The structure of a forest stand is characterized by: (a) species composition, (b) age, (c) size (diameter and height), and (d) spatial (horizontal and vertical) arrangement of the trees. Depending on the species, site, and disturbance history, the stand structure varies with time, thus providing a snapshot of a particular development stage. Research on growth and stand structure has shown that the spatial distribution of trees is one of the key determinants of stand productivity. Forest inventories and ecological surveys carried out in British Columbia (BC) have shown that the structure of naturally established, unmanaged stands varies from simple (single-species, single-storied, and even-aged) to complex (multi-species, multi-storied, and uneven-aged). Only a few studies have quantitatively characterized this range of structural complexity, with nearly all studies focusing on old-growth stands. BC forest policy requires that harvested areas be regenerated with a mixture of tree species whenever a mixture is suited to the site. This policy is based upon the assumption that under appropriate conditions, increases in stand productivity, reliability, and/or biodiversity can be attained in mixed-species stands. This assumption has not yet been tested for forest ecosystems. One mechanism by which different tree species can reduce crown competition for light is through vertical separation (the development of multiple canopy strata). Canopy stratification is not easily recognized in mixed-species stands, particularly when species have similar shade tolerance and height growth patterns, and no quantitative methods have been developed to detect stratification. The diameter frequency distribution of two-storied stands have been characterized by inverted J-shaped as well as modal curves. Although it would be more appropriate to characterize stand structure by height frequency distributions, these distributions have not been developed. We suggest that (i) a stand is stratified if there are distinct, quantitatifiable modes in the size distribution; either diameter, height, or crown height, and (ii) height or crown height distributions will be the most sensitive measures. To characterize the structure of western hemlock (Tsuga heterophylla (Raf.) Sarg.) (Hw) and western redcedar (Thuja plicata Donn ex D. Don in Lamb.) (Cw) second-growth stands, and to investigate its influence on tree growth, we (1) described and compared size (diameter, height, and crown height) frequency distributions in single- and mixed-species stands, (2) determined whether mixed-species stands develop a stratified canopy, and (3) examined whether interactions between hemlock and redcedar affect tree growth.

BARROSO, Juarez Coelho. Avaliação da Pesca da Lagosta Vermelha (Panulirus argus) e da Lagosta verde (Panulirus laevicauda) na Plataforma Continental do Brasil. 2012. 109 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-18T13:17:31Z No. of bitstreams: 1 2012_dis_jcbarroso.pdf: 2594115 bytes, checksum: ce2b67584a13e444ae16d1c1c08898f1 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-18T13:17:44Z (GMT) No. of bitstreams: 1 2012_dis_jcbarroso.pdf: 2594115 bytes, checksum: ce2b67584a13e444ae16d1c1c08898f1 (MD5) / Made available in DSpace on 2016-07-18T13:17:44Z (GMT). No. of bitstreams: 1 2012_dis_jcbarroso.pdf: 2594115 bytes, checksum: ce2b67584a13e444ae16d1c1c08898f1 (MD5) Previous issue date: 2012 / Extractive fishing lobster in Brazil is an important economic activity which includes different social sectors in the coastal region and provides an average annual income of USD$ 84 million. The great demand for the product, the high value in international market, expansion of the artisanal fleet, failure in enforce of conservation measures, the fishing impact on ecosystems and perhaps climate variability, have led to a high exploitation or overexploitation of the crustacean stocks. The evaluation and fishery prediction depends of biological and fisheries data collection, in the last two decades the absence of these data and the lack in the life cycle study generated a high level of uncertainty in the management of the fishery. In the present study, a comprehensive analysis is done of biological and fishery information generated by the thesis project and the data that precedes. The areas of the stock aggregation were distributed into 31 strata covering an area of 356.610 km², divided into two regions: shallow < 50 m (160.510 km²) and depth between 50 and 100 m (196.100 km²). The medium productivity index (1999-2006) between species was 29,75 kg/km² in Panulirus argus and 8,39 kg/km² in P. laevicauda; in different strata varied between 0.02 and 217.0 kg/km² (both species). Catchability coefficients ranged between 0.10 and 0.14, showing that the fishing gears (caçoeira, manzuá and cangalha) have a low efficiency in the lobster fishery. The sampling of landings between different fishing periods (1970-1979, 1980-1988 and 1989-1993) showed a progressive decrease in the small lobsters and as a result the mean length showed an increasing trend. The random samples on boats that fished between 20 and 35 m (1999), revealed that lobsters recruited (50 and 75 mm, Lc) accounted for 91% (P. argus) and 96% (P. laevicauda) of the total catch, which with the expansion of fishing (increased effort) was accompanied by a decreasing of the CPUE by fishing grids (between 1974 and 1991), showed a growth overfishing which are probably influencing in the high variations of the annual catches and its negative trend observed in the last fifteen years (1995-2009). The analysis between CPUE and abundance (N), revealed a lack of proportionality (hyperstability) between both parameters, which could be affecting the relationship between CPUE and effort and overestimating yield maximum sustainable (YMS). We estimated a yield maximum sustainable per unit area of 14 kg/km² and a yield maximum sustainable preliminary between 5,000 and 5,604 t. This empirical result should be confirmed through the development of stratified random sampling is proposed in this study. There is not evidence of recruitment overfishing in the stocks, but high rates of exploitation in the deep stock (50 to 100 m) of P. argus, composed mainly of older specimens and high reproductive power, could be accentuating the risk of low recruitment and collapse. This high level of uncertainty which takes the lobster fishery on the continental shelf of Brazil must be addressed by new ways of thinking, by a long-term and acquiring new skills and knowledge to develop fisheries sustainable. / A pesca extrativa de lagosta no Brasil é uma atividade econômica importante que engloba diferentes setores sociais na região costeira e que aporta um ingresso médio anual de 84 milhões de dólares. A grande demanda do produto, o elevado valor no mercado internacional, a expansão da frota artesanal, o não cumprimento das medidas de conservação, o impacto da pesca no ecossistema e possivelmente a variabilidade do clima, tem propiciado uma elevada explotação ou sobre-explotação dos estoques destes crustáceos. A avaliação e previsão da pescaria dependem da coleta de informação biológica e pesqueira, em que nas duas últimas décadas a ausência destes dados e a falta de estudo do ciclo de vida gerou um elevado nível de incerteza na administração da pescaria. No presente estudo, foi realizada uma análise integral da informação biológico-pesqueira gerada pelo projeto de mestrado e pelos dados que o precedem. As zonas de agregação dos estoques pesqueiros se distribuíram em 31 estratos que cobrem uma área de 356.610 km², divididos em duas regiões: rasa < 50 m (160.510 km²) e profunda entre 50 e 100 m (196.100 km²). O índice de produtividade médio (1999-2006) entre espécies foi de 29,75 kg/km² em Panulirus argus e de 8,39 kg/km² em P. laevicauda; nos diferentes estratos variou entre 0,02 e 217,0 kg/km² (ambas as espécies). Os coeficientes de capturabilidade variaram entre 0,10 e 0,14, demonstrando-se que os aparelhos de pesca (caçoeira, manzuá e cangalha) apresentam uma baixa eficiência na pescaria de lagosta. A amostragem dos desembarques entre diferentes períodos de pesca (1970-1979, 1980-1988 e 1989-1993) mostrou uma diminuição progressiva das lagostas pequenas e, como resultado, o comprimento médio mostrou uma tendência crescente. As amostragens aleatórias nas embarcações que pescaram entre 20 e 35 m (1999) revelaram que as lagostas recrutadas (50 e 75 mm, CC) representaram 91% (P. argus) e 96% (P. laevicauda) do total capturado, que conjuntamente com a expansão da área de pesca (aumento do esforço) e a diminuição da CPUE por quadrículas de pesca (entre 1974 e 1991), evidenciaram uma sobrepesca de crescimento que provavelmente esteja influenciando nas elevadas variações das capturas anuais e em sua tendência negativa observada nos últimos 15 anos (1995-2009). A análise realizada entre a CPUE e a abundância (N), revelou uma falta de proporcionalidade (hiperestabilidade) entre ambos os parâmetros, que poderia estar afetando a relação entre a CPUE e o esforço, e sobre-estimando as estimativas do rendimento máximo sustentável (RMS). Foi estimado um rendimento máximo sustentável por unidade de área de 14 kg/km² e um rendimento máximo sustentável preliminar entre 5.000 e 5.604 t. Este resultado empírico deve ser corroborado a partir do desenvolvimento da amostragem aleatória estratificada que foi proposto no presente estudo. Não existem evidências de uma sobrepesca de recrutamento nos estoques, mas as altas taxas de explotação no estoque do setor profundo (50 e 100 m) de P. argus, composto principalmente por exemplares mais velhos e de elevado poder reprodutor, poderia estar acentuando o risco dos recrutamentos baixos e dos colapsos. Este grande nível de incerteza pelo que transcorre a pescaria de lagosta na plataforma continental do Brasil deve ser abordado por formas de pensar novas e diferentes, por uma visão em longo prazo e pela obtenção de novos conhecimentos científicos que permitam desenvolver uma pesca sustentável.

Made available in DSpace on 2015-03-26T13:40:07Z (GMT). No. of bitstreams: 1 texto completo.pdf: 372745 bytes, checksum: 6f1e60efc5a019ffb5aabeff2579b6ad (MD5) Previous issue date: 2007-07-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to select superior genotypes of the yellow passion flower related to productivity and quality of the fruits. A population of 26 families of whole brothers was evaluated in the second year of production, in a design of random plots, with three repetitions, starting with four plants per plot. The experiment was carried out in the experimental area of Fruitculture in the Departamento de Fitotecnia of the Universidade Federal de Viçosa, in Viçosa, Minas Gerais State, Brazil. In the selection among and within the families, the efficiency of the direct and indirect selection as well as that based on the classical index was verified. The selection strategies among and within, combined, massal and stratified massal were compared. The results found by the selection among and within were compared with those obtained from the selection made in this same population in the first year of production. The characteristics measured were number of fruits per plant, estimated production per plant, length of the fruit, diameter of the fruit, weight of the fruit, weight of the peel, thickness of the peel, weight of the pulp, color of the pulp, percentage of the pulp, total content of soluble solids, titrable total acidity and the rate between the total soluble solids/titrable total acidity. Samples of 10 fruits of each plant were obtained to evaluate the qualitative characteristics of the fruits. The collection of the fruits for the analyses was made as they became yellowishgreen, during the second year of production, from January to July 2006. All the statistical analyses were made with the genetics and statistics software GENES. The selection gains were estimated based on a percentage of 24% among families and of 25% within families for all the characteristics measured. The selection criterium adopted for all the characteristics was the increase in peel their original mediuns, except for the weight and thickness of the peel for which a decrease was desired. For the characteristics choice that were part of the classic index of selection, the multicolinearity diagnosis was carried out, using the autovalues and the autovectors analyses. The selected characteristics to make up the index were estimated production per plant, diameter of the fruit, pulp percentage, pulp color and total titrable acidity. The use of the strategy of simultaneous selection of characters, based on the classic index showed estimations of gains greater than those of the other methodologies, in estimated production per plant and pulp percentage. In the direct selection, the estimations of gains were greater in pulp color and total titrable acidity. The combined selection, when compared to the among and within selection massal and stratified massal, provided the greatest estimations of gains in 11 out of 13 characteristics evaluated, except length and weight of the fruit, thus being the most suitable strategy for the breeding of the population studied. The evaluations made in the first year of production generated satisfactory results, which practically were reproduced in the second year, and therefore can be recommended, because of costs and time reduction of the selection cycle. / Com o objetivo de selecionar genótipos de maracujazeiro amarelo superiores quanto à produtividade e qualidade dos frutos, uma população constituída de 26 famílias de irmãos completos foi avaliada no segundo ano de produção, em delineamento de blocos casualizados, com três repetições e originalmente com quatro plantas por parcela. O trabalho foi realizado na área experimental de Fruticultura do Departamento de Fitotecnia da Universidade Federal de Viçosa, em Viçosa, MG. Verificou-se, na seleção entre e dentro de famílias, a eficiência da seleção direta, indireta e com base em índice clássico. Compararam-se as estratégias de seleção entre e dentro, combinada, massal e massal estratificada. Os resultados encontrados pela seleção entre e dentro foram confrontados com os obtidos em seleção realizada, nessa mesma população, no primeiro ano de produção. As características mensuradas foram número de frutos por planta, produção estimada por planta, comprimento do fruto, diâmetro do fruto, massa do fruto, massa da casca, espessura da casca, massa da polpa, coloração da polpa, porcentagem de polpa, teor de sólidos solúveis totais, acidez total titulável e relação entre teor de sólidos solúveis totais/acidez total titulável. Foi obtida amostra de 10 frutos de cada planta, para avaliação das características qualitativas dos frutos. A colheita dos frutos foi feita de forma parcelada durante o segundo ano de produção, de janeiro a julho de 2006. Os frutos destinados à análise foram colhidos a partir do estádio verde-amarelo . Todas as análises estatísticas foram realizadas com o aplicativo computacional em genética e estatística (GENES). Foram estimados os ganhos de seleção em função de uma porcentagem de seleção de 24% entre famílias e 25% dentro de famílias para todas as características mensuradas. O critério de seleção adotado para todas as características foi o acréscimo em suas médias originais, exceto em massa e espessura da casca, em que se buscou o decréscimo. Para escolha das características que fizeram parte do índice clássico de seleção, foi realizado o diagnóstico de multicolinearidade, empregando para isso a análise dos autovalores e autovetores. As características selecionadas para compor o índice foram produção estimada por planta, diâmetro do fruto, porcentagem de polpa, coloração da polpa e acidez total titulável. A utilização da estratégia de seleção simultânea de caracteres, com base no índice clássico apresentou estimativas de ganhos superiores às das outras metodologias em produção estimada por planta e porcentagem de polpa. Na seleção direta, as estimativas de ganhos foram superiores em coloração de polpa e acidez total titulável. A seleção combinada, quando comparada à seleção entre e dentro, massal e massal estratificada, proporcionou as maiores estimativas de ganhos em 11 das 13 características avaliadas, exceto comprimento e massa do fruto, sendo, assim, a estratégia mais apropriada para o melhoramento genético da população estudada. A realização das avaliações no primeiro ano de produção gera resultados satisfatórios, os quais praticamente, se reproduzem no segundo ano, podendo ser recomendada, por reduzir o custo e o tempo de realização do ciclo de seleção.

Made available in DSpace on 2015-03-26T13:40:07Z (GMT). No. of bitstreams: 1 texto completo.pdf: 372745 bytes, checksum: 6f1e60efc5a019ffb5aabeff2579b6ad (MD5) Previous issue date: 2007-07-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to select superior genotypes of the yellow passion flower related to productivity and quality of the fruits. A population of 26 families of whole brothers was evaluated in the second year of production, in a design of random plots, with three repetitions, starting with four plants per plot. The experiment was carried out in the experimental area of Fruitculture in the Departamento de Fitotecnia of the Universidade Federal de Viçosa, in Viçosa, Minas Gerais State, Brazil. In the selection among and within the families, the efficiency of the direct and indirect selection as well as that based on the classical index was verified. The selection strategies among and within, combined, massal and stratified massal were compared. The results found by the selection among and within were compared with those obtained from the selection made in this same population in the first year of production. The characteristics measured were number of fruits per plant, estimated production per plant, length of the fruit, diameter of the fruit, weight of the fruit, weight of the peel, thickness of the peel, weight of the pulp, color of the pulp, percentage of the pulp, total content of soluble solids, titrable total acidity and the rate between the total soluble solids/titrable total acidity. Samples of 10 fruits of each plant were obtained to evaluate the qualitative characteristics of the fruits. The collection of the fruits for the analyses was made as they became yellowishgreen, during the second year of production, from January to July 2006. All the statistical analyses were made with the genetics and statistics software GENES. The selection gains were estimated based on a percentage of 24% among families and of 25% within families for all the characteristics measured. The selection criterium adopted for all the characteristics was the increase in peel their original mediuns, except for the weight and thickness of the peel for which a decrease was desired. For the characteristics choice that were part of the classic index of selection, the multicolinearity diagnosis was carried out, using the autovalues and the autovectors analyses. The selected characteristics to make up the index were estimated production per plant, diameter of the fruit, pulp percentage, pulp color and total titrable acidity. The use of the strategy of simultaneous selection of characters, based on the classic index showed estimations of gains greater than those of the other methodologies, in estimated production per plant and pulp percentage. In the direct selection, the estimations of gains were greater in pulp color and total titrable acidity. The combined selection, when compared to the among and within selection massal and stratified massal, provided the greatest estimations of gains in 11 out of 13 characteristics evaluated, except length and weight of the fruit, thus being the most suitable strategy for the breeding of the population studied. The evaluations made in the first year of production generated satisfactory results, which practically were reproduced in the second year, and therefore can be recommended, because of costs and time reduction of the selection cycle. / Com o objetivo de selecionar genótipos de maracujazeiro amarelo superiores quanto à produtividade e qualidade dos frutos, uma população constituída de 26 famílias de irmãos completos foi avaliada no segundo ano de produção, em delineamento de blocos casualizados, com três repetições e originalmente com quatro plantas por parcela. O trabalho foi realizado na área experimental de Fruticultura do Departamento de Fitotecnia da Universidade Federal de Viçosa, em Viçosa, MG. Verificou-se, na seleção entre e dentro de famílias, a eficiência da seleção direta, indireta e com base em índice clássico. Compararam-se as estratégias de seleção entre e dentro, combinada, massal e massal estratificada. Os resultados encontrados pela seleção entre e dentro foram confrontados com os obtidos em seleção realizada, nessa mesma população, no primeiro ano de produção. As características mensuradas foram número de frutos por planta, produção estimada por planta, comprimento do fruto, diâmetro do fruto, massa do fruto, massa da casca, espessura da casca, massa da polpa, coloração da polpa, porcentagem de polpa, teor de sólidos solúveis totais, acidez total titulável e relação entre teor de sólidos solúveis totais/acidez total titulável. Foi obtida amostra de 10 frutos de cada planta, para avaliação das características qualitativas dos frutos. A colheita dos frutos foi feita de forma parcelada durante o segundo ano de produção, de janeiro a julho de 2006. Os frutos destinados à análise foram colhidos a partir do estádio verde-amarelo . Todas as análises estatísticas foram realizadas com o aplicativo computacional em genética e estatística (GENES). Foram estimados os ganhos de seleção em função de uma porcentagem de seleção de 24% entre famílias e 25% dentro de famílias para todas as características mensuradas. O critério de seleção adotado para todas as características foi o acréscimo em suas médias originais, exceto em massa e espessura da casca, em que se buscou o decréscimo. Para escolha das características que fizeram parte do índice clássico de seleção, foi realizado o diagnóstico de multicolinearidade, empregando para isso a análise dos autovalores e autovetores. As características selecionadas para compor o índice foram produção estimada por planta, diâmetro do fruto, porcentagem de polpa, coloração da polpa e acidez total titulável. A utilização da estratégia de seleção simultânea de caracteres, com base no índice clássico apresentou estimativas de ganhos superiores às das outras metodologias em produção estimada por planta e porcentagem de polpa. Na seleção direta, as estimativas de ganhos foram superiores em coloração de polpa e acidez total titulável. A seleção combinada, quando comparada à seleção entre e dentro, massal e massal estratificada, proporcionou as maiores estimativas de ganhos em 11 das 13 características avaliadas, exceto comprimento e massa do fruto, sendo, assim, a estratégia mais apropriada para o melhoramento genético da população estudada. A realização das avaliações no primeiro ano de produção gera resultados satisfatórios, os quais praticamente, se reproduzem no segundo ano, podendo ser recomendada, por reduzir o custo e o tempo de realização do ciclo de seleção.

CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / A pesca extrativa de lagosta no Brasil à uma atividade econÃmica importante que engloba diferentes setores sociais na regiÃo costeira e que aporta um ingresso mÃdio anual de 84 milhÃes de dÃlares. A grande demanda do produto, o elevado valor no mercado internacional, a expansÃo da frota artesanal, o nÃo cumprimento das medidas de conservaÃÃo, o impacto da pesca no ecossistema e possivelmente a variabilidade do clima, tem propiciado uma elevada explotaÃÃo ou sobre-explotaÃÃo dos estoques destes crustÃceos. A avaliaÃÃo e previsÃo da pescaria dependem da coleta de informaÃÃo biolÃgica e pesqueira, em que nas duas Ãltimas dÃcadas a ausÃncia destes dados e a falta de estudo do ciclo de vida gerou um elevado nÃvel de incerteza na administraÃÃo da pescaria. No presente estudo, foi realizada uma anÃlise integral da informaÃÃo biolÃgico-pesqueira gerada pelo projeto de mestrado e pelos dados que o precedem. As zonas de agregaÃÃo dos estoques pesqueiros se distribuÃram em 31 estratos que cobrem uma Ãrea de 356.610 kmÂ, divididos em duas regiÃes: rasa < 50 m (160.510 kmÂ) e profunda entre 50 e 100 m (196.100 kmÂ). O Ãndice de produtividade mÃdio (1999-2006) entre espÃcies foi de 29,75 kg/km em Panulirus argus e de 8,39 kg/km em P. laevicauda; nos diferentes estratos variou entre 0,02 e 217,0 kg/km (ambas as espÃcies). Os coeficientes de capturabilidade variaram entre 0,10 e 0,14, demonstrando-se que os aparelhos de pesca (caÃoeira, manzuà e cangalha) apresentam uma baixa eficiÃncia na pescaria de lagosta. A amostragem dos desembarques entre diferentes perÃodos de pesca (1970-1979, 1980-1988 e 1989-1993) mostrou uma diminuiÃÃo progressiva das lagostas pequenas e, como resultado, o comprimento mÃdio mostrou uma tendÃncia crescente. As amostragens aleatÃrias nas embarcaÃÃes que pescaram entre 20 e 35 m (1999) revelaram que as lagostas recrutadas (50 e 75 mm, CC) representaram 91% (P. argus) e 96% (P. laevicauda) do total capturado, que conjuntamente com a expansÃo da Ãrea de pesca (aumento do esforÃo) e a diminuiÃÃo da CPUE por quadrÃculas de pesca (entre 1974 e 1991), evidenciaram uma sobrepesca de crescimento que provavelmente esteja influenciando nas elevadas variaÃÃes das capturas anuais e em sua tendÃncia negativa observada nos Ãltimos 15 anos (1995-2009). A anÃlise realizada entre a CPUE e a abundÃncia (N), revelou uma falta de proporcionalidade (hiperestabilidade) entre ambos os parÃmetros, que poderia estar afetando a relaÃÃo entre a CPUE e o esforÃo, e sobre-estimando as estimativas do rendimento mÃximo sustentÃvel (RMS). Foi estimado um rendimento mÃximo sustentÃvel por unidade de Ãrea de 14 kg/km e um rendimento mÃximo sustentÃvel preliminar entre 5.000 e 5.604 t. Este resultado empÃrico deve ser corroborado a partir do desenvolvimento da amostragem aleatÃria estratificada que foi proposto no presente estudo. NÃo existem evidÃncias de uma sobrepesca de recrutamento nos estoques, mas as altas taxas de explotaÃÃo no estoque do setor profundo (50 e 100 m) de P. argus, composto principalmente por exemplares mais velhos e de elevado poder reprodutor, poderia estar acentuando o risco dos recrutamentos baixos e dos colapsos. Este grande nÃvel de incerteza pelo que transcorre a pescaria de lagosta na plataforma continental do Brasil deve ser abordado por formas de pensar novas e diferentes, por uma visÃo em longo prazo e pela obtenÃÃo de novos conhecimentos cientÃficos que permitam desenvolver uma pesca sustentÃvel. / Extractive fishing lobster in Brazil is an important economic activity which includes different social sectors in the coastal region and provides an average annual income of USD$ 84 million. The great demand for the product, the high value in international market, expansion of the artisanal fleet, failure in enforce of conservation measures, the fishing impact on ecosystems and perhaps climate variability, have led to a high exploitation or overexploitation of the crustacean stocks. The evaluation and fishery prediction depends of biological and fisheries data collection, in the last two decades the absence of these data and the lack in the life cycle study generated a high level of uncertainty in the management of the fishery. In the present study, a comprehensive analysis is done of biological and fishery information generated by the thesis project and the data that precedes. The areas of the stock aggregation were distributed into 31 strata covering an area of 356.610 kmÂ, divided into two regions: shallow < 50 m (160.510 kmÂ) and depth between 50 and 100 m (196.100 kmÂ). The medium productivity index (1999-2006) between species was 29,75 kg/km in Panulirus argus and 8,39 kg/km in P. laevicauda; in different strata varied between 0.02 and 217.0 kg/km (both species). Catchability coefficients ranged between 0.10 and 0.14, showing that the fishing gears (caÃoeira, manzuà and cangalha) have a low efficiency in the lobster fishery. The sampling of landings between different fishing periods (1970-1979, 1980-1988 and 1989-1993) showed a progressive decrease in the small lobsters and as a result the mean length showed an increasing trend. The random samples on boats that fished between 20 and 35 m (1999), revealed that lobsters recruited (50 and 75 mm, Lc) accounted for 91% (P. argus) and 96% (P. laevicauda) of the total catch, which with the expansion of fishing (increased effort) was accompanied by a decreasing of the CPUE by fishing grids (between 1974 and 1991), showed a growth overfishing which are probably influencing in the high variations of the annual catches and its negative trend observed in the last fifteen years (1995-2009). The analysis between CPUE and abundance (N), revealed a lack of proportionality (hyperstability) between both parameters, which could be affecting the relationship between CPUE and effort and overestimating yield maximum sustainable (YMS). We estimated a yield maximum sustainable per unit area of 14 kg/km and a yield maximum sustainable preliminary between 5,000 and 5,604 t. This empirical result should be confirmed through the development of stratified random sampling is proposed in this study. There is not evidence of recruitment overfishing in the stocks, but high rates of exploitation in the deep stock (50 to 100 m) of P. argus, composed mainly of older specimens and high reproductive power, could be accentuating the risk of low recruitment and collapse. This high level of uncertainty which takes the lobster fishery on the continental shelf of Brazil must be addressed by new ways of thinking, by a long-term and acquiring new skills and knowledge to develop fisheries sustainable.

Escoamentos bifásicos estão presentes em diversos processos naturais e industriais, como na indústria de petróleo. Podem apresentar-se em diferentes configurações topológicas, ou, padrões de escoamento, entre eles o escoamento estratificado ondulado e o estratificado com mistura na interface. Os escoamentos bifásicos estratificados óleo-água têm sido utilizados como uma forma conveniente de evitar a formação de emulsões de água em óleo em oleodutos e possuem uma ocorrência comum em poços de petróleo direcionais. Quando a onda interfacial ultrapassa determinado limite geométrico e cinemático, surge o fenômeno do entranhamento de gotas, representado por misturas entre as fases junto à interface que promovem um aumento na queda de pressão. Modelos têm sido apresentados pela literatura na tentativa de descrever o fenômeno do entranhamento de gotas. Neste trabalho é apresentada uma nova proposta de modelagem matemática unidimensional para o entranhamento de gotas com o objetivo de melhorar a previsão dos parâmetros envolvidos, em especial, da fração volumétrica de óleo e da queda de pressão bifásica. Também foi utilizada simulação numérica computacional, CFD (Computational Fluid Dynamics), com o uso de software comercial para obtenção dos valores dos parâmetros do escoamento estratificado ondulado óleo-água (fração volumétrica de óleo, queda de pressão, amplitude e comprimento da onda interfacial). Os resultados da modelagem fenomenológica para entranhamento e os de CFD foram comparados com bancos de dados experimentais. Os resultados em CFD mostram concordância com os resultados experimentais, tanto na análise qualitativa das propriedades geométricas das ondas interfaciais, quanto na comparação direta com os dados para fração volumétrica e queda de pressão. Os resultados numéricos da modelagem fenomenológica para fatores de entranhamento apresentam boa concordância com dados da literatura. / Two-phase flows are present in many natural and industrial processes, such as in the oil industry. They may be found arranged in several flow patterns, including the wavy stratified flow and the stratified with mixing at the interface. The stratified oil-water flow has been used as a convenient way to avoid the formation of emulsions of water in oil and have a common occurrence in directional oil wells. When the interfacial wave exceeds a certain geometric and kinematic limit the phenomenon of drop entrainment arises at the interface, causing an increase of pressure drop. Models have been presented in the literature in an attempt to describe the phenomenon of drop entrainment. In this work, we present a new method for the one-dimensional mathematical modeling of entrainment in order to improve the prediction of oil volume fraction and pressure drop. It was also used a commercial computational fluid dynamics tool (CFD) to obtain the values of flow parameters of wavy stratified oil-water flow, such as oil volume fraction, pressure drop, amplitude and length of the interfacial waves. The results of the phenomenological modeling for entrainment and CFD were compared with experimental databases. The CFD results are in agreement with the experimental results in both the qualitative analysis of the geometric properties of the interfacial waves and in direct comparison with oil-volumetric-fraction and pressure-drop data. The numerical results of the phenomenological model for entrainment factors are in agreement with data from the literature.

La marée interne générée sur une topographie est un élément clé des transferts énergétiques des échelles de forçage de l'océan vers les échelles de mélange turbulent. Elle contribuerait à près de la moitié du mélange turbulent nécessaire au maintien de la stratification océanique. Une compréhension plus approfondie des processus mis en jeu est nécessaire pour décrire plus précisément son rôle dans le maintien de la circulation océanique. Cette thèse s'inscrit dans la continuité des travaux d'Y. Dossmann (2012) portant sur les ondes internes solitaires générées au dessus d'une dorsale océanique. Ces travaux reposent sur une utilisation complémentaire d'expériences physiques menées dans le grand canal du CNRM-GAME et d'expériences numériques à l'échelle du laboratoire effectuées avec le modèle d'océanographie côtière SNH. L'utilisation simultanée de ces deux outils a notamment permis d'évaluer la validité des hypothèses sous-jacentes de ce modèle et le développement de nouveaux schémas numériques. Dans cette thèse, des simulations numériques utilisant la version non-hydrostatique et non-Boussinesq du modèle SNH sont utilisées pour décrire les différents régimes d'ondes internes dans des régions " supercritiques ". Le terme supercritique désigne à la fois des courants de marée intenses dont la vitesse U est supérieure à la vitesse de propagation des ondes internes cn, et des topographies très abruptes dont l'angle de la pente est supérieur à l'angle du rayon d'onde interne dans la pycnocline . De telles conditions environnementales correspondent à des régions de mélange intense, jusqu'à 10 000 fois supérieur au mélange turbulent observé dans l'océan ouvert. Les processus physiques ayant lieu dans ces régions restent encore mal compris et mal représentés par les paramétrisations d'ondes internes existantes. De plus, ces régions sont également des zones propices à la génération d'ondes internes non-linéaires pouvant se propager pendant plusieurs jours et entraînant ainsi des transferts d'énergie significatifs loin de leur zone de génération. La description des processus turbulents en jeu dans ces régions " extrêmes " constitue le cœur de ma thèse. Dans une première partie, des configurations académiques à l'échelle du laboratoire sont mises en place pour étudier les processus en jeu dans différents régimes " supercritiques " de génération d'onde internes. Des simulations numériques directes sont réalisées et permettent d'identifier un nombre limité de paramètres physiques adimensionnés contrôlant la dynamique des ondes internes dans ces régions. Une attention particulière est portée sur le rôle joué par la topographie sur la génération des modes verticaux d'ondes internes et sur la formation de modes " hauts " d'ondes internes solitaires. Le second objectif de cette thèse est de faire le lien entre les précédentes études académiques à l'échelle du laboratoire et l'échelle océanique. Pour cela, un principe de similitude permettant de conserver la dynamique des ondes internes tout en modifiant l'échelle de l'écoulement est mise en place. Par le biais de ce principe de similitude, nous partons de cas idéalisés à l'échelle du laboratoire, que nous transposons à l'échelle océanique, pour nous rapprocher de cas océaniques plus réalistes et de plus en plus complexes. Puis notre étude de régime est étendue à deux régions océaniques " supercritiques " bien connues : le détroit de Gibraltar et le plateau situé à l'entrée du golfe du Maine (nommé " Georges Bank " en anglais). L'applicabilité de nos paramètres clés est étudiée dans le cas de ces deux environnements complexes par le biais de simulations haute résolution de grande échelle (LES). / Internal tides are involved in the Meridional Overturning Circulation energy balance. The issue about the relative importance of the mechanical and thermodynamical energy sources induces a need for a quantitative evaluation of the energy transfers and for a clear understanding of the physical processes involved in these energy transfers. In supercritical regions such as the strait of Gibraltar or the Hawaiian Ridge, large topography variations and strong currents lead to more complex generation mechanisms of internal waves and environmental interactions. They can be subject locally to spectacular breaking, with turbulent structures observed hundreds of meters above the seafloor, and driving turbulence orders of magnitude higher than open-ocean levels. These regions are also effective at generating nonlinear internal waves (ISWs) which persist for days after their generation and are suspected to be responsible for important remote energy transfers. In these "extreme" regions, ISWs dynamics is also more difficult to model. These situations are highly non-hydrostatic and non-linear with strong instabilities, strong velocity and density gradients and steep slopes. Moreover, in these regions, actual internal wave's parameterizations are often inadequate. So there is a real need to understand and represent better the ISWs dynamic in these areas. This thesis follows the line of research of Dossmann (2012), on topographically induced internal solitary waves which used a complementary approach relying on numerical and experimental configurations at laboratory scale. In this context, we continue to explore internal tide regimes but in "supercritical" regions: internal tide generation area with supercritical topography and hydraulic control. Simulations are performed using the nonhydrostatic and non-Boussinesq version of the regional oceanic circulation model SNH. In a first part, taking an idealized modeling approach at laboratory scale, we examined a range of different internal waves regimes in "supercritical" regions. Relying on quasi-direct numerical simulations (quasi-DNS), a regime analysis has been proposed using and identifying key non-dimensional parameters for ISWs dynamics. This analysis has permitted to recover a topographic control on vertical mode generation characterized by the ratio of vertical mode wavelength to topography width, even above supercritical topography. The topographic selection criterion has proven to be a useful indicator of high mode solitary wave formation in non-linear regime. The purpose of the second part is to extend the previous studies at laboratory scales towards more realistic oceanic conditions. In this regard, the regime analysis is applied to a idealized large scale oceanic strait through a similitude principle. The idealized strait configuration succeeds in representing laboratory scale strait regime at largest and realistic scales. Then our analysis is applied to two well-known realistic cases: the Strait of Gibraltar and Georges Bank through large eddy simulations. These two oceanographic "supercritical" regions are particularly interesting for their specific topography and stratification conditions.

Le couplage entre un écoulement instable et des résonances acoustiques dans des systèmes de conduites peut conduire à des phénomènes d’oscillations auto-induites. Ce type de phénomènes trouve principalement place dans des conduites latérales fermées, par exemple dans des systèmes de transport ou de compression de gaz. L’objectif de ce travail est d’étudier les oscillations auto-induites dans le cas où le fluide transporté ne se limite pas à un gaz, mais est un mélange de gaz et de liquide. Les pulsations sont mesurées dans des conduites latérales fermées, pour deux types de configurations (en tandem et en croix), avec écoulement d’un mélange variable d’air et d’eau. La position de l’injection d’eau est variable afin d’obtenir plusieurs régimes d’écoulement diphasique. Les résultats indiquent que la présence d’eau a un effet important sur les niveaux de pulsations dans les conduites. Cet effet a pu être attribué à deux mécanismes dus à la présence d’eau : les instabilités de couches de mélange sont modifiées et l’amortissement des ondes acoustiques est amplifié.Le deuxième mécanisme a été quantifié à l’aide de mesures sur un montage expérimental dédié conçu pour avoir un écoulement stratifié. On a observé que, dans tous les cas, la présence d’eau augmente l’amortissement. Cette augmentation a pu être attribuée à la réduction de la section effective de la conduite (due au remplissage partiel par l’eau) et à l’augmentation de la friction turbulente à l’interface entre les phases liquide et gazeuse. / Coupling between flow instabilities and acoustic resonances in ducts with closed side branches leads to Flow Induced Pulsations (FIPs). This is a typical phenomenon in engineering applications (gas transport systems, compressor installations, and chemical plants). The objective of this work is to extend the knowledge about FIPs when the transported medium is not uniquely gas but a combination of gas and (a small quantity of) liquid. For two configurations of double side branches (in tandem and in quasi-cross), the amplitude of pressure pulsations in the side branches was measured for different liquid injection rates. This was repeated with the liquid injection point located at different places to allow different flow regimes at the pipe connections. The results show a strong effect of the water content on the pulsations. On basis of these results and additional measurements, the following hypotheses for the effect of liquid were made: (1) interaction of the liquid with the flow instability and (2) increase of the acoustical damping in the ducts in presence of liquid.The effect of liquid on damping was measured with a dedicated test setup designed to have a stratified flow. It was found that the liquid always increases the acoustical damping, mainly due to the reduction of the effective cross section by the liquid, and because of the increased turbulent friction at the interface between gas and liquid.

Cette thèse est consacrée à l'étude théorique de quelques modèles d'évolution non-linéaires issus de la mécanique des fluides. Nous distinguons trois parties indépendantes. La première partie de la thèse traite essentiellement de l'existence des poches de tourbillon en rotation uniforme (appelées aussi V-states) pour un modèle quasi-géostrophique non visqueux. Notre étude est répartie sur deux chapitres où les poches présentent des structures topologiques différentes. Dans le premier chapitre nous étudions le cas simplement connexe et nous validons l'existence de ces structures dans un voisinage du tourbillon de Rankine en utilisant des techniques de bifurcation. Dans le deuxième chapitre nous abordons le cas doublement connexe où la poche admet un seul trou. Plus précisément, proche d'un anneau donné, nous décrivons cette famille par des branches dénombrables bifurquant de cet anneau à certaines valeurs explicites des vitesses angulaires liées aux fonctions de Bessel. Notre étude théorique a été complétée par des simulations numériques portant sur les V-states limites et un bon nombre de constatations ont été formulées ouvrant la porte à de nouvelles perspectives de recherche. La seconde partie concerne l'étude du problème de Cauchy pour le système de Boussinesq non visqueux 2D avec des données initiales de type Yudovich. Le problème est dans un certain sens critique à cause de quelques termes comportant la transformée de Riesz dans la formulation tourbillon-densité. Nous donnons une réponse positive pour une sous-classe comprenant les poches de tourbillon régulières et singulières. Dans la dernière partie nous analysons le problème de la limite incompressible pour les équations d'Euler isentropiques 2D associées à des données initiales très mal préparées et pour lesquelles les tourbillons ne sont pas forcément bornés mais appartiennent plutôt à des espaces de type ''BMO'' à poids. On utilise principalement deux ingrédients: d'un côté les estimations de Strichartz pour contrôler la partie acoustique. D'un autre côté, on se sert de la structure de transport compressible du tourbillon et on démontre une estimation de propagation linéaire dans l'esprit d'un travail récent de Bernicot et Keraani mené dans le cas incompressible. / In this dissertation, we are concerned with the study of some non-linear evolution models arising in fluid mechanics. We distinguish three independent parts. The first part of the thesis deals with the existence of the rotating vortex patches (called also V-states) for an inviscid quasi-geostrophic model. Our study is divided into two chapters dealing with different topological structures of the V-states. In the first chapter we study the simply connected case and we prove the existence of such structures in a neighborhood of the Rankine vortices by using the bifurcation theory. In the second chapter we discuss the doubly connected case where the patches admit only one hole. More precisely, close to a given annulus we describe this family by countable branches bifurcating from this annulus at some explicit angular velocities related to Bessel functions of the first kind. Our theoretical study was completed by numerical simulations on the limiting V-states and a number of interesting numerical observation were formulated opening new research perspectives. The second part of the thesis concerns the local well-posedness theory for the inviscid Boussinesq system with rough initial data. The problem is in some sense critical due to some terms involving Riesz transforms in the vorticity-density formulation. We give a positive answer for a special sub-class of Yudovich data including smooth and singular vortex patches. In the last part we address the problem of the incompressible limit for the 2D isentropic fluids associated to ill-prepared initial data and for which the vortices are not necessarily bounded and belong to some weighted BMO spaces. We mainly use two ingredients: On one hand, the Strichartz estimates to control the acoustic part and prove that it does not contribute for low Mach number. On the other hand, we use the transport compressible structure of the vorticity and we establish a linear propagation estimate in the spirit of a recent work of Bernicot and Keraani conducted in the incompressible case. The first part of the thesis deals with the existence of the rotating vortex patches (called also V-states) for an inviscid quasi-geostrophic model. Our study is divided into two chapters dealing with different topological structures of the V-states. In the first chapter we study the simply connected case and we prove the existence of such structures in a neighborhood of the Rankine vortices by using the bifurcation theory. In the second chapter we discuss the doubly connected case where the patches admit only one hole. More precisely, close to a given annulus we describe this family by countable branches bifurcating from this annulus at some explicit angular velocities related to Bessel functions of the first kind. Our theoretical study was completed by numerical simulations on the limiting V-states and a number of interesting numerical observation were formulated opening new research perspectives. The second part of the thesis concerns the local well-posedness theory for the inviscid Boussinesq system with rough initial data. The problem is in some sense critical due to some terms involving Riesz transforms in the vorticity-density formulation. We give a positive answer for a special sub-class of Yudovich data including smooth and singular vortex patches. In the last part we address the problem of the incompressible limit for the 2D isentropic fluids associated to ill-prepared initial data and for which the vortices are not necessarily bounded and belong to some weighted BMO spaces. We mainly use two ingredients: On one hand, the Strichartz estimates to control the acoustic part and prove that it does not contribute for low Mach number. On the other hand, we use the transport compressible structure of the vorticity and we establish a linear propagation estimate in the spirit of a recent work of Bernicot and Keraani conducted in the incompressible case.

Les ondes internes jouent un rôle essentiel dans la dynamique de l'atmosphère et de l'océan. Elles sont entres autres invoquées pour expliquer le mélange irréversible de ce dernier. Dans des géométries particulières, ces ondes sont susceptibles de converger vers des trajectoires limites appelées attracteurs. Dans cette thèse, nous étudions expérimentalement ces attracteurs dans une cuve trapézoïdale. Dans un premier temps, nous nous intéressons à leur bilan énergétique, en mesurant les différentes dissipations ainsi que la puissance injectée par le générateur d'onde. Si cette puissance est suffisante, l'attracteur est susceptible de se déstabiliser par interactions triadiques. Nous quantifions la part de dissipation portée par ces ondes secondaires ainsi générées. La mesure de la puissance injectée en régime linéaire a montré qu'elle est plus importante pour les attracteurs. Cette résonance, observée jusqu'ici sous une excitation monochromatique, est ici observée en étudiant la réponse du système à une impulsion. Un développement théorique est proposé et permet de comparer quantitativement les deux méthodes. Enfin, nous étudions le régime non linéaire des attracteurs, qui présente des spectres temporel et spatial très riches. Après avoir caractérisé le régime non linéaire, nous exhibons deux comportements non linéaires très différents et apportons des pistes d'explication à leur existence / Internal waves are very important to atmospheric and oceanic dynamics. Among others, they might explain the irreversible mixing of the oceans. In particular geometries, these waves can focus on limit cycles called attractors. Firstly, we investigate the energy budget of these attractor by measuring the different dissipative terms and the injected power coming from the waves source. If this power is sufficient, the attractor destibilise throught triadic instabilities. We quantify how much these secondary are important to the global dissipation rate.The measurement of injected power in the linear regime has shown that it is bigger for the attractors. This resonance, which had been observed under a monochromatic excitation, is here study by analysing the response of the system to an impulse. A theoretical development is proposed to compare quantitatively these two methods. Finally, we study the non linear regime of attractors, which present some complex spatial and temporal spectrum. We caracterise this non linear regime and show that two very different non linear beahviors exist. We bring up some explanation to these behaviors