Station study area be protected in its natural state, with controlled educational, research, traditional, and recreational activities permitted.
62

Towards ecosystem-based management of shellfish aquaculture in British Columbia, Canada: an industry perspective.

Mamoser, Melanie Paula 31 August 2011 (has links)
With declining wild fisheries and increasing seafood demand from a growing population, attention has turned to aquaculture in general, and shellfish aquaculture in particular, to meet this demand. Aquaculture has grown dramatically in the last twenty years through intensification of operations and the expansion of the industry into new areas. This growth has been associated with environmental degradation and social conflict leading some to question its sustainability. However, those studying the problem point to significant opportunities for sustainable forms of aquaculture by focusing on the cultivation of species such as shellfish and the adoption of ecosystem-based management (EBM). Shellfish aquaculture has a long history in British Columbia (B.C.), Canada with an abundance of coastline and suitable water conditions. There is significant development potential for shellfish aquaculture in B.C., which creates an opportunity to ensure this development occurs in an ecologically sound way through the use of governance approaches like ecosystem-based management. Transitioning from conventional approaches to resource management to an ecosystem-based approach presents several challenges particularly for the management of one sector. This study highlights how an understanding of the industry and the existing governance context can inform the implementation of EBM. The specific research objectives include: (1) to understand the governance system for shellfish aquaculture in B.C.; (2) to understand the shellfish aquaculture industry within the context of EBM; and (3) to explore EBM as an approach to governance in the shellfish aquaculture industry in B.C. The main method of inquiry is a questionnaire survey (October 2006 to February 2008) of the shellfish aquaculture industry. Supporting methods include an analysis of industry data, an in-depth analysis of government documents, policies and regulations, and targeted interviews with federal and provincial government regulators. The empirical knowledge gained through the main research instrument was combined with the contextual knowledge gained through the supporting methods to achieve a more holistic understanding of the case study. The results show that the governance setting for the shellfish aquaculture industry is multi-lateral and the lack of comprehensive and targeted legal instruments, and the ill-use of marine spatial planning and conflicts with other coastal users have together contributed to an inefficient and costly site application process. EBM has the potential to address some of these challenges with the current governance process by making some decisions on an ecosystem-scale as opposed to an application-by-application basis, such as assessing the presence of fish habitat and consulting with stakeholders. The results of the survey of the shellfish aquaculture industry show that the industry is geographically diverse, and understands and values the connection between their business and the large ecosystem. This suggests that the industry may be supportive of EBM. However, the industry faces many economic challenges that may influence their capacity to participate, as such regulators should look towards the use of economic incentives to achieve policy objectives. Although this research provided several recommendations for management and the industry in moving forward with this new approach to governance, three fundamental elements are needed: • marine spatial planning that is integrated within the governance framework; • the integration science and management through adaptive management including an ongoing monitoring framework that informs governance strategies; and, • engaging the industry as active partners in this governance approach through co-management. This research makes significant contribution to understanding the shellfish aquaculture industry in B.C. Prior to this study there was little information available characterizing the structure and socio-economic make-up of the industry. The results of the survey and the in-depth analysis of the governance context for the shellfish aquaculture industry provide a previously unavailable base of information from which to build future studies. In addition this research contributes to the growing body of literature on EBM assessing the potential challenges and opportunities for moving the theoretical concept into practice. / Graduate
63

The ecology, management and monitoring of wildlife populations in fragmented landscapes: A Koala case study

Rhodes, J. Unknown Date (has links)
No description available.
64

The ecology, management and monitoring of wildlife populations in fragmented landscapes: A Koala case study

Rhodes, J. Unknown Date (has links)
No description available.
65

Assessing the population dynamics and stock viability of striped trumpeter (Latris lineata) in a data limited situation

Tracey, SR Unknown Date (has links)
No description available.
66

Fisheries CPUE-Abundance Relationships: Examination using a Resource-Fisher Integrated Model

Sporcic, M Unknown Date (has links)
No description available.
67

Individual-based artificial ecosystems for design and optimization

Vulli, Srinivasa Shivakar, January 2008 (has links) (PDF)
Thesis (M.S.)--Missouri University of Science and Technology, 2008. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 18, 2008) Degree granted by Missouri University of Science and Technology, formerly known as University of Missouri-Rolla. Includes bibliographical references (p. 67-73).
68

Improving larval sea lamprey assessment in the Great Lakes using adaptive management and historical records

Anderson, Gretchen J. January 2006 (has links)
Thesis (M.S.)--Michigan State University, Dept. of Fisheries and Wildlife, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 89-95). Also issued in print.
69

Pollution of soils by lead and its uptake and pathways in the ecosystem

Eastwood, Ian Wynne January 1987 (has links)
The thesis reviews literature relating to lead in the environment with particular reference to the distribution and pathways of lead in the soil and plant ecosystem. Methods of conducting large area soil surveys and assessing the distribution of lead and other heavy metals including cadmium, copper and zinc are also examined. A survey was conducted over a 370 km2 area of North East Derbyshire, England. Maps showing the distribution of the metals reveal anomalously high concentrations related in many instances to past industrial activity. A simple reliable and rapid acid digestion procedure was developed and the procedure evaluated through an interlaboratory survey involving 22 laboratories. This demonstrated that analysts should seek to improve analytical performance through achieving better interlaboratory correlation rather than intralaboratory precision. A stratified random sampling protocol was developed and evaluated which allowed an estimate of precision to be placed on the results of the trace metal soil survey. An assessment was carried out of the contribution that lead fromaerially deposited dust and soil sources makes to the distribution of lead in potato plants. A micro sampling cup technique was developed which permitted (for the first time as far as can be ascertained) the analysis of lead in discrete sections of solid plant tissue from single plants grown under field conditions. This overcomes the problems of sensitivity which normally requires that samples are bulked or dosed with lead salts. Results are presented for the distribution of lead in potato plants grown in several field locations and in soils containing varying concentrations of lead. The major source of lead in the plants via the soil with aerial sources having a negligible effect on tissue distribution. Comparisons are made between results obtained by conventional flame atomic absorption spectrometry and the microsampling cup procedure.
70

Security and privacy in app ecosystems

Taylor, Vincent January 2017 (has links)
Smartphones are highly-capable mobile computing devices that have dramatically changed how people do business, interact with online services, and receive entertainment. Smartphone functionality is enhanced by an ecosystem of apps seemingly covering the entire gamut of functionality. While smartphone apps have undoubtedly provided immeasurable benefit to users, they also contribute their fair share of drawbacks, such as increases in security risks and the erosion of user privacy. In this thesis, I focus on the Android smartphone operating system, and pave the way for improving the security and privacy of its app ecosystem. Chapter 3 starts by doing a comprehensive study on how Android apps have evolved over a three-year period, both in terms of their dangerous permission usage and the vulnerabilities they contain. It uncovers a trend whereby apps are using increasing numbers of dangerous permissions over time and at the same time becoming increasingly vulnerable to attack by adversaries. By analysing the Google Play Store, Android's official app marketplace, Chapter 4 shows that many general-purpose apps can be replaced with functionallysimilar alternatives to the benefit of the user. This confirms that users still wield power to improve their own security and privacy. Chapter 5 combines this insight with real-world data from approximately 30,000 smartphones to understand the actual risk that the average user faces as a result of their use of apps, and takes an important first step in measuring the improvements that can be made. Users, however, are not always aware of the risks they face and thus Chapter 6 demonstrates the feasibility of a classification system that can transparently and unobtrusively identify and alert users to the presence of apps of concern on their devices. This classification system identifies apps from features in the network traffic they generate, without itself analysing the payload of their traffic, thus maintaining a high threshold of privacy. While the work presented in this thesis has uncovered undesirable trends in app evolution, and shows that a large fraction of users are exposed to non-trivial risk from the apps they use, in many cases there is suficient diversity in the offerings of general-purpose apps in the Google Play Store to empower users to mitigate the risks coming from the apps they use. This work takes us a step further in keeping users safe as they navigate and enjoy app ecosystems.

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