Spelling suggestions: "subject:"generalist"" "subject:"eneralist""
31 |
A invenção do pedagogo generalista : problematizando discursos implicados no governamento de professores em formaçãoCarvalho, Rodrigo Saballa de January 2011 (has links)
Esta Tese, a partir da linha de pesquisa dos Estudos Culturais em Educação e das contribuições dos Estudos desenvolvidos por Michel Foucault, entre outros autores que trabalham em uma perspectiva pós-estruturalista, tem como objetivo problematizar os discursos implicados na invenção do pedagogo generalista e em seu correlato governamento. Pedagogo generalista, entendido a partir da homologação das Novas Diretrizes Curriculares Nacionais para o Curso de Pedagogia (2006), como o profissional habilitado para atender a educação de crianças de zero a dez anos, de jovens e adultos, o ensino médio na modalidade normal, a gestão escolar e cursos técnicos na área educacional. Para produção dos dados da pesquisa, foi ministrado um curso de extensão na área de Educação Infantil com duração de vinte horas, que contou com a participação de vinte cinco acadêmicas do Curso de Pedagogia da Faculdade de Educação da Universidade Federal do Rio Grande do Sul – UFRGS. Durante a realização do curso, foram propostas atividades envolvendo a escrita de narrativas, produções visuais, análises fílmicas, análises de obras de arte, esquetes teatrais e rodas de conversa, tendo em vista a discussão das práticas implicadas no processo formativo. Através da análise dos discursos decorrentes das produções escritas das participantes da pesquisa, são evidenciadas produtivas estratégias de governamento (e autogovernamento) que operam (intensamente) na constituição das mesmas enquanto futuras pedagogas. Para tanto, inicialmente, são apresentadas na Tese algumas notas a respeito da história do curso de Pedagogia em nosso país, evidenciando a vontade de poder e de saber presente nos discursos (críticos) legais, que historicamente têm prescrito (e circunscrito de um determinado modo) a formação do pedagogo enquanto profissional da educação – responsabilizado (muitas vezes) pela mudança social através de seu trabalho. Em um segundo momento, são analisados os discursos das Novas Diretrizes Curriculares Nacionais para formação do pedagogo, destacando a ênfase acentuadamente moral e normalizadora presente nas orientações da legislação que norteiam atualmente os cursos de Pedagogia em nosso país. Nesse âmbito, são enfocados os jogos de verdade (que procuram definir modos de ser pedagogo) presentes nos discursos das acadêmicas participantes da pesquisa. As memórias de formação, a produção da gramática normativa do “bom professor”, o imperativo do amor aos alunos e a gestão da formação são as estratégias de governamento problematizadas no decorrer da pesquisa – entendidas, desse modo, como unidades analíticas da Tese. Portanto, a partir das análises desenvolvidas, é visível o governamento operado sob as acadêmicas em formação e o processo de normalização incorporado nos discursos das mesmas (autogovernamento) – uma espécie de reedição dos ditos que estão em voga no meio educacional. Por outro lado, também é possível perceber que a necessidade e viabilidade de promover espaços (permanentes) de discussão e produção de novas experiências formativas desde a graduação, problematizando com os próprios acadêmicos os discursos que os tornam pedagogos de um determinado tipo, ou seja – críticos (que lutam destemidamente pela “salvação” do mundo através da educação), cognitivistas (que assumem os discursos da psicologia enquanto saber científico), afetuosos (que tomam o amor como imperativo principal do trabalho que desenvolvem) e gestores da profissão (que incorporam o empreendedorismo e a correlata cultura do management em suas vidas), entre outras tantas características, “pasteurizam” a docência e impedem o exercício ético de composição da professoralidade dos mesmos. / This thesis joined to Cultural Studies in Education, to the contributions of Michel Foucault‟s studies, and other post-structuralist authors, aims to debate the discourses on the invention of the generalist pedagogue and on his/her governmentality. From the approval of New National Curriculum Guidelines for the Bachelor of Education course (2006), generalist pedagogue is understood as the professional enable to deal with from zero-to-ten-years-old children, youth and adult education, high school in the professorship course, the school management, and technical courses in education. For the production of research data, a twenty hours course was taught to twenty-five students of area of the early childhood education. They were academics from Faculdade de Educação at UFRGS (Universidade Federal do Rio Grande do Sul). During the course, many activities were proposed, such as writing narratives, visual productions, movie analyses, works of art analyses, theatrical sketches, and conversation, in order to discussing the practices in the process of teacher training. Through discourse analysis came from the participants‟ writings, governmentality (and self-governmentality) strategies became evident. They work (hard) to the constitution of the academic participants as future pedagogues. Thus, some notes about the history of the Bachelor Education Course in Brazil are initially presented in this thesis. These notes show the will to power and knowledge in legal (critical) discourses which have historically prescribed (and have limited in a certain way) the training of pedagogues as professionals of education – who are (usually) seen as the responsible for social changes through their work. In a second step, the discourses on New National Curriculum Guidelines for training of pedagogue are analyzed. Through these analyses, it is possible to highlight the strong emphasis on morality and standardization which are presented in the guidelines of the currently legislation that adjusts the Bachelor of Education Course in Brazil. In this context, this thesis focuses on the truth games (which aim to define ways of being a pedagogue) presented in the discourses of the academic participants. Memories of training, production of the grammar rules of “the good teacher”, the imperative of love for students and management training are strategies of governmentality discussed during the research – understood as analytical units of this thesis. Therefore, from the developed analyses, the governmentality undertaken the academics and the standardization process embedded in their discourses (self governmentality) are remarkable – it is a kind of replay of the sayings that are in vogue in the educational scope. On the other hand, it is also possible to notice the need and the feasibility of promoting (permanent) spaces for discussion and production of new teacher training since graduation, discussing with academics the discourses that make them pedagogue of the particular type, that is, critical pedagogue (the ones who courageously fight for the “salvation” of the world through education), cognitive pedagogue (the ones who take the psychology discourse as a scientific knowledge), affectionate pedagogue (the ones who assume that love is the main goal of their work), the manager pedagogue (the ones who incorporate in their lives the entrepreneurship with a management culture), besides many other features that “pasteurize” the teaching and prevent the ethical exercise of a composition of professorial pedagogue.
|
32 |
A invenção do pedagogo generalista : problematizando discursos implicados no governamento de professores em formaçãoCarvalho, Rodrigo Saballa de January 2011 (has links)
Esta Tese, a partir da linha de pesquisa dos Estudos Culturais em Educação e das contribuições dos Estudos desenvolvidos por Michel Foucault, entre outros autores que trabalham em uma perspectiva pós-estruturalista, tem como objetivo problematizar os discursos implicados na invenção do pedagogo generalista e em seu correlato governamento. Pedagogo generalista, entendido a partir da homologação das Novas Diretrizes Curriculares Nacionais para o Curso de Pedagogia (2006), como o profissional habilitado para atender a educação de crianças de zero a dez anos, de jovens e adultos, o ensino médio na modalidade normal, a gestão escolar e cursos técnicos na área educacional. Para produção dos dados da pesquisa, foi ministrado um curso de extensão na área de Educação Infantil com duração de vinte horas, que contou com a participação de vinte cinco acadêmicas do Curso de Pedagogia da Faculdade de Educação da Universidade Federal do Rio Grande do Sul – UFRGS. Durante a realização do curso, foram propostas atividades envolvendo a escrita de narrativas, produções visuais, análises fílmicas, análises de obras de arte, esquetes teatrais e rodas de conversa, tendo em vista a discussão das práticas implicadas no processo formativo. Através da análise dos discursos decorrentes das produções escritas das participantes da pesquisa, são evidenciadas produtivas estratégias de governamento (e autogovernamento) que operam (intensamente) na constituição das mesmas enquanto futuras pedagogas. Para tanto, inicialmente, são apresentadas na Tese algumas notas a respeito da história do curso de Pedagogia em nosso país, evidenciando a vontade de poder e de saber presente nos discursos (críticos) legais, que historicamente têm prescrito (e circunscrito de um determinado modo) a formação do pedagogo enquanto profissional da educação – responsabilizado (muitas vezes) pela mudança social através de seu trabalho. Em um segundo momento, são analisados os discursos das Novas Diretrizes Curriculares Nacionais para formação do pedagogo, destacando a ênfase acentuadamente moral e normalizadora presente nas orientações da legislação que norteiam atualmente os cursos de Pedagogia em nosso país. Nesse âmbito, são enfocados os jogos de verdade (que procuram definir modos de ser pedagogo) presentes nos discursos das acadêmicas participantes da pesquisa. As memórias de formação, a produção da gramática normativa do “bom professor”, o imperativo do amor aos alunos e a gestão da formação são as estratégias de governamento problematizadas no decorrer da pesquisa – entendidas, desse modo, como unidades analíticas da Tese. Portanto, a partir das análises desenvolvidas, é visível o governamento operado sob as acadêmicas em formação e o processo de normalização incorporado nos discursos das mesmas (autogovernamento) – uma espécie de reedição dos ditos que estão em voga no meio educacional. Por outro lado, também é possível perceber que a necessidade e viabilidade de promover espaços (permanentes) de discussão e produção de novas experiências formativas desde a graduação, problematizando com os próprios acadêmicos os discursos que os tornam pedagogos de um determinado tipo, ou seja – críticos (que lutam destemidamente pela “salvação” do mundo através da educação), cognitivistas (que assumem os discursos da psicologia enquanto saber científico), afetuosos (que tomam o amor como imperativo principal do trabalho que desenvolvem) e gestores da profissão (que incorporam o empreendedorismo e a correlata cultura do management em suas vidas), entre outras tantas características, “pasteurizam” a docência e impedem o exercício ético de composição da professoralidade dos mesmos. / This thesis joined to Cultural Studies in Education, to the contributions of Michel Foucault‟s studies, and other post-structuralist authors, aims to debate the discourses on the invention of the generalist pedagogue and on his/her governmentality. From the approval of New National Curriculum Guidelines for the Bachelor of Education course (2006), generalist pedagogue is understood as the professional enable to deal with from zero-to-ten-years-old children, youth and adult education, high school in the professorship course, the school management, and technical courses in education. For the production of research data, a twenty hours course was taught to twenty-five students of area of the early childhood education. They were academics from Faculdade de Educação at UFRGS (Universidade Federal do Rio Grande do Sul). During the course, many activities were proposed, such as writing narratives, visual productions, movie analyses, works of art analyses, theatrical sketches, and conversation, in order to discussing the practices in the process of teacher training. Through discourse analysis came from the participants‟ writings, governmentality (and self-governmentality) strategies became evident. They work (hard) to the constitution of the academic participants as future pedagogues. Thus, some notes about the history of the Bachelor Education Course in Brazil are initially presented in this thesis. These notes show the will to power and knowledge in legal (critical) discourses which have historically prescribed (and have limited in a certain way) the training of pedagogues as professionals of education – who are (usually) seen as the responsible for social changes through their work. In a second step, the discourses on New National Curriculum Guidelines for training of pedagogue are analyzed. Through these analyses, it is possible to highlight the strong emphasis on morality and standardization which are presented in the guidelines of the currently legislation that adjusts the Bachelor of Education Course in Brazil. In this context, this thesis focuses on the truth games (which aim to define ways of being a pedagogue) presented in the discourses of the academic participants. Memories of training, production of the grammar rules of “the good teacher”, the imperative of love for students and management training are strategies of governmentality discussed during the research – understood as analytical units of this thesis. Therefore, from the developed analyses, the governmentality undertaken the academics and the standardization process embedded in their discourses (self governmentality) are remarkable – it is a kind of replay of the sayings that are in vogue in the educational scope. On the other hand, it is also possible to notice the need and the feasibility of promoting (permanent) spaces for discussion and production of new teacher training since graduation, discussing with academics the discourses that make them pedagogue of the particular type, that is, critical pedagogue (the ones who courageously fight for the “salvation” of the world through education), cognitive pedagogue (the ones who take the psychology discourse as a scientific knowledge), affectionate pedagogue (the ones who assume that love is the main goal of their work), the manager pedagogue (the ones who incorporate in their lives the entrepreneurship with a management culture), besides many other features that “pasteurize” the teaching and prevent the ethical exercise of a composition of professorial pedagogue.
|
33 |
La perception de la déontologie par les journalistes en France : une étude sur les médias généralistes des années 1990-2010 / Journalists' perceptions of professional ethics in FranceSilva da Costa, Helena da 05 May 2012 (has links)
Cette recherche explore un sujet encore très peu étudié empiriquement: où en sont “l’éthique professionnelle” et la “déontologie” chez les journalistes en France? Qu’ont-ils à dire? À quelles embûches sont-ils confrontés ? Quel est le rôle des rédacteurs en chef ? En raison de la concurrence accrue, de la concentration de la propriété des médias, des changements technologiques et de plusieurs autres facteurs, « l’éthique » se situe à l’épicentre du journalisme contemporain. La thèse repose d’abord sur une analyse de contenu des points de vue d’une centaine de journalistes professionnels qui furent interviewés en face à face, dans la presse nationale, écrite et audiovisuelle, privée et publique. Elle repose également sur une observation participante : une dizaine de stages dans divers média. Elle analyse de surcroît une vingtaine de chartes ou codes de déontologie, de même qu’elle se fonde sur une brève enquête de certains directeurs d’école de journalisme. La thèse révèle la montée récente des enjeux déontologiques et la bonne volonté des journalistes et de leurs médiateurs pour faire face à cette situation. Elle montre aussi les différences entre les pratiques éthiques concrètes des différents médias, l’impuissance des écoles de journalisme à enseigner l’éthique, l’importance névralgique de l’attitude des patrons de presse envers l’éthique journalistique et parfois les difficultés des journalistes devant certains dilemmes et certaines pressions. Un des enjeux majeurs pour l’avenir est de rendre plus cohérentes les chartes ou codes écrits, les différentes formes de gouvernance de la presse et les pratiques journalistiques. / This study is an exploratory research on a topic that has been slightly studied empirically. What are the issues of “professional ethics” and “deontology” amongst French journalists? What do they have to say? What problems are they confronted with? What is the role of chief editors? Because of increased competition, the concentration of press ownership, new technologies and other factors, “ethics” has now become a central issue in journalism. The thesis is, above all, a content analysis of journalists’ points of view, as recorded in some 100 face to face interviews of journalists in the generalist, private and public French press, newspapers and broadcasters. Participant observation was also a key methodology: some 10 quite lengthy internships in several media were done. Furthermore, the thesis analyses some 20 charters and codes of ethics and conducted a brief enquiry within schools of journalism. The thesis shows that ethics is now an absolutely central issue and that journalists (and their ombudsmen) have a very good will to cope with this new situation. Yet more, the thesis also shows the difference in the concrete practices of various medias, the incapacity of journalism schools to teach ethics, the extreme importance of the attitudes of the main editors, as well as sometimes the difficulties of journalists to cope with some pressures and dilemmas. One major issue for the future is to make the written charters and codes, press governance and journalistic practices more coherent.
|
34 |
Interação entre plantas produtoras de óleo floral e abelhas coletoras de óleo floral (Apidae, Hymenoptera) / Interaction between oil plants and oil collecting bees (Apidae, Hymenoptera).Silva, Carlos Eduardo Pinto da 27 November 2013 (has links)
A interação entre plantas e seus visitantes florais forma uma rede de interação complexa. Essa rede de interação possui propriedades emergentes que caracterizam a estrutura da rede. A composição, a riqueza e o papel das espécies nas redes de interação podem variar espaço-temporalmente e levar a alteração na estrutura das redes. A estrutura também pode variar de acordo com o grau de dependência entre os pares de espécies. É esperado que interações com elevado grau de dependência mútua variem menos no tempo e no espaço. A interação entre as plantas produtoras de óleo floral e as abelhas coletoras de óleo é de alta dependência mútua, já que as abelhas necessitam do óleo para alimentar as larvas e construir ninhos e são polinizadores mais importantes dessas plantas. O alimento larval destas abelhas é composto por pólen, óleo e néctar. A quantidade de alimento disponível para as larvas pode influenciar o tamanho dos adultos quando emergirem. As espécies de abelhas coletoras de óleo são solitárias, ou seja, não existe contato entre as gerações. Assim uma abelha recém-emergida deve ser capaz de encontrar as fontes de óleo, seguindo algum sinal de atração, que poderia ser através de odores voláteis. No presente trabalho analisamos se a estrutura da rede de interação formada pelas plantas produtoras de óleo floral e seus visitantes coletores de óleo varia espacialmente e temporalmente. Para a análise temporal coletamos dados da interação por dois anos em Itirapina, São Paulo. No estudo de variação espacial comparamos as redes de interação em cinco áreas de cerrado no interior de São Paulo. Em ambos os estudos usamos métricas de redes complexas. Além disso, estudamos a relação entre tamanho de célula de cria e quantidade de alimento disponível para as larvas e tamanho das abelhas adultas ao emergirem, para uma espécie de abelha coletora de óleo: Tetrapedia diversipes. Para isso medimos abelhas e suas células de cria e relacionamos estas medidas. Também manipulamos a quantidade de alimento disponível para as larvas e medimos os adultos emergidos. Por fim, procuramos odores voláteis em Byrsonima intermedia. Coletamos odores voláteis com a técnica de dynamic headspace. Analisamos as coletas com GCMS. A estrutura da rede de interação entre as plantas produtoras de óleo floral e as abelhas coletoras de óleo variou espaço-temporalmente. A análise temporal mostrou que o grau de especialização da rede foi fortemente alterado entre os anos de estudo e que a abundância foi um fator importante para explicar a ocorrência das interações. As espécies que tiveram suas abundâncias alteradas entre os anos também tiveram alteração no número de interações. Na análise espacial observamos que as interações e as espécies compartilhadas entre os locais de estudo foram aquelas com maior grau de interação (generalista). Além das interações e espécies generalistas se manterem nas cinco localidades, as espécies generalistas sustentam as espécies localmente raras. Byrsonima intermedia foi considerada uma espécie super-generalista nas cinco redes analisadas e 77% das interações compartilhadas envolveram esta espécie. A morfometria dos indivíduos de Tetrapedia diversipes estudados foi positivamente correlacionada com o volume da célula de cria e a quantidade de alimento. Quando relacionamos o volume das células de cria com as medidas corpóreas das abelhas verificamos que as abelhas maiores emergiram em células maiores. No entanto essa relação foi fraca. Após o experimento de manipulação de alimento verificamos que as abelhas emergidas de células sem manipulação foram maiores que as abelhas que tiveram o alimento retirado, e que entre as abelhas manipuladas aquelas que receberam mais alimento foram maiores. Nós não encontramos odores voláteis em flores de Byrsonima intermedia. / The plant pollinator interaction forms a complex network. These networks have emergent properties that characterize the structure of network. The number, identity and species role of the network may vary spatio-temporally and lead to changes in the structure of the networks. Moreover, the structure may vary according to the dependence degree of the interacting pairs. It is expected that interactions with a high mutual dependence degree are more stable. The interaction between oil producing plants and oil collecting bees is highly mutual dependence, since bees need oil to feed the larvae and are pollinators of these plants. The larval diet consists of pollen and oil/nectar. The amount of food available to the larvae may influence the adults size. The oil collecting bees are solitary, i.e., there is no contact between generations. Thus, a naive emerged bee should be able to find the oil plants, using some attractive cues that could be volatile odor. In this work we want to answer if the network structure of the interaction between oil producing plants and oil collecting bees varies spatially and temporally. For the temporal analysis we carried out field work for two years at Itirapina, São Paulo. In the study of spatial variation we compare interaction networks in five areas of cerrado. In both studies we use metrics of complex networks. Furthermore, we studied the relation between size of adult bees (Tetrapedia diversipes) and brood cell sizes and the amount of food available for the larvae. We measured the bees and their brood cells and relate it. Also we manipulated the amount of food available for the larvae and we took measures of the adults. Finally, we search for volatile odors in Byrsonima intermedia. We collect volatile odors with the technique of dynamic headspace. We analyzed the samples with GCMS. The network structure of interaction between oil producing plants and oil collecting bees varied spatio-temporally. The temporal analysis showed that the specialization degree of the network changed between the years and that the abundance has a key role to explain the occurrence of interactions. Species that had changed their abundances between years were also changed in the number of interactions. Spatial analysis found out that the interactions and species ubiquitous among the study sites were those that had the greatest interaction degree (generalist specie). Moreover, generalist species maintain the locally rare species. Byrsonima intermedia was regarded a super-generalist specie in the five networks analyzed and 77% of ubiquitous interactions involved this species. The morphometry of Tetrapedia diversipes individuals was positively correlated with the volume of the brood cells and the amount of food. When relating the volume of brood cells with measures of bees we found that larger bees emerged in larger cells. However this relationship was weak. The experiment of handling food showed that bees emerged from control cells were larger than bees that had the food removed, and between the manipulated bees those who received more food became bigger. We did not detect volatile odors in flowers Byrsonima intermedia.
|
35 |
Policy and pedagogy in the further education sector : an emerging professional identityNormand, Carey January 2013 (has links)
No description available.
|
36 |
Pollination ecology of Trachymene incisa (Apiaceae): Understanding generalised plant-pollinator systemsDavila, Yvonne Caroline January 2006 (has links)
Doctor of Philosophy (PhD) / A renewed focus on generalised pollinator systems has inspired a conceptual framework which highlights that spatial and temporal interactions among plants and their assemblage of pollinators can vary across the individual, population, regional and species levels. Pollination is clearly a dynamic interaction, varying in the number and interdependence of participants and the strength of the outcome of the interaction. Therefore, the role of variation in pollination is fundamental for understanding ecological dynamics of plant populations and is a major factor in the evolution and maintenance of generalised and specialised pollination systems. My study centred on these basic concepts by addressing the following questions: (1) How variable are pollinators in a generalised pollination system? To what degree do insect visitation rates and assemblage composition vary spatially among populations and temporally among flowering seasons? (2) How does variation in pollinators affect plant reproductive success? I chose to do this using a model system, Trachymene incisa subsp. incisa (Apiaceae), which is a widespread Australian herbaceous species with simple white flowers grouped into umbels that attract a high diversity of insect visitors. The Apiaceae are considered to be highly generalist in terms of pollination, due to their simple and uniform floral display and easily accessible floral rewards. Three populations of T. incisa located between 70 km and 210 km apart were studied over 2-3 years. The few studies investigating spatial and temporal variation simultaneously over geographic and yearly/seasonal scales indicate that there is a trend for more spatial than temporal variation in pollinators of generalist-pollinated plants. My study showed both spatial and temporal variation in assemblage composition among all populations and variation in insect visitation rates, in the form of a significant population by year interaction. However, removing ants from the analyses to restrict the assemblage to flying insects and the most likely pollinators, resulted in a significant difference in overall visitation rate between years but no difference in assemblage composition between the Myall Lakes and Tomago populations. These results indicate more temporal than spatial variation in the flying insect visitor assemblage of T. incisa. Foraging behaviour provides another source of variation in plant-pollinator interactions. Trachymene incisa exhibits umbels that function as either male or female at any one time and offer different floral rewards in each phase. For successful pollination, pollinators must visit both male and female umbels during a foraging trip. Insects showed both preferences and non-preferences for umbel phases in natural patches where the gender ratio was male biased. In contrast, insects showed no bias in visitation during a foraging trip or in time spent foraging on male and female umbels in experimental arrays where the gender ratio was equal. Pollinator assemblages consisting of a mixture of different pollinator types coupled with temporal variation in the assemblages of populations among years maintains generalisation at the population/local level. In addition, spatial variation in assemblages among populations maintains generalisation at the species level. Fire alters pollination in T. incisa by shifting the flowering season and reducing the abundance of flying insects. Therefore, fire plays an important role in maintaining spatial and temporal variation in this fire-prone system. Although insect pollinators are important in determining the mating opportunities of 90% of flowering plant species worldwide, few studies have looked at the effects of variation in pollinator assemblages on plant reproductive success and mating. In T. incisa, high insect visitation rates do not guarantee high plant reproductive success, indicating that the quality of visit is more important than the rate of visitation. This is shown by comparing the Agnes Banks and Myall Lakes populations in 2003: Agnes Banks received the highest visitation rate from an assemblage dominated by ants but produced the lowest reproductive output, and Myall Lakes received the lowest visitation rate by an assemblage dominated by a native bee and produced the highest seedling emergence. Interestingly, populations with different assemblage composition can produce similar percentage seed set per umbel. However, similar percentage seed set did not result in similar percentage seedling emergence. Differences among years in reproductive output (total seed production) were due to differences in umbel production (reproductive effort) and proportion of umbels with seeds, and not seed set per umbel. Trachymene incisa is self-compatible and suffers weak to intermediate levels of inbreeding depression through early stages of the life cycle when seeds are self-pollinated and biparentally inbred. Floral phenology, in the form of synchronous protandry, plays an important role in avoiding self-pollination within umbels and reducing the chance of geitonogamous pollination between umbels on the same plant. Although pollinators can increase the rate of inbreeding in T. incisa by foraging on both male and female phase umbels on the same plant or closely related plants, most consecutive insect movements were between plants not located adjacent to each other. This indicates that inbreeding is mostly avoided and that T. incisa is a predominantly outcrossing species, although further genetic analyses are required to confirm this hypothesis. A new conceptual understanding has emerged from the key empirical results in the study of this model generalised pollination system. The large differences among populations and between years indicate that populations are not equally serviced by pollinators and are not equally generalist. Insect visitation rates varied significantly throughout the day, highlighting that sampling of pollinators at one time will result in an inaccurate estimate and usually underestimate the degree of generalisation. The visitor assemblage is not equivalent to the pollinator assemblage, although non-pollinating floral visitors are likely to influence the overall effectiveness of the pollinator assemblage. Given the high degree of variation in both the number of pollinator species and number of pollinator types, I have constructed a model which includes the degree of ecological and functional specialisation of a plant species on pollinators and the variation encountered across different levels of plant organisation. This model describes the ecological or current state of plant species and their pollinators, as well as presenting the patterns of generalisation across a range of populations, which is critical for understanding the evolution and maintenance of the system. In-depth examination of pollination systems is required in order to understand the range of strategies utilised by plants and their pollinators, and I advocate a complete floral visitor assemblage approach to future studies in pollination ecology. In particular, future studies should focus on the role of introduced pollinators in altering generalised plant-pollinator systems and the contribution of non-pollinating floral visitors to pollinator assemblage effectiveness. Comparative studies involving plants with highly conserved floral displays, such as those in the genus Trachymene and in the Apiaceae, will be useful for investigating the dynamics of generalised pollination systems across a range of widespread and restricted species.
|
37 |
Pollination ecology of Trachymene incisa (Apiaceae): Understanding generalised plant-pollinator systemsDavila, Yvonne Caroline January 2006 (has links)
Doctor of Philosophy (PhD) / A renewed focus on generalised pollinator systems has inspired a conceptual framework which highlights that spatial and temporal interactions among plants and their assemblage of pollinators can vary across the individual, population, regional and species levels. Pollination is clearly a dynamic interaction, varying in the number and interdependence of participants and the strength of the outcome of the interaction. Therefore, the role of variation in pollination is fundamental for understanding ecological dynamics of plant populations and is a major factor in the evolution and maintenance of generalised and specialised pollination systems. My study centred on these basic concepts by addressing the following questions: (1) How variable are pollinators in a generalised pollination system? To what degree do insect visitation rates and assemblage composition vary spatially among populations and temporally among flowering seasons? (2) How does variation in pollinators affect plant reproductive success? I chose to do this using a model system, Trachymene incisa subsp. incisa (Apiaceae), which is a widespread Australian herbaceous species with simple white flowers grouped into umbels that attract a high diversity of insect visitors. The Apiaceae are considered to be highly generalist in terms of pollination, due to their simple and uniform floral display and easily accessible floral rewards. Three populations of T. incisa located between 70 km and 210 km apart were studied over 2-3 years. The few studies investigating spatial and temporal variation simultaneously over geographic and yearly/seasonal scales indicate that there is a trend for more spatial than temporal variation in pollinators of generalist-pollinated plants. My study showed both spatial and temporal variation in assemblage composition among all populations and variation in insect visitation rates, in the form of a significant population by year interaction. However, removing ants from the analyses to restrict the assemblage to flying insects and the most likely pollinators, resulted in a significant difference in overall visitation rate between years but no difference in assemblage composition between the Myall Lakes and Tomago populations. These results indicate more temporal than spatial variation in the flying insect visitor assemblage of T. incisa. Foraging behaviour provides another source of variation in plant-pollinator interactions. Trachymene incisa exhibits umbels that function as either male or female at any one time and offer different floral rewards in each phase. For successful pollination, pollinators must visit both male and female umbels during a foraging trip. Insects showed both preferences and non-preferences for umbel phases in natural patches where the gender ratio was male biased. In contrast, insects showed no bias in visitation during a foraging trip or in time spent foraging on male and female umbels in experimental arrays where the gender ratio was equal. Pollinator assemblages consisting of a mixture of different pollinator types coupled with temporal variation in the assemblages of populations among years maintains generalisation at the population/local level. In addition, spatial variation in assemblages among populations maintains generalisation at the species level. Fire alters pollination in T. incisa by shifting the flowering season and reducing the abundance of flying insects. Therefore, fire plays an important role in maintaining spatial and temporal variation in this fire-prone system. Although insect pollinators are important in determining the mating opportunities of 90% of flowering plant species worldwide, few studies have looked at the effects of variation in pollinator assemblages on plant reproductive success and mating. In T. incisa, high insect visitation rates do not guarantee high plant reproductive success, indicating that the quality of visit is more important than the rate of visitation. This is shown by comparing the Agnes Banks and Myall Lakes populations in 2003: Agnes Banks received the highest visitation rate from an assemblage dominated by ants but produced the lowest reproductive output, and Myall Lakes received the lowest visitation rate by an assemblage dominated by a native bee and produced the highest seedling emergence. Interestingly, populations with different assemblage composition can produce similar percentage seed set per umbel. However, similar percentage seed set did not result in similar percentage seedling emergence. Differences among years in reproductive output (total seed production) were due to differences in umbel production (reproductive effort) and proportion of umbels with seeds, and not seed set per umbel. Trachymene incisa is self-compatible and suffers weak to intermediate levels of inbreeding depression through early stages of the life cycle when seeds are self-pollinated and biparentally inbred. Floral phenology, in the form of synchronous protandry, plays an important role in avoiding self-pollination within umbels and reducing the chance of geitonogamous pollination between umbels on the same plant. Although pollinators can increase the rate of inbreeding in T. incisa by foraging on both male and female phase umbels on the same plant or closely related plants, most consecutive insect movements were between plants not located adjacent to each other. This indicates that inbreeding is mostly avoided and that T. incisa is a predominantly outcrossing species, although further genetic analyses are required to confirm this hypothesis. A new conceptual understanding has emerged from the key empirical results in the study of this model generalised pollination system. The large differences among populations and between years indicate that populations are not equally serviced by pollinators and are not equally generalist. Insect visitation rates varied significantly throughout the day, highlighting that sampling of pollinators at one time will result in an inaccurate estimate and usually underestimate the degree of generalisation. The visitor assemblage is not equivalent to the pollinator assemblage, although non-pollinating floral visitors are likely to influence the overall effectiveness of the pollinator assemblage. Given the high degree of variation in both the number of pollinator species and number of pollinator types, I have constructed a model which includes the degree of ecological and functional specialisation of a plant species on pollinators and the variation encountered across different levels of plant organisation. This model describes the ecological or current state of plant species and their pollinators, as well as presenting the patterns of generalisation across a range of populations, which is critical for understanding the evolution and maintenance of the system. In-depth examination of pollination systems is required in order to understand the range of strategies utilised by plants and their pollinators, and I advocate a complete floral visitor assemblage approach to future studies in pollination ecology. In particular, future studies should focus on the role of introduced pollinators in altering generalised plant-pollinator systems and the contribution of non-pollinating floral visitors to pollinator assemblage effectiveness. Comparative studies involving plants with highly conserved floral displays, such as those in the genus Trachymene and in the Apiaceae, will be useful for investigating the dynamics of generalised pollination systems across a range of widespread and restricted species.
|
38 |
Interação entre plantas produtoras de óleo floral e abelhas coletoras de óleo floral (Apidae, Hymenoptera) / Interaction between oil plants and oil collecting bees (Apidae, Hymenoptera).Carlos Eduardo Pinto da Silva 27 November 2013 (has links)
A interação entre plantas e seus visitantes florais forma uma rede de interação complexa. Essa rede de interação possui propriedades emergentes que caracterizam a estrutura da rede. A composição, a riqueza e o papel das espécies nas redes de interação podem variar espaço-temporalmente e levar a alteração na estrutura das redes. A estrutura também pode variar de acordo com o grau de dependência entre os pares de espécies. É esperado que interações com elevado grau de dependência mútua variem menos no tempo e no espaço. A interação entre as plantas produtoras de óleo floral e as abelhas coletoras de óleo é de alta dependência mútua, já que as abelhas necessitam do óleo para alimentar as larvas e construir ninhos e são polinizadores mais importantes dessas plantas. O alimento larval destas abelhas é composto por pólen, óleo e néctar. A quantidade de alimento disponível para as larvas pode influenciar o tamanho dos adultos quando emergirem. As espécies de abelhas coletoras de óleo são solitárias, ou seja, não existe contato entre as gerações. Assim uma abelha recém-emergida deve ser capaz de encontrar as fontes de óleo, seguindo algum sinal de atração, que poderia ser através de odores voláteis. No presente trabalho analisamos se a estrutura da rede de interação formada pelas plantas produtoras de óleo floral e seus visitantes coletores de óleo varia espacialmente e temporalmente. Para a análise temporal coletamos dados da interação por dois anos em Itirapina, São Paulo. No estudo de variação espacial comparamos as redes de interação em cinco áreas de cerrado no interior de São Paulo. Em ambos os estudos usamos métricas de redes complexas. Além disso, estudamos a relação entre tamanho de célula de cria e quantidade de alimento disponível para as larvas e tamanho das abelhas adultas ao emergirem, para uma espécie de abelha coletora de óleo: Tetrapedia diversipes. Para isso medimos abelhas e suas células de cria e relacionamos estas medidas. Também manipulamos a quantidade de alimento disponível para as larvas e medimos os adultos emergidos. Por fim, procuramos odores voláteis em Byrsonima intermedia. Coletamos odores voláteis com a técnica de dynamic headspace. Analisamos as coletas com GCMS. A estrutura da rede de interação entre as plantas produtoras de óleo floral e as abelhas coletoras de óleo variou espaço-temporalmente. A análise temporal mostrou que o grau de especialização da rede foi fortemente alterado entre os anos de estudo e que a abundância foi um fator importante para explicar a ocorrência das interações. As espécies que tiveram suas abundâncias alteradas entre os anos também tiveram alteração no número de interações. Na análise espacial observamos que as interações e as espécies compartilhadas entre os locais de estudo foram aquelas com maior grau de interação (generalista). Além das interações e espécies generalistas se manterem nas cinco localidades, as espécies generalistas sustentam as espécies localmente raras. Byrsonima intermedia foi considerada uma espécie super-generalista nas cinco redes analisadas e 77% das interações compartilhadas envolveram esta espécie. A morfometria dos indivíduos de Tetrapedia diversipes estudados foi positivamente correlacionada com o volume da célula de cria e a quantidade de alimento. Quando relacionamos o volume das células de cria com as medidas corpóreas das abelhas verificamos que as abelhas maiores emergiram em células maiores. No entanto essa relação foi fraca. Após o experimento de manipulação de alimento verificamos que as abelhas emergidas de células sem manipulação foram maiores que as abelhas que tiveram o alimento retirado, e que entre as abelhas manipuladas aquelas que receberam mais alimento foram maiores. Nós não encontramos odores voláteis em flores de Byrsonima intermedia. / The plant pollinator interaction forms a complex network. These networks have emergent properties that characterize the structure of network. The number, identity and species role of the network may vary spatio-temporally and lead to changes in the structure of the networks. Moreover, the structure may vary according to the dependence degree of the interacting pairs. It is expected that interactions with a high mutual dependence degree are more stable. The interaction between oil producing plants and oil collecting bees is highly mutual dependence, since bees need oil to feed the larvae and are pollinators of these plants. The larval diet consists of pollen and oil/nectar. The amount of food available to the larvae may influence the adults size. The oil collecting bees are solitary, i.e., there is no contact between generations. Thus, a naive emerged bee should be able to find the oil plants, using some attractive cues that could be volatile odor. In this work we want to answer if the network structure of the interaction between oil producing plants and oil collecting bees varies spatially and temporally. For the temporal analysis we carried out field work for two years at Itirapina, São Paulo. In the study of spatial variation we compare interaction networks in five areas of cerrado. In both studies we use metrics of complex networks. Furthermore, we studied the relation between size of adult bees (Tetrapedia diversipes) and brood cell sizes and the amount of food available for the larvae. We measured the bees and their brood cells and relate it. Also we manipulated the amount of food available for the larvae and we took measures of the adults. Finally, we search for volatile odors in Byrsonima intermedia. We collect volatile odors with the technique of dynamic headspace. We analyzed the samples with GCMS. The network structure of interaction between oil producing plants and oil collecting bees varied spatio-temporally. The temporal analysis showed that the specialization degree of the network changed between the years and that the abundance has a key role to explain the occurrence of interactions. Species that had changed their abundances between years were also changed in the number of interactions. Spatial analysis found out that the interactions and species ubiquitous among the study sites were those that had the greatest interaction degree (generalist specie). Moreover, generalist species maintain the locally rare species. Byrsonima intermedia was regarded a super-generalist specie in the five networks analyzed and 77% of ubiquitous interactions involved this species. The morphometry of Tetrapedia diversipes individuals was positively correlated with the volume of the brood cells and the amount of food. When relating the volume of brood cells with measures of bees we found that larger bees emerged in larger cells. However this relationship was weak. The experiment of handling food showed that bees emerged from control cells were larger than bees that had the food removed, and between the manipulated bees those who received more food became bigger. We did not detect volatile odors in flowers Byrsonima intermedia.
|
39 |
Hepáticas (Marchantiophyta) do Parque Estadual do Ibitipoca (MG-Brasil): florística e ecologiaMachado, Priscila de Souza 31 March 2016 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-08-25T14:33:45Z
No. of bitstreams: 0 / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-30T14:34:13Z (GMT) No. of bitstreams: 0 / Made available in DSpace on 2017-08-30T14:34:13Z (GMT). No. of bitstreams: 0
Previous issue date: 2016-03-31 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A Floresta Atlântica é considerada um hotspot de biodiversidade mundial por apresentar altas taxas de endemismos, grande riqueza e abundância de espécies vegetais, incluindo de briófitas (antóceros, hepáticas, musgos). A Floresta Atlântica apresenta heterogeneidade de paisagens incluindo diferentes fitofisionomias. No Parque Estadual do Ibitipoca, a heterogeneidade da Floresta Atlântica se revela em um complexo mosaico de fitofisionomias florestais, arbustivas, campestres e savânicas, que são contínuas umas as outras formando regiões de borda. As bordas podem ser naturais, constituídas pela dinâmica natural de formação do ambiente ou formadas pelo homen que causa impacto ao estabelecer suas atividades. As bordas apresentam modificações na riqueza florística, abundância, densidade e diversidade, processo conhecido como efeito de borda. As hepáticas (Marchantiophyta) são importantes na composição e riqueza da Floresta Atlântica e em estudos sobre a influência da borda por serem organismos bioindicadores. Estudos sobre efeito de borda na composição de especies na Floresta Atlântica Mineira são importantes para a sua conservação. Deste modo, o trabalho foi desenvolvido na área que compreende a Floresta Latifoliada Nebular Perenifólia Tropical Superomontana (Floresta Nebular) do Parque Estadual de Ibitipoca (Minas Gerais, Brasil), também conhecida como Mata Grande, com o objetivo de estudar as hepáticas (Marchantiophyta), através de coletas sistemáticas, identificação das espécies e avaliações ecológicas (agrupamento, One-way ANOSIM, riqueza, abundância, freqüência e tolerância à luz). As coletas foram realizadas nos anos de 2013 e 2014, distribuindo-se 20 parcelas de 5x5m2; a partir da borda em direção ao interior da Floresta Nebular. Os resultados indicam abundância de 1220 espécimes e riqueza de 90 espécies, distribuídas em 29 gêneros e nove famílias. Do total de espécies identificadas, nove são endêmicas do Brasil e oito representam novos registros para o estado de Minas Gerais. A família Lejeuneaceae é a mais rica e abundante. A análise de agrupamento mostra a formação de dois grupos distintos (borda e interior florestal) e a análise One-way ANOSIM atesta que tal diferença é significativa. A riqueza da borda foi de 64 espécies (22 exclusivas). Já no interior florestal, a riqueza foi de 68 espécies (26 exclusivas). A distribuição das classes de frequência, na região da borda apresentou predominância de espécies consideradas raras, seguidas das pouco frequentes, assíduas, muito freqüentes e frequentes. Enquanto as parcelas do interior florestal inverteram a classe pouco frequente por assídua. As espécies foram classificadas em especialistas de sol, de sombra e generalistas e quando comparadas, a distribuição do grupo ecológico de tolerância à luz não mostrou diferenças estatísticas significativas entre a borda e o interior florestal. Ressalta-se o tamanho da floresta estudada (64 ha) como importante para a conservação das briófitas, devido à sua elevada riqueza específica associada à ocorrência de táxons endêmicos para o Brasil. / The Atlantic Forest is considered a global biodiversity hotspot by presenting high rates of endemism, great richness and plant abundance, including bryophytes (hornworts, liverworts, mosses). Liverworts are important organisms in the composition and richness of Atlantic Forest and they belong to Marchantiophyta. The Atlantic Forest is composed by heterogeneous landscapes including different phytophysiognomies. In Parque Estadual de Ibitipoca such heterogeneity forms a complex mosaic of forest vegetation types, shrub, countryside and savannas, which are continuous to each other forming regions of edge. The edges can be natural created by the natural dynamics of environmental formation, and caused by mankind in order to establish their activities. The edges support community with different characteristics from continuing communities, showing changes in species richness, abundance, density and diversity, a process known as edge effect. The liverworts are bioindicators organisms and then they are important in studies on edge influence. Studies on edge effect on species composition in Minas Gerais Atlantic Forest are essential for their conservation. Therefore, this study was developed in Broadleaved Cloud Evergreen Upper Highlands Tropical Forest (Broadleaved Forest) from Parque Estadual de Ibitipoca (Minas Gerais, Brazil), also known as “Mata Grande”, and with a goal of studying the liverworts species (Marchantiophyta) through systematic collections, identification of species and ecological assessments (cluster analysis, One-way ANOSIM, richness, abundance, frequency and tolerance to light). Samples were collected in 2013 and 2014 distributing 20 plots of 5x5m2 each from the edge through the interior of Broadleaved Forest. The results indicate abundance 1220 specimens and richness of 90 species distributed in 29 genera and nine families. From the total species identified nine are endemic to Brazil and eight represent new records for Minas Gerais State. The Lejeuneaceae family is the most rich and abundant in the forest studied. The cluster analysis showed the formation of two distinct groups (edge and forest interior), and One-way ANOSIM analysis confirms that this difference is significant. The edge richness was 64 species (22 exclusive) and in the forest interior the richness was 68 species (26 exclusive). The frequency classes distribution in the edge area presented predominance of species considered rare, followed by infrequent, assiduous, very common and common. However, the forest interior plots reversed infrequent class by assiduous. The species were classified as generalist, sun specialist and/or shade specialist and when they were compared the difference were not statistically significative between the edge and forest interior. It is important to highligh this forest for bryophytes conservation because of its size (64 ha) and its high species richness associated with the occurrence of endemic taxa to Brazil.
|
40 |
L'hétérogénéité spatiale et temporelle des paysages agricoles influence les auxiliaires généralistes des cultures et le potentiel de contrôle biologique des ravageurs / Spatial and temporal heterogeneity of agricultural landscapes influences generalist natural enemies and the potential for biological pest controlBertrand, Colette 10 December 2015 (has links)
Les carabes et les araignées sont des auxiliaires généralistes susceptibles d'exercer un contrôle efficace des ravageurs des cultures. La structure et composition de leurs communautés, ainsi que l'efficacité du contrôle biologique, dépendent de l'hétérogénéité des paysages, et en particulier de la présence d'habitats semi-naturels. Mais le rôle de la mosaïque agricole, susceptible de présenter une forte hétérogénéité dans l'espace et dans le temps, reste aujourd'hui peu connu. L'objectif de ce travail a été d'évaluer les effets de l'hétérogénéité spatiale et temporelle des paysages agricoles sur des auxiliaires généralistes et sur le potentiel de contrôle biologique. Nous avons échantillonné les communautés de carabes et d'araignées dans des parcelles de céréales, et estimé le potentiel de prédation par des pucerons sentinelles collés sur des cartes de prédation. Nous avons caractérisé l'hétérogénéité spatiale des paysages autour des parcelles de céréales par le pourcentage d'éléments boisés et la longueur du réseau de haies, la taille moyenne des parcelles agricoles, et la diversité des cultures. Nous avons également mis au point quatre nouvelles métriques qui synthétisent différents aspects de l'hétérogénéité temporelle interannuelle des surfaces cultivées. Nos résultats montrent qu'au printemps les araignées sont plus abondantes dans les parcelles de céréales situées dans des paysages composés de petites parcelles. Au début de l'été, ces paysages favorisent également les taux de prédation de pucerons mesurés par les cartes de prédation, et l'abondance des carabes qui se reproduisent au printemps et qui hivernent en tant qu'adultes dans des habitats semi-naturels. Les carabes qui hivernent dans le sol des parcelles au stade larvaire et se reproduisent à l'automne sont quant à eux favorisés par la diversité des cultures dans le paysage. Nos résultats montrent enfin que l'hétérogénéité temporelle de la mosaïque agricole - caractérisée par les changements de la diversité de cultures au cours des cinq dernières années - favorise elle aussi certaines espèces de carabes communément rencontrées dans les parcelles agricoles (Poecilus cupreus ou Pterostichus melanarius) et susceptibles de jouer un rôle important en tant qu'auxiliaires. Ces résultats mettent en avant le rôle complémentaire des bordures de champs non cultivées et de la mosaïque des cultures pour différents groupes d'auxiliaires, et soulignent l'importance de prendre en compte l'hétérogénéité spatiale et temporelle des surfaces cultivées dans l'étude de la biodiversité des paysages agricoles. Dans le contexte de réduction des produits phytosanitaires, nos résultats suggèrent que des paysages présentant une diversité de cultures importante variable dans le temps, et des petites parcelles qui favorisent l'intrication entre les habitats semi-naturels et les cultures, sont susceptibles de favoriser les auxiliaires généralistes ainsi que le potentiel de contrôle biologique des ravageurs. / In the context of reducing pesticide use, the potential role of some arthropod groups as pest natural enemies provides them an ecological and economic interest. In particular, ground beetles and spiders are generalist predators likely to be effective biocontrol agents. Previous studies have shown that the structure and composition of their communities, as well as the effectiveness of biological control, are influenced by landscape heterogeneity, and in particular by the presence of semi-natural habitats. However, the role of the crop mosaic, which can be highly heterogeneous in space and time, have been little considered. The main objective of our study was to determine the influences of spatial and temporal heterogeneity of agricultural landscapes on generalist natural enemies and the potential for biological pest control. We sampled carabid and spider communities in winter cereal fields, and estimated biological control potential using sentinel aphids glued on predation cards. We characterized the spatial heterogeneity of the landscapes around each cereal field by 1) the amount of wooded habitats and the length of the hedgerow network, 2) the average size of the agricultural fields, and 3) crop diversity. We also proposed four new metrics that synthesize different aspects of the multi-year temporal heterogeneity of cropped areas. Our results show that in spring, landscapes characterized by small fields, and therefore by a high density of non-cropped field margins, promote spiders abundance in cereal fields. In early summer, landscapes with small fields also promote aphid predation rates and the abundance of carabid spring breeders, which overwinter as adults in semi-natural habitats. Crop diversity promotes the abundance of carabids overwintering in soils of arable fields and breeding in autumn. Our results also show that the temporal heterogeneity of the crop mosaic - characterized among other things by the changes in crop diversity over a five year period - benefits some carabid species commonly found in agricultural landscapes (such as Poecilus cupreus and Pterostichus melanarius) which are likely to play an important role as pest natural enemies. These results highlight the complementary role of the crop mosaic and the non-cropped field borders for generalist natural enemies, and show the importance of taking into account the spatial and temporal heterogeneity of the cultivated area in further ecological studies on biodiversity in agricultural landscapes. In the context of reducing pesticide use, our results suggest that landscapes with 1) a high crop diversity that change over time, and 2) small fields that promote the interspersion between crops and semi-natural habitats, are likely to promote generalist natural enemies and biological pest control.
|
Page generated in 0.0826 seconds