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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.
21

The effect of spatial scale on the use of biodiversity surrogates and socio-economic criteria in systematic conservation assessments

Payet, Karine 12 1900 (has links)
Thesis (MSc (Conservation Ecology and Entomology)--Stellenbosch University, 2007. / A systematic conservation assessment is the first phase of a systematic conservation planning protocol; it uses spatial data and representation targets for the setting of priority areas and the assessment of risk to biodiversity. This thesis describes the findings of investigations on the use of data in systematic conservation assessments. Conservation planning can be done at different spatial scales (from global to local). Systematic Conservation planning can be done at different spatial scales (from global to local). Systematic conservation assessments rely on the use of surrogates for biodiversity and often, as well, socioeconomic criteria. Biodiversity surrogates can be classified as taxonomic, community and environmental. In Chapter 2, a literature review was performed (i) to quantify the use of biodiversity surrogates and socio-economic criteria in conservation assessments; and (ii) to test the hypothesis that surrogates are chosen in respect to the hierarchical organisation of biodiversity. In other words, fine scale conservation assessments are correlated with taxonomic surrogates, large scale conservation assessments are correlated with environmental surrogates, and assemblage surrogates are assessed at an intermediary scale. The literature review was based on a structured survey of 100 ISI journal publications. The analysis revealed that spatial scale had a weak effect on the use of biodiversity surrogates in conservation assessments. Taxonomic surrogates were the most used biodiversity surrogates at all scales. Socioeconomic criteria were used in many conservation assessments. I argue that it is crucial that assemblage and environmental data be more used at larger spatial scales. The allocation of conservation resources needs to be optimised because resources are scarce. A conservation assessment can be a lengthy and expensive process, especially when conducted at finescale. Therefore the need to undertake a fine-scale conservation assessment, as opposed to a more rapid and less expensive broader one, should be carefully considered. The study of Chapter 3 assessed the complementarity between regional- and local-scale assessments and the implications on the choice of biodiversity features at both scales. The study was undertaken in Réunion Island. A biodiversity assessment was performed at a regional scale and measured against a finer-scale assessment performed over a smaller planning domain. Two datasets composed of species distributions, habitat patterns and spatial components of ecological and evolutionary processes were compiled as biodiversity surrogates at each scale. Targets for local-scale processes were never met in regional assessments, while threatened species and fragmented habitats were also usually missed. The regional assessment targeting habitats represented a high proportion of local-scale species and habitats at target level (67%). On the contrary, the one targeting species was the least effective. The results highlighted that all three types of surrogates are necessary. They further suggested (i) that a spatial strategy based on a complementary set of coarse filters for regional-scale assessments and fine filters for local-scale ones can be an effective approach to systematic conservation assessments; and (ii) that information on habitat transformation should help identify where efforts should be focused for the fine-scale mapping of fine filters. Together with priority-area setting, the identification of threatened biodiversity features has helped to prioritise conservation resources. In recent years, this type of assessment has been applied more widely at ecosystem-level. Ecosystems can be categorised into critically endangered, endangered and vulnerable, following the terminology of the IUCN Red List of threatened species. Various criteria such as extent and rate of habitat loss, species diversity and habitat fragmentation can be used to identify threatened ecosystems. An approach based only on the criterion of the quantification of habitat loss was investigated in Chapter 4 for the Little Karoo, South Africa. Habitat loss within ecosystem type is quantified on land cover information. The study analysed the sensitivity of the categorisation process to ecosystem and land cover mapping, using different datasets of each. Three ecosystem classifications and three land cover maps, of different spatial resolutions, were used to produce nine assessments. The results of these assessments were inconsistent. The quantification of habitat loss varied across land cover databases due to differences in their mapping accuracy. It was reflected on the identification of threatened ecosystems of all three ecosystem classifications. Less than 14% of extant areas were classified threatened with the coarsest land cover maps, in comparison to 30% with the finest one; and less than 9% of ecosystem types were threatened with the coarsest land cover maps, but between 15 and 23% were threatened with the finest one. Furthermore, the results suggested that the identification of threatened ecosystems is more sensitive to the accuracy of habitat loss quantification than the resolution of the ecosystem classification. Detailed land cover mapping should be prioritised over detailed ecosystem maps for this exercise. This thesis highlighted the importance of ecosystems and processes as biodiversity surrogates in conservation assessments and suggested that results of conservation assessments based on these data, should be more widely presented in published articles. Finally, it also made apparent the important role of mapping habitat transformation for systematic conservation plans.
22

Planning considerations for conservation and development within Deep Bay Buffer Zones in North West New Territories Hong Kong

Chu, Ha-fan., 朱霞芬. January 1995 (has links)
published_or_final_version / Urban Planning / Master / Master of Science in Urban Planning
23

Biogeography of upland bird communities in the Peruvian Amazon

Pomara, Lazarus Yates 20 August 2010 (has links)
The western Amazon is known to be one of the most biologically diverse regions in the world, yet information about the spatial distribution of that biodiversity and the processes governing its distribution remains scarce. An improved understanding of those biogeographic patterns and processes can inform conservation and development planning in areas where anthropogenic landscape change is ongoing. Spatial components of biodiversity are known to be influenced by historical and present-day physical and human geographic processes. There is evidence that major Amazonian rivers form the boundaries of biological regions, at least for birds. Other factors that may influence bird species composition include the dispersal limitations of individual species, forest plant species composition and structure, topography, forest fragmentation, and hunting. Sites where bird species composition was measured in this study represented mature, upland forest on both sides of the Amazon River, and a range of non-flooded forest types, as indicated by soil and plant surveys. Bird species compositional variation was closely correlated with variation in plant species composition, human disturbance associated with forest fragmentation, and position north or south of the Amazon River. The strongest differences were between opposite sides of the river, even though local environments, including plant composition, were not different on the two sides. This strongly suggests that historical biogeographic factors, rather than present-day environmental gradients, are responsible for bioregional boundaries at Amazonian rivers. The difference between plant and bird distributions at this scale underscores the pressing need to re-evaluate general notions of bioregional complexity and pattern in the Amazon basin. Locally, the influence of habitat fragmentation on animal communities, including reduced species richness, was confirmed. The influence of local floristic variation is of particular importance due to its ubiquity across western Amazonia. Thus, understanding the distributions of soils and vegetation is critical for explaining Amazonian animal diversity. The use of these factors to model bird community heterogeneity contradicts assumptions that the processes shaping Amazonian animal community diversity are too complex to measure efficiently, and their use contributes a new understanding of the dimensions of that diversity. / text
24

Integrating systematic conservation planning and ecosystem services : an indicators approach in the Hill Country of Central Texas

Fougerat, Matthew Gerald 30 September 2014 (has links)
Ecosystem services are the aspects of the environment utilized to produce human well-being and are key elements of landscape sustainability. Increasingly, measures of ecosystem services are being incorporated into conservation decision making. However, a framework for evaluating systematic conservation planning ranked selection scenarios with indicators of ecosystem services has not been developed. Using the Central Texas counties of Blanco, Burnet, Hays, Llano, San Saba, and Travis as a study, a suite of spatially explicit modeling tools, Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST), are used to quantify carbon storage, soil conservation, and water provision. A fourth service metric, ecosystem richness, is derived using Texas Parks and Wildlife ecological systems classification data. The values of these four services are then used to evaluate four conservation scenarios, developed in conjunction with a local conservation non-profit, Hill Country Conservancy (HCC), and derived using Marxan decision-support software. The evaluation process consists of both geographic information system (GIS) and statistical analysis. GIS based overlay analysis is used to identify areas of multiple ecosystem service overlap. Spearman correlation tables are used to test the spatial relationship among ecosystem services, as well as the relationship among each of the four conservation scenarios. Wilcox-Mann-Whitney U tests (WMW) are used to assess the statistical significance of each scenario’s ecosystem service values as compared to the values of a random control scenario. The results of this work reinforce the findings that there is often significant variability in the spatial congruence of multiple ecosystem services and their provision across a landscape. This work also supports the conclusion that the targeting of ecological phenomena for conservation concurrently targets areas supporting multiple ecosystem services. More distinctively, the results verify the capacity of ecosystem service indicators to effectively inform an iterative systematic conservation planning process. At the local landscape-scale, this work provides HCC with defensible support of their conservation decisions based not only on organizational priorities, but also on ecosystem service values. More broadly, this work provides a framework for evaluating conservation scenarios with spatially explicit values of ecosystem services which can be replicated across a wide range of project scales and objectives. / text
25

Conservation and land use planning applications in Gabon, Central Africa

Lee, Michelle E. January 2014 (has links)
Spatial prioritization and systematic conservation planning methods are designed to improve land use decisions and conservation outcomes, yet remain underutilized in many biologically-rich places that need them most. This thesis applies the theory and methods developed in the discipline of spatial prioritization to conservation and land use decisions in the Central African country of Gabon. Creating a spatial information base of priority species, habitats and land uses in a region that is notoriously data-poor, I reveal that many features important for both conservation and natural resource production are highly localized; their coincidence has important implications for management. Setting conservation targets for species and habitats, I find that representation in existing protected areas is relatively low, and identify a number of near-optimal solutions that meet all targets, with minimal impact on land used for local livelihoods. I distill these solutions down to a handful of critical biodiversity sites that are top priority to protect, and make management actions explicit for the species and habitats they contain. To make the work more widely applicable, I also develop a novel method to identify where field surveys are most likely to improve decisions about protected area expansion, providing decision-makers with more options of places that could be protected to achieve conservation goals. This study contributes to the research, development and practice of conservation prioritization and spatial planning, particularly in data-poor contexts like Gabon, which still have a wealth of biodiversity, and need to carefully plan for its conservation alongside development.
26

Spatial analysis of marine mammal distributions and densities for supporting coastal conservation and marine planning in British Columbia, Canada

Harvey, Gillian Kohl Allyson 23 December 2016 (has links)
Human impacts on ocean ecosystems are driving declines in marine biodiversity, including marine mammals. Comprehensive spatial data are vital for making informed management decisions that may aid species recovery and facilitate the sustainable use of ocean ecosystems. However, marine mammal studies are often data limited, thereby restricting possible research questions. Developing novel analytical approaches and incorporating unconventional datasets can expand the scope of analysis by increasing the information content of existing data sources. The goal of our research is to support conservation and management of marine mammals in British Columbia (BC), Canada, through the application of advanced spatial statistical methodology to characterize spatial distribution and density patterns and provide assessments of data uncertainty. Our first objective is to generate statistical models to map spatially continuous predictions of marine mammal distributions and densities within BC’s north coast and apply methodology from spatial statistics to identify hotspots of elevated use. We use species observations collected from systematic line transect surveys previously adjusted to generate estimates of density per nautical mile of transect. We predict the distribution and density patterns of nine marine mammal species by employing a species-habitat model to relate species densities to environmental covariates using a generalized additive model. We use spatial statistical hotspot analysis (Getis-Ord Gi*statistic) and an aspatial threshold approach to identify hotspots of high density. Our analysis reveals that hotspots selected using a top percentage threshold produced smaller and more conservative hotspots than those generated using the Gi*statistic. The Gi*statistic demonstrates a robust and objective technique for quantifying spatial hotspots and offers an alternative method to the commonly applied aspatial threshold measure. We find that maps show agreement with prior research and hotspots align with ecologically important areas previously identified by expert opinion. Our second objective is to apply map comparison techniques to compare cetacean density maps from disparate data collection methods (systematic surveys and citizen science) to evaluate the information content of each map product and quantify similarities and differences. Discrepancies are quantified by performing image differencing techniques on the rank order values of each map surface. We subsequently use the Gi*statistic to isolate regions where extreme differences occur. To assess similarities, a Gi*statistic is applied to both maps to locate spatially explicit areas of high cetacean density. Where clusters of high density values in both maps overlap we infer higher confidence that the datasets are representing a true ecological signal, while areas of difference we recommend as targeted locations for future sampling effort. We contextualize map similarities and differences using a dataset of human activity in the form of cumulative human effect scores. Overall, our analytical approach integrates novel spatial datasets from systematic surveys, citizen science, and remote sensing to provide updated information on cetacean distributions in BC. Our study generates geographic data products that fill knowledge gaps and results provide baseline information valuable for future decision-making. The methodology applied in this study can be generalized across species and locations to support spatial planning and conservation prioritization in both marine and terrestrial contexts. / Graduate / 2017-11-13
27

Planejamento sistemático das unidades de conservação no Estado do Tocantins / Systematic planning of protected areas in Tocantins State

Ferreira, Mariana Napolitano e 13 June 2011 (has links)
O crescimento dos sistemas de áreas protegidas nas últimas décadas é considerado um dos maiores esforços da humanidade para conter a atual crise da biodiversidade. No entanto, a cobertura da superfície global por áreas protegidas é um indicador simplificado, sendo necessário ir mais além e avaliar se os sistemas de áreas protegidas representam os diferentes componentes da biodiversidade e processos ecológicos e se estão sendo geridos de forma efetiva para garantir a manutenção da biodiversidade no longo prazo. O objetivo geral do presente estudo foi realizar uma análise da efetividade de gestão e representatividade biológica do sistema de unidades de conservação (UCs) no Estado do Tocantins, avaliando como os diferentes níveis de gestão de áreas protegidas podem interferir nos processos de planejamento sistemático da conservação. Os resultados indicaram a existência de lacunas significativas na implementação das áreas protegidas existentes, apesar do desempenho relativamente bom em alguns elementos. As quatro ameaças mais importantes para o sistema de UCs avaliado foram: infraestrutura, queimadas descontroladas, caça e pecuária. A análise da distribuição de 109 espécies de vertebrados e plantas indicou a presença de padrões biogeográficos claros na biota do Tocantins, que coincidem com padrões relatados por outros autores para alguns grupos taxônomicos. No entanto, lacunas significativas foram observadas tanto na proteção das espécies, quanto na representação dos elementos bióticos identificados. Para testar os impactos dos baixos valores de efetividade e altos valores de ameaças das UCs no planejamento do sistema, reduzimos o estado de conservação das áreas protegidas em 25% e 50%. Isso resultou em acréscimos de 250.000 ha e 590.000 ha, respectivamente, no sistema de áreas protegidas, necessário ao cumprimento das metas de conservação. A representatividade dos sistemas de áreas protegidas depende da persistência da biodiversidade dentro dessas áreas, que é reconhecidamente comprometida por níveis elevados de ameaça associados à efetividade de gestão incipiente. Portanto, sugerimos que o estado de conservação da biodiversidade dentro das áreas protegidas seja incorporado a exercícios de planejamento sistemático de conservação. A definição de prioridades para a criação de novas áreas protegidas deve fazer parte de um planejamento integrado, que aborde também a consolidação de áreas protegidas existentes e estratégias mais amplas para mitigar os efeitos dos fatores principais da perda de biodiversidade fora das reservas. / The growth of protected areas (PAs) in the last decades is considered one of the humanity\'s best efforts to refrain the current crisis of biodiversity. However, the global PA coverage is a simplified indicator; it is necessary to go further and assess whether PA systems represent the different components of biodiversity and ecological processes and are being managed effectively to ensure the maintenance of their values in the long term. The main goal of this study was to analyze the management effectiveness and representation of PA system in Tocantins State, assessing how the different levels of PA management may impact the systematic conservation planning process. Results indicated the existence of significant gaps in the implementation of Tocantins PAs, despite the relatively good performance found in some elements. The four most important threats to the PAs evaluated were: infrastructure, uncontrolled fires, hunting and cattle ranching. Analysis of the distribution of 109 vertebrates and plants indicated that selected species represent biogeographical patterns of Tocantins biota and that there are significant gaps in the protection of the species and biotic elements in the current PA system. In order to test for the effects of detected low management effectiveness and high levels of threat, we reduced the conservation status of protected areas by 25% and 50%. This resulted in an increase in the conservation area network needed to achieve targets of around 250,000 ha and 590,000 ha, respectively. Our results strongly indicate that the representation of PA systems depends on the persistency of biodiversity inside PAs, which are known to be impacted by high levels of threat associated to poor management effectiveness. Therefore, we advocate that biodiversity status within PAs should be incorporated in systematic conservation planning exercises. The definition of priority areas for the establishment of new reserves should be part of an integrated planning process that addresses both the consolidation of existing protected areas and broader strategies to mitigate the effects of major drivers of biodiversity loss outside reserves.
28

A Combined Energy and Geoengineering Optimization Model (CEAGOM) for Climate Policy Analysis

Anasis, John George 16 November 2015 (has links)
One of the greatest challenges that will face humanity in the 21st century is the issue of climate change brought about by emissions of greenhouse gases. Energy use is one of the primary sources of greenhouse gas emissions. However, it is also one of the most important contributors to improved human welfare over the past two centuries and will continue to be so for years to come. This quandary has led a number of researchers to suggest that geoengineering may be required in order to allow for continued use of fossil fuels while at the same time mitigating the effects of the associated greenhouse gas emissions on the global climate. The goal of this research was to develop a model that would allow decision-makers and policy analysts to assess the optimal mix of energy and geoengineering resources needed to meet global or regional energy demand at the lowest cost while accounting for appropriate emissions, greenhouse gas concentration, or temperature rise constraints. The resulting software model is called the Combined Energy and Geoengineering Optimization Model (CEAGOM). CEAGOM was then used to analyze the recently announced U.S.-China emissions agreement and to assess what the optimal global energy resource mix might be over the course of the 21st century, including the associated potential need for geoengineering. These analyses yielded optimal mixes of energy and geoengineering resources that could be used to inform regional and global energy and climate management strategies.
29

Testing the Feasibility of Bioacoustic Localization in Urban Environments

O'neal, Blaire 17 March 2014 (has links)
Bioacoustics is a relatively new field of research focused on studying the acoustic signals of vocal animal species. The field has been a topic of interest for many years due its passive approach and avoidance of species-level limitations, such as tracking rare or nocturnal species. It has been used to locate birds in terrestrial environments; however, localization in urban environments remains unstudied. This research aims to fill the gap by attempting to estimate the location of 30 discrete calls in eight unique, urban environments. Sites represented two distinct traffic scenarios: moderate traffic and high traffic. Three system arrays of three different sizes utilizing the Song Meter SM2+ units were tested at each site to determine the effect of array size on call visibility and location estimation. An American robin (Turdus migratorius) distress call was played through a loudspeaker at the thirty locations for each array. The spectrogram of each of these calls was examined to determine the number of channels with a visible call signature. If the file contained at least one visible call per song meter (36% of our sound files), cross correlation was used to determine the differences in the time of arrival of calls at all the microphones in the array, called lag values, which were used to calculate the origin location of the call. However, resulting lag values in this study were too large to produce reliable location estimates. This was likely due to imprecise synchronization in the field or poorly defined calls within the spectrograms. Our overall low visibility is likely a result of the high signal to noise ratio common in urban environments. Further research is necessary to continue to test the viability of acoustic localization in urban environments.
30

River conservation planning: accounting for condition, vulnerability and connected systems

Linke, Simon, n/a January 2006 (has links)
Conservation science in rivers is still lagging behind its terrestrial and marine counterparts, despite increasing threats to freshwater biodiversity and extinction rates being estimated as five times higher than in terrestrial ecosystems. Internationally, most protected rivers have been assigned reserve status in the framework of terrestrial conservation plans, neglecting catchment effects of disturbance. While freshwater conservation tools are mainly index based (e.g. richness, rarity), modern terrestrial and marine conservation planning methods use complementarity-based algorithms - proven to be most efficient at protecting a large number of taxa for the least cost. The few complementarity-based lotic conservation efforts all use broad river classifications instead of biota as targets, a method heavily disputed in the literature. They also ignore current condition and future vulnerability. It was the aim of this thesis to develop a framework for conservation planning that: a) accounts for the connected nature of rivers b) is complementarity based and uses biota as targets c) integrates current status and future vulnerability I developed two different approaches using macroinvertebrate datasets from Australia, Canada and the USA. The first new method was a site/based two-tiered approach integrating condition and conservation value, based on RIVPACS/AUSRIVAS � a modelling technique that predicts macroinvertebrate composition. The condition stage assesses biodiversity loss by estimating a site-specific expected assemblage and comparing it to the actual observed assemblage. Sites with significant biodiversity loss are flagged for restoration, or other management actions. All other sites progress to the conservation stage, in which an index of site-specific taxonomic rarity is calculated. This second index (O/E BIODIV) assesses the number of rare taxa (as defined by &lt50% probability of occurrence). Using this approach on a dataset near Sydney, NSW, Australia, I was able to identify three regions: 1) an area in need of restoration; 2) a region of high conservation value and 3) an area that had high conservation potential if protection and restoration measures could counteract present disturbance. However, a second trial run with three datasets from the USA and Canada highlighted problems with O/E (BIODIV). If common taxa are predicted at lower probabilities of occurrence (p&lt50%) because of model error, they enter the index and change O/E (BIODIV). Therefore, despite an attractive theoretical grounding, the application of O/E (BIODIV) will be restricted to datasets where strong environmental gradients explain a large quantity of variation in the data and permit accurate predictions of rare taxa. It also requires extensive knowledge of regional species pools to ensure that introduced organisms are not counted in the index. The second approach was a proper adaptation of terrestrial complementarity algorithms and an extension to the Irreplaceability-Vulnerability framework by Margules and Pressey (2000). For this large-scale method, distributions for 400 invertebrate taxa were modeled across 1854 subcatchments in Victoria, Australia using Generalised Additive Models (GAMs). The best heuristic algorithm to estimate conservation value was determined by calculating the minimum area needed to cover all 400 taxa. Solutions were restricted to include rules for the protection of whole catchments upstream of a subcatchment that contained the target taxon. A summed rarity algorithm proved to be most efficient, beating the second best solution by 100 000 hectares. To protect 90% of the taxa, only 2% of the study area need to be protected. This increases to 10% of the study area when full representation of the targets is required. Irreplaceability was calculated by running the heuristic algorithm 1000 times with 90% of the catchments randomly removed. Two statistics were then estimated: f (the frequency of selection across 1000 runs) and average c (contribution to conservation targets). Four groups of catchments were identified: a) catchments that have high contributions and are always selected; b) catchments that have high contributions and are not always selected; c) catchments that are always chosen but do not contribute many taxa; d) catchments that are rarely chosen and did not contribute many taxa. Summed c, the sum of contributions over 1000 runs was chosen as an indicator of irreplaceability, integrating the frequency of selection and the number of taxa protected. Irreplaceability (I) was then linked to condition (C) and vulnerability (V) to create the ICVframework for river conservation planning. Condition was estimated using a stressor gradient approach (SGA), in which GIS layers of disturbance were summarised to three principal axes using principal components analysis (PCA). The main stressor gradient � agriculture � classified 75% of the study area as disturbed, a value consistent with existing assessments of river condition. Vulnerability was defined as the likelihood that land use in a catchment would intensify in the future. Hereby current tenure was compared to land capability. If a catchment would support a land use that would have a stronger effect on the rivers than its current tenure, it was classified as vulnerable. 79% of catchments contained more than 50% vulnerable land. When integrating the three estimators in the ICV-framework, seven percent of catchments were identified as highly irreplaceable but in degraded condition. These were flagged for urgent restoration. Unprotected, but highly irreplaceable and highly vulnerable catchments that were still in good condition made up 2.5% of the total area. These catchments are prime candidates for river reserves. The ICV framework developed here is the first method for systematic conservation planning in rivers that is complementarity-based, biota-driven but flexible to other conservation targets and accounts for catchment effects, thus fulfilling all the gaps outlined in the aims.

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