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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
171

Metabolismo do nitrogênio e concentração de nutrientes no cafeeiro irrigado em razão da dose de N / Nitrogen metabolism and nutrient concentration in irrigated coffee plants due to nitrogen fertilization rates.

Ana Paula Neto 29 January 2010 (has links)
A adubação nitrogenada e sua implicação no metabolismo do cafeeiro ainda não são bem conhecidas nas condições de campo, em cafeicultura altamente tecnificada, com temperatura média de outono-inverno superior a 22 ºC e maior quantidade de horas-luz. O objetivo da presente pesquisa foi avaliar a atividade das enzimas redutase do nitrato (RN), glutamina sintetase (GS) e urease em função da dose de nitrogênio (sem N, 200, 400, 600 e 800 kg ha-1). Avaliou-se também a influência das doses de N (uréia) nas concentrações de N-total, nitrato, amônio, clorofila e carotenóides presentes nas folhas; as flutuações de macro e micronutrientes; bem como a correlação entre a produtividade e doses de N. Objetivou-se também identificar a época do pico da atividade da RN. Os experimentos foram realizados no Oeste baiano e em Piracicaba, SP. As avaliações foram realizadas nas fases fenológicas: vegetação, antese, fruto chumbinho, granação e maturação. A maior atividade da RN ocorreu com o fornecimento de 800 kg ha-1 de N, sem variação nas demais doses, bem como não influenciou a atividade da GS e urease. As concentrações de nitrato e amônio não aumentaram com as doses de N, mas a concentração de aminoácidos foi crescente com a dose do nutriente. A maior atividade da RN verificou-se na fase de vegetação e granação dos frutos, a qual foi superior às 12:00 h, enquanto as atividades da GS e urease foram superiores na fase de granação dos frutos. A maior concentração de nitrato se deu entre a fase de fruto chumbinho e início da granação e do amônio no final da granação. O pico da atividade da RN aconteceu aos 25 dias após a adubação nitrogenada. O uso de altas doses de N não prejudicou a concentração de macro e micronutrientes foliar. Finalmente, a máxima produtividade do cafeeiro foi obtida com a aplicação de 400 kg ha-1 de N. / The nitrogen fertilization and its implication in the nitrogen metabolism of coffee plants are not well known in high technology production under field conditions with autumn-winter average temperatures above 22 º C and a larger photoperiod. The objective of this work was to evaluate the nitrate reductase, glutamine synthetase and urease activity due to nitrogen fertilization rates (without N, 200, 400, 600 e 800 kg ha-1). In the present work was evaluated also the influence of nitrogen rates on total nitrogen, nitrate, ammonium, chlorophylls and carotenoids concentration in the leaves, the variation of macro and micronutrients as well as the correlationship between coffee yield and nitrogen fertilization rates. Moreover, the goal of this study was to identify the period of peak activity of nitrate reductase. The experiment was carried out at western of Bahia State and Piracicaba, State of Sao Paulo, Brazil. The periods of evaluations were plant growth, anthesis, pin head fruits, filling and maturation fruits stage development. The highest nitrate reductase activity occurred with 800 kg ha-1 N supply and no changes on this enzyme were observed regarding other rates. Therefore, the nitrogen rates did not affect the glutamine synthetase and urease activity. The nitrate and ammonium concentration did not increase with nitrogen rates; however, the aminoacids concentration increased due to nitrogen fertilization rates. The highest activity of nitrate reductase was observed at 12:00h during plant growth and filling fruits stage development. On the other hand, the higher activity of glutamine synthetase and urease were during filling fruits stage. The highest nitrate concentration was detected during between pin head and beginning of filling fruits stage, and the highest ammonium concentration was during end of filling fruits stage development. The peak activity of nitrate reductase was 25 days after nitrogen fertilization. The high nitrogen rates did not affect the macro and micronutrients concentration in the leaves. The greater coffee yield was provided with 400kg ha-1 of nitrogen supply.
172

Presença de nematoides em plantas de soja: relação com a ocorrência de sementes esverdeadas e seu potencial fisiológico / Nematodes in soybean plants: relationship with the occurrence of green seeds and their physiological potential

Victor Augusto Forti 17 May 2013 (has links)
A ocorrência de estresses abióticos e bióticos em plantas imaturas de soja, o que inclui a presença de nematoides, podem resultar em morte prematura da planta ou maturação forçada e produzir sementes esverdeadas e de baixo potencial fisiológico. Assim, o objetivo deste trabalho foi avaliar a presença de Meloidogyne javanica e Pratylenchus brachyurus em plantas de soja e a relação com o desenvolvimento da planta, com a ocorrência de sementes esverdeadas e com o potencial fisiológico das sementes. Para isso, foram conduzidos três experimentos. O experimento I foi realizado utilizando plantas da cultivar Pintado, as quais foram submetidas à diferentes tratamentos de inóculo inicial e avaliadas quanto à fenologia e à produtividade e as sementes quanto ao potencial fisiológico. No experimento II foi analisada a resistência de dez cultivares de soja à M. javanica e P. brachyurus. No experimento III foram utilizadas plantas de duas cultivares de soja (TMG-115RR e M 7908 RR, previamente selecionados no experimento II), dois tratamentos de população de nematoides (0 e 7000 nematoides) e dois tratamentos de estresse hídrico (com e sem), cujas plantas foram avaliadas quanto a fenologia e produção de vagens e sementes, as raízes quanto à multiplicação de nematoides e as sementes quanto as determinações do grau de umidade, do potencial fisiológico (testes de germinação, tetrazólio, envelhecimento acelerado, condutividade elétrica, emergência de plântulas em areia e análise computadorizada de imagens de plântulas), ocorrência de sementes esverdeadas (método visual e fluorescência de clorofila) e citometria de fluxo. Com os resultados do experimento I, observou-se que a presença de M. javanica e de P. brachyurus em plantas de soja, independentemente da população inicial, provoca a redução do ciclo da planta devido exclusivamente à diminuição do estádio de senescência destas, porém a qualidade de sementes não foi afetada com população inicial de nematoides mais elevada (2400 espécimes). Todas as cultivares testadas no experimento II foram classificadas como suscetíveis, porém a cultivar TMG-115RR e M 7908 RR foram escolhidas para a condução do experimento III por permitirem boa reprodução dos nematoides em estudo e por serem consideradas por algumas empresas produtoras de sementes com sendo sensíveis a ocorrência de sementes esverdeadas. Finalmente, com os resultados do experimento III verificou-se que a população inicial de 7000 nematoides afeta, negativamente, a produção, a ocorrência de sementes esverdeadas e a qualidade de sementes. Entretanto, a intensidade do efeito de M. javanica e de P. brachyurus no desenvolvimento de plantas de soja, na ocorrência de sementes esverdeadas e no seu potencial fisiológico depende da população inicial e da espécie do nematoide, da cultivar e das condições ambientais as quais as plantas são submetidas. / Abiotic and biotic stresses in immature soybean plants, including nematodes presence, can result in premature plant death and can produce green seeds with low physiological potential. The aim of this study was to evaluate the Meloidogyne javanica and Pratylenchus brachyurus presence on soybean plants and the relationship with plant development, the green seeds occurrence and the seed physiological potential. For this, three experiments were done. The experiment I was carried out using the cultivar Pintado, which was inoculated with different nematode population and the phenology, productivity, and the seed physiological potential were evaluated. In experiment II it was analyzed the resistance of ten soybean cultivars to M. javanica and P. Brachyurus. In experiment III plants of two soybean cultivars (TMG-115RR and M 7908 RR, chosen by experiment II) were submitted to two nematode population treatments (0 nematodes and 7000) and two levels of water stress (with and without) and they were evaluated as phenology and production of pods and seeds, the multiplication of nematodes on roots and the determinations of moisture content, physiological potential (germination, tetrazolium, accelerated aging, electrical conductivity, sand seedling emergence and seedling computerized image analysis), the occurrence of green seeds (visual method and chlorophyll fluorescence) and flow cytometry on seeds. It was observed in the results of experiment I that the M. javanica and P. brachyurus on soybean plants, regardless of the initial population, decreases of cycle plant due the decrease on senescence phase, however, the seed quality was unaffected with higher initial nematode population (2400 nematodes). All the cultivars in experiment II were classified as susceptible, but the cultivar TMG-115RR and M 7908 RR were chosen for the experiment III because they allowed a good nematode reproduction and because some seed companies considered them as sensible to soybean green seed occurrence. Finally, the results of experiment III showed that the initial population of 7000 nematodes affected negatively the production, the soybean green seeds occurrence and the seed quality. However, the effect of M. javanica and P. brachyurus in the soybean plantas development, in the soybean green seeds occurrence and their physiological potential depends on the initial nematode population and species, cultivar and environmental conditions which the plants are exposed.
173

Comportamento de Podium denticulatum F. Smith, 1856 (hymenoptera, Sphecidae) em ninhos-armadilha / Behavior of Podium denticulatum F. Smith, 1856 (Hymenoptera, Sphecidae) in trap-nests

Favi Ribeiro 24 March 2006 (has links)
Podium denticulatum é uma espécie de vespa solitária que pertence ao gênero Podium, família Sphecidae, sendo encontrada desde o México o Brasil. As fêmeas desse gênero são caçadoras, capturam e aprovisionam o ninho com baratas paralisadas. As espécies de Podium nidificam em cavidades preexistentes, como ninhos abandonados de outras espécies de vespas, cavidades em troncos e em ninhos-armadilha (NA). O principal objetivo do presente trabalho foi estudar os aspectos comportamentais das atividades realizadas pelas fêmeas de P.denticulatum no processo de nidificação, e a obtenção de dados do tempo de desenvolvimento, número de gerações por ano e novas informações sobre a biologia e fenologia da espécie, permitindo uma análise comparativa com aquelas reportadas por outros autores. O estudo foi realizado no Campus da USP de Ribeirão Preto, SP, onde o clima é tropical quente e úmido. Foram utilizados NA que consistiram de gomos de bambus, fechados em uma das extremidades pelo nó, com comprimentos e diâmetros variados. Esses NA foram inspecionados, frequentemente, de setembro de 2003 a setembro de 2005, para constatação de fêmeas trabalhando e coleta de dados. Com isso, pôde-se constatar que as fêmeas exibem comportamento de inspeção e escolha dos NA antes de começar a captura de presas, as quais são representantes da família Blattellidae. Os ovos são colocados entre o primeiro par de pernas da presa e o desenvolvimento total, ou seja, do ovo até o adulto, foi maior nas fêmeas que nos machos. Uma característica importante observada neste estudo é que as fêmeas fecham a célula ao final do dia caso não tenham completado o aprovisionamento, retornado no dia seguinte. Esse comportamento pode ser interpretado como uma forma de proteção ao alimento larval ou ovo. O material utilizado para fechar as células e o ninho consiste de barro coletado no campo. A parede de fechamento pode ser revestida com uma resina de origem desconhecida. A fêmea pode terminar o aprovisionamento de uma célula em até cinco dias; na conclusão do ninho, ela pode demorar até nove dias, e esse tempo está relacionado à fatores externos. Foram observadas 6 gerações e um período de diapausa e a razão sexual não diferiu significantemente da proporção de 1:1. As fêmeas foram produzidas preferencialmente nas primeiras células de cria, que são dispostas em série linear. Cada ninho continha de 1 a 6 células de cria e, em 43,8% dos ninhos a fêmea construiu uma célula vestibular. Foram encontradas ainda ninhos com célula intercalar e célula vazia de fundo. As paredes de fechamento do ninho foram significantemente mais espessas do que as partições celulares. Os casulos eram de coloração castanho-médio, fusiformes, flexíveis, lisos e mais ou menos brilhantes. Foram encontrados parasitóides da família Chrysididae e Eulophidae (Hymenoptera) e Tachinidae (Díptera) atacando ninhos de P. denticulatum. As atividades de nidificação das fêmeas só foram observadas no período quente e chuvoso. / Podium denticulatum it is a solitary wasp specie which belongs to the Podium class, Sphecidae, found from Mexico to Brazil. The females from this class are hunters, they catch and provide the nest with paralyzed cockroaches that are feed for their lavas. Podium species nesting in preexisting cavities, such as abandoned nests from other species, stem cavities and in nest traps. The major objective in this work it was to study the behavior aspects in detail from the P. denticulatum females, during the nesting process, besides the developing time, generation numbers by year and new information from the biology and phenology from the specie, allowing a comparative analysis from other authors. The study was done at the University of Sao Paulo, Ribeirao Preto Campus, where the weather is tropical, hot and humid showing two seasons will defined. Using trap-nests that were bamboo, tied in one end with a diversity of length and diameters. These trap-nests were inspected frequently, from September 2003 to September 2005, to assure that the females were working and to collect data. With this it was observed that the females show an inspection behavior to choose the nest-traps before the prey capture which are from the Blattellidae family. The eggs are placed between the first pair of legs from the prey and the whole development, from egg to adult, it was bigger among the females than the males. An important characteristic observed in this study is that the females close the cell at the end of the day if they didn?t complete the provision, returning next day. This behavior can be understood as a way to protect the lava feed or the egg. The material used to close the nest is mud collected in the country, which is casted by the female. The closing wall can be coated with a unknown resin. The female can finish the provision from one cell in a day or take up to five days, at the nest conclusion it can take up to nine days, and this time is related to outside factors. It was observed six generations and a period of day pause to the studied specie. The sexual cause wasn?t significantly different from the 1:1 proportion and the females were produced on the first brood cell. The cells are placed on a lineal series and the length and diameter in the trap-nests were diversified. Each nest had from one to six brood cell and in 43,8% of the nests the female built a vestibular cell. It was found nests with intercalary cells and empty space. The nest closing walls were significantly thicker than the cell division, fusiforme, flexible, plain and more less shiny. It was found parasitoids from the Chrysididae and Eulophidae (Hymenoptera) and Tachinidae (Diptera) attacking P. denticulatum nests. The nesting activities from the females were only observed at the hot and rainy days.
174

Aspectos fenol?gicos e produ??o de mudas de tr?s esp?cies nativas do ecossistema manguezal / Phenological aspects and production of seedlings of three native species of the mangrove ecosystem

RODRIGUES, Guilherme de Assis 25 February 2015 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-12T18:01:06Z No. of bitstreams: 1 2015 - Guilherme de Assis Rodrigues.pdf: 3641383 bytes, checksum: 0b63e2c57403684dda6281aef509440e (MD5) / Made available in DSpace on 2017-04-12T18:01:06Z (GMT). No. of bitstreams: 1 2015 - Guilherme de Assis Rodrigues.pdf: 3641383 bytes, checksum: 0b63e2c57403684dda6281aef509440e (MD5) Previous issue date: 2015-02-25 / A main sure of environmental restore of an ecosystem is the restoration of its growth vegetation,which may occur through the production of seedlings of native species and subsequent planting, although in the case of mangroves, the subjectis are low discussed. Thus, there is a lack for studies that discuss the theme about production practices of the mangrove ecosystem species seedlings. This study had the objective of: describe the phonological pattern of three typical species of mangrove ecosystem in order to provide information about the collection times and know the degree of correlation with environmental variables with the phonological periodsassess thein fluence of saline fertilization with NaCl and KCl on the production of seedlings of different mangrove species. This study showed that the environmental variables related of temperature were the most influential factors on phenology of Laguncularia racemosa, while the fluctuation of the water level acted strongly on the phenology of R. mangle. For Avicennia schaueriana the Salinity was the highest correlation with phenological events. The results showed that for L. racemosa species fertilization with NaCl at a concentration of 2 grams per liter of water gave larger increments to the seedlings. For R. mangle is recommended that 16 g of NaCl per liter of water, 10 ml of this solution applied weekly. / Uma das principais medidas de recupera??o ambiental de um ecossistema ? o restabelecimento de sua vegeta??o, que pode ocorrer por meio da produ??o de mudas de esp?cies nativas e posterior plantio, embora em se tratando dos Manguezais, o tema ? pouco debatido. Dessa forma, h? a necessidade de estudos que abordem o tema e discutam as pr?ticas de produ??o de mudas de esp?cies do ecossistema Manguezal. Assim, este trabalho teve como objetivos: descrever o padr?o fenol?gico de tr?s esp?cies t?picas do ecossistema Manguezal, no intuito de fornecer informa??es acerca das ?pocas de coleta e conhecer o grau de correla??o com as vari?veis ambientais com os per?odos fenol?gicos; avaliar a influ?ncia da aduba??o salina com NaCl e KCl sobre a produ??o de mudas de diferentes esp?cies de mangue. Este estudo comprovou que a as vari?veis ambientais ligadas ? temperatura foram os fatores de maior influ?ncia sobre os eventos fenol?gicos de Laguncularia racemosa, enquanto que a flutua??o do n?vel da mar? atuou fortemente sobre a fenologia de Rhizophora mangle. Para Avicennia schaueriana a salinidade foi a de maior correla??o com os eventos fenol?gicos. A an?lise dos resultados mostrou que para a esp?cie L. racemosa a aduba??o com NaCl a uma concentra??o de 2 gramas por litro de ?gua proporcionou maiores incrementos ?s mudas. J? para R. mangle ? recomendada a de 16 g de NaCl por litro de ?gua, aplicados 10 ml desta solu??o semanalmente.
175

História natural e performance larval de Oospila pallidaria (Schaus, 1897) (Lepidoptera, Geometridae, Geometrinae): uma mariposa esmeralda do Cerrado / Natural history and larval performance of the Oospila pallidaria (Schaus, 1897) (Lepidoptera, Geometridae, Geometrinae): a emerald moth of Cerrado.

Lopes, Bruno de Sousa 23 May 2016 (has links)
São estimadas 90 mil espécies de insetos para o Cerrado, o segundo maior bioma brasileiro, com enorme heterogeneidade de habitats e rica fauna. Dentre esses insetos, os Lepidoptera representam cerca de 10% do total de espécies. Entretanto, estudos sobre seus imaturos (ovo, larva e pupa) ainda são incipientes para o bioma, principalmente sobre as mariposas, cujas histórias naturais de muitas espécies ainda são desconhecidas. A falta desses estudos faz com que sejam ignoradas as interações multitróficas em que esses organismos estão envolvidos e, portanto, inviabiliza futuros estudos relacionados ao seu papel em comunidades e redes ecológicas. Esse é o caso de muitas espécies da família Geometridae, incluindo Oospila pallidaria, que é uma mariposa esmeralda (devido à coloração verde esmeralda das suas asas). Oospila pallidaria é uma espécie herbívora que não possuía até o momento nenhuma informação publicada sobre a sua biologia e fatores que condicionam sua ocorrência, tais como: a fenologia da planta hospedeira, que pode determinar o período de melhores condições para crescimento e reprodução; a qualidade nutricional dos recursos alimentares (e. g. quantidade de água e nitrogênio), que pode determinar quais recursos conferem melhor desenvolvimento/performance a um herbívoro; os inimigos naturais, que podem restringir a ocorrência dos herbívoros e a temperatura e pluviosidade, que podem alterar a qualidade e a distribuição geográfica dos recursos alimentares utilizados pelos herbívoros. Nesse sentido, o objetivo principal deste estudo foi descrever, pela primeira vez, aspectos da biologia e história natural de O. pallidaria (Capítulo 1) e avaliar a sua performance larval, a partir de diferentes dietas (Capítulo 2). Os resultados apresentados no Capítulo 1 mostraram que os ovos de O. pallidaria, verdes e com duração média de sete dias, foram solitários e ovipostos principalmente nos tricomas das folhas maduras. As larvas se alimentaram de folhas maduras predominantemente, mas utilizaram folhas jovens e botões florais oportunisticamente. As larvas tiveram coloração críptica, se camuflaram em meio às folhas de Mimosa setosa (Leguminosae: Mimosoideae), sua única hospedeira, e desenvolveram o comportamento de auto-limpeza. Há cinco ínstares larvais, com coloração que variou de amarelo a verde. As larvas apresentaram também um par de projeções no protórax e linha mediana marrom na região dorsal. O comprimento máximo do corpo das larvas foi de 28 mm. As pupas foram predominantemente verdes, com no máximo 10 mm de comprimento. O desenvolvimento do ovo ao adulto durou cerca de 50 dias ( = 42; S = 6; n = 11). Seu único inimigo natural registrado foi o microhimenóptero Cotesia sp. (Braconidae, Microgastrinae). Fêmeas de O. pallidaria produziram 65 ovos em média (S = 7,07; n = 2). A ocorrência de O. pallidaria foi sazonal e sobreposta ao pico de presença de folhas maduras. Larvas foram negativamente relacionadas à temperatura e pluviosidade, com significância estatística somente para a primeira (r = - 0.5889, P < 0.05). No Capítulo 2, foi mostrado que as folhas maduras de M. setosa foram o único recurso alimentar disponível durante todo o ano. Os botões florais foram o recurso com maior qualidade nutricional (conteúdo relativo de água e nitrogênio total), seguidos por folhas jovens e maduras respectivamente. Entretanto, a sobrevivência de O. pallidaria foi maior com folhas maduras. Os resultados indicam que para o herbívoro especialista O. pallidaria, a fenologia da planta hospedeira é crucial para sua sobrevivência, em especial a presença de folhas maduras de M. setosa. Por outro lado, os botões florais são recursos efêmeros, porém importantes para a sobrevivência das larvas de últimos ínstares no final da estação seca, quando as folhas maduras estão ressecadas e/ou senescentes. / It is estimated 90.000 species of insects for the Cerrado, the second largest Brazilian biome, with great diversity of habitats and rich fauna. Among these insects, Lepidoptera represents about 10% of all species. However, studies on their immature stages (egg, larvae and pupae) are incipient for the biome, mostly on moths, whose natural histories of many species are unknown. The lack of these studies makes the multitrophic interactions in that these organisms are involved ignored and, therefore, prevent future studies related to their role in communities and ecological networks. This is the case of many species of Geometridae, including Oospila pallidaria, which is an emerald moth (due to emerald green color of their wings). Oospila pallidaria is a herbivorous species that had not published any information on their biology and factors that influence their occurrence, such as: the phenology of the host plant, which can determine the time of better conditions for growth and reproduction; the nutritional quality of food resources (e. g. amount of water and nitrogen), which can determine what resources provide better development/performance to a herbivore; natural enemies, that could restrict the occurrence of herbivores and the temperature and rainfall, which can change the quality and geographical distribution of food resources used by herbivores. Accordingly, the aim of this study was to describe, for the first time, aspects of the biology and natural history of O. pallidaria (Chapter 1) and to assess their larval performance from different diets (Chapter 2). The results presented in Chapter 1 showed that eggs of O. pallidaria, green and lasting an average of seven days, were lonely and laid especially in trichomes of mature leaves. The larvae fed on mature leaves predominantly, but used young leaves and flower buds opportunistically. Larvae had cryptic coloration, they camouflaged among the leaves of Mimosa setosa (Leguminosae: Mimosoideae), a single host, and developed the self-cleaning behavior. There are five larval instars, with color ranging from yellow to green. The larvae also had a pair of projections on prothorax and brown midline in the dorsal region. The maximum length of the larvaes body was 28 mm. The pupae were predominantly green, with a maximum of 10 mm in length. The development from egg to adult lasted about 50 days ( = 42, S = 6, n = 11). Their only natural enemy recorded was the microhymenopteran Cotesia sp. (Braconidae, Microgastrinae). Oospila pallidaria females produced 65 eggs on average (S = 7.07; n = 2). The occurrence of O. pallidaria was seasonal and overlapped on the peak presence of mature leaves. Larvae were negatively related to temperature and rainfall, with statistical significance only for the first (r = - 0.5889, P < 0.05). In Chapter 2, it was shown that mature leaves of M. setosa were the only food source available throughout the year. The flower buds were the resource with higher nutritional quality (relative water content and total nitrogen), followed by young and mature leaves respectively. However, the survival of O. pallidaria was greater with mature leaves. The results indicate that for the specialist herbivore O. pallidaria, the host plant phenology is critical for its survival, especially the presence of mature leaves of M. setosa. On the other hand, the flower buds are ephemeral resources, but important for the survival of the last instar larvae in the dry season, when mature leaves are withered and/or senescent.
176

Propriedades mecânicas da madeira de clones de seringueira (Hevea brasiliensis-RRIM600 E GT1) analisadas em duas épocas do seu ciclo fenológico anual / Mechanical properties of rubber tree (Heveabrasiliensis) clones wood (RRIM600 E-GT1) analyzed in two stages of its annual phenological cycle

Servolo Filho, Henrique José 12 March 2013 (has links)
O presente trabalho teve como objetivo avaliar as propriedades mecânicas da madeira de seringueira (Hevea brasiliensis), clones RRIM600 e GT1, para melhorar o aproveitamento comercial dessa madeira, que por falta de pesquisa não está no mercado brasileiro. A compreensão desse estudo contribuiu para a tecnologia de manufatura de produtos madeireiros de boa qualidade, determinados pelas propriedades mecânicas de importância na teoria das estruturas. Foram efetuados testes de compressão, cisalhamento e flexão estática em corpos de prova obtidos em duas épocas do desenvolvimento fenológico anual da cultura, analisando-se a influência do teor de amido da madeira da H.brasiliensis nas propriedades mencionadas acima. As árvores de Hevea foram cortadas com 26 anos de idade, depois de terem sido submetidas ao processo de extração de látex (\"sangria\") desde os sete anos do plantio. Foram cortadas para o estudo completo 72 árvores, sendo metade delas antes da senescência provocada por uma desfolha artificial e metade após o refolhamento. O experimento foi conduzido em área pertencente ao Departamento de Produção Vegetal da Escola Superior de agricultura \"Luiz de Queiroz\" da Universidade de São Paulo (ESALQ-USP) localizada em Piracicaba - SP (22º 42´30´´ S, 47º 38´00´´ W), à altitude de 550 m. Os resultados permitiram verificar que houve diferenças nas propriedades mecânicas entre as épocas fenológicas estudadas. Os clones GT1 e RRIM 600 puderam ser considerados de mesma resistência à compressão paralela e de mesma resistência à flexão estática, mas foram considerados diferentes na resistência ao cisalhamento e no módulo de elasticidade à flexão estática. Dentro das classes de perímetro do tronco estudadas os resultados foram similares para as resistências à compressão, ao cisalhamento e ao módulo de ruptura e diferentes para o módulo de elasticidade. O teor de amido na madeira caiu acentuadamente durante o refolhamento principalmente no clone GT1 e isso contribuiu para o aumento das propriedades mecânicas da época final da senescência para a época final da brotação. / This study aimed to evaluate the mechanical properties of the wood of rubber trees (Heveabrasiliensis) clones GT1 and RRIM600, to improve commercial uses of this wood, which is not in the Brazilian market due to a lack of research.The comprehension of this study has contributed to the technology of manufacturing of good quality wood products, determined by the mechanical properties of importance in the theory of structures.It were carried out tests of compression, shear and bending on specimens obtained at two stages of the crop annual phenological development, analyzing the influence of starch content of H.brasiliensis wood on the properties mentioned above. Hevea trees were cut at 26 years old, after being subjected to the extracting latex process (\"bleeding\") since seven years after planting.It were cut for the complete study 72 trees, half of them before senescence caused by an artificial defoliation and half after sprouting leaf. The experiment was conducted in an area which belongs to the Department of Plant Production of the School of Agriculture \"Luiz de Queiroz\" of the University of São Paulo (USP-ESALQ) located in Piracicaba - SP (22 º 42\'30\'\' S, 47 º 38\'00 \'\' W), at an elevation of 550 m. Results showed that there were differences in mechanical properties between the studied phenological stages. The GT1 and RRIM 600 clones could be considered of the same compression strength in parallel to the grain and same bending strength, but they were considered different in shear strength and modulus of elasticity in static bending. In the range of stem girth studied the results were similar for compression, shear and bending strength and different for modulus of elasticity. The starch content of wood decreased sharply during the sprout leaf mainly in GT1 clone and this contributed to the increase the mechanical properties from the final period of senescence to the final period of shooting.
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Maternal Denning Phenology and Substrate Selection of Polar Bears (<em>Ursus maritimus</em>) in the Southern Beaufort and Chukchi Seas

Olson, Jay Wesley 01 December 2015 (has links)
Loss of sea ice due to global warming may affect the phenology and distribution of polar bear (Ursus maritimus) denning by altering access to denning habitats. We examined trends in the selection of maternal denning substrate (land versus sea-ice denning) in the southern Beaufort Sea (SB), addressing the potential influence of summer land-use and fall sea-ice conditions on substrate selection. We developed an algorithm based on statistical process control methods to remotely identify denning bears and estimate denning phenology from temperature sensor data collected on collars deployed 1985–2013 in the SB and Chukchi Sea (CS). We evaluated cub survival relative to den entrance, emergence, and duration, and examined differences in the phenology of land and sea-ice dens. Land denning in the SB was more common during years when ice retreated farther from the coast and off of the continental shelf in September. All SB bears that occupied land prior to denning subsequently denned on land; however, only 29% of denning bears that summered on sea ice denned on land. Den entrance and duration in the SB and CS were similar, although CS bears emerged later. Land dens were occupied longer than those on ice. Bears later observed with cubs remained in dens 23 days longer and emerged from denning 17 days later on average than bears that denned but were subsequently observed without cubs, suggesting that den exit dates are related to cub survival. The increase in land-based denning in the SB when sea ice retreated farther from shore, along with the positive correlation between fall land-use and land denning, suggest that further sea-ice declines may result in continued increases of onshore denning. Growing numbers of denning females along the coast may increase the potential for human-bear interactions.
178

Public Participation in Plant-Pollinator Conservation: Key Assessment Areas that Support Networked Restoration and Monitoring

Battle, Kerissa 19 March 2018 (has links)
Environmental problems are growing at a pace and scale that traditional research methods alone can no longer tackle. Innovative research models that utilize contributory, participatory and crowdsourcing methods are rapidly emerging to fill this gap. For these participatory efforts to be effective and sustainable, however, closer attention must be paid to key components that can promote coordinated action and sustainability. Through the lens of public participation in plant-pollinator conservation, I have, with rigorous social-ecological inquiry, offered three foundational assessment areas that can provide scientific support to this nascent field: accuracy, ecological significance and scalability. In the first study (Chapter 2), I explored a common concern about citizen science: that a lack of foundational knowledge, or familiarity with following scientific protocols could lead to inaccurate data collection. I evaluated the accuracy of plant phenology observations collected by citizen scientist volunteers following protocols designed by the USA National Phenology Network (USA-NPN). Phenology observations made by volunteers receiving several hours of formal training were compared to those collected independently by a professional ecologist. Approximately 11,000 observations were recorded by 28 volunteers over the course of one field season. Volunteers consistently identified phenophases correctly (91% overall and 70% during transitions) for the 19 species observed. Accuracy varied significantly by phenophase and species (p<0.0001). Volunteers who submitted fewer observations over the period of study did not exhibit a higher error rate than those who submitted more total observations, suggesting that volunteers with limited training and experience can provide reliable observations when following explicit, standardized protocols. Overall, these findings demonstrate the ii legitimacy of phenology observations collected by volunteers, an important finding for the increasing number of analysts relying on data collected by citizen scientists. In Chapter 3, I explored a common concern that restoration efforts implemented by the public may not have adequate ecological value. I addressed key ecological variables to determine how small-scale patches attracted pollinators and explored which of these variables might be best to prioritize for restoration efforts suited to public initiatives. This study demonstrated that in small-scale plant restoration sites, plant diversity and resource (nectar) availability significantly affects the abundance and diversity of pollinating insects. Specifically, the treatments which contained high-resource (nectar-rich) plant species increased pollinator abundance and diversity the most. Plant diversity increased pollinator diversity and abundance only in the absence of high-resource plants. Pollination facilitation was observed in high resource treatments, but varied among species. Competition for pollinators was observed in high diversity treatments but did not affect seed set for high-resource plants in any of the treatments. Together, these results suggest that managers or landowners who are restoring patches of native plants as habitat for pollinators should prioritize including species with high nectar production, and secondarily, a diverse mix of species if space and resources allow. In Chapter 4, I explored an emergent approach to public participation in regional community science initiatives (and networks) through an exploratory case study of the New York Phenology Project. I demonstrated that local organizations have the opportunity to utilize existing data aggregation platforms to activate regional collaborative alliances to achieve what is often challenging for large-scale contributory projects. I describe our hands-on experience of conceiving and launching a regional network and outline a model that could serve as a guide for catalyzing networks. Drawing on direct experience and interviews with network partners, I developed a description of key categories related to network node success, and a linked assessment tool that could be used to evaluate network node capacity and project outcomes. The assessment tool will be used to test preliminary findings in a more formal quantitative and qualitative exploration in future studies. In Chapter 5, I explored an exceptional long-term, community-level phenology data set that spans New York State, USA (1802-2017), and found interesting and significant patterns of phenological change over time. The data set provides statewide phenology and temperature data that extend further back in time than any previously known data set for the region, extending to years prior to or at the beginning of recent human-caused global warming. I found that most species are flowering and leafing earlier in recent years (2009-2017) than they did in the early 19th century (1802-1861). Plants are flowering 11 days earlier and leafing 18.8 days earlier, with some species flowering up to 27 days earlier and leafing up to 31 days earlier over that time period. Most of this change was driven by warming mean spring temperatures (MST) over that time; mean spring temperatures warmed by 1.0°C statewide (2.5°C in New York City) on average between the historical and contemporary periods. Seasonality, Life Form, and the interaction between Seasonality and Life Form explained variation in phenology among species. The large number of geographically distinct sites in this dataset permitted novel investigation into differential changes in phenology between urban and rural areas (urban areas have more advanced phenology than their rural counterparts) and between insect and wind pollinated trees by seasonal category (insect pollinated trees are showing more advanced phenology than wind pollinated trees in both early and late spring). This analysis has brought the efforts of a historical network into a modern context and has illustrated how organized long-term monitoring efforts can be valuable for ecological discovery. This combined work provides a diverse contribution to the field of public participation in monitoring and conservation efforts. While thorough and disciplined ecological theories drive the design of the research, I simultaneously strove to help meet the ongoing demand for useable, purposeful insights into how to support public efforts to restore plant-pollinator habitats, monitor key ecological dynamics such as phenology, and scale networks capable of collecting data that address issues of global change.
179

Tree Water Use Strategies in a Neotropical Dry Forest

Butz, Jan Philipp 04 September 2019 (has links)
No description available.
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Environmental factors controlling the distribution of forest plants with special reference to floral mixture in the boreo-nemoral ecotone, Hokkaido Island / 森林植物の分布と環境要因、特に北海道の森林フロラの混在様式に関する生態学的研究

Uemura, Shigeru 30 June 1992 (has links)
Effects of climatic factors on the plant distribution were examined by means of direct gradient analysis, and the relationship of forest flora, life form and phytogeographical distribution was examined. Subsequently, leaf phenology of forest plants were analyzed to evaluate the adaptive significance in relation to the environments in forest understory. In the boreo-nemoral forest ecotone, Hokkaido Island, northern Japan, co-ccurrence of northern and southern plants in a certain forest site is more notable in the understory than in the crown, and this dates back to the late-uaternary period, where the decrease in temperature associated with the glacial period forced the understory flora to adapt their life form or leaf habits to snowcover and light conditions of the interior forests. / Hokkaido University (北海道大学) / 博士 / 環境科学

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