• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 7
  • 7
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Schriftenreihe des Forschungsverbundes KoReMi

Holländer, Robert 19 September 2014 (has links)
An den Universitäten Leipzig und Halle-Wittenberg ist ein Forschungsvorhaben mit dem Titel "Ziele und übertragbare Handlungsstrategien für ein kooperatives regionales Flächenmanagement unter Schrumpfungstendenzen in der Kernregion Mitteldeutschland" (KoReMi) angesiedelt. Vor dem Hintergrund demographischer Transformationsprozesse werden Leitbilder und Instrumente der Regionalentwicklung auf ihre Anwendbarkeit unter Nachhaltigkeitsgesichtspunkten untersucht und modifiziert. Das Projekt ist eingebunden in das Forschungsfeld "Forschung für die Reduzierung der Flächeninanspruchnahme und ein nachhaltiges Flächenmanagement (REFINA)" des Bundesministeriums für Bildung und Forschung (BMBF). Mit der Schriftenreihe des Forschungsverbundes KoReMi soll fortlaufend sowohl über das Projekt und seine wesentlichen Arbeitsergebnisse als auch über weiterführende Erkenntnisse der Fachdisziplinen berichtet werden. Die Kommunikation zwischen Wissenschaft und Praxis sowie auch zwischen den einzelnen wissenschaftlichen Disziplinen, die sich aus ganz unterschiedlichen Blickwinkeln mit den Problemen nachhaltiger Entwicklung von Regionen unter dem Vorzeichen von demographischer Transformation beschäftigen, soll mit dieser Schriftenreihe forciert und intensiviert werden.
2

Using shell morphology to characterise abalone populations across multiple spatial scales.

Saunders, Thor M. January 2009 (has links)
Many sedentary marine invertebrates have a fine-scale (100s m) population structure that complicates their conservation and management. This is a consequence of the limited information on the boundaries between component populations and the biological variability among them. Blacklip abalone (Haliotis rubra) form discrete populations many of which are ‘stunted’ with individuals reaching a maximum length less than those in adjacent areas. A range of morphological measurements from samples of stunted and ‘non-stunted’ H. rubra collected from sites spread across broad (10s km) and fine (100s m) spatial scales in southern South Australia. In addition, information on the growth, size at maturity and fecundity of H. rubra was obtained from these same sites. The ratio between shell length and shell height showed clear and significant differences among samples from stunted and non-stunted sites. The fine-scale morphometric collections suggested that stunted populations existed at smaller spatial scales compared to those for non-stunted populations. Spatial variation in these key life history parameters could primarily be attributed to differences between stunted and non-stunted sites. Relationships between each of these parameters and the ratio between shell length and shell height were also examined. The spatial patterns in morphology and biology were highly correlated suggesting that shell length:shell height ratio can be used as a simple ‘morphometric marker’ to distinguish among populations of abalone and identify their biological characteristics. The detection of differences H. rubra morphology among variable environments cannot determine whether these differences represent a plastic response to the local environment, or whether morphology is genetically fixed. A reciprocal transplant experiment was used to test whether stunted H. rubra are the result of a plastic response to the environment or fixed genetic trait. Furthermore, environmental factors that affect food availability were related to differences in morphology. Morphological plasticity was confirmed as the mechanism causing morphological variation in H. rubra. Individuals transplanted to sites with non-stunted H. rubra grew significantly faster when compared to stunted controls, while individuals transplanted to stunted sites grew significantly slower compared to non-stunted controls. It is suggested that these differences are related to resource availability with areas limited in food supply resulting in stunted populations and areas with abundant food resulting in non-stunted populations. To reduce the risks of over-fishing and localised depletion of H. rubra, management units (MUs) that encompass individual populations need to be determined and then managed according to their life-history characteristics. Potential MUs in the South Australian abalone fishery were identified from the broad-scale, spatial distribution of stunted and non-stunted populations of H. rubra, by applying the morphometric marker to commercial shell samples. Key life-history parameters of the H. rubra populations within the potential MUs were estimated using relationships between this marker and H. rubra biology. Data from fine-scale systematic sampling by commercial fishers were used to validate spatial patterns observed from the more broadly distributed commercial catch samples. The location, distribution and size of potential MUs were largely inconsistent with that of current management. The locations of two MUs were consistent across the broad- and fine-scale datasets with the fine-scale samples being more informative for identifying a potential boundary between these. These results suggest that this morphometric marker can used as a tool for the spatial management of abalone fisheries by simply and inexpensively inferring key biological parameters for individual populations and identify the boundaries among these based on these differences. This approach is among the first to provide a practical means of more closely aligning the scales of assessment and management with biological reality for sedentary marine invertebrates. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009
3

Using shell morphology to characterise abalone populations across multiple spatial scales.

Saunders, Thor M. January 2009 (has links)
Many sedentary marine invertebrates have a fine-scale (100s m) population structure that complicates their conservation and management. This is a consequence of the limited information on the boundaries between component populations and the biological variability among them. Blacklip abalone (Haliotis rubra) form discrete populations many of which are ‘stunted’ with individuals reaching a maximum length less than those in adjacent areas. A range of morphological measurements from samples of stunted and ‘non-stunted’ H. rubra collected from sites spread across broad (10s km) and fine (100s m) spatial scales in southern South Australia. In addition, information on the growth, size at maturity and fecundity of H. rubra was obtained from these same sites. The ratio between shell length and shell height showed clear and significant differences among samples from stunted and non-stunted sites. The fine-scale morphometric collections suggested that stunted populations existed at smaller spatial scales compared to those for non-stunted populations. Spatial variation in these key life history parameters could primarily be attributed to differences between stunted and non-stunted sites. Relationships between each of these parameters and the ratio between shell length and shell height were also examined. The spatial patterns in morphology and biology were highly correlated suggesting that shell length:shell height ratio can be used as a simple ‘morphometric marker’ to distinguish among populations of abalone and identify their biological characteristics. The detection of differences H. rubra morphology among variable environments cannot determine whether these differences represent a plastic response to the local environment, or whether morphology is genetically fixed. A reciprocal transplant experiment was used to test whether stunted H. rubra are the result of a plastic response to the environment or fixed genetic trait. Furthermore, environmental factors that affect food availability were related to differences in morphology. Morphological plasticity was confirmed as the mechanism causing morphological variation in H. rubra. Individuals transplanted to sites with non-stunted H. rubra grew significantly faster when compared to stunted controls, while individuals transplanted to stunted sites grew significantly slower compared to non-stunted controls. It is suggested that these differences are related to resource availability with areas limited in food supply resulting in stunted populations and areas with abundant food resulting in non-stunted populations. To reduce the risks of over-fishing and localised depletion of H. rubra, management units (MUs) that encompass individual populations need to be determined and then managed according to their life-history characteristics. Potential MUs in the South Australian abalone fishery were identified from the broad-scale, spatial distribution of stunted and non-stunted populations of H. rubra, by applying the morphometric marker to commercial shell samples. Key life-history parameters of the H. rubra populations within the potential MUs were estimated using relationships between this marker and H. rubra biology. Data from fine-scale systematic sampling by commercial fishers were used to validate spatial patterns observed from the more broadly distributed commercial catch samples. The location, distribution and size of potential MUs were largely inconsistent with that of current management. The locations of two MUs were consistent across the broad- and fine-scale datasets with the fine-scale samples being more informative for identifying a potential boundary between these. These results suggest that this morphometric marker can used as a tool for the spatial management of abalone fisheries by simply and inexpensively inferring key biological parameters for individual populations and identify the boundaries among these based on these differences. This approach is among the first to provide a practical means of more closely aligning the scales of assessment and management with biological reality for sedentary marine invertebrates. / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2009
4

Effective design of marine reserves : incorporating alongshore currents, size structure, and uncertainty

Reimer, Jody January 2013 (has links)
Marine populations worldwide are in decline due to anthropogenic effects. Spatial management via marine reserves may be an effective conservation method for many species, but the requisite theory is still underdeveloped. Integrodifference equation (IDE) models can be used to determine the critical domain size required for persistence and provide a modelling framework suitable for many marine populations. Here, we develop a novel spatially implicit approximation for the proportion of individuals lost outside the reserve areas which consistently outperforms the most common approximation. We examine how results using this approximation compare to the existing IDE results on the critical domain size for populations in a single reserve, in a network of reserves, in the presence of alongshore currents, and in structured populations. We find that the approximation consistently provides results which are in close agreement with those of an IDE model with the advantage of being simpler to convey to a biological audience while providing insights into the significance of certain model components. We also design a stochastic individual based model (IBM) to explore the probability of extinction for a population within a reserve area. We use our spatially implicit approximation to estimate the proportion of individuals which disperse outside the reserve area. We then use this approximation to obtain results on extinction using two different approaches, which we can compare to the baseline IBM; the first approach is based on the Central Limit Theorem and provides efficient simulation results, and the second modifies a simple Galton-Watson branching process to include loss outside the reserve area. We find that this spatially implicit approximation is also effective in obtaining results similar to those produced by the IBM in the presence of both demographic and environmental variability. Overall, this provides a set of complimentary methods for predicting the reserve area required to sustain a population in the presence of strong fishing pressure in the surrounding waters.
5

Schriftenreihe des Forschungsverbundes KoReMi

Holländer, Robert 19 September 2014 (has links)
An den Universitäten Leipzig und Halle-Wittenberg ist ein Forschungsvorhaben mit dem Titel 'Ziele und übertragbare Handlungsstrategien für ein kooperatives regionales Flächenmanagement unter Schrumpfungstendenzen in der Kernregion Mitteldeutschland' (KoReMi) angesiedelt. Vor dem Hintergrund demographischer Transformationsprozesse werden Leitbilder und Instrumente der Regionalentwicklung auf ihre Anwendbarkeit unter Nachhaltigkeitsgesichtspunkten untersucht und modifiziert. Das Projekt ist eingebunden in das Forschungsfeld 'Forschung für die Reduzierung der Flächeninanspruchnahme und ein nachhaltiges Flächenmanagement (REFINA)' des Bundesministeriums für Bildung und Forschung (BMBF). Mit der Schriftenreihe des Forschungsverbundes KoReMi soll fortlaufend sowohl über das Projekt und seine wesentlichen Arbeitsergebnisse als auch über weiterführende Erkenntnisse der Fachdisziplinen berichtet werden. Die Kommunikation zwischen Wissenschaft und Praxis sowie auch zwischen den einzelnen wissenschaftlichen Disziplinen, die sich aus ganz unterschiedlichen Blickwinkeln mit den Problemen nachhaltiger Entwicklung von Regionen unter dem Vorzeichen von demographischer Transformation beschäftigen, soll mit dieser Schriftenreihe forciert und intensiviert werden.
6

“Borders don’t protect areas, people do”: multi-scalar insights to promote the development and support of Indigenous Protected and Conserved Areas

Tran, Tanya Chi 28 June 2020 (has links)
Given the ongoing biodiversity decline during a time of Indigenous resurgence, Indigenous Protected and Conserved Areas (IPCAs) are garnering interest from the academic community, Indigenous and state governments, and protected area practitioners. Though Indigenous forms of land and sea protection have existed for millennia, these actors are exploring how IPCA development and support can meet needs to protect biodiversity and respect Indigenous rights and roles in conservation. My main research objective was to advance academic and practical applications of IPCAs by drawing from global IPCA research while assisting the Kitasoo/Xai’xais Nation’s IPCA planning process. I investigated two research questions: 1. What are the key successes, challenges, and lessons from IPCA research globally? 2. What can we learn from the Kitasoo/Xai’xais Nation’s rationale and process for developing an IPCA? To answer my first question, I reviewed 58 papers, describing 86 specific IPCA initiatives involving at least 68 Indigenous Peoples across 25 countries. Indigenous Peoples established IPCAs independently and through local- and broad-scale partnerships. Where state IPCA support existed, it was through formal legislation, agreements, and policies, and informally through local relationships and shared values. IPCAs created socio-cultural, political, and ecological benefits. Challenges limited benefits while demanding additional resources for mitigation. I recommend that states and other external actors create/improve IPCA policies, legislations, and resources as defined by Indigenous Peoples; facilitate Indigenous leadership to shape external IPCA establishment and development mechanisms; and create internal Indigenous engagement/partnerships mechanisms. I suggest that Indigenous Peoples would benefit from building partnerships to support and manage their IPCAs. Finally, I recommend that IPCA managers commit more resources, particularly in monitoring and management that integrates management priorities with local and larger scale social-environmental issues. To answer my second question, in collaboration with the Kitasoo/Xai’xais Nation, we used participatory action research to assist efforts to plan a land-and-sea IPCA in Kitasoo/Xai’xais Territory. Together, we used mixed methods to summarize the Nation’s rationale and process. IPCA development is an iteration of ongoing efforts to address limitations of state protected areas to better reflect Kitasoo/Xai’xais rights and responsibilities while preserving culture, biodiversity, and economic opportunity. The Kitasoo/Xai’xais process is rooted in long-term Territory planning and contemporary stewardship capacity building, has benefitted from global IPCA research, and has ongoing multi-generational engagement. The Nation faces challenges similar to other protected areas and is additionally burdened by ongoing colonization impacts. To address these challenges, the Nation is seeking state legislative IPCA recognition, applying Indigenous and complementary western stewardship approaches, and pursuing responsibility-based partnerships. This research makes both practical and academic contributions. It assisted the Kitasoo/Xai’xais IPCA process by contributing to planning and documentation, to be used and modified by the Nation to implement current and future IPCAs. Other Indigenous organizations can adapt the lessons and processes described for their IPCA interests. Additionally, this work provides recommendations for states and other actors at various scales to improve IPCA support and recognition. This work also contributes to literature which highlight Indigenous-led conservation initiatives, including IPCAs, as potential pathways towards supporting biodiversity conservation and Indigenous resurgence. / Graduate
7

Exploring complexities of fishery closures using octopus movements : an individual-based modelling approach

Berrío-Martínez, Jineth January 2022 (has links)
Temporary closures of octopus fishing areas constitute a promising co-management measure that aims to improve local governance, food security and incomes in coastal small-scale fishing communities. Although positive social and economic outcomes of temporary closures are increasingly reported, the underlying social-ecological and ecological interactions, and their impact on closure benefits are rarely studied. This lack of systemic understanding may lead to undesired outcomes. Here, I extend an existing agent-based model of temporary closures to explore the influence of individual octopus movements on ecological outcomes and fishers’ benefits in Zanzibar. First, I conceptualized the octopus closure system by analyzing empirical qualitative data and literature. Next, I iteratively developed and tested an individual-based model extension. This extension simulates between-den movements across a hypothetical seascape and formalizes intrinsic attributes of Octopus cyanea such as movement patterns and maturity stages. I analyzed the effects of varying closure size of fishing grounds temporarily closed to illustrate potential implications for outcomes of octopus closures. Simulation results show that individual octopus movements triggered by fishing activities have noticeable impacts on octopus sizes, their spatial and temporal distribution, and fishers’ catches, particularly when considering different social groups that depend on the fishery. Scenarios with closures in place show higher mean octopus weight in closed areas in contrast to open-access areas. Mean catches for women foot-fishers are lower compared to freedivers’ catches and even slightly lower when allowing octopuses to move in response to disturbance in all scenarios. Catch rates and distribution of mature octopuses are highly sensitive to closure size revealing a social-ecological trade-off when implementing larger closures. This study demonstrates an approach to integrating individual octopus movements and interactions between fishers and octopuses in a fishery management context, and suggests that reactive movement of octopus contributes to unequal distribution of the closure benefits between different social groups. / Octopus and People In Novel Transdisciplinary Simulations (OctoPINTS project)

Page generated in 0.0714 seconds