Eucalyptus pellita is a commercially important plantation hardwood species for the humid tropics of north Queensland. This species is favoured by both small-scale growers for use in mixed species woodlots targeting low-volume high-value sawn timber, and also by industrial forest companies growing monocultures for integrated pulp – sawn timber regimes. This study investigated whether mixed-species designs can increase the growth of this tropical eucalypt when compared to monocultures.A replacement series experiment with monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) was used to examine questions about growth and productivity. The trial was located on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence of acacia trees at age five years and this effect generally increased with time up to age 10 years. However, the stand volume and basal area increased with increasing proportions of E. pellita, due to its larger individual tree size. Conventional analysis did not offer convincing support for mixed-species designs. Preliminary individual-based modelling using a modified Hegyi competition index offered a solution and an equation that indicates acacias have positive ecological interactions (facilitation or competitive reduction), and definitely do not cause competition like E. pellita. These results suggest that significantly increased growth rates could be achieved with mixed-species designs over E. pellita monocultures. This statistical methodology could enable a better 4 understanding of species interactions in similarly altered experiments, or undesigned mixed-species plantations.The effects of trees on soils are highly variable and highly site and species specific. That trees can change soil chemistry over time is well established. The soil chemical properties under the eucalypt: acacia experiment were compared to several potential baseline data sources: the reference description of this soil type; those measured at 7 months after planting; and with those of soils under two adjacent vegetation types (forest and pasture) when the experiment was aged 9 years. At 9 years after planting soil total nitrogen increased with increasing proportion of acacias in the treatment. The mean total N under the acacia monoculture was significantly higher (P = 0.041) than that of either the eucalypt monoculture, or the surrounding pasture. The proportion of acacia in the treatment was positively linearly correlated with soil total N (r2 = 0.46; P = 0.018). Soils under the eucalypt monocultures were more similar to those under pasture for a range of soil chemical properties, compared with soils under treatments containing acacias. Results from this site show that the two species alter the soil chemistry in different ways. It is possible that the increased total N under the acacias could be facilitating the growth of the E. pellita, however without n-fixation analysis or tissue sampling it is not possible to confirm that the eucalypt is using the N. Similar cause and effect (or ‘supply and use’) questions also remain for soil pH and available phosphorus changes with increasing acacia in treatment. This study also demonstrates the difficulty in monitoring changes in soil properties over long cycles of forest plantations.The photosynthetic response to light was assessed in the stratified canopy of the mixed species field trial of the eucalypt: acacia experiment, and among commonly planted taxa of E. pellita in glasshouse pot trials. In the field trial photosynthetic capacity of fully5 expanded sun and shade leaves of both species was measured. E. pellita has a wide natural distribution with considerable variation in morphology and growth within the species, with several provenances commonly planted in north Queensland. Photosynthetic capacity and leaf nutrient content of three of these taxa (two from northern occurrences and one from southern occurrences of E. pellita) were measured on two occasions in glasshouse pot trials. A non rectangular hyperbolic function was used to describe the light response curves, and analysis of variance was used to determine differences in the biologically relevant curve parameters between treatments. In the field trial sun and shade leaves of E. pellita produced similar light saturated photosynthetic rates, and experienced little competition for light from the acacia crowns. In contrast there was significant variation in the photosynthetic response between acacia sun and shade leaves. In the glasshouse trials, differences in leaf and petiole morphology were observed, which were coupled with differences in leaf nutrient content and highly significant variation in light saturated photosynthetic rate between the three taxa. This study characterised the light response of E. pellita and suggests that differences in physiological responses to resource availability should be expected among taxa within this species, which may be important for forest productivity models which endeavour to predict tree growth and resource use.An empirical model of growth of E. pellita from a designed monocultures vs. mixedspecies experiment has been used to explore system behaviour rather than predict production of this species from specific forests. This approach has allowed examination of the effect of plantation design on competition, soil nutrient pool change with time and physiological responses to light; leading to a greater understanding of why mixtures can lead to greater productivity than monocultures.

Eucalyptus pellita is a commercially important plantation hardwood species for the humid tropics of north Queensland. This species is favoured by both small-scale growers for use in mixed species woodlots targeting low-volume high-value sawn timber, and also by industrial forest companies growing monocultures for integrated pulp – sawn timber regimes. This study investigated whether mixed-species designs can increase the growth of this tropical eucalypt when compared to monocultures.A replacement series experiment with monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) was used to examine questions about growth and productivity. The trial was located on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence of acacia trees at age five years and this effect generally increased with time up to age 10 years. However, the stand volume and basal area increased with increasing proportions of E. pellita, due to its larger individual tree size. Conventional analysis did not offer convincing support for mixed-species designs. Preliminary individual-based modelling using a modified Hegyi competition index offered a solution and an equation that indicates acacias have positive ecological interactions (facilitation or competitive reduction), and definitely do not cause competition like E. pellita. These results suggest that significantly increased growth rates could be achieved with mixed-species designs over E. pellita monocultures. This statistical methodology could enable a better 4 understanding of species interactions in similarly altered experiments, or undesigned mixed-species plantations.The effects of trees on soils are highly variable and highly site and species specific. That trees can change soil chemistry over time is well established. The soil chemical properties under the eucalypt: acacia experiment were compared to several potential baseline data sources: the reference description of this soil type; those measured at 7 months after planting; and with those of soils under two adjacent vegetation types (forest and pasture) when the experiment was aged 9 years. At 9 years after planting soil total nitrogen increased with increasing proportion of acacias in the treatment. The mean total N under the acacia monoculture was significantly higher (P = 0.041) than that of either the eucalypt monoculture, or the surrounding pasture. The proportion of acacia in the treatment was positively linearly correlated with soil total N (r2 = 0.46; P = 0.018). Soils under the eucalypt monocultures were more similar to those under pasture for a range of soil chemical properties, compared with soils under treatments containing acacias. Results from this site show that the two species alter the soil chemistry in different ways. It is possible that the increased total N under the acacias could be facilitating the growth of the E. pellita, however without n-fixation analysis or tissue sampling it is not possible to confirm that the eucalypt is using the N. Similar cause and effect (or ‘supply and use’) questions also remain for soil pH and available phosphorus changes with increasing acacia in treatment. This study also demonstrates the difficulty in monitoring changes in soil properties over long cycles of forest plantations.The photosynthetic response to light was assessed in the stratified canopy of the mixed species field trial of the eucalypt: acacia experiment, and among commonly planted taxa of E. pellita in glasshouse pot trials. In the field trial photosynthetic capacity of fully5 expanded sun and shade leaves of both species was measured. E. pellita has a wide natural distribution with considerable variation in morphology and growth within the species, with several provenances commonly planted in north Queensland. Photosynthetic capacity and leaf nutrient content of three of these taxa (two from northern occurrences and one from southern occurrences of E. pellita) were measured on two occasions in glasshouse pot trials. A non rectangular hyperbolic function was used to describe the light response curves, and analysis of variance was used to determine differences in the biologically relevant curve parameters between treatments. In the field trial sun and shade leaves of E. pellita produced similar light saturated photosynthetic rates, and experienced little competition for light from the acacia crowns. In contrast there was significant variation in the photosynthetic response between acacia sun and shade leaves. In the glasshouse trials, differences in leaf and petiole morphology were observed, which were coupled with differences in leaf nutrient content and highly significant variation in light saturated photosynthetic rate between the three taxa. This study characterised the light response of E. pellita and suggests that differences in physiological responses to resource availability should be expected among taxa within this species, which may be important for forest productivity models which endeavour to predict tree growth and resource use.An empirical model of growth of E. pellita from a designed monocultures vs. mixedspecies experiment has been used to explore system behaviour rather than predict production of this species from specific forests. This approach has allowed examination of the effect of plantation design on competition, soil nutrient pool change with time and physiological responses to light; leading to a greater understanding of why mixtures can lead to greater productivity than monocultures.

Eucalyptus pellita is a commercially important plantation hardwood species for the humid tropics of north Queensland. This species is favoured by both small-scale growers for use in mixed species woodlots targeting low-volume high-value sawn timber, and also by industrial forest companies growing monocultures for integrated pulp – sawn timber regimes. This study investigated whether mixed-species designs can increase the growth of this tropical eucalypt when compared to monocultures.A replacement series experiment with monocultures of Eucalyptus pellita (E) and Acacia peregrina (A) and mixtures in various proportions (75E:25A, 50E:50A, 25E:75A) was used to examine questions about growth and productivity. The trial was located on the Atherton Tablelands of north Queensland, Australia. High mortality in the establishment phase due to repeated damage by tropical cyclones altered the trial design. Effects of experimental designs on tree growth were estimated using a linear mixed effects model with restricted maximum likelihood analysis (REML). Volume growth of individual eucalypt trees were positively affected by the presence of acacia trees at age five years and this effect generally increased with time up to age 10 years. However, the stand volume and basal area increased with increasing proportions of E. pellita, due to its larger individual tree size. Conventional analysis did not offer convincing support for mixed-species designs. Preliminary individual-based modelling using a modified Hegyi competition index offered a solution and an equation that indicates acacias have positive ecological interactions (facilitation or competitive reduction), and definitely do not cause competition like E. pellita. These results suggest that significantly increased growth rates could be achieved with mixed-species designs over E. pellita monocultures. This statistical methodology could enable a better 4 understanding of species interactions in similarly altered experiments, or undesigned mixed-species plantations.The effects of trees on soils are highly variable and highly site and species specific. That trees can change soil chemistry over time is well established. The soil chemical properties under the eucalypt: acacia experiment were compared to several potential baseline data sources: the reference description of this soil type; those measured at 7 months after planting; and with those of soils under two adjacent vegetation types (forest and pasture) when the experiment was aged 9 years. At 9 years after planting soil total nitrogen increased with increasing proportion of acacias in the treatment. The mean total N under the acacia monoculture was significantly higher (P = 0.041) than that of either the eucalypt monoculture, or the surrounding pasture. The proportion of acacia in the treatment was positively linearly correlated with soil total N (r2 = 0.46; P = 0.018). Soils under the eucalypt monocultures were more similar to those under pasture for a range of soil chemical properties, compared with soils under treatments containing acacias. Results from this site show that the two species alter the soil chemistry in different ways. It is possible that the increased total N under the acacias could be facilitating the growth of the E. pellita, however without n-fixation analysis or tissue sampling it is not possible to confirm that the eucalypt is using the N. Similar cause and effect (or ‘supply and use’) questions also remain for soil pH and available phosphorus changes with increasing acacia in treatment. This study also demonstrates the difficulty in monitoring changes in soil properties over long cycles of forest plantations.The photosynthetic response to light was assessed in the stratified canopy of the mixed species field trial of the eucalypt: acacia experiment, and among commonly planted taxa of E. pellita in glasshouse pot trials. In the field trial photosynthetic capacity of fully5 expanded sun and shade leaves of both species was measured. E. pellita has a wide natural distribution with considerable variation in morphology and growth within the species, with several provenances commonly planted in north Queensland. Photosynthetic capacity and leaf nutrient content of three of these taxa (two from northern occurrences and one from southern occurrences of E. pellita) were measured on two occasions in glasshouse pot trials. A non rectangular hyperbolic function was used to describe the light response curves, and analysis of variance was used to determine differences in the biologically relevant curve parameters between treatments. In the field trial sun and shade leaves of E. pellita produced similar light saturated photosynthetic rates, and experienced little competition for light from the acacia crowns. In contrast there was significant variation in the photosynthetic response between acacia sun and shade leaves. In the glasshouse trials, differences in leaf and petiole morphology were observed, which were coupled with differences in leaf nutrient content and highly significant variation in light saturated photosynthetic rate between the three taxa. This study characterised the light response of E. pellita and suggests that differences in physiological responses to resource availability should be expected among taxa within this species, which may be important for forest productivity models which endeavour to predict tree growth and resource use.An empirical model of growth of E. pellita from a designed monocultures vs. mixedspecies experiment has been used to explore system behaviour rather than predict production of this species from specific forests. This approach has allowed examination of the effect of plantation design on competition, soil nutrient pool change with time and physiological responses to light; leading to a greater understanding of why mixtures can lead to greater productivity than monocultures.

Les herbivores invertébrés sont présents dans presque tous les habitats de la planète et peuvent grandement affecter la performance des plantes en nature. Que ce soit en communautés naturelles ou artificielles, une grande variation des taux d'herbivorie entre différentes espèces de plante [i.e. plantes] peut être observée. Ceci s'explique par le fait que les caractéristiques fonctionnelles des plantes, aussi appelées « traits », affectent les préférences des herbivores. Une espèce de plante, de par ces traits physiologiques, morphologiques ou phénologiques, peut donc décourager et/ou éviter l'herbivorie. La compréhension des relations entre les herbivores invertébrés et les traits des plantes est donc indispensable à la compréhension de l'assemblage des communautés herbivores-plantes. Cependant, les connaissances sur les liens entre les différents traits des plantes et la préférence des herbivores sont diffuses et incomplètes. Ce mémoire vise donc à quantifier et caractériser les effets de plusieurs traits fonctionnels de plantes herbacées sur la quantité de dommage foliaire faite par des herbivores invertébrés et à comparer ces effets entre monocultures et polycultures. Pour ce faire, j'ai participé au projet du Jena Experiment , une prairie expérimentale située en Allemagne visant à étudier la biodiversité. Cette prairie est exposée aux herbivores invertébrés naturels se trouvant sur le site de l'étude. Pour réaliser mon projet, les degrés d'herbivorie causés par les invertébrés ainsi que les valeurs de plusieurs traits fonctionnels des plantes ont été mesurés pour chacune de 51 espèces de plante [i.e. plantes] se trouvant sur le site d'étude. Travaillant d'abord avec des monocultures, sept traits sur 42 mesurés ont été sélectionnés dans une régression multiple en tant que prédicteurs importants de l'herbivorie. Le modèle est robuste et explique 63% de la variation en dommage subi par les espèces à l'étude. Parmi ces sept traits, deux sont physiologiques (concentration de lignine et d' azote dans les feuilles), deux sont morphologiques (architecture des racines et érection de la tige), un est phénologique (durée de vie du feuillage) et deux sont reliés aux herbivores (nombre d'espèces de coléoptère et d'hémiptère pouvant potentiellement prédater les plantes). Dans une seconde étape, à partir de l'herbivorie mesurée en monoculture et des sept traits sélectionnés dans le premier volet, trois modèles ont été développés pour prédire l'herbivorie dans des communautés formant un gradient de biodiversité de une à 60 espèces de plantes. Pour les trois différents modèles, le pouvoir de prédiction était faible; de 6 à 32% de variance en dommage foliaire expliquée. De plus, la déviation entre valeurs observées et valeurs prédites de l'herbivorie augmentait significativement avec l'augmentation du niveau de biodiversité dans les communautés. Les résultats de ce mémoire suggèrent que des patrons complexes de corrélation entre les différents traits des plantes existent et qu'il est donc nécessaire de travailler avec le plus de traits possibles pour identifier ceux qui contrôlent vraiment l'herbivorie. De plus, des interactions entre les différentes espèces de plante [i.e. plantes] d'une communauté semblent affecter de façon importante, directement ou pas, les dommages foliaires infligés par les herbivores invertébrés.Les conclusions de ce mémoire remettent en question l'importance relative des traits agrégés pour prédire des processus écologiques à facteur biotique tel que l'herbivorie et soulignent la complexité des relations entre deux niveaux trophiques.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-09-23T18:03:24Z No. of bitstreams: 2 Campos, Washington Pereira-2013-dissertação.pdf: 2646607 bytes, checksum: 435ea1d6cb82cec1157664cf7367b969 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-09-23T18:23:43Z (GMT) No. of bitstreams: 2 Campos, Washington Pereira-2013-dissertação.pdf: 2646607 bytes, checksum: 435ea1d6cb82cec1157664cf7367b969 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-23T18:23:43Z (GMT). No. of bitstreams: 2 Campos, Washington Pereira-2013-dissertação.pdf: 2646607 bytes, checksum: 435ea1d6cb82cec1157664cf7367b969 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This paper presented a study, made from a field research in Goiatuba city, in order to observe the effects on ruralities and changes in this city through the expansion of monoculture of sugar cane. Seventy six farms were interviewed and 11 sugar cane suppliers too. These 87 farmers were divided into three actors’ categories - pluriactives farmers, not pluriactives farmers and sugar cane suppliers. Overall, it was created 32 indicators which were divided in four dimensions (economic, social, environmental and institutional). For the environmental and social dimension were created eight indicators, for the economic dimension were studied seven other indicators, and nine indicators were studied for the institutional dimension. All indicators were wheelset in the tool Dashboard of Sustainability and one sub-index was calculated for each dimension. As from these four sub-indexes were calculated a General Index of Sustainability - GIS. This study showed that pluriactives farmers have the per capita income, and other economic and social indicators, higher than not pluriactives farmers. Furthermore, pluriactives farmers category represented the best performance within the environmental dimension. For the other two categories the sugar cane suppliers showed better performance. Overall, the category of actors who performed the best, according to the Dashboard of Sustainability, was the category represents pluriactives farmers in second place was the category represented by the sugar cane suppliers and in third place came the not pluriactives farmers. However, this study showed that the lack of institutional coordination can be one of the factors that limit the growth of income of the small farmers of Goiatuba city. The reason is that the families farmers majority have little insertion in the local labor market and in the supply of products from the property and that could supply the local market and the local schools, what could / O presente trabalho apresentou um estudo, feito a partir de uma pesquisa de campo em Goiatuba, com objetivo de observar os efeitos nas ruralidades e as mudanças no município a partir da expansão do monocultivo da cana-de-açúcar. Foram pesquisados 76 agricultores familiares e 11 fornecedores de cana-de-açúcar, sendo que, esses 87 agricultores foram divididos em três categorias de atores – agricultores pluriativos, agricultores não pluriativos e fornecedores de cana-deaçúcar. No total, fez-se um levantamento de 32 indicadores, os quais foram divididos em quatro dimensões, quais sejam: econômica, social, ambiental e institucional. Para a dimensão ambiental e social foram levantados 08 indicadores, sendo outros sete indicadores estudados para a dimensão econômica, 09 indicadores para a dimensão institucional. Todos os indicadores foram rodados na ferramenta Dashboard of Sustainability e foi calculado um subíndice para cada dimensão. A partir desses quatro subíndices, calculou-se um Índice Geral de Sustentabilidade – IGS. O trabalho demonstrou que os agricultores pluriativos têm renda per capita, além de outros indicadores econômicos e sociais, mais elevada do que os agricultores não pluriativos. Ademais, os agricultores pluriativos representaram a categoria que teve melhor desempenho dentro da dimensão ambiental. Para as outras duas categorias, os fornecedores de cana-de-açúcar apresentaram melhor performance. Em geral, a categoria de atores que apresentou melhor desempenho, segundo o Dashboard of Sustainability, foi a categoria representada pelos agricultores pluriativos, em segundo lugar, ficou a categoria representada pelos fornecedores de cana-de-açúcar e em pior situação de sustentabilidade, ficaram os agricultores não pluriativos. O estudo, no entanto, mostrou que a falta de articulação institucional pode ser um dos fatores que limitam o crescimento da renda do pequeno produtor rural de Goiatuba. Isso deve-se ao fato de grande parte dos agricultores familiares ter pouca inserção tanto no mercado de trabalho local quanto no fornecimento de produtos oriundos da propriedade e que poderiam abastecer o comércio local e as escolas do município, que resultaria numa elevação da renda do agricultor familiar e no aumento do seu bem-estar.

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No. of bitstreams: 1 silva_ej_me_bot.pdf: 2557428 bytes, checksum: 2dc6b800c0ffb529ef1c83f5ffe1d6be (MD5) Previous issue date: 2017-12-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Um dos grandes desafios dos produtores agrícolas é elevar os níveis de produção e produtividade das plantações e ao mesmo tempo atender aos anseios da sociedade para que os sistemas de produção sejam mais sustentáveis. Neste cenário, a adoção do sistema de sucessão de culturas surge como uma opção conservacionista ao convencional sistema de monocultura, graças às vantagens como a melhoria das propriedades físicas, químicas e biológicas do solo, melhora o aproveitamento de fertilizantes, reduz os riscos de mercado, entre outras. Entretanto, a adoção contínua do sistema de sucessão de culturas traz malefícios ao solo, como erosão, compactação e esgotamento de nutrientes, os mesmos efeitos do uso contínuo do sistema de monocultura. O objetivo geral deste trabalho foi avaliar a rentabilidade e os riscos econômicos para a adoção do sistema de sucessão de culturas anuais (cultivos de verão seguidos de cultivos de inverno) em relação ao sistema em monocultura no estado do Mato Grosso. Como objetivos específicos, buscou-se identificar quais as principais fontes potenciais de risco para cada cultura e avaliar como elas influenciaram os resultados finais das simulações de cada sistema. Foram realizadas simulações de cenários para ambos os sistemas por meio do método de simulação de Monte Carlo e as culturas selecionadas para esta análise foram a soja, o algodão e o milho dada sua relevância para a economia local e nacional. Para cada sistema foram feitas as análises estatística, de sensibilidade e de percentis de risco utilizando os indicadores de rentabilidade renda líquida (RL) e índice de lucratividade (IL), nos cenários pessimista, médio ou de maior ocorrência e pessimista para as variáveis de produção. Os resultados das simulações indicaram que a monocultura da soja é a atividade com o desempenho mais conservador dentre as analisadas, com as menores probabilidades de prejuízos no cenário mais pessimista de valores e os mais baixos retornos prováveis nos cenários médio e otimista, a baixos níveis de risco, sendo mais indicada a produtores conservadores e avessos a assumirem elevados riscos. A monocultura do algodão e a sucessão de culturas soja-algodão apresentaram os maiores prejuízos no cenário pessimista e as maiores probabilidades de retornos econômicos no cenário otimista, mas com elevados níveis de risco, sendo mais indicados a produtores dispostos a assumirem elevados riscos. A sucessão soja-milho apresentou relevantes resultados nos três cenários, com baixa probabilidade de prejuízos no cenário pessimista e alto retorno econômico nos cenários médio e otimista, a níveis médios de risco, sendo indicada para produtores que estão dispostos a assumirem níveis de riscos mais elevados do que os produtores conservadores. Além disso, as fontes de risco mais impactantes nos resultados das simulações de cenários de ambos os sistemas foram os preços de venda da soja e da pluma de algodão, ambas com impacto positivo, e os custos do inseticida do algodão e do fertilizante da soja, ambas com impacto negativo. No geral, o sistema de sucessão de culturas apresentou maiores resultados a menores níveis de risco. / One of the greatest challenges of agricultural producers is to raise production levels and productivity of plantations and additionally meet the yearnings of society for the production systems more sustainable. In this scenario, the adoption of the crop succession system emerges as a conservationist option front of conventional monoculture system, to the advantages as improvement of physical, chemical and biological properties of the soil, improves the use of fertilizers, reducing market risks, among others. However, the continuous adoption of the crop succession system brings harm to the ground effects, such as erosion, compaction and nutrient depletion, the same effects of the use of the monoculture system. The general goal of this research was to evaluate the profitability and the economic risks for the adoption of the crop succession system for annual crops (summer crops followed by winter crops) regarding to the monoculture system in the State of Mato Grosso. The specific goals of this study were to identify the main potential sources of risk for each culture and evaluate how they have influenced the final results of each system simulations. Scenarios were carried out for both systems by Monte Carlo simulation method and the crops selected for this analysis were soybean, cotton and maize, due to their relevance to the local and national economy. For each system the following analyses were obtained: statistical, sensitivity and percentiles of risk, using the profitability indicators, net income (NI) and profitability index (PI), for three scenarios, pessimistic, medium or higher occurrence and optimistic, for the variables of production. The results of the simulations indicated that the monoculture of soybean is the activity with the most conservative performance analyzed, with the lowest probability of losses in the pessimistic scenario and the lowest probable return on medium and optimistic ones, at low levels of risk. This case is more indicated to the conservative producers and averse to assume high risks. The cotton monoculture and the crop succession soybean-cotton presented the biggest losses in the pessimistic scenario and the greater probability of economic return in the optimistic ones, but, at high levels of risk. These cases are most suitable to producers willing to take higher risks. The soybean-maize succession presented relevant results in all scenarios, with low probability of losses in the pessimistic scenario and high economic return on medium and optimistic ones, with average levels of risk, being indicated for producers who are willing to take higher risk levels than the conservative producers. In addition, the more impactful sources of risks for monoculture and crop succession systems were the sale prices of soybeans and cotton feather, both with positive impact, and the cost of cotton insecticide and fertilizer of soybean, with negative impact. In general, the crop succession system presented higher results at lower levels of risk against the monoculture system.

Dissertação(mestrado)-Universidade Federal do Rio Grande, Programa de Pós-Graduação em Aqüicultura, Instituto de Oceanografia, 2009. / Submitted by Cristiane Silva (cristiane_gomides@hotmail.com) on 2012-07-27T00:36:17Z No. of bitstreams: 1 dissertao la costa.pdf: 778123 bytes, checksum: 5e1013f3ec79c5831a44cf3f91f24d2f (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2012-07-27T17:42:57Z (GMT) No. of bitstreams: 1 dissertao la costa.pdf: 778123 bytes, checksum: 5e1013f3ec79c5831a44cf3f91f24d2f (MD5) / Made available in DSpace on 2012-07-27T17:42:57Z (GMT). No. of bitstreams: 1 dissertao la costa.pdf: 778123 bytes, checksum: 5e1013f3ec79c5831a44cf3f91f24d2f (MD5) Previous issue date: 2009 / O presente experimento teve como objetivo avaliar o desempenho do camarão Litopenaeus vannamei e da tainha Mugil platanus em sistema de monocultivo e de policultivo. A criação dos organismos foi realizada em viveiros escavados, localizados no Laboratório de Aquacultura Continental da Universidade Federal do Rio Grande. Os viveiros com área aproximada de 200 m² foram previamente tratados com cal virgem e fertilizados com esterco bovino curtido. Os tratamentos, em triplicata, foram: monocultivo de camarão (CM); policultivo de camarão com tainha (P); e monocultivo de tainha (TM). As pós-larvas (PL) de camarão foram estocadas numa densidade de 10 PL m-2 com peso inicial de 0,02 g (± 0,003 g) e as tainhas na densidade de 0,67 peixes m-2, pesando inicialmente 1,67g (± 0,32 g). Peixes e camarões foram alimentados com ração comercial para camarão (38% PB) uma vez por dia. A quantidade de ração ministrada aos camarões inicialmente foi de 20% da biomassa total, decrescendo até 5% no final do experimento. Às tainhas, foi ofertada a quantidade de 5% da sua biomassa, durante todo o experimento. Os parâmetros físico e químicos da água foram registrados diariamente. O experimento teve duração de 79 dias durante o verão de 2007/2008. O acompanhamento do crescimento dos animais foi realizado por biometria semanal. No final do experimento foi verificado o ganho de peso, a taxa de crescimento específico, a conversão alimentar aparente, a sobrevivência e a produção dos animais cultivados, além do fator de condição para as tainhas. Os camarões em monocultivo apresentaram ganho de peso (15,59g), taxa de crescimento específico (8,40 % dia-1), conversão alimentar aparente (0,88), sobrevivência (91%) e produção (1.454 kg ha-1) significativamente maior (p < 0,05) do que no policultivo. As tainhas no policultivo apresentaram ganho de peso (42,72 g) e taxa de crescimento específico (3,99) significativamente maior (p < 0,05) que no monocultivo, enquanto seu fator de condição foi significativamente (p < 0,05) menor no policultivo (1,06). A conversão alimentar aparente das tainhas não apresentou diferenças significativas (p > 0,05) entre o monocultivo (2,50) e o policultivo (2,40). Os parâmetros físicos e químicos não foram significativamente diferentes (p > 0,05) entre os tratamentos adotados, com exceção da transparência que foi maior em viveiro de monocultivo de tainha. / The study objected to evaluate Litopenaeus vannamei (Boone, 1931) shrimp and Mugil platanus (Günther, 1880) mullet performance in monoculture and polyculture system. Culture of organisms was conducted in earthen ponds at Continental Aquaculture Laboratory of Rio Grande University. The ponds, with approximately 200 m², were early treated with lime and organic fertilization. The treatment were: shrimp monoculture (CM); shrimp and mullet polyculture (P); and mullet monoculture (TM), with three replicates. Shrimp post-larvae (PL) was stocked at a rate of 10 PL m-2 with mean initial weight of 0,02 g (± 0,003 g) and mullets were stocked at rate of 0,67 fish m-2, weighing 1,67g (± 0,32 g). The organisms have been fed with commercial meal to shrimp (38%PB) once a day at evening. Meal rate initially given to shrimp was 20% total biomass, it decreased until 5%, at the end of experiment. To mullets, it was given the same rate throughout experiment (5%). The water quality parameters were measured daily. Experiment had duration of 79 days in summer, from December, 5th, 2007 until February, 22th, 2008. Four biometry was done (at days 0, 30, 60 and 79) to accompany animals weight. At end experiment, gain weight, specific growth rate, feed conversion apparent rate, survival rate and yield of organisms cultured were analyzed. To mullets was analyzed too factor condition. Shrimp showed weight gain, specific growth, feed conversion apparent rate, survival rate and yield on monoculture significantly higher than on polyculture (p < 0,05). Mullet showed weight gain and specific growth rate significantly higher on polyculture (p < 0,05), while its condition factor was significantly higher (p < 0,05) on monoculture. There was no significant difference (p > 0,05) between feed conversion apparent rate of mullets among treatments. The water quality parameters had not significantly different between treatments, excepting transparency witch was biggest to mullet’s monoculture. The shrimp’s performance was suppressed in present mullets; it showed better zootechnic performance in monoculture.

Over the last century, flowering rush (Butomus umbellatus L.: Butomaceae) has escaped its native Eurasian range and has become a problematic species in North America. As an aquatic invasive species, flowering rush has degraded native wetlands and has interfered with human water usage. Although experimental work has been done regarding the reproductive biology of the species, few empirical studies regarding the ecology of the species have been conducted. The research reported here demonstrates that flowering rush is capable of aggressive clonal growth and propagation, and can perform well along a depth gradient from zero to 132cm. Proper management and control of invasive species relies on sound ecological knowledge of the target species, and this work aims to help gather that information.

Le Grand hamster (Cricetus cricetus), l’un des mammifères les plus menacés d’Europe, est en voie d’extinction en France. Toutefois, nous manquons d’information sur les causes de son déclin et sur comment améliorer sa conservation. Durant ma thèse, je me suis intéressée à l’effet des cultures sur la reproduction du hamster. Les principaux résultats indiquent qu’une consommation importante de maïs conduit à une diminution drastique du succès reproducteur en raison d’une carence en vitamine B3. Une autre étude démontre que des associations de cultures (blé-soja ou maïs-tournesol) sont favorables au hamster et devraient être mises en place en Alsace. En parallèle, j’ai développé un tube anti-prédation (TAP) pour améliorer les passages à faune et reconnecter les populations sauvages. Des tests comportementaux ont révélé que les hamsters présentent des comportements audacieux face au prédateur, mais utilisent tout de même le TAP comme refuge, validant sa fonction anti-prédation. Le TAP sera maintenant mis en place dans plusieurs passages à faune en Alsace. Les résultats de cette thèse vont maintenant bénéficier à la conservation du hamster en France et en Europe. / The European hamster (Cricetus cricetus), one of the most endangered mammal in Europe, is on the verge of extinction in France. However, we are still lacking information on the causes of its decline and on how to improve its conservation. During my PhD, I therefore investigated for the nutritional effects of crops on hamsters’ fitness. The main results highlight that elevated maize consumption is severely reducing hamsters’ reproduction because of a major deficiency in vitamin B3. Then, I found that crop associations such as wheat-soybean and maize-sunflower are favorable to the species and should be implemented in the Alsace. I also developed an anti-predation tube (APT) that will serve to upgrade wildlife underpasses and ultimately allow to reconnect wild populations. Moreover, behavioral tests presented in this thesis reveal that hamsters display bold behaviors when facing a predator. Nonetheless, they use the APT as a refuge in such cases, which validated its anti-predatory function. Therefore, the APT will now be implemented in wildlife underpasses in the Alsace. Results of this PhD will now benefit the conservation of the species in France and in Europe.

<p>Examensarbetets syfte är att undersöka vilka strategier lärare har för att historieundervisningen skall bli meningsfull i ett mångkulturellt klassrum. Med meningsfull i detta sammanhang menas att även andra länders historia, utöver den svenska historien, belyses i undervisningen. Ur syftet formulerades två frågeställningar, som avsåg undersöka hur historieundervisningens ser ut vad gäller val av innehåll och genomförande i ett mångkulturellt klassrum, samt hur historieundervisningen motiveras av lärare i ett mångkulturellt klassrum. För att finna dessa meningsfulla strategier har ett antal kvalitativa intervjuer med lärare som är verksamma i mångkulturella klasser genomförts.</p><p>Den tidigare forskningen visar på en monokulturell historieundervisning baserad på historisk tradition, normer, styrdokument, läromedel och lärares inställning. Utgångspunkt har därför varit att lärarna försätts i en situation där undervisningen inte kan bli annat än monokulturell.</p><p>Undersökningen visar på en historieplanering som främjar den svenska historien. Lärarna motiverar detta genom styrdokument, läromedel och tidsbrist. Vissa lärare har dock utvecklat olika strategier för att skapa en meningsfull historieundervisning för elever med rötter i andra länder. Jämförande anknytningar till andra länder görs genom den svenska historien och traditioner undervisningen. Modersmålsundervisningen åläggs också ett ansvar att låta respektive elever studera sitt ursprungs historia.</p> / <p>This essay examines the strategies teachers may develop in multicultural classrooms in order to make the historical schoolwork meaningful to the students that have their origin in foreign countries. By meaningful this essay points out a teaching in History in multicultural classes that focuses on other countries, besides the history of Sweden.</p><p>In order to find meaningful strategies a number of interviews have been made with teachers that are active in multicultural classes.</p><p>The result of the interviews shows that the teachers planning in History promotes the history of Sweden. They motivate this by pointing out the guideline documents, history textbooks and lack of time. But at the same time the teachers have developed strategies to make their teaching in History meaningful to the students with an origin in other countries. This, by making comparing attachments to other countries history, while teaching the history of Sweden. Other strategies, that is often used by the interviewed teachers, is to bring in different cultural traditions to compare and letting the teachers in the subject of mother tongue be responsible for the learning of their native history.</p>