Submitted by (edna.saturno@ufrpe.br) on 2016-07-05T15:37:36Z No. of bitstreams: 1 Erika Socorro Alves Graciano.pdf: 691160 bytes, checksum: faf5b85667aa75d7307d79f2acf9ddb2 (MD5) / Made available in DSpace on 2016-07-05T15:37:36Z (GMT). No. of bitstreams: 1 Erika Socorro Alves Graciano.pdf: 691160 bytes, checksum: faf5b85667aa75d7307d79f2acf9ddb2 (MD5) Previous issue date: 2009-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Belonging to Leguminoseae Family, peanut is a very important crop to the food industry, because its high oil and protein contents essential for nutrition. The market enlargement due to the high industry demand and mainly the biodiesel production brings news and favorable perspectives to expand this crop in the semi-arid region of Brazilian northeastern. However, the low water availability is the main limiting factor to agriculture expansion in these areas. Although peanut crop shows well adapted to water deficit conditions, there are still so much to be studied to improve its potential and performance in the semi-arid areas. Thus, an experiment was carried out in greenhouse conditions aiming to evaluate some physiological and biochemical parameters of two peanuts cultivars under water deficit. A randomized experimental design was used in a factorial 2 (cultivars) x 3 (water treatments), with six replications. The cultivars studied were BR1 and BRS Havana. The water treatments were: daily watering, five days intervals of watering and water withholding. Growth analysis was accomplished over all the experimental period. At the end of the experiment, leaf water potential and relative water content was measured. For the biochemical analyses, leaf and root tissues were collected to the determination of total soluble carbohydrates, amino acids, protein and free proline. For growth analysis, the plants were separated in leaves, stems and roots to determination of dry matter. Leaf area, root:shoot ratioand biomass allocation were calculated. The obtained data were submitted to variance analysis and the means were compared by Tukey Multiple Range Test (P<0.05). Soluble arbohydrates, proteins, amino acids and free proline contents increased with the water deficiency in the leaves and roots of peanut cultivars. Plants water relations were influenced by water deficit reducing leaf water potential to more negative values. The growth of the peanuts cultivars was reduced proportionally to water availability, with marked varietal differences. The cultivar BR1 is more adapted to water deficiency conditions by showing physiological mechanisms capable to accumulate more organics solutes osmotically actives, reducing its leaf water potential to more negatives values, and for showing less growth alterations. / Pertencente a família Leguminosae, o amendoim é uma cultura muito importante para a indústria alimentícia, por ser constituído de alto teor de óleo e proteínas essenciais à nutrição. A ampliação do mercado tendo em vista a alta demanda pelas indústrias e principalmente a produção de óleo traz novas e favoráveis perspectivas de ampliação dessa cultura na região semi-árida do Nordeste brasileiro. Embora essa cultura mostre-se bem adaptada à condição de deficiência hídrica, principal fator limitante da produtividade, há muito ainda a ser estudado para um melhor aproveitamento do potencial e desempenho dessa cultura no semi-árido. Portanto, foi desenvolvido um experimento em casa de vegetação com objetivo de avaliar alguns parâmetros fisiológicos e bioquímicos de duas cultivares de amendoim submetidas à deficiência hídrica. O delineamento experimental utilizado foi o inteiramente casualizado, em um arranjo fatorial de 2 x 3 (Cultivares x Tratamentos hídricos), com seis repetições. As cultivares estudadas foram BR1 e BRS Havana, e os tratamentos hídricos utilizados foram: rega diária, rega a cada cinco dias e suspensão de rega. As análises de crescimento foram realizadas durante todo o período experimental. No final do experimento, foi avalia as relações hídricas, mensurando o potencial hídrico foliar e determinado o conteúdo relativo de água foliar. Para as análises bioquímicas, foram coletadas amostras das folhas e das raízes para a determinação dos carboidratos solúveis, proteínas solúveis, aminoácidos livres totais eprolina livre. Também foi determinada a área foliar e a matéria seca, com esses dados calculou-se a alocação de biomassa para as folhas, hastes e raízes e a relação raiz/parte aérea.Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey. Os teores de carboidratos solúveis, proteínas solúveis, aminoácidos livres e prolina livre aumentam com a deficiência hídrica nas folhas e raízes das cultivares de amendoim. As relações hídricas das plantas são influenciadas com a deficiência hídrica, reduzindo o potencial hídrico foliar a valores mais negativos. O crescimento das cultivares de amendoim é reduzido proporcionalmente com a disponibilidade hídrica, com marcada diferença varietal. A cv. BR1 é mais adaptada às condições de deficiência hídrica, por apresentar mecanismos fisiológicos capazes de acumular mais solutos orgânicos osmoticamente ativos, reduzir seu potencial hídrico a valores mais negativo e por sofre menores alterações no crescimento.

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第13321号 / 論理博第1568号 / 新制||理||1663(附属図書館) / 名古屋大学大学院生命農学研究科 / (主査)教授 石田 厚, 教授 田村 実, 教授 永益 英敏 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DFAM

Surface mines in mountainous areas cause environmental deterioration at lower elevations in the watershed. The most successful long term solution to the downstream problem is revegetation. However, mine spoils are low in essential plant nutrients, have low water holding capacity, and are often acidic. These factors limit plant colonization. Plants must also be adapted to the environmental conditions of high elevations. At the McLaren Mine, }1ontana, at 2800 m, it was observed that seedlings on revegetation plots were desiccated, indicating possible water deficits. Field and growth chamber studies were carried out to determine the effects of some spoil ameliorating treatments on leaf water potentials, leaf pressure potentials and seedling development and mortality. Poa alpina L. and Alopecurus pratensis L., the two plant species seeded are successful revegetation species in the area. The four treatments were: 1) a control group with no spoil treatment, 2) peatmoss incorporated into the spoils, 3) a surface mulch of jute net, and 4) peatmoss-plus-jute net. Results showed a decrease in water stress experienced by plants on plots with spoil ameliorating treatments. The jute net, or peatmoss-plus-jute net treatments were the most effective in reducing water stress. Leaf pressure potential data were extremely variable, making it difficult to determine trends. In the field seedling mortality was reduced on plots with jute net or peatmoss--plus-jute net. No trends were apparent in the growth chamber study. In both studies seedlings were larger with jute net or peatmoss-plus-jute net treatments.

There are numerous situations where trees are grown together with herbaceous plants. In these situations there will be some degree of competition between their root zones, depending on the water content of the soils and crop and tree root distribution . Two studies were conducted : the first with maple (Acer platanoides) grown in turf grass, and the second with willow (Salix matsudana) grown in more deeply rooted barley . The objectives of this study were to quantify the effect of herbaceous competition of potential tree water stress under irrigation and when the soil is allowed to dry-down . Soil water uptake was measured in both studies to 1.2 m depth and outwards to 1.2-2.10 m away from the tree . In the maple-turf grass study, water content was measured in a single line away from the tree , while four lines covering a quadrant of the surface area were measured in willow . Water relations stomatal conductance and water potential, and tree growth were also monitored in both studies. Water uptake in turf plots was statistically different from mulch plots by depth and distance during three seasons. Water uptake was greatest at 0-60 cm depth in the turf treatments compared with mulch treatments. Soil water in mulched plots decreased slowly during the growing season. There were no statistical differences between bare soil and barley competition water uptake after soil surface water was depleted. There were marked differences in tree root characteristics as a result of competition from turf or barley roots. The root systems of maples in the mulch and willow in bare soil extended laterally and fine roots were evident. Tree roots extended deeper and fine root were reduced under competition from turf and barley. Trees growing with turf and barley had fewer roots in the top 0.3 m soil surface while trees in mulch and bare soil had more and greater diameter roots at the same depth. Early in the season, when water content is high, root competition for water was not evident, and late in the season after turf roots and barley had depleted the soil water, trees exhibited more negative predawn leaf water potential and less stomatal conductance in response to water stress during a soil dry-down period. Tree growth was measured periodically during 1994, 1995, and 1996. Leaf area and stem growth comparisons showed a significant increase in size as a result of the absence of competition in both species, with mulch and bare soil treatments. Leaf area in mulched trees was twice that in turf treatments. In summary, we found that competition resulted in deeper tree root growth and less top growth in the presence of herbaceous competitors.

No description available.

One goal of this research was to characterize shoot tissue-level responses in loblolly pine to soil moisture limitation in combination with fertilization as well as to more severe soil moisture limitation. We found that neither fertilization alone, nor fertilization in combination with soil moisture limitation resulted in changes to shoot tissue water relations parameters classically characterized in drought response studies. More severe water limitation was necessary to elicit responses, and those responses had not been fully described previously. The more severe water limitation resulted in increased capacitance beyond turgor loss, increased relative water content at turgor loss, a more negative turgor loss point, an increased bulk modulus of elasticity, more negative osmotic potential at 100% relative water content, and an increased apoplastic water fraction. As there were indications of reduced water use and moisture stress in the absence of shoot level responses under less severe drought, such parameters are insufficient alone to characterize moisture stress in fertilized and in less severely water limited loblolly trees. Additionally, we sought a morphological or physiological explanation for the reduced transpiration and increased water use efficiency reported for fertilized trees in the Virginia Piedmont. Our characterizations of the responses of root distribution and hydraulics to limited soil moisture here complement existing research, which demonstrated changes to root distribution and hydraulics in response to fertilization. The responses we discovered in fertilized trees that accompanied reduced transpiration and increased water use efficiency that differed from responses to reduced soil moisture alone were primarily large decreases to shallow root presence. We found this to be readily quantified using measures of root length density. Decreases to whole-tree hydraulic conductivity were also shown to occur with fertilization and were shown not to occur in shoot tissue, suggesting limitation via rhizosphere or root xylem conductance. Our results support the supposition that fertilization narrows hydraulic safety margins and potentially predisposes loblolly trees to moisture stress, particularly prolonged, severe water limitation following fertilization. Finally, we tested the validity of throughfall exclusion for simulating reduced rainfall using a greenhouse 'split-pot' study, which applied spatially fixed heterogeneous soil moisture to young, well-watered loblolly pines. The 'split-pot' experiments demonstrated that spatially fixed soil moisture heterogeneity does not confound drought effects; needle area specific transpiration was not decreased, nor was water use efficiency increased. This supports the validity of inferences taken from drought simulation experiments with loblolly pine where throughfall exclusion troughs reduce soil moisture content in a consistent, spatially heterogeneous manner. / Doctor of Philosophy / We investigated various effects of soil moisture limitation alone, and in combination with common fertilization practices in loblolly pine production. Responses at the shoot and needle level to different levels of soil moisture limitation produced new findings concerning how tissues respond to more severe water limitation. A 30% decrease in throughfall precipitation alone, or in combination with fertilization did not elicit drought related shoot tissue responses despite the presence of other indications of moisture stress and reduced water use. We also sought to explain why fertilized trees experiencing water limitation had environmental sensitivities that were different from unfertilized tree receiving ambient rainfall amounts or from trees only experiencing water limitation without fertilization. We found that changes to shallow root presence, especially root length density, accompanied the different patterns of environmental sensitivity and water use. Also, the water conducting ability of roots changed unevenly in soil with uneven moisture levels. The ability of roots to resist loss of conductivity to water did not change unevenly in the same way. We did another set of experiments to determine if using impervious troughs to catch rain is a valid approach to reducing soil moisture for the purpose of testing how loblolly responds to water limitation. These throughfall exclusion troughs create uneven soil moisture reduction, which can have effects on plant water use that are separate from water limitation alone. We found that in well-watered young trees, uneven soil moisture alone did not produce responses that could be confused with the effects of water limitation. This finding indirectly validates the use of throughfall exclusion troughs to simulate reduced rainfall.

Rhododendron is a monophyletic group that inhabits many different climates. One clearly defined diversification was from temperate ancestors into tropical habitats. The focus of this work was to explore leaf and stem anatomical traits in relation to habitat (temperate and tropical) and elevation of the native range. A closely-related group of Rhododendron was selected to reduce variation in genetic history and reveal environment–associated adaptive traits. Vessel anatomical traits of Rhododendron accessions were assayed for the trade of between safety (protection against catastrophic failure) and efficiency (high theoretical conductivity). Rhododendron wood and vessels were found to be relatively safe. The metrics of wood efficiency were higher for the tropical species. Thus, a trade-off between safety and efficiency was found although the wood of Rhododendron is characterized as highly safe. Leaf anatomical traits of Rhododendron were assayed for habitat and elevation. Leaves on tropical species were thicker and denser compared with temperate species. Idioblasts were always found in tropical leaves but not in temperate species. Leaves of tropical species were more xeromorphic (drought tolerant) than those of temperate species. Increasing elevation of the native range did not influence leaf anatomical traits. Idioblast abundance and leaf water relations traits were assayed for tropical Rhododendron species. Idioblast expression varied from 5% to 28% and stomatal pore index varied from 0.08 to 3.3. Idioblast expression was highly correlated with leaf succulence, and water deficit at the turgor loss point. Idioblast expression was positively associated with leaf capacitance for thin (< 0.5 mm) leaves. Thus, idioblasts can serve as a water buffer for relatively thin leaves. Synthesis–Wood traits of evergreen Rhododendron shrubs reflect adaptation for safety. Although tropical species have significantly higher efficiency, wood safety is still the dominant feature. The implication of high wood safety is constrained water flow and a potential for low water potential. Both leaf succulence and the presence of idioblasts in thin leaves enhances leaf capacitance and provides some buffering against short-term drought. These leaf adaptations in tropical Rhododendron shrubs likely reflect the abundance of epiphytes in this group. / Ph. D.

Predicting the interactions between climate change and ecosystems remains a core problem in global change research; tropical forest ecosystems are of particular importance because of their disproportionate role in global carbon and water cycling. Amazonia is unique among tropical forest ecosystems, exhibiting a high degree of coupling with its regional hydrometeorology, such that the stability of the entire forest-climate system is dependent on the functioning of its component parts. Belowground ecohydrological interactions between soil moisture environments and the roots which permeate them initiate the water transport pathway to leaf stomata, yet despite the disproportionate role they play in vegetation-atmosphere coupling in Amazonian forest ecosystems, the impacts of climate variability on the belowground environment remain understudied. The research which follows is designed to address critical knowledge gaps in our understanding of root functioning in Amazonian tropical forests as it relates to seasonality and extremes in belowground moisture regime as well as discerning which ecohydrological mechanisms govern ecosystem-level processes of carbon and water flux. A secondary research theme is the evaluation and use of models of ecosystem function as applied to Amazonia - these models are the "knowledge boxes" which build in the ecohydrological hypotheses (some testable than others) deemed to be most important for the forest ecosystems of Amazonia. In what follows, I investigate (i) which mechanisms of water supply (from the soil environment) and water demand (by vegetation) regulate the magnitude and seasonality of evapotranspiration across broad environmental gradients of Amazonia, (ii) how specific hypotheses of root function are or are not corroborated by soil moisture measurements conducted under normal seasonal and experimentally-induced extreme drought conditions, and (iii) the linkage between an extreme drought event with associated impacts on root zone soil moisture, the inferred response of root water uptake, and the observed impacts on ecosystem carbon and water flux in an east central Amazonian forest.

Submitted by (edna.saturno@ufrpe.br) on 2016-06-29T11:16:36Z No. of bitstreams: 1 Marcio de Oliveira Martins.pdf: 440128 bytes, checksum: 5ba7365173598f9d4616a77b83aa6232 (MD5) / Made available in DSpace on 2016-06-29T11:16:36Z (GMT). No. of bitstreams: 1 Marcio de Oliveira Martins.pdf: 440128 bytes, checksum: 5ba7365173598f9d4616a77b83aa6232 (MD5) Previous issue date: 2008-02-20 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The work was performed aiming to evaluate the effect of water deficit on growth of neem seedlings and water relations. The experimental design was entirely randomized, with seven treatments (100, 80, 60, 40, 20% of pot capacity, without water and re-watering). The height, number of leaves and stem diameter were analyzed weekly. At the end of the experiment, dry matter of the leaves,shoots, roots, root to shoot ratio and biomass allocation were determined. Leaf area, leaf area ratio and specific leaf area were also calculated. Leaf water potential (predawn and noon), relative water content and contents of compatible solutes were evaluated at the same day. Water stress reduced the height, number of leaves and shoot diameter in the plants of the severe treatments. Water stress reduced leaf, stem and root dry matter. Biomass allocation was sufficient to reduce only in case of leaves. Leaf area was also reduced; however, there were no significant differences in leaf area ratio and specific leaf area. The recovery of the re-watering plants was evident by emitting new leaves. Leaf water potential was reduced by the water deficit in the treatments with 20% of pot capacity and without. The same behavior was verified for the relative water content. On the re-watering plants, though was verified rehabilitation of plants but at the end of experiment, these plants showed reductions in the leaf water potential and relative water content. Carbohydrates, proteins and proline contents increased with the water deficit. This elevation was possible because of reduction in relative water content. The results indicate that neem seedlings reduced leaf water potential because of the reduction on the relative water content and this specie can be cultivated, at the initial phase of development, under 80% of pot capacity, with highest production. / A pesquisa teve como objetivo avaliar a influência do déficit hídrico no crescimento e nas relações hídricas de plantas jovens de nim indiano. O delineamento experimental utilizado foi inteiramente casualizado, com sete tratamentos hídricos (100, 80, 60, 40 e 20% da capacidade de pote (CP), suspensão de rega e Reirrigado). Foram avaliados semanalmente altura, número de folhas e diâmetro do caule. Ao final do experimento, as plantas foram levadas à estufa para obtenção da matéria seca das folhas, caule, raízes e total. De posse destes dados, foram calculadas a alocação de biomassa das folhas, caule e raízes. Também foram calculadas a área foliar, a razão de área foliar e a área foliar específica. O potencial hídrico foliar foi avaliado em três épocas (30, 45 e 60 dias após a diferenciação dos tratamentos hídricos) em dois horários de avaliação (pré-dawn e meio-dia). O teor relativo de água também foi avaliado em três épocas (30, 45 e 60 dias após a diferenciação dos tratamentos hídricos) utilizando-se as folhas da análise do potencial hídrico de meio-dia. O déficit hídrico reduziu a altura, número de folhas e diâmetro do caule das plantas nos tratamentos mais severos. Os efeitos do estresse também foram observados na redução da matéria seca das folhas, caule, raízes e total. Na alocação de biomassa, houve redução apenas na alocação para as folhas. Também ocorreram reduções significativas na área foliar, mas a razão de área foliar e a área foliar específica não diferiram entre os tratamentos. As plantas reirrigadas mostraram recuperação, evidenciada principalmente, pela emissão de novas folhas. Em todas as épocas e horários de avaliação, as plantas reduziram o potencial hídrico foliar nos tratamentos com 20% da CP, suspensão de rega e reirrigado. Nestes mesmos tratamentos, o teor relativo de água mostrou alteração semelhante, com reduções significativas nas três épocas de avaliação. Nas plantas do tratamento reirrigado, nas avaliações às 24h e 15 dias após essa reposição, foram verificadas recuperações significativas, mas, à medida que a umidade do solo decrescia, foram verificadas novas reduções no potencial hídrico foliar e teor relativo de água. Com relação às quantificações de carboidratos solúveis, proteínas solúveis e prolina livre, foram verificados aumentos significativos de acordo com a severidade dos tratamentos. Correlacionando esses dados com o teor relativo de água, verificou-se que o aumento na concentração de solutos se deu principalmente em função da redução na quantidade de água da célula.Deste modo, sugere-se que o nim indiano reduz o potencial hídrico foliar em função da queda no conteúdo relativo de água e, conclui-se também, que esta espécie pode ser cultivada na fase inicial de desenvolvimento com 80% da capacidade de pote, obtendo-se o máximo de produção.

Orientador: Rafael Silva Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T00:59:11Z (GMT). No. of bitstreams: 1 Eller_CleitonBreder_M.pdf: 21288842 bytes, checksum: a40ec901911bfd6ea80a8976e0a4dd1b (MD5) Previous issue date: 2012 / Resumo: Florestas nebulares são ecossistemas importantes devido a sua alta biodiversidade, alta taxa de endemismo e funções ecossistêmicas. Plantas de florestas nebulares são constantemente expostas a eventos de neblina, entretanto as consequências ecofisiológicas dessa interação entre vegetação e neblina ainda não estão completamente elucidadas. Em nosso estudo pretendemos investigar como eventos de neblina influenciam as relações hídricas de Drimys brasiliensis, mediante a avaliação das respostas do fluxo de seiva do xilema das plantas em condições de campo e casa de vegetação. Nós também avaliamos as consequências ecofisiológicas da neblina sob condições de escassez de água no solo em experimentos com plantas em casa de vegetação. D. brasiliensis apresentou reversões no fluxo de seiva de alta magnitude (de até 26% da taxa transpiratória diurna máxima) no tronco e na raiz durante eventos de neblina. A frequência e magnitude dos fluxos reversos foram influenciadas pelo conteúdo volumétrico de água no solo. Durante o experimento em casa de vegetação, nebulizações noturnas mantiveram a água no solo e o potencial hídrico das plantas constantes ao longo do experimento mesmo sem irrigação no solo. As plantas nebulizadas também apresentaram maiores taxas de assimilação de carbono, condutância estomática e sobrevivência do que plantas que não foram nebulizadas, embora não tenhamos observado diferenças em taxas de crescimento entre os tratamentos. Nossos resultados sugerem que eventos de neblina são importantes para manutenção do desempenho ecofisiológico e sobrevivência de D. brasiliensis durante períodos de seca. Essa importância pode ser atribuída à capacidade de D. brasiliensis de usar a água da neblina não apenas para reidratar seus tecidos, mas também redistribuindo a água para a rizosfera. Esse processo de redistribuição pode ser importante em ecossistemas frequentemente expostos à neblina, porém mais estudos são necessários para avaliar sua ocorrência em outras espécies, assim como suas consequências ecológicas / Abstract: Cloud forests are considered important ecosystems due to its high biodiversity, endemism levels and ecosystem functions. Cloud forests vegetation is often subjected to fog, however the physiological processes that determines how the vegetation interacts with the fog are still not clearly understood. In this study we investigate how fog events can affect the water relations of Drimys brasiliensis, focusing on the xylem sap flow dynamics in plants at field and greenhouse conditions. We also evaluate the ecophysiological importance of fog during drought periods with greenhouse experiments. D. brasiliensis showed high magnitude reversals of sap flow (up to 26% of the maximum diurnal sap flow rate) on the roots and stem during fog events. The frequency and magnitude of reversals were influenced by the soil volumetric water content. During the greenhouse experiment overnight nebulizations led to maintenance in the soil volumetric water content and plant water status. The fogged plants also showed higher assimilation rates, stomatal conductance and survivability than plants that were not subjected to fog, however we didn't found any difference in the growth rates between the treatments. Our result suggests that fog is important to the maintenance of ecophysiological performance and survival of D. brasiliensis during drought periods. This importance may be attributed to D. brasiliensis capacity to use fog water to rehydrate its tissues and also redistribute the water all the way to the rizosphere. This hydraulic redistribution process can be important in ecosystems subjected to frequent fog events; however more studies are necessary to evaluate the occurrence of this process in other species and its ecological consequences / Mestrado / Ecologia / Mestre em Ecologia