The climate is a highly dynamic system and has a great influence on human activities and biodiversity. One of the guiding principles of this research is the "change" as a natural aspect of climatic components, since the Earth throughout its history has experienced moments of heating and cooling. The second guiding principle of this work is grounded in the tradition of using plant species as indicators of the environment they grow. The overall objective is to evaluate the occurrence of climate change in tropical environments by phenological and biogeographic characteristics of fitoindicator species of the genus Clitoria L. occurring in the state of Sergipe, namely: Clitoria fairchildiana Howard , C. guianensis Aubl (Benth ) and C . laurifolia Poir . As specific objectives, phenological and climatic factors of C. fairchildiana were monitored in different environments and ecological niche modeling were applied to the three mentioned species. The areas of collecting phenological and climate data were the Refugio de Vida Silvestre Mata do Junco , the Área de Proteção Ambiental Morro do Urubu and the Parque dos Cajueiros. Given the statistical analysis of correlation and difference applied to phenological and climatic data, it was found that there was no significant differences between temperature and rainfall in the areas of occurrence of C. fairchildiana and this species has the phenophases of flowering, leaf emergence and fall directed mainly by climatic factors, and the fruiting phenophase of the same guided by other factors not identified in this study. A significant difference between fruiting events in analyzed populations of C. fairchildiana has been identified, although not derived from the difference between climatic factors. By modeling the distribution of the three species of Clitoria L. from Sergipe, it was possible to verify that since the last glacial maximum, given the climatic changes in the macroscale, the species have undergone a process of loss of habitat suitable to their survival, with the formation of dispersal corridors with connections between the Atlantic Forest and Amazon, occurring an increase in processes of disjunction of distribution and loss of area due to the application of future scenarios for the end of the century. Clitoria laurifolia was the species that most lost area. It is necessary to develop researches based on the integrated analysis of the effects of climate change on biomes from functional and distributive processes, providing greater accuracy in predictions, an improvement of evaluation processes and providing more reliable information for decision taking in the context of biodiversity conservation. / O clima é um sistema altamente dinâmico, tendo grande influência sobre as atividades humanas e a biodiversidade. Um dos eixos norteadores desta pesquisa é a mudança como um aspecto natural dos componentes climáticos, já que a Terra, ao longo de sua história passou por momentos de aquecimento e resfriamento. O segundo eixo norteador deste trabalho se alicerça na tradição do uso de espécies vegetais como indicadoras do ambiente onde se encontram. O objetivo geral é avaliar a ocorrência de mudanças climáticas em ambientes tropicais pelas características fenológicas e biogeográficas de espécies fitoindicadoras do gênero Clitoria L. com ocorrência no estado de Sergipe, a saber: Clitoria fairchildiana Howard, C. guianensis Aubl (Benth.) e C. laurifolia Poir. Como objetivos específicos, foram monitorados fatores fenológicos e climáticos de C. fairchildiana em diferentes ambientes e foram aplicados modelos de nicho ecológico para as três espécies citadas. As áreas de coleta de dados fenológicos e climáticos foram o Refúgio de Vida Silvestre Mata do Junco, a Área de Proteção Ambiental Morro do Urubu e o Parque dos Cajueiros. Dadas as análises estatísticas de correlação e diferença aplicadas aos dados fenológicos e climáticos coletados, foi possível constatar que não há diferenças significativas entre temperatura e pluviosidade nas áreas de ocorrência de Clitoria fairchildiana e que esta espécie tem as fenofases de floração, queda e emissão de folhas direcionadas principalmente por fatores climáticos, e a frutificação da mesma por fatores outros não identificados nesta pesquisa. Foi identificada uma diferença significativa entre os eventos de frutificação nas populações de C. fairchildiana analisadas, porém não oriundas da diferença entre fatores climáticos. Pela modelagem da distribuição das três espécies sergipanas de Clitoria L. foi possível averiguar que, desde o último máximo glacial, dadas as mudanças climáticas em macroescala, as espécies passaram por processos de perda de habitats adequados à sobrevivência das mesmas, com a formação de corredores de dispersão com conexões entre os biomas da Mata Atlântica e Amazônia, havendo um agravamento nos processos de perda de área e disjunção da distribuição com a aplicação dos cenários futuros para o fim do século, sendo Clitoria laurifolia a espécie que mais perdeu área. Faz-se necessário o desenvolvimento de pesquisas que tenham como base a análise integrada dos efeitos das mudanças do clima nos biomas a partir de processos funcionais e distributivos, proporcionando uma maior acurácia nas previsões, uma melhoria dos processos avaliativos e propiciando informações mais seguras para a tomada de decisão no âmbito da conservação da biodiversidade.

Acompanha: Uso de filmes de entretenimento no ensino de ecologia / Este trabalho apresenta a utilização de trechos de filmes de entretenimento, como recurso para discussão dos conteúdos de maneira que estimulasse os alunos na aprendizagem de Biomas Brasileiros e Mundiais. Buscou se a compreensão acerca do processo de aprendizagem dos conceitos científicos pelos alunos, a partir da aplicação de duas Sequências Didáticas, elaboradas como produto educacional, sustentadas pela Teoria da Aprendizagem Significativa de Ausubel e nas reflexões de Moreira (2010). Como metodologia, a abordagem foi qualitativa, utilizando o método fenomenológico. Os dados foram obtidos por meio da aplicação de um questionário para obtenção dos conhecimentos prévios e da confecção de Mapas Conceituais pelos alunos, a partir da aplicação da atividade. Após a elaboração dos Mapas, os alunos explicaram oralmente sua produção a fim de se compreender as relações e hierarquizações que eles fizeram acerca do conteúdo. Por meio dessa pesquisa, foi possível demonstrar que a utilização de vídeos de entretenimento no ensino colabora para a aprendizagem de conceitos, quando utilizadas de maneira estruturada e planejada, tendo o professor como mediador de debates, promovendo as relações entre o objeto apresentado e o conhecimento científico. Sendo assim, pode- se afirmar que, ao incorporar trechos de filmes de entretenimento no ensino, é possível promover a aprendizagem significativa de conceitos e não somente a motivação dos alunos. / This paper presents the use of entertainment film clips as a resource for discussion of the contents so as to stimulate students in learning Brazilian Biomes and World. Sought to understanding the learning process of scientific concepts by students from the application of two Teaching Units, designed as an educational product, supported by the Meaningful Learning Theory of Ausubel and the reflections Moreira (2010). As methodology, the qualitative approach using the phenomenological method. Data were obtained through the application of a questionnaire to obtain the prior knowledge and making concept maps by students from the application of the activity. After the preparation of maps, students orally explained their production in order to understand the relationships and hierarchies they did about the content. Through this research, it was possible to demonstrate that the use of entertainment videos in education contributes to learning concepts when used in a structured and planned way, with the teacher as facilitator of debates, promoting relations between the presented object and knowledge scientific. Thus, it can be said that by incorporating entertainment film clips in teaching can promote meaningful learning of concepts and not only the motivation of students.

A busca por ideias, modelos e paradigmas computacionais biologicamente inspirados e plausíveis sempre atraiu o interesse de cientistas da computação, especialmente na área de Computação Natural. Além disso, o conceito de otimização pode ser abstraído de vários processos naturais como, por exemplo, na evolução das espécies, no comportamento de grupos sociais, na dinâmica do sistema imunológico, nas estratégias de busca por alimento e nas relações ecológicas entre populações de animais. Com o melhor de nosso conhecimento, os ecossistemas naturais e seus conceitos ainda não foram explorados computacionalmente no contexto de otimização de funções e, portanto, eles são abordados nesta tese. Este trabalho destaca as principais propriedades de ecossistemas naturais que podem ser importantes para a construção de ferramentas computacionais para resolver problemas complexos de otimização. Também, a modelagem computacional para tais funcionalidades são introduzidas. A principal discussão apresentada nesta tese refere-se ao uso cooperativo de populações de soluções candidatas, co-evoluindo em um contexto ecossistêmico. Com esta analogia, cada população comportar-se de acordo com uma estratégia de busca específica que é empregada na evolução das soluções candidatas. Além da possibilidade de utilizar diferentes estratégias de busca cooperativamente, esta analogia abre a possibilidade de inserção de conceitos ecológicos no processo de otimização, permitindo o desenvolvimento de novos sistemas de otimização biologicamente inspirados e plausíveis. O potencial de alguns conceitos ecológicos é apresentado em um algoritmo canônico ecologicamente inspirado, chamado ECO (Ecological-inspired Optimiaztion algorithm). Alguns algoritmos baseados em população são utilizados para compor a abordagem proposta. Os problemas resolvidos nesta tese são várias funções contínuas de benckmark com um número alto de dimensões ($D = 200$) e o problema de predição de estrutura de proteínas para o modelo 2D AB. Além disso, o uso de dinâmica populacional para auto-regular o tamanho das populações; o uso de modelos heterogêneos com diferentes estratégias de busca; e o uso de agrupamento hierárquico para ajustar dinamicamente a formação de habitats e probabilisticamente definir as topologias de comunicação são alguns estudos de caso investigados. Os resultados obtidos se mostraram promissores considerando a aplicação do ecossistema computacional. Finalmente, conclusões e várias ideias para pesquisas futuras são apresentadas. / The search for plausible biologically inspired ideas, models and computational paradigms always drew the interest of computer scientists, particularly those from the Natural Computing area. Also, the concept of optimization can be abstracted from several natural processes, for instance, in the evolution of species, in the behavior of social groups, in the dynamics of the immune system, in the food search strategies and in the ecological relationships of different animal populations. To the best of our knowledge, ecosystems and their concepts have not been explored computationally in the context of function optimization and, therefore, they are addressed in this thesis. This work highlights the main properties of ecosystems that can be important for building computational tools to solve complex problems. Also, it is introduced the computational modelling for such biologically plausible functionalities (e.g., habitats, ecological relationships, ecological succession, and another). The main discussion presented in this work relates to the cooperative use of populations of candidate solutions, coevolving in an ecological context. With this ecology-based analogy, each population can behave according to a specific search strategy, employed in the evolution of candidate solutions. In addition to the possibility of using different optimization strategies cooperatively, this analogy opens the possibility of inserting ecological concepts in the optimization process, thus allowing the development of new bio-plausible hybrid systems. The potentiality of some ecological concepts is also presented in a canonical Ecology-inspired Algorithm for Optimization, named ECO. Some population-based algorithms are used to compose the ecology-based approach. The problems solved in this thesis are several continuous benchmark functions with a high number of dimensions ($D = 200$), and the protein structure prediction problem for the 2D AB model. Also, the use of population dynamics to self-regulate the size of populations during ecological successions; the use of heterogeneous models embedding different search strategies into the system; and the use of hierarchical clustering to dynamically adjust the habitats formation and probabilistically define the habitats communication are some case studies investigated. Results were promising concerning the application of the proposed computational ecosystem for optimization. Finally, concluding remarks and several ideas for future research are presented.

Acompanha: Uso de filmes de entretenimento no ensino de ecologia / Este trabalho apresenta a utilização de trechos de filmes de entretenimento, como recurso para discussão dos conteúdos de maneira que estimulasse os alunos na aprendizagem de Biomas Brasileiros e Mundiais. Buscou se a compreensão acerca do processo de aprendizagem dos conceitos científicos pelos alunos, a partir da aplicação de duas Sequências Didáticas, elaboradas como produto educacional, sustentadas pela Teoria da Aprendizagem Significativa de Ausubel e nas reflexões de Moreira (2010). Como metodologia, a abordagem foi qualitativa, utilizando o método fenomenológico. Os dados foram obtidos por meio da aplicação de um questionário para obtenção dos conhecimentos prévios e da confecção de Mapas Conceituais pelos alunos, a partir da aplicação da atividade. Após a elaboração dos Mapas, os alunos explicaram oralmente sua produção a fim de se compreender as relações e hierarquizações que eles fizeram acerca do conteúdo. Por meio dessa pesquisa, foi possível demonstrar que a utilização de vídeos de entretenimento no ensino colabora para a aprendizagem de conceitos, quando utilizadas de maneira estruturada e planejada, tendo o professor como mediador de debates, promovendo as relações entre o objeto apresentado e o conhecimento científico. Sendo assim, pode- se afirmar que, ao incorporar trechos de filmes de entretenimento no ensino, é possível promover a aprendizagem significativa de conceitos e não somente a motivação dos alunos. / This paper presents the use of entertainment film clips as a resource for discussion of the contents so as to stimulate students in learning Brazilian Biomes and World. Sought to understanding the learning process of scientific concepts by students from the application of two Teaching Units, designed as an educational product, supported by the Meaningful Learning Theory of Ausubel and the reflections Moreira (2010). As methodology, the qualitative approach using the phenomenological method. Data were obtained through the application of a questionnaire to obtain the prior knowledge and making concept maps by students from the application of the activity. After the preparation of maps, students orally explained their production in order to understand the relationships and hierarchies they did about the content. Through this research, it was possible to demonstrate that the use of entertainment videos in education contributes to learning concepts when used in a structured and planned way, with the teacher as facilitator of debates, promoting relations between the presented object and knowledge scientific. Thus, it can be said that by incorporating entertainment film clips in teaching can promote meaningful learning of concepts and not only the motivation of students.

The climate is a highly dynamic system and has a great influence on human activities and biodiversity. One of the guiding principles of this research is the "change" as a natural aspect of climatic components, since the Earth throughout its history has experienced moments of heating and cooling. The second guiding principle of this work is grounded in the tradition of using plant species as indicators of the environment they grow. The overall objective is to evaluate the occurrence of climate change in tropical environments by phenological and biogeographic characteristics of fitoindicator species of the genus Clitoria L. occurring in the state of Sergipe, namely: Clitoria fairchildiana Howard , C. guianensis Aubl (Benth ) and C . laurifolia Poir . As specific objectives, phenological and climatic factors of C. fairchildiana were monitored in different environments and ecological niche modeling were applied to the three mentioned species. The areas of collecting phenological and climate data were the Refugio de Vida Silvestre Mata do Junco , the Área de Proteção Ambiental Morro do Urubu and the Parque dos Cajueiros. Given the statistical analysis of correlation and difference applied to phenological and climatic data, it was found that there was no significant differences between temperature and rainfall in the areas of occurrence of C. fairchildiana and this species has the phenophases of flowering, leaf emergence and fall directed mainly by climatic factors, and the fruiting phenophase of the same guided by other factors not identified in this study. A significant difference between fruiting events in analyzed populations of C. fairchildiana has been identified, although not derived from the difference between climatic factors. By modeling the distribution of the three species of Clitoria L. from Sergipe, it was possible to verify that since the last glacial maximum, given the climatic changes in the macroscale, the species have undergone a process of loss of habitat suitable to their survival, with the formation of dispersal corridors with connections between the Atlantic Forest and Amazon, occurring an increase in processes of disjunction of distribution and loss of area due to the application of future scenarios for the end of the century. Clitoria laurifolia was the species that most lost area. It is necessary to develop researches based on the integrated analysis of the effects of climate change on biomes from functional and distributive processes, providing greater accuracy in predictions, an improvement of evaluation processes and providing more reliable information for decision taking in the context of biodiversity conservation. / O clima é um sistema altamente dinâmico, tendo grande influência sobre as atividades humanas e a biodiversidade. Um dos eixos norteadores desta pesquisa é a mudança como um aspecto natural dos componentes climáticos, já que a Terra, ao longo de sua história passou por momentos de aquecimento e resfriamento. O segundo eixo norteador deste trabalho se alicerça na tradição do uso de espécies vegetais como indicadoras do ambiente onde se encontram. O objetivo geral é avaliar a ocorrência de mudanças climáticas em ambientes tropicais pelas características fenológicas e biogeográficas de espécies fitoindicadoras do gênero Clitoria L. com ocorrência no estado de Sergipe, a saber: Clitoria fairchildiana Howard, C. guianensis Aubl (Benth.) e C. laurifolia Poir. Como objetivos específicos, foram monitorados fatores fenológicos e climáticos de C. fairchildiana em diferentes ambientes e foram aplicados modelos de nicho ecológico para as três espécies citadas. As áreas de coleta de dados fenológicos e climáticos foram o Refúgio de Vida Silvestre Mata do Junco, a Área de Proteção Ambiental Morro do Urubu e o Parque dos Cajueiros. Dadas as análises estatísticas de correlação e diferença aplicadas aos dados fenológicos e climáticos coletados, foi possível constatar que não há diferenças significativas entre temperatura e pluviosidade nas áreas de ocorrência de Clitoria fairchildiana e que esta espécie tem as fenofases de floração, queda e emissão de folhas direcionadas principalmente por fatores climáticos, e a frutificação da mesma por fatores outros não identificados nesta pesquisa. Foi identificada uma diferença significativa entre os eventos de frutificação nas populações de C. fairchildiana analisadas, porém não oriundas da diferença entre fatores climáticos. Pela modelagem da distribuição das três espécies sergipanas de Clitoria L. foi possível averiguar que, desde o último máximo glacial, dadas as mudanças climáticas em macroescala, as espécies passaram por processos de perda de habitats adequados à sobrevivência das mesmas, com a formação de corredores de dispersão com conexões entre os biomas da Mata Atlântica e Amazônia, havendo um agravamento nos processos de perda de área e disjunção da distribuição com a aplicação dos cenários futuros para o fim do século, sendo Clitoria laurifolia a espécie que mais perdeu área. Faz-se necessário o desenvolvimento de pesquisas que tenham como base a análise integrada dos efeitos das mudanças do clima nos biomas a partir de processos funcionais e distributivos, proporcionando uma maior acurácia nas previsões, uma melhoria dos processos avaliativos e propiciando informações mais seguras para a tomada de decisão no âmbito da conservação da biodiversidade.

This Master's Thesis presents the results of research conducted under the Project ASSESSMENT OF POTENTIAL AS SEQUESTRANT MANGROVE FORESTS CARBON - UFRJ / UFS / UERJ (Case Study of Mangrove Forest River Estuarine Region of San Francisco - Sergipe / Alagoas), with the support of the Erosion and Sedimentation Laboratory, part of the Department of Agricultural Engineering, Federal University of Sergipe. The environmental liabilities created on account of unsustainable use of natural resources over the years has been suppressing and / or degrading a significant portion of mangroves due to the disorderly occupation and exploitation of their areas. Thus, gathering information on vegetation structure becomes a valuable tool for understanding the current state of the same. In this context, the objective of this study was to characterize the floristic, phytosociological structure and litterfall of the mangrove estuary of the river São Francisco, Sergipe. This action will provide a structural description of the community of mangrove trees and shrubs and the factors that promote change in these communities. The results show that the mangrove river São Francisco present a heterogeneous development, presenting higher in the intermediate region of the estuary, where there is less influence of anthropogenic impacts. We recorded species: schaueriana Avicennia, Avicennia germinans, Laguncularia racemosa, Conocarpus erectus and Rhizophora mangle. The average height of forests ranged from 2.88 to 15.63 m, the DBH 3.95 to 19.74 cm, basal area, live from 4.22 to 47.83 m2.ha-1 and density logs Live 375-9100 trunks.ha-1. The annual litter production was 274.43 t.ha-1.year-1 in the first year and 267.92 t.ha-1.year-1 in the second year. Generally, litter production, per compartment, submitted the following descending order: Leaves > Twigs and Branches > Stipules > Fruits and Propagating Material > Miscellaneous > Flowers. Tensors identified in the estuary, the largest impacts are promoting marine erosion and human activities, both promote the removal of large areas. / A presente Dissertação de Mestrado apresenta os resultados da pesquisa realizada no âmbito do Projeto AVALIAÇÃO DO POTENCIAL DE FLORESTAS DE MANGUE COMO SEQUESTRADORAS DE CARBONO UFRJ / UFS / UERJ (Estudo de Caso da Floresta de Mangue da Região Estuarina do rio São Francisco - Sergipe/Alagoas), com o apoio do Laboratório de Erosão e Sedimentação, vinculado ao Departamento de Engenharia Agronômica da Universidade Federal de Sergipe. O passivo ambiental criado por conta do uso não sustentável dos recursos naturais ao longo dos anos vem suprimindo e/ou degradando uma porção significativa de manguezais, principalmente no que diz respeito a ocupação e exploração desordenada de suas áreas. Dessa forma, o levantamento de informações sobre a estrutura da vegetação torna-se uma valiosa ferramenta para o conhecimento do estado atual dos mesmos. Neste contexto, o objetivo deste trabalho foi caracterizar a composição florística, estrutura fitossociológica e produção de serrapilheira do manguezal do estuário do rio São Francisco, Sergipe. Essa ação fornecerá uma descrição estrutural da comunidade arbóreo-arbustiva do manguezal e os fatores que promovem alterações nessas comunidades. Os resultados encontrados revelam que o manguezal do rio São Francisco apresenta desenvolvimento heterogêneo, apresentando-se mais elevado na região intermediária do estuário, onde é menor a influência dos impactos antropogênicos. Foram registradas as espécies: Avicennia schaueriana, Laguncularia racemosa e Rhizophora mangle. A altura média das árvores variou de 2,88 a 15,63 m, o DAP médio de 3,95 a 19,74 cm, a área basal viva de 4,22 a 47,83 m2.ha-1 e a densidade de troncos vivos de 375 a 9100 troncos.ha-1. A produção média anual de serrapilheira foi de 13,53 t.ha-1.ano-1 e 13,21 t.ha-1.ano-1, no primeiro e segundo ano, respectivamente. De modo geral, a produção de serapilheira, por compartimento, apresentou a seguinte ordem decrescente: Folhas > Galhos e Ramos > Estípulas > Frutos e Propágulos > Miscelânea > Flores. Dos tensores identificados no estuário, os que promovem maiores impactos são a erosão marinha e atividades antrópicas, ambos promovem a supressão de grandes áreas.

Mangrove ecosystems thrive in (sub)tropical, intertidal areas where adaptations<p>like vivipary and the hydrochorous dispersal of propagules become an absolute<p>necessity. As propagule dispersal and early growth allow for the replenishment of<p>existing stands and colonization of new habitats, many authors recognize the<p>importance of these stages in structuring mangrove populations and communities.<p>However, when it comes to the actual propagule dispersal and recruitment<p>mechanisms, there is an apparent lacuna in the current understanding of<p>mangrove ecology. The period between the mature propagule falling from the<p>parental mangrove tree and the early growth of the established seedling, under<p>various possible circumstances, remains in the dark. In this study we focus on this<p>particular period by investigating both the places where these propagules end up<p>as the pathways their dispersal units follow. And we go one step further.<p><p>Mangrove forests are being destroyed worldwide at a threatening pace despite<p>their tremendous asset to coastal human communities and associated biological<p>species. The effect of human-induced (cutting and mangrove conversion to<p>aquaculture ponds) as well as indirectly and/or ‘naturally’ evolving disturbances<p>(sea level rise) on propagule hydrochory occupies an important place in this study.<p><p>Dispersal of water-buoyant propagules of the family Rhizophoraceae and<p>Acanthaceae (now including the Avicenniaceae) was studied in Gazi Bay (Kenya),<p>Galle and the Pambala-Chilaw Lagoon Complex (Sri Lanka). The study sites<p>differ both in tidal regime and vegetation structure, covering an interesting variety<p>of ecological settings to examine propagule dispersal. Field data and experiments<p>ranging from micro/ mesotopographical measurements and successive propagule<p>counts to hydrodynamic and propagule dispersal experiments were collected or<p>executed in situ.<p><p>Two main methodological approaches were employed. Firstly, the question on<p>mechanisms of propagule recruitment was addressed by statistically investigating<p>the effect of microtopography, top soil texture and above-ground-root complexes on<p>the stranding and self-planting of propagules (Chapter 2&3). Afterwards,<p>suitability maps were created using Geographical Information Systems (GIS) to<p>assess whether a particular mangrove stand has the ability to succesfully<p>rejuvenate. Furthermore, the effect of degradation (tree cutting) (Chapter 2&3),<p>sea level rise (Chapter 2&4) and microtopography-altering burrowing activities of<p>the mangrove mud lobster Thalassina anomala (Chapter 3), was incoporated in the<p>GIS-analyses. Secondly, the combined set-up of hydrodynamic modelling and<p>ecological dispersal modelling was developed to simulate propagule dispersal<p>pathways influenced by dispersal vectors (tidal flow, fresh water discharge, wind),<p>trapping agents (retention by vegetation or aerial root complexes) and seed<p>characteristics (buoyancy, obligated dispersal period) (Chapter 5&6). This type of<p>approach provided the possibility to explore propagule dispersal within its<p>ecological context, but was also applied to an implication of shrimp pond area<p>restoration (Pambala-Chilaw Lagoon Complex, Sri Lanka) (Chapter 5) and to<p>evaluate changes in propagule dispersal when sea level rises (Gazi Bay, Kenya)<p>(Chapter 6).<p><p>The main findings regarding propagule recruitment indicate that propagules are<p>not distributed equally or randomly within a mangrove stand, yet species-specific<p>distribution for anchorage occurs. Characteristics of the environment<p>(microtopography, top soil texture and above-ground root complex) influence<p>propagule recruitment in a way that complex root systems (e.g. pencil roots and<p>prop roots) facilitate the entanglement of dispersal units and a more compact soil<p>texture (like clay and silt) and a predominant flat topography creates suitable<p>areas for stranding and self-planting of propagules. This combines effects of<p>existing vegetation and abiotic factors on mangrove propagule establishment.<p>Since propagule dispersal is not solely determined by species-specific propagule<p>characteristics (e.g. buoyancy, longevity, etc.), I emphasize that propagule sorting<p>by hydrochory has to be viewed within its ecological context. Propagule retention<p>by vegetation and wind as a dispersal vector, deserve a prominent role in studies<p>on propagule dispersal. The significance of dense vegetation obstructing long<p>distance dispersal (LDD in its definition of this work), mainly in inner mangrove<p>zones, supports our main finding that propagule dispersal is largely a short<p>distance phenomenon. ‘Largely’ is here understood as quantitatively, not<p>excluding epic colonization events of rare but important nature.<p>In accordance with the Tidal Sorting Hypothesis (TSH) of Rabinowitz (1978a),<p>smaller, oval-shaped propagules were found to disperse over larger distances than<p>bigger, torpedo-shaped propagules. We can however not fully support the TSH<p>because (1) these differences are no longer valid when comparing between torpedoshaped<p>propagules of different sizes and (2) propagule dispersal is not always<p>directed towards areas more inland, but can be strongly concentrated towards the<p>edges of lagoons and channels<p><p>Anthropogenic pressure on mangrove ecosystems, more specifically clear-felling or<p>mangrove conversion to aquaculture ponds, imposes limitations on propagule<p>recruitment due to reduced propagule availability and a decrease in suitable<p>stranding areas where the architecture of certain root complexes, like prop roots<p>and pencil roots, function as propagule traps. These types of pressure appear to<p>have more severe consequences on propagule dispersal than the effect of sea level<p>rise on mangroves. Mangrove forests, which are not situated in an obviously<p>vulnerable setting, can be resilient to a relative rise in sea level if a landward shift<p>of vegetation assemblages and successful early colonization is not obstructed by<p>human-induced pressures. Also, and this renders mangrove forests vulnerable in<p>spite of their intrinsic resilience, when the ‘capital’ of forest is severely reduced or<p>impoverished as happens extensively worldwide, the ‘interest’ on this capital,<p>understood as propagule availability, delivery and trapping, will not allow them to<p>efficiently cope with sea level rise, putting sustainability of mangrove ecosystem<p>services and goods at risk.<p><p>In a larger framework of mangrove vegetation dynamics, knowledge on propagule<p>dispersal will benefit management strategies for the conservation of mangroves<p>worldwide, besides its fundamental interest to fully fathom the ecology of this<p>particular marine-terrestrial ecotone formation. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

M.A. / White-collar crime has had a significant impact on the economy and the quality of life of all the citizens of this country. The emphasis in addressing this problem has traditionally been on the limitation of risk to commit white-collar crime as well ason the 'typical' characteristics of white-collar offenders. The aim of this study was to understand this phenomenon from a different perspective: the ecosystems that have an influence on the causation and maintenance of white-collar crime. To determine which ecosystems played a role the researcher interviewed white-collar criminals who had already been convicted, and were serving prison sentences in the Gauteng Province. They were from both sexes, different race groups, different ages and they had committed different types of white-collar crime. The following ecosystems and subsystems were identified as contributing to causation and maintenance of white-collar crime: the individual: behaviour, emotion and relationships (in general and specific relationships). The bank environment Opportunity, as an element of all the systems, was also identified as a contributing factor. The researcher also identified two patterns in which the ecosystems interact. Different white-collar crime processes are indicated through these patterns. The main difference between these patterns is that some people commit the crime because they consider it to be the best solution to problem situation whereas other people commit the crime only because the opportunity to do so, exists. Most of the findings in the interviews can be confirmed by existing literature although there were some findings for which literature can't indicate a direct relationship. Recommendations are aimed at addressing the dynamics between the ecosystems as identified by the respondents. The most important aspect to bear in mind is that people do not function in isolation and constantly influence each other. We are co-creators of our reality and can therefore influence our environment by what we contribute to it through interaction and dialogue.

Two species of hake (Merluccius capensis and Merluccius paradoxus) account for most of Namibia’s fisheries catch, and they are important secondary consumers in the Benguela Current ecosystem. Inferences on their trophic relationships have been based mainly on stomach content analyses. However, such data are limited temporally because they represent only snapshots of recent feeding, and are quantitatively biased because of variation in the digestion rates of different prey. The principal aim of the thesis was to understand the trophic relationships of two hake species relative to each other, their known prey and top predators (demersal sharks) in the northern Benguela Current ecosystem (Namibia), using time-integrating trophic biomarkers. By using stable isotope (carbon and nitrogen) and fatty acid signatures of their muscle tissues, my overall objectives were to produce new knowledge about 1) hake ontogenic trophic relationships, 2) the contributions of different prey to hake diets, 3) hake dietary differences, and 4) some aspects of hake’s trophic relationships with demersal sharks. Tissues of hake (n=358), their potential prey (n=455), and demersal sharks (n=42) were collected between 2008 and 2012 during demersal bottom trawl surveys off Namibia, for stable isotope and fatty acid analyses. And more...

Please read the abstract in the 00front part of this document / Thesis (PhD (Botany))--University of Pretoria, 2006. / Plant Science / unrestricted