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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.
181

Resource use, competition, grazing behavior, and ecosystem invasion impacts of Pomacea maculata

Unknown Date (has links)
Invasion of exotic species is a global threat to native species, biological diversity, and ecological restoration projects. Pomacea maculata is a macrophyte herbivore often misidentified with one of the world’s most invasive and destructive exotic snail, Pomacea canaliculata, but has a broader geographical distribution and climate tolerance, and greater egg production. This research examines whether the exotic P. maculata and native Pomacea paludosa occupy identical vegetation communities, mechanisms of interference competition, grazing impact differences on Vallisneria americana and to develop an exploratory agent based model. This model uses historical and present data to project how differences between species in life history and grazing patterns can potentially impact South Florida ecosystems. This model examined how P. maculate invasion of South Florida could affect two of the Central Everglades Planning Project’s main environmental restoration goals: function of key vegetative communities and conservation of endangered or threatened species. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
182

Demographic characteristics of lion (Panthera leo) in the Kalahari Gemsbok National Park

Beukes, Barend Otto January 2016 (has links)
Thesis (MTech (Nature Conservation))--Cape Peninsula University of Technology, 2016. / Lions are threatened across their natural range. The Kgalagadi Transfrontier Park (KTP), comprising the Kalahari Gemsbok National Park (KGNP; South Africa) and Gemsbok National Park (GNP; Botswana), is a stronghold for the species. Population size and demography of lions in the KGNP has been addressed in four historic studies. Studies in mid-1970 and 1990 reported a female biased population whereas in 2010 the sex structure was skewed towards males (56%). The bias in sex ratios towards males was first observed in cubs and sub-adults in 2001 and later, in 2010, throughout the population. Furthermore, in the 2010 assessment of the lion population, a smaller proportion of cubs (< 2 yrs) were observed in comparisons to the preceding studies (10% vs. ≥ 23%). The skew in age and sex structures that were observed in the KGNP led to concerns over the long-term sustainability of the greater KTP lion population. The lion population carries further risks associated with the stochastic, arid environment, in which the KTP lion population persists. Human-lion conflict on the borders of the KTP and anthropogenic alterations of the environment further threaten lion demographic stability.
183

<i>In Rhizomia</i> : Actors, Networks and Resilience in Urban Landscapes

Ernstson, Henrik January 2008 (has links)
<p>With accelerating urbanization it is crucial to understand how urban ecosystems play a part in generating ecosystem services for urban dwellers, such as clean water, spaces for recreation, stress relief and improved air quality. An equally important question relate to who gets to enjoy these benefits, i.e. the distribution of ecosystem services, and how issues of power and equity influence the management of ecosystems. Through case studies from the urban landscape of Stockholm, this doctoral thesis engages with these perspectives through combining ecological theory with social theory, including social network analysis, actor-network theory and social movement theory. Strategies for how to improve urban ecosystem management are presented along with frameworks for how to analyze issues of power and equity in relation to natural resource management.</p><p><b>Paper I </b>shows that ecosystem management can be studied through analyzing the structure of social networks, i.e. the patterns of relations between agencies, stake-holders and user groups. <b>Paper II</b> and <b>Paper III</b> analyze, based on a network survey of 62 civil society organizations and in-depth interviews, a transformational process of how an urban local movement managed to protect a large urban green area from exploitation (The Stockholm National Urban Park). <b>Paper IV</b> discusses, based on several case studies from Stockholm, a conducive network structure for linking managers and user groups (e.g. allotment gardens, cemetery managers, and urban planners) across spatial ecological scales so as to improve urban green area management. <b>Paper V</b> presents a framework to analyze the social-ecological dynamics behind the generation and distribution of ecosystem services in urban landscapes.</p><p>The thesis points towards the notion of "a social production of ecosystem services" and argues for deeper engagement with urban political ecology and critical geography to inform governance and collective action in relation to urban ecosystems.</p>
184

Applied ecosystem services in working forests: A direct market valuation

Hale, Darin Stuart 01 December 2010 (has links)
Ecosystem services, or the benefits humans obtain from natural ecosystems, have long been recognized as critical to human health. Efforts have been taken by many to determine the non-market values of these services but few have offered a direct market valuation. Increasing awareness, scarcity, and regulation have fostered transactions, and markets are emerging that can allow for direct valuation and could provide landowners the opportunity to merchandise this natural capital. This paper provides a valuation and comparison, as a case study, of a traditional management scheme, including the marketing of fiber and recreational leases, and an ecosystem services management scheme, including the marketing of fiber, recreational leases, carbon sequestration, watershed services, and biodiversity. The traditional forest management scheme had an estimated present value at three pricing scenarios ranging from “pessimistic” at $538,714.63 to “optimistic” at $868,528.27 for the entire 3,976-acre project area. The ecosystem services management scheme had an estimated present value at three pricing scenarios ranging from “pessimistic” at $621,508.61 to “optimistic” at $1,363,628.13 for the entire 3,976-acre project area. This paper concludes that even in these early stages of ecosystem markets, an ecosystem services management scheme may offer more revenue to landowners than a traditional management scheme.
185

In Rhizomia : Actors, Networks and Resilience in Urban Landscapes

Ernstson, Henrik January 2008 (has links)
With accelerating urbanization it is crucial to understand how urban ecosystems play a part in generating ecosystem services for urban dwellers, such as clean water, spaces for recreation, stress relief and improved air quality. An equally important question relate to who gets to enjoy these benefits, i.e. the distribution of ecosystem services, and how issues of power and equity influence the management of ecosystems. Through case studies from the urban landscape of Stockholm, this doctoral thesis engages with these perspectives through combining ecological theory with social theory, including social network analysis, actor-network theory and social movement theory. Strategies for how to improve urban ecosystem management are presented along with frameworks for how to analyze issues of power and equity in relation to natural resource management. <b>Paper I </b>shows that ecosystem management can be studied through analyzing the structure of social networks, i.e. the patterns of relations between agencies, stake-holders and user groups. <b>Paper II</b> and <b>Paper III</b> analyze, based on a network survey of 62 civil society organizations and in-depth interviews, a transformational process of how an urban local movement managed to protect a large urban green area from exploitation (The Stockholm National Urban Park). <b>Paper IV</b> discusses, based on several case studies from Stockholm, a conducive network structure for linking managers and user groups (e.g. allotment gardens, cemetery managers, and urban planners) across spatial ecological scales so as to improve urban green area management. <b>Paper V</b> presents a framework to analyze the social-ecological dynamics behind the generation and distribution of ecosystem services in urban landscapes. The thesis points towards the notion of "a social production of ecosystem services" and argues for deeper engagement with urban political ecology and critical geography to inform governance and collective action in relation to urban ecosystems.
186

Nurturing resilience in social-ecological systems : Lessons learned from bridging organizations

Schultz, Lisen January 2009 (has links)
In an increasingly complex, rapidly changing world, the capacity to cope with, adapt to, and shape change is vital. This thesis investigates how natural resource management can be organized and practiced to nurture this capacity, referred to as resilience, in social-ecological systems. Based on case studies and large-N data sets from UNESCO Biosphere Reserves (BRs) and the UN Millennium Ecosystem Assessment (MA), it analyzes actors and social processes involved in adaptive co-management on the ground. Papers I &amp; II use Kristianstads Vattenrike BR to analyze the roles of local stewards and bridging organizations. Here, local stewards, e.g. farmers and bird watchers, provide on-site management, detailed, long-term monitoring, and local ecological knowledge, build public support for ecosystem management, and hold unique links to specialized networks. A bridging organization strengthens their initiatives. Building and drawing on multi-level networks, it gathers different types of ecological knowledge, builds moral, political, legal and financial support from institutions and organizations, and identifies windows of opportunity for projects. Paper III synthesizes the MA community-based assessments and points to the importance of bridging organizations, leadership and vision, knowledge networks, institutions nested across scales, enabling policies, and high motivation among actors for adaptive co-management. Paper IV explores learning processes catalyzed by bridging organizations in BRs. 79 of the 148 BRs analyzed bridge local and scientific knowledge in efforts to conserve biodiversity and foster sustainable development, provide learning platforms, support knowledge generation (research, monitoring and experimentation), and frame information and education to target groups. Paper V tests the effects of participation and adaptive co-management in BRs. Local participation is positively linked to local support, successful integration of conservation and development, and effectiveness in achieving developmental goals. Participation of scientists is linked to effectiveness in achieving ‘conventional’ conservation goals and policy-makers enhance the integration of conservation and development. Adaptive co-management, found in 46 BRs, is positively linked to self-evaluated effectiveness in achieving developmental goals, but not at the expense of conservation. The thesis concludes that adaptive collaboration and learning processes can nurture resilience in social-ecological systems. Such processes often need to be catalyzed, supported and protected to survive. Therefore, bridging organizations are crucial in adaptive co-management.
187

Assessing community capacity for ecosystem management : Clayoquot Sound and Redberry Lake biosphere reserves

Mendis, Sharmalene Ruwanthi 29 October 2004
Biosphere reserves are regions that are internationally recognized for their ecological significance and work towards ecosystem management. The concept of community capacity, as developed in the resource management and health promotion literatures, was applied to two such regions that were designated in 2000: Clayoquot Sound and Redberry Lake. The purpose of this comparative research was to better understand what constitutes the collective ability, or community capacity, these places have for fulfilling their functions as biosphere reserves. Community capacity is the collective mobilization of resources (ecological, economic/built, human and social capitals) for a specified goal. A mixed methods approach was taken. Self-assessments, both qualitative and quantitative, were used to determine community capacity in focus groups with biosphere reserve management, residents, and youth (grades 9-12). The results were compared to a statistics-based assessment of socioeconomic well-being. Semi-structured interviews for a related research project provided further insight. This comparative research made theoretical advancements by identifying key constituents of community capacity, including dimensions of the capitals and mobilizers, or factors that motivate people to work for communal benefit. Mobilizers were found to be key drivers of the process of using and building community capacity. Four mobilizer categories were identified: the existence of, and changes to capital resources; individual traits; community consciousness; and, commitment. The practical implications of applying both qualitative and quantitative assessment methods were examined. It was found that there are several ways to conduct the socioeconomic assessment, and that adaptive methodological application is advised in research that attempts to be truly community-basednot just about, but for and with communities. It was found that, while it does not ensure a biosphere reserves success, economic capital plays a key role in activating other resources beyond a time frame of three years, where social capital can be the primary driver for activity. Despite substantial differences politically, socially, and economically, both regions experienced similar challenges that can be largely attributed to a general lack of understanding of the biosphere reserve concept, and a lack of consistent, core funding.
188

Estudio de la pesca artesanal en el entorno de la reserva marina de Cabo de Palos – Islas Hormigas. Estrategias de pesca, efecto de la protección y propuestas para la gestión

Esparza Alaminos, Oscar 19 November 2010 (has links)
Los objetivos de la tesis fueron estudiar los factores que pueden explicar la variabilidad existente en la distribución e intensidad de la pesca artesanal en torno a una reserva marina (RM), valorar el efecto de la protección sobre la pesca y analizar y valorar los efectos bio-económicos de configuraciones alternativas de diseño y gestión. Los resultados revelaron que las embarcaciones artesanales calan más artes, de menor longitud, en zonas de elevada diversidad de hábitats. El rendimiento pesquero depende del nivel de protección, la distancia a la RM y la diversidad de artes por unidad de área. La protección está teniendo resultados positivos sobre las poblaciones de peces explotadas y beneficiando a la economía local. El aumento de superficie protegida, distribuido en varias reservas integrales en emplazamientos adecuados, distanciadas unas decenas kilómetros, más que la reducción del esfuerzo, tendría efectos positivos sobre el poblamiento de peces y la economía local. / The aim of the present work is to study the factors that may explain the variability in distribution and intensity of artisanal fishing around a marine reserve, evaluate the reserve effect and analyze and assess the biological and economic effects of alternative configurations of a marine protected area. The results revealed that artisanal vessels used more fishing gears, but shorter, in high habitat diversity areas. The fishing yield depends of protection level, distance to marine reserve and diversity of fishing gears per unit area. The protection measures have had positive results on exploited fish populations and in the local economy. The increase of protected area surface, distributed on several no take zones at appropriate locations, a few kilometers apart, more than the reduction of the fishing effort, would have positive effects on the population of commercial fishes and the local economy.
189

Assessing community capacity for ecosystem management : Clayoquot Sound and Redberry Lake biosphere reserves

Mendis, Sharmalene Ruwanthi 29 October 2004 (has links)
Biosphere reserves are regions that are internationally recognized for their ecological significance and work towards ecosystem management. The concept of community capacity, as developed in the resource management and health promotion literatures, was applied to two such regions that were designated in 2000: Clayoquot Sound and Redberry Lake. The purpose of this comparative research was to better understand what constitutes the collective ability, or community capacity, these places have for fulfilling their functions as biosphere reserves. Community capacity is the collective mobilization of resources (ecological, economic/built, human and social capitals) for a specified goal. A mixed methods approach was taken. Self-assessments, both qualitative and quantitative, were used to determine community capacity in focus groups with biosphere reserve management, residents, and youth (grades 9-12). The results were compared to a statistics-based assessment of socioeconomic well-being. Semi-structured interviews for a related research project provided further insight. This comparative research made theoretical advancements by identifying key constituents of community capacity, including dimensions of the capitals and mobilizers, or factors that motivate people to work for communal benefit. Mobilizers were found to be key drivers of the process of using and building community capacity. Four mobilizer categories were identified: the existence of, and changes to capital resources; individual traits; community consciousness; and, commitment. The practical implications of applying both qualitative and quantitative assessment methods were examined. It was found that there are several ways to conduct the socioeconomic assessment, and that adaptive methodological application is advised in research that attempts to be truly community-basednot just about, but for and with communities. It was found that, while it does not ensure a biosphere reserves success, economic capital plays a key role in activating other resources beyond a time frame of three years, where social capital can be the primary driver for activity. Despite substantial differences politically, socially, and economically, both regions experienced similar challenges that can be largely attributed to a general lack of understanding of the biosphere reserve concept, and a lack of consistent, core funding.
190

Plants in the garden: an approach to modeling the impact of industrial activities in ecosystems

Reap, John J. 09 April 2004 (has links)
Humanity's interactions with the supporting environment are, to state the obvious, complex. Humanity's industrial activities effect the environment over time and space, and the same activities even produce different results in different locations. Since the complexities of these interactions may preclude the successful use of eco-performance metrics, humanity may need a means of informing environmental management decisions that accounts for changes with time, spatial patterns and local uniqueness. The objective of this effort is to interface engineering and ecological systems models to better estimate environmental impacts by modeling the dynamic, spatially explicit and location dependent changes caused by industrial activities. Building upon previously developed, dynamic, spatially explicit, location specific ecosystem modeling software, a technical framework for estimating the impacts of industrial systems in ecosystems is developed. Ecological disturbances endemic to engineering systems are integrated into these existing ecosystem models. The results of these integrations are discussed, and from these results, the potential for estimating impacts using dynamic, spatially explicit and location based modeling is evaluated. In other words, one learns the result of placing industrial plants in mother natures garden.

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