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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.
11

An investigation of the distribution and transfer of Traditional Ecological Knowledge based on generation, gender and resource use

Agbemenya, Seyram Awushie 23 June 2011 (has links)
The state of Traditional Ecological Knowledge (TEK) is of importance to ecologists and conservationists considering the recent trends in the loss of local culture and indigenous knowledge systems worldwide. An understanding of the factors that affect the distribution and transmission of TEK may offer scientists an insight into how it can be conserved to persist to inform ecological decisions. This study investigated the distribution and transmission of TEK based on gender, age and tree resource use in two rural communities in the Mpumalanga Province of South Africa. The distribution of this knowledge was assessed based on respondents’ ability to identify local tree species, their uses and conservation techniques. Their ecological knowledge of a number of common and rare indigenous tree species was also assessed. This was done mainly through focus group discussions, individual interviews and a participatory appraisal technique. Age group rather than gender had a significant effect on the distribution of TEK with old age respondents being more knowledgeable than youths and middle aged respondents. Resource use also affected the distribution of knowledge indicating that knowledge was highly dependent on resource use. Females were the main actors in the transfer of TEK in this community and majority of this knowledge was acquired through passive means. The results revealed a combination of factors that may pose a threat to the loss of TEK in these communities. These factors include; the continuous and unregulated harvesting of trees in the area, the effects of modernisation and globalization on aspects of the traditional community and the high levels of rural urban-migration.
12

Invasão, competição e uso de recursos por uma gramínea nativa e uma gramínea invasora do cerrado / Invasion, competition and resource use by a native and invasive grass in the Brazilian savanas

Zupo, Talita Marques 08 December 2010 (has links)
No Brasil, varias espécies de gramíneas africanas introduzidas se tornaram importantes invasoras dos cerrados e constituem uma das principais ameaças para a sua biodiversidade. Atributos envolvendo trade-offs evolutivos que influenciam na adaptabilidade das espécies - aquisição, alocação e perda de recursos pelas plantas por meio de competição, facilitação, estresse e distúrbio - irão influenciar o desempenho dos indivíduos e a manutenção das populações nas comunidades vegetais. Deste modo, e de extrema importância entender quais os mecanismos que levam uma espécie invasora a ter um desempenho melhor sobre as espécies nativas. Comparações envolvendo características entre espécies exóticas e nativas podem levar a uma melhor compreensão sobre o processo da invasão. Diante disso, este trabalho procurou identificar algumas das estratégias competitivas adotadas por uma gramínea invasora, Urochloa decmbens, e por uma gramínea nativa, Echinolaena inflexa, em ecossistema de cerrado. Para verificar aspectos relativos às estratégias de colonização das espécies foram analisadas suas fenologias reprodutivas, as taxas de viabilidade e de germinação das sementes. Em um experimento com plantas envasadas, sementes de ambas as espécies foram semeadas em diferentes proporções relativas uma a outra. Três censos foram realizados durante o período de um ano para avaliar a sobrevivência, crescimento e fecundidade das espécies. Medidas da capacidade fotossintética e das taxas de assimilação foram tomadas para ambas as espécies tanto em parcelas puras quanto em parcelas mistas; também foi quantificada a área foliar especifica e total das espécies. No experimento com as plantas envasadas, quando sementes de ambas as espécies foram colocadas juntas, a nativa teve seu crescimento suprimido pela invasora. Nos tratamentos puros, os indivíduos da espécie nativa cresceram em tamanho, mas somente três se tornaram reprodutivos. No entanto, muitos indivíduos da espécie invasora cresceram em tamanho e se reproduziram em todos os tratamentos, mostrando uma alocação de recursos tanto para crescimento quanto para reprodução. A espécie invasora apresentou uma taxa fotossintética maior, porem ambas as espécies tiveram sua capacidade fotossintética e sua taxa fotossintética reduzida nos parcelas mistas, sugerindo que a competição afeta tanto a espécie nativa como a espécie invasora. Uma vez que a espécie nativa possui área foliar especifica menor em relação à espécie invasora, espera-se que ela apresente uma perda menor de nutrientes e, conseqüentemente, uma maior conservação/retenção dos nutrientes, o que favoreceria sua persistência em ambientes como o cerrado. No entanto, com a ocorrência de distúrbios e possíveis alterações na disponibilidade de nutrientes, a gramínea nativa pode ser deslocada pela invasora, que apresenta maior capacidade de colonizar novas áreas por meio de maiores taxas de germinação e estabelecimento; e maior produtividade, apresentando maiores taxas fotossintéticas, sendo mais eficiente no uso do nitrogênio. / Many African grasses have been introduced in Brazil and have invaded areas of Brazilian savannas, thus becoming a major threat to the biological diversity of this biome. Traits involving evolutionary trade-offs that influence the species adaptive strategies, such as differences in nutrient uptake, nutrient loss and biomass allocation in response to plant competition and facilitation, and environmental stress and disturbance, will influence individual performance and population maintenance in plant communities. Therefore, it is extremely important to identify the mechanisms associated with invasiveness that lead to a better performance of exotic species over co-occuring natives. Comparisons involving traits of both native and exotic species may lead to a better understanding concerning the success of invasions. This study sought to recognize possible competitive strategies adopted by an invasive grass, Urochloa decmbens, and a native grass, Echinolaena inflexa, in a Brazilian savanna. In order to identify aspects relative to their colonization strategies, the reproductive fenologies and seed viability and germination rates of both species were analyzed. An experiment with potted plants was performed where seeds of both species were sown in different relative proportions to each other. Three census were carried out during a period of 12 months to evaluate survival, growth and fecundity of both species. Gas exchange and chlorophyll fluorescence were quantified for each species in pure and mixed stands in the field; total and specific leaf area for both species were also measured. In the potted experiment, when seeds of both species were sown together, the growth of the native species was suppressed by the exotic species. In pure treatments, however, individuals of the native species grew in size, but only 2% reproduced. On the other hand, individuals of the exotic species grew in size and reproduced in all treatments, demonstrating that this species allocated enough resources for both growth and reproduction. The photosynthetic rates were greater for the invasive species, however, in mixed stands, both species had their photosynthetic rates and capacities decreased. The smaller specific leaf area of the native species suggests lower rates of nutrient loss than the invasive species, which would favor its persistence in nutrient poor environments, as the Brazilian savannas. Yet, with the occurrence of disturbances and variable nutrient availabilities, the native species might be displaced by the invasive species, since the later possesses traits leading to a higher competitive ability in such conditions.
13

A conservation perspective on the mechanisms that influence plant-pollinator interactions

BIELLA, Paolo January 2018 (has links)
Several aspects of plant-pollinator interactions are presented in the thesis. It contains a review on the open questions of plant-pollinator interactions from single species to complex networks. The following sections document novel results. Firstly, the conservation of complex pollination networks is addressed through the hierarchy of species' importance. In addition, the habitat requirements and interactions of a threatened rare pollinator species are explored. In the following chapters, the results from manipulative approaches applied in the field to plant-pollinator interactions are presented. The effect of pollinator's population decline on pollinators' foraging for pollen is investigated. Moreover, the way plant species loss impact several aspects of pollinator visitation is presented. Lastly, the impact of species removal on plant-pollinator network topology and on species ability of establishing new interactions is investigated.
14

Honey bee foraging in agricultural landscapes / Sammelverhalten von Honigbienen in der Agrarlandschaft

Danner, Nadja January 2017 (has links) (PDF)
1. Today honey bee colonies face a wide range of challenges in modern agricultural landscapes which entails the need for a comprehensive investigation of honey bees in a landscape context and the assessment of environmental risks. Within this dissertation the pollen foraging of honey bee colonies is studied in different agricultural landscapes to gain insight into the use of pollen resources and the influence of landscape structure across the season. General suggestions for landscape management to support honey bees and other pollinators are derived. 2. Decoding of waggle dances and a subsequent spatial foraging analysis are used as methods in Chapters 4 and 5 to study honey bee colonies in agricultural landscapes. The recently developed metabarcoding of mixed pollen samples was applied for the first time in honey bee foraging ecology and allowed for a detailed analysis of pollen, that was trapped from honey bees in front hive entrances (Chapter 6). 3. Pollen identification through molecular sequencing and DNA barcoding has been proposed as an alternative approach to light microscopy, which still is a tedious and error-prone task. In this study we assessed mixed pollen probes through next-generation sequencing and developed a bioinformatic workflow to analyse these high-throughput data with a newly created reference database. To evaluate the feasibility, we compared results from classical identification based on light microscopy from the same samples with our sequencing results. Abundance estimations from sequencing data were significantly correlated with counted abundances through light microscopy. Next-generation sequencing thus presents a useful and efficient workflow to identify pollen at the genus and species level without requiring specialized palynological expert knowledge. 4. During maize flowering, four observation hives were placed in and rotated between 11 landscapes covering a gradient in maize acreage. A higher foraging frequency on maize fields compared to other landuse types showed that maize is an intensively used pollen resource for honey bee colonies. Mean foraging distances were significantly shorter for maize pollen than for other pollen origins, indicating that effort is put into collecting a diverse pollen diet. The percentage of maize pollen foragers did not increase with maize acreage in the landscape and was not reduced by grassland area as an alternative pollen resource. Our findings allow estimating the distance-related exposure risk of honey bee colonies to pollen from surrounding maize fields treated with systemic insecticides. 5. It is unknown how an increasing area of mass-flowering crops like oilseed rape (OSR) or a decrease of semi-natural habitats (SNH) change the temporal and spatial availability of pollen resources for honey bee colonies, and thus foraging distances and frequency in different habitat types. Sixteen observation hives were placed in and rotated between 16 agricultural landscapes with independent gradients of OSR and SNH area within 2 km to analyze foraging distances and frequencies. SNH and OSR reduced foraging distance at different spatial scales and depending on season, with possible benefits for the performance of honey bee colonies. Frequency of pollen foragers per habitat type was equally high for SNH, grassland and OSR fields, but lower for other crops and forest. In landscapes with a small proportion of SNH a significantly higher density of pollen foragers on SNH was observed, indicating the limitation of pollen resources in simple agricultural landscapes and the importance of SNH. 6. Quantity and diversity of collected pollen can influence the growth and health of honey bee colonies, but little is known about the influence of landscape structure on pollen diet. In a field experiment we rotated 16 honey bee colonies across 16 agricultural landscapes (see also Chapter 5), used traps to get samples of collected pollen and observed the intra-colonial dance communication to gain information about foraging distances. Neither the amount of collected pollen nor pollen diversity were related to landscape diversity. The revealed increase of foraging distances with decreasing landscape diversity suggests that honey bees compensate for a lower landscape diversity by increasing their pollen foraging range in order to maintain pollen amount and diversity. 7. Our results show the importance of diverse pollen resources for honey bee colonies in agricultural landscapes. Beside the risk of exposure to pesticides honey bees face the risk of nutritional deficiency with implications for their health. By modifying landscape composition and therefore availability of resources we are able to contribute to the wellbeing of honey bees. Agri-environmental schemes aiming to support pollinators should focus on possible spatial and temporal gaps in pollen availability and diversity in agricultural landscapes. / 1. Honigbienen stehen heutzutage vor einer Vielzahl von Herausforderungen in der modernen Agrarlandschaft, was umfassende Untersuchungen von Honigbienen im Landschafskontext erforderlich macht. Im Rahmen dieser Arbeit wurde das Pollensammeln von Honigbienenvölkern in verschiedenen Agrarlandschaften studiert, um Einblick in die Nutzung von Pollenressourcen und auf den Einfluss der Landschaftsstruktur zu gewinnen. 2. Die Dekodierung von Schwänzeltänzen und eine anschließende räumliche Analyse des Sammelverhaltens werden als Methoden in den Kapiteln 4 und 5 eingesetzt, um Bienenvölker in Agrarlandschaften zu untersuchen. Das kürzlich entwickelte Metabarcoding von gemischten Pollenproben wurde zum ersten Mal in der Honigbienenökologie angewandt und ermöglichte eine detaillierte Analyse von Pollenproben, die per Pollenfallen vor den Stockeingängen gesammelt wurden (Kapitel 6). 3. Pollenbestimmung durch molekulare Sequenzierung und DNA Barcoding wurde als Alternative zur Lichtmikroskopie vorgeschlagen, die immer noch sehr mühsam und fehlerbehaftet ist. In dieser Studie bestimmten wir gemischte Pollenproben durch Next-Generation-Sequenzierung und entwickelten einen bioinformatischen Arbeitsablauf um diese Hochdurchsatz-Daten mit einer neu kreierten Referenzdatanbank zu analysieren. Um die Durchführbarkeit zu evaluieren verglichen wir Ergebnisse aus der klassischen Identifizierung via Lichtmikroskopie derselben Proben mit unseren Sequenzier-Ergebnissen. Häufigkeitsschätzungen auf Basis der Sequenzierdaten waren signifikant mit den gezählten Häufigkeiten via Lichtmikroskopie korreliert. Next-Generation-Sequenzierung stellt daher einen nützlichen und effizienten Arbeitsablauf dar, um Pollen auf dem Gattungs- und Artniveau zu bestimmen ohne spezielles palynologisches Expertenwissen zu benötigen. 4. Während der Maisblüte wurden vier Beobachtungsstöcke in 11 Landschaften mit einem Maisflächengradienten platziert und zwischen diesen rotiert. Maisfelder wurden intensiver genutzt als Flächen anderer Landnutzungstypen. Die mittleren Sammeldistanzen waren signifikant niedriger für Maispollen als Pollen anderer Herkunft, was darauf hinweist, dass Aufwand in das Sammeln einer diversen Pollendiät gesetzt wird. Der Anteil an Maispollensammlerinnen stieg nicht mit der Maisanbaufläche in der Landschaft und wurde nicht durch Grünlandfläche als alternative Pollenressource reduziert. Unsere Ergebnisse ermöglichen die Schätzung des entfernungsbezogenen Expositionsrisikos von Honigbienenvölker auf Pollen aus den umliegenden Maisfeldern, die mit systemischen Insektiziden behandelt werden. 5. Es ist nicht bekannt, wie eine Zunahme von Massentrachten wie Raps (OSR) oder eine Abnahme von halbnatürlichen Habitaten (SNH) die zeitliche und räumliche Verfügbarkeit von Pollenressourcen für die Honigbienen, und damit Sammeldistanzen und -frequenzen in verschiedenen Lebensraumtypen verändert. Sechzehn Beobachtungsstöcke wurden in 16 Agrarlandschaften mit unabhängigen Gradienten an OSR- und SNH-Fläche innerhalb von 2 km platziert und regelmäßig rotiert, um Sammeldistanzen und -frequenzen zu analysieren. SNH und OSR reduzierten die Sammeldistanzen auf verschiedenen räumlichen Skalen und je nach Saison, mit möglichen Vorteilen für die Leistungsfähigkeit von Bienenvölkern. Die Häufigkeit der Pollensammler pro Habitattyp war gleich hoch für SNH, Grünland und OSR, aber niedriger für andere Kulturen und Wald. In Landschaften mit einem kleinen Anteil von SNH wurde eine deutlich höhere Dichte von Pollensammlerinnen auf SNH beobachtet, was auf die Begrenzung der Pollenressourcen in einfachen Agrarlandschaften und die Bedeutung von SNH hinweist. 6. Menge und Diversität des gesammelten Pollens können das Wachstum und die Gesundheit von Honigbienenvölkern beeinflussen, aber es ist wenig über den Einfluss der Landschaftsstruktur auf die Pollendiät bekannt. In einem Feldexperiment rotierten wir 16 Honigbienenkolonien über 16 Agrarlandschaften (siehe auch Kapitel 5), nutzten Pollenfallen um Proben des gesammelten Pollens zu nehmen und beobachteten die intrakoloniale Tanzkommunikation, um Informationen über die Sammeldistanzen zu erhalten. Weder Pollenmenge noch -diversität waren von der Landschaftsdiversität abhängig. Der offenbarte Anstieg von Sammeldistanzen mit abnehmender Landschaftsdiversität legt nahe, dass Honigbienen durch die Erweiterung des Pollensammelbereichs eine niedrigere Landschaftsdiversität kompensieren, um Pollenmenge und -diversität zu erhalten. 7. Unsere Ergebnisse zeigen die Bedeutung eines diversen Pollenangebots für Bienenvölker in der Agrarlandschaft. Neben dem Risiko einer Exposition gegenüber Pestiziden, stehen Bienenvölker vor der Gefahr von Mangelernährung mit Auswirkungen auf ihre Gesundheit. Durch eine Änderung der Landschaftzusammensetzung und damit der Verfügbarkeit von Ressourcen können wir zum Wohlergehen der Honigbienen beitragen. Agrarumweltmaßnahmen mit dem Ziel Bestäuber zu unterstützen, sollten sich auf mögliche räumliche und zeitliche Lücken in der Pollenverfügbarkeit und Vielfalt in der Agrarlandschaft konzentrieren.
15

Social metabolism and patterns of material use Mexico, South-America and Spain

González Martínez, Ana Citlalic 20 October 2008 (has links)
La presente tesis se compone de tres artículos publicados y uno enviado para publicación. Son cuatro casos de estudio que comparten el mismo eje teórico: el metabolismo social. Usando la metodología Contabilidad de Flujos de Materiales se han medido las entradas de materiales de varias economías. Los indicadores que se obtienen aplicando esta metodología permiten caracterizar los perfiles metabólicos de las economías estudiadas, identificando los factores más importantes que los determinan. Asimismo, estos indicadores pueden considerarse como una medida indirecta de la presión que una economía ejerce en el medio ambiente. Por otra parte, esta tesis tiene como objetivo dar evidencia empírica sobre la ausencia de desmaterialización de las economías. La principal conclusión es que en este mundo globalizado, los países son cada vez más dependientes del comercio internacional y el papel que un país juega en el concierto internacional determina en gran medida la manera como utiliza sus recursos materiales. Sin embargo, esta dependencia sigue diversas trayectorias. Por una parte, identificamos un conjunto de países como España que se ha beneficiado de este proceso. En las últimas dos décadas, este país ha logrado aumentar su bienestar económico usando intensivamente recursos provenientes de otros sistemas socioeconómicos, como el petróleo. Sin embargo, el principal factor determinante de su perfil biofísico ha sido el sector de la construcción. Por otra parte, identificamos aquellos países que históricamente han basado sus economías en la extracción de recursos naturales como Chile, Ecuador, México y Perú y que actualmente no presentan un patrón uniforme de uso de recursos naturales. En Ecuador, Chile y Perú, el comercio internacional ha sido el principal determinante del patrón e intensidad del uso de los recursos naturales. Sin embargo, Ecuador sigue siendo el ejemplo típico de economía extractiva mientras que Chile ha logrado una diversificación de sus exportaciones con mayor valor agregado. Este proceso se observa pero de manera muy incipiente en Perú. Chile puede considerarse como el ejemplo más exitoso en la región del modelo basado en exportaciones de materias primas al lograr un fuerte crecimiento económico. México es un caso especial y contradictorio, porque a pesar de ser un importante exportador de petróleo, ha logrado una diversificación de su producción hacía sectores con un mayor componente tecnológico debido a la creciente presencia de la industria maquiladora. Sin embargo, no son sus flujos de exportaciones ni el crecimiento económico los principales determinantes del uso que hace de sus recursos materiales sino el crecimiento de la población. Por otra parte, se observa un incremento considerable en el uso de materiales de construcción y energéticos fósiles en toda la economía mientras que al mismo tiempo, la población rural sigue dependiendo de fuentes tradicionales de energía como la leña para satisfacer sus necesidades energéticas. Otra conclusión general es que no se observa un proceso de desmaterialización ni absoluta ni relativa en ninguno de los países analizados. / This thesis is composed of three published articles and a submitted one. All share the same theoretical approach: social metabolism. By tracing all material flows into several economic systems by means of the Material Flows Accounting methodology (MFA), this thesis aims on the one hand at characterizing current metabolic profiles of different economies, identifying their main driving forces; on the other hand, it aims at providing empirical evidence on dematerialisation of the economies. The main conclusion is that in our globalised world, countries are becoming more dependent on international trade and that the role a country plays in the international markets strongly determines its pattern of material use. This dependency followed different trajectories. On the one hand, we identify countries such as Spain that benefited from this process as it increased welfare based in an intensive use of strategic natural resources coming from other economic systems such as fossil fuels. Nevertheless, the main driving force shaping the biophysical profile of this economy was the construction sector, an internal factor. On the other hand, we identify those countries that historically have relied on the extraction of natural resources such as Chile, Ecuador, Mexico and Peru although we can no longer talk about a uniform pattern of natural resource use in the region. In Ecuador, Chile and Peru, international trade was the main driving force for material use. Ecuador remains the typical example of an extractive economy whereas a diversification of exports away from bulk commodities towards products with more added value could be observed to a greater extent in Chile and incipiently in Peru. Chile can be regarded as a successful example of the staple theory of growth as its GDP increased considerably. Mexico is a special and contradictory case. Firstly, despite being an important oil exporter, it has achieved a diversification of production, moving towards technology-intensive products due to the assembly industries. Secondly, despite it has a great potential of biomass extraction, it is undergoing a substitution process of imported biomass for national biomass, in particular, basic crops for human consumption. Instead of international trade, population growth was the main driving force for biophysical growth in this economy. Thirdly, it was observed an increasing emphasis on the use of construction materials and fossil fuels in the whole economy whereas in the countryside, rural households still rely heavily on traditional biomass flows such as fuelwood to satisfy their energetic needs. A general conclusion is that neither absolute dematerialisation nor relative dematerialisation occurred in any of the analysed countries.
16

Consequences of intraspecific genetic variation for population dynamics and niche expansion

Agashe, Deepa Ashok 10 June 2011 (has links)
Intraspecific genetic diversity is an important attribute of natural populations and is deemed critical for their adaptive potential and persistence. However, we have limited empirical understanding of the impact of genetic diversity on population performance under different conditions. For my dissertation, I conducted long-term laboratory experiments with populations of the flour beetle Tribolium castaneum to test the consequences of genetic variation for population dynamic stability and niche evolution. In Chapter 1, I show that genetic variation prevented population extinction in a novel habitat. In addition, genetically diverse populations were more stable, both in a novel heterogeneous habitat and in their ancestral habitat. In the ancestral habitat, alleles from a single founding lineage dominated the dynamics, leading to increased stability of genetically diverse populations. However, such as selective effect was not observed in the novel heterogeneous habitat. Therefore, while genetic variation within populations increased their stability and persistence, the magnitude of the impact and its mechanism depended on the selective habitat. In Chapter 2, I ask whether genetic variation also facilitates resource niche expansion, i.e., use of a novel resource. Using stable carbon isotopes, I analyzed diets of beetles sampled from the above experiment and quantified the rate of change in resource use. Contrary to theoretical predictions, I found that genetic variation for resource use had no effect on the rate of niche evolution. Furthermore, behavioral niche expansion accounted for most of the adaptation to the novel resource, and the behavioral change hindered subsequent evolutionary change in resource use. It is thus apparent that in the short term, behavioral plasticity in niche use may impose far greater constraints on niche evolution than the amount of standing genetic variation. Mathematical models predict that intraspecific competition generates selection for niche evolution, and that genetic variation increases the response to selection. Therefore, I hypothesized that the impact of genetic variation on resource niche evolution may depend on the degree of intraspecific competition. In the final chapter of this thesis, I describe results of an experiment to test this hypothesis. I found that genetic variation and competition indeed interacted to increase the rate of niche expansion in T. castaneum, but that their impacts were temporally variable. Furthermore, the two factors acted on different components of niche evolution: while competition only affected the degree of niche expansion, genetic variation also promoted maintenance of individual variation in resource use. In summary, my thesis describes experiments to test for the ecological and evolutionary impacts of intraspecific genetic variation; and its interaction with behavioral plasticity, intraspecific competition, and resource availability. Genetic diversity and behavioral plasticity are common features of living organisms, and therefore it is vital to understand their combined consequences for population ecological and evolutionary dynamics. In addition, natural populations often face intense competition for limited resources. Hence the experimental results presented here can help us to better understand how populations overcome these resource constraints, given their specific genetic composition. Biologists are increasingly aware that the intricate connection between ecological and evolutionary dynamics is important to gain a more complete understanding of population biology. The work described here represents one of the few experiments providing such detailed mechanistic understanding of the interactions between- and consequences of - key ecological and evolutionary parameters. Finally, the results have important implications for conservation biology, because they show that the effects of genetic diversity can vary greatly depending on a number of population and environmental parameters. / text
17

Variation in diet and habitat resource use in desert adapted lizards in Western Australia

Goodyear, Stephen Edward 04 November 2011 (has links)
Impacts of ecological competition are reduced when organisms play different roles in their environment. More individuals can survive on varied but finite sets of resources when organisms eat different kinds of prey, live in different places, or are active at different times. Species within an assemblage of small fossorial snakes have ecologies that vary mostly by diet. Different species eat very different things. Species live in different habitats on sand ridges, but the differences are less dramatic than in diet. Disparity in resource use typically varies the most according to species, so that individuals of the same species are more similar to each other than they are to individuals of other species. However, variation exists in resource use within species over time and space. Wide variation exists in dietary resource use in four well-sampled species of comb-eared skinks. However, where species occur at the same study site there are clear distinctions in resource use between species despite the wide variation in diets observed between individuals of the same species. Additionally, strict ecological distances in diet between species are maintained during five censuses that were conducted over a 16-year period. These results illustrate the basic ecological principals of fundamental and realized niches. Here, individuals ate many different food items and species have the potential to overlap in diet but that overlap is reduced because of realized ecological boundaries between species within a single place and time, which result in decreased competition for resources. / text
18

The Impact of Urinary Incontinence Severity on Direct Healthcare Utilization, Work Productivity, and Clinical Events among Individuals with Overactive Bladder

Tsai, Kathleen January 2013 (has links)
Introduction: The purpose of this research was to assess the relationship between the degree of incontinence severity and treatment seeking behavior, healthcare utilization, and work productivity; and to compare overactive bladder (OAB) related disease burden from a global perspective. Methods: A cross-sectional online survey was administered to eligible participants with idiopathic OAB residing in Australia, Canada, France, Germany, Italy, Spain, United Kingdom, and the United States. Participants were categorized into subgroups with dry, mild (1 leak/per day), moderate (2 leaks/day), and severe (3 leaks/day) urinary incontinence (UI) severity groups. Results: A total of 1,334 participants completed the survey. Persons with more severe urinary incontinence symptoms related to OAB consumed more healthcare resources, had a higher occurrence of OAB related clinical consequences, and higher work productivity loss compared to individuals with less severe symptoms. Even though OAB is associated with significant disease burden, many patients do not seek treatment.
19

Consumption-based material flow indicators - Comparing six ways of calculating the Austrian raw material consumption providing six results

Eisenmenger, Nina, Wiedenhofer, Dominik, Schaffartzik, Anke, Giljum, Stefan, Bruckner, Martin, Schandl, Heinz, Wiedmann, Thomas, Lenzen, Manfred, Tukker, Arnold, Arjan, de Koning January 2016 (has links) (PDF)
Understanding the environmental implications of consumption and production depends on appropriate monitoring tools. Material flow accounting (MFA) is a method to monitor natural resource use by countries and has been widely used in research and policy. However, the increasing globalization requires the consideration of "embodied" material use of traded products. The indicator raw material consumption (RMC) represents the material use - no matter where in the world it occurs - associated with domestic final demand. It provides a consumption-based perspective complementary to the MFA indicators that have a territorial focus. Several studies on RMC have been presented recently but with diverging results; hence, a better understanding of the underlying differences is needed. This article presents a comparison of Austrian RMC for the year 2007 calculated by six different approaches (3 multi-regional input-output (MRIO) and 3 hybrid life-cycle analysis-IO approaches). Five approaches result in an RMC higher than the domestic material consumption (DMC). One hybrid LCA-IO approach calculates RMC to be lower than DMC. For specific material categories, results diverge by 50% or more. Due to the policy relevance of the RMC and DMC indicators it is paramount that their robustness is enhanced, which needs both data and method harmonization.
20

Structure of mutualistic networks between bats and plants and other feeding strategies in a semiarid caatinga forest of Rio Grande do Norte, Brazil

Schmidt, Eugenia Cordero 19 February 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-12-26T20:08:57Z No. of bitstreams: 1 EugeniaCorderoSchmidt_DISSERT.pdf: 37502107 bytes, checksum: 8ea90c3282a2c39d9600a891b990f41e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-12-26T20:17:54Z (GMT) No. of bitstreams: 1 EugeniaCorderoSchmidt_DISSERT.pdf: 37502107 bytes, checksum: 8ea90c3282a2c39d9600a891b990f41e (MD5) / Made available in DSpace on 2016-12-26T20:17:54Z (GMT). No. of bitstreams: 1 EugeniaCorderoSchmidt_DISSERT.pdf: 37502107 bytes, checksum: 8ea90c3282a2c39d9600a891b990f41e (MD5) Previous issue date: 2016-02-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A Caatinga ? uma forma??o florestal escler?fila, dec?dua e espinhosa. Situase em uma regi?o semi-?rida, com cerca de 730 000 km2, exclusiva do territ?rio brasileiro. Este ambiente apresenta grande varia??o de tipos de vegeta??o que foram atribu?das ? varia??es em larga escala no clima, padr?es de geomorfologia e diferen?as de pequena escala em relevo e solos. A precipita??o escassa e flutuante das regi?es ?ridas e semi-?ridas, exercem um forte controle sobre: hist?rias de vida, caracter?sticas fisiol?gicas e composi??o de esp?cies de sua biota. Pelo menos 77 esp?cies de morcegos das 178 esp?cies presentes no Brasil s?o encontrados na Caatinga, dos quais 13 s?o frug?voros e cinco nectarivorous incluindo o end?mica Xeronycteris vieirai. Os morcegos s?o conhecidos por desempenharem pap?is importantes no controle de pragas, poliniza??o e dispers?o de sementes. No entanto, pouca informa??o foi gerada sobre o papel ecol?gico dessas esp?cies em um ambiente como Caatinga. Em geral, esse habitat ? o ecossistema brasileiro mais negligenciado em termos de pesquisa e conserva??o da sua biodiversidade. Especificamente no caso dos morcegos, o Rio Grande do Norte possui uma das maiores lacunas de conhecimento no Brasil. Os dados aqui apresentados, representam uma das primeiras pesquisas formais com morcegos na Caatinga do Rio Grande do Norte. Foram geradas informa??es sobre a estrutura aninhada e assim?trica da rede mutual?stica entre morcegos nectar?voros e esp?cieschave de plantas para a manuten??o da comunidade de morcegos nectar?voros nesta regi?o. Al?m disso, a primeira evid?ncia de folivoria de pelo menos 16 esp?cies de plantas pelo morcego frug?voro Artibeus planirostris foi documentada. Isto representa o primeiro registro para um ambiente semi-?rido e o primeiro registro para a esp?cie. Finalmente, o primeiro ?insight? para aspectos biol?gicos do morcego end?mico X. vieirai, incluindo dieta, poleiros e dados de reprodu??o, assim como a extens?o de sua distribui??o a n?vel nacional. / Caatinga is a deciduous thorny woodland and sclerophyllous vegetation, encountered in a semi-arid region of around 730 000 km2 entirely within the Brazilian territory . This environment presents high variation of vegetation types that have been attributed to large-scale variations in the climate, geomorphology patterns, and smallscale differences in topography and soils. The sparse and fluctuation precipitation of arid and semiarid regions is believed to exert strong control over life histories, physiological characteristics, and species composition of their biotas. At least 77 bat species of the 178 species present in Brazil are found in Caatinga, of which 13 are frugivorous and five nectarivorous including the endemic Xeronycteris vieirai. Bats are known play important roles in pest control, pollination and seed dispersal, nonetheless little information has been generated regarding the ecological role these species play in an environment like Caatinga. In general, this habitat is the most neglected Brazilian ecosystem in terms of investigation and conservation of its biodiversity. Specifically in the case of bats, Rio Grande do Norte is one of the biggest knowledge gaps in Brazil. The data presented here represent one of the first formal investigations with bats in the Caatinga in Rio Grande do Norte. Information on the nested and asymmetric structure of the mutualistc network between nectarivorous bats and plants was generated, with data on key plant species for the maintenance of the community of nectar-feeding bats in this region. Also, the first evidence of folivory of at least 16 plant species by the fruit-eating bat Artibeus planirostris was documented, representing the first record for a semi arid enviroment and the first record for the bat species. Finally, the first insight to biological aspects of the endemic X. vieirai including diet, roosts and reproduction data were registered as well the extention of its range distribution at a national level.

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