1- The ecology of a population of the tropical palm tree Euterpe edulis Mart. was studied at the Municipal Reserve of Santa Genebra, Campinas (Sao Paulo, Brazil). This palm has been intensively exploited due to the quality of its heart of palm (palmito). The heart of palm corresponds to the apical meristem of the plant together with the developing new leaves. 2- The indiscriminate exploitation that this palm has been subject to over recent years in southern Sao Paulo may result in it becoming extinct in many forest fragments. The biodiversity of large animals in these forests has declined as a consequence of hunting, and the overexploitation of E. edulis has also led to a decline in the number of large frugiverous birds. The financial benefits generated by the sustainable exploitation of palmito can exceed those from a single extraction or those from forest conversion to agriculture. 3- The seed and seedling ecology of the population of E. edulis was examined. On average each plant produced approximately 1500 fruits and, there was a tendency for plants of intennediate size to be slightly more fecund. Most seeds were found in close proximity to adult plants; the distance of dispersal could be described by a negative power curve. Five species of birds belonging to the Family Turdidae were observed to feed on the fruits of E. edulis while on the tree, while subsequent dispersal along the gro':lnd was found to occur by water. The probability of surviving and growing to the next Sl~ class was inversely related to the number of seedlings. The maximum survival of seedlIngs and growth to the next size class occurred approximately 4 m from adult plants, indicating that the survival and growth of seedlings was suppressed in the immediate vicinity of conspecific adults. 4- The spatial pattern of the population of E. edulis, in the Municipal Reserve of Santa Genebra, was significantly clumped. The data indicate that the spatial distribution of individuals becomes less clumped with time as individuals develop. 5- The transition matrix analysis of the population revealed that the population is increasing at a rate of 14% year-I. The highest sensitivity was observed in the transition from size-class 1 (0-10 mm diameter) to class 2 (10.1 - 20 mm). According to the elasticity analysis, most of the value of the finite rate of population increase is accounted for by the probability of surviving and remaining in the same size class. The results from the haryesting simulations, indicate that it is possible to harvest E. edulis sustainably when harvesting is restricted to size class 6 plants (Le. reproductive adults). 6- The density-dependence observed for survival and growth of plants in the smallest size class was s~ong enough to affect the population dynamics of E. edulis. Elasticity analysis of the transItion matrix shows that the position of populations of E. edulis in G-L-F space moves towards the L apex of the demographic triangle as the density of plants increases.

This thesis takes data from the Infectious Diseases of East African Livestock (IDEAL) project. The project was a longitudinal calf cohort study based in Western Kenya. Indigenous short horn zebu calves were recruited at birth and then visited every 5 weeks through their first year of life. The aim of this thesis was to improve understanding of the epidemiology of Theileria parva, with a particular focus on variation in host response. 362 of the 548 calves in the study cohort were classified as having seroconverted to T. parva, and 381 to T. mutans before 1 year old. The diagnostic tools used to identify exposure in the calf were compared, and environmental and calf level risk factors associated with the age at seroconversion were sought. Decreased elevation of the homestead and increased size of the herd were found to be significantly associated with an increased hazard of seroconversion to T. parva. There was little variation in hazard of T. mutans captured across the study site. The outcome ‘clinical episode’ was used to classify whether the calf was ill at each routine visit. A large number of calves passed through their first year of life without clinical disease being observed, and a minority of calves experienced the majority of clinical episodes. Multiple clinical episodes were apparently related in time, suggesting that they were due either to the same or connected pathogenic processes. A low birth weight, larger herds, and older farmers were all risk factors for being a sick calf. Both high helminth burden and T. parva were found to be significantly associated with clinical disease at a population level. A lot of variation was seen in the clinical presentation of disease. The clinical signs associated with fatal East Coast Fever (ECF), the clinical disease associated with T. parva infection, were found to be very variable. Although this may have been partly due to the varying times in the disease process that calves were observed prior to death, the complication of the clinical picture was also suggested to be due to co-infections. 71% of the cohort was infected with T. parva in their first year of life, but only a fraction (8.7%) went on to die from that infection. Unmatched and matched nested case control study formats were used to investigate the risk factors associated with death following T. parva infection (ECF death) in these calves. It was found that being infected young was a risk factor for death. Calves owned by older farmers were also at higher risk of death following infection. Going out grazing was found to be protective, and equivocal evidence was found for an association between prior T. mutans exposure and reduced odds of ECF death. If these initial findings from this work are correct, it is likely that T. mutans is influencing the clinical presentation of T. parva in endemic regions.

Memoria para optar al título de Bioquímico / La enfermedad neurológica conocida como Paraparesia Espástica Tropical, mielopatía asociada al HTLV-I (TSP/HAM) se caracteriza por la degeneración axonal de los haces córtico-espinales. Aunque no se conoce mucho como el HTLV-I afecta selectivamente a los axones más largos del sistema nervioso central (SNC), es la proteína viral Tax secretada desde los linfocitos T-CD4+ el principal candidato por su actividad estimuladora de factores transcripcionales a través de varias vías de señalización. Esta proteína, se encuentra presente en forma crónica en el líquido cefalorraquídeo (LCR), pudiendo alterar el transporte axonal actuando extracelularmente, siendo afectados principalmente los axones más largos por su mayor vulnerabilidad. Estudios in vitro de la proteína Tax muestran que se une a varias proteínas celulares que regulan vías relacionadas con la transcripción y el citoesqueleto, incluyendo fosfatasas y quinasas, por lo que se sugiere que en esta patogenia podría haber un desbalance en el nivel de fosforilación/desfosforilación de las proteínas del citoesqueleto. Se han propuesto como biomarcadores de varias enfermedades neurodegenerativas los niveles de Tau total y/o fosfo-Tau en el LCR. Por lo tanto, los objetivos de esta investigación fueron comparar la fosforilación de Tau presente en el LCR de pacientes con TSP/HAM y sujetos controles, a fin de aclarar si estas proteínas están involucradas en la patogenia de esta enfermedad, y aislar la proteína Tau desde el LCR para posteriores estudios de proteómica de sus fosfoformas. Los niveles de Tau en el LCR y la evaluación del patrón molecular de fosforilación de residuos específicos como Tre181, Ser199, Tre205, Tre231, Ser262, Ser356, Ser396, Ser404 y Ser422 fue realizada por “immunowestern blot” utilizando anticuerpos policlonales monoespecíficos. Con todos los anticuerpos ensayados se observó la presencia de una banda principal de 52 kDa. Los niveles de Tau en el LCR de los TSP/HAM no fueron significativamente distintos de los de controles, y aunque no fue significativamente diferente (p = 0,06), se podría sugerir sólo una anormal hiperfosforilación de Tre181. Si se confirmara este mayor nivel fosforilación en Tre181 trabajando con un número mayor de pacientes o utilizando otros métodos más confiables, sugeriría un aumento en la actividad o una sobre-expresión de dos quinasas dirigidas a Ser/Tre-Pro, GSK3-α y β, Cdk5. Una caracterización completa de la fosforilación de los distintos residuos de Tau en el LCR de los controles y pacientes con TSP/HAM requirió la aplicación adicional de la técnica analítica de Espectrometría de Masas (MS). Por lo tanto, se trató de aislar Tau desde LCR utilizando una columna de afinidad por fosfopéptidos de Ga(III), y dos métodos de inmunoprecipitación, uno usando proteínas A/G acopladas a agarosa y una segunda con unión covalente de los anticuerpos (“Sepharose” activada con CNBr). Ni la columna de Ga(III) ni el primer método de inmunoprecipitación fueron adecuados para posterior análisis por MS. Después de demostrar por SDS/PAGE que el método que usaba los anticuerpos unidos covalentemente mostraba una banda principal de 52 kDa, se eluyó la proteína del gel, tripsinizó y analizó por MS MALDI-TOF. Se observó la posible presencia de proteínas asociadas al citoesqueleto que podrían haber coinmunoprecipitados con Tau. Estos resultados no fueron confirmatorios por el bajo “score” observado. En conclusión, dos de los resultados muestran diferencias entre TSP/HAM y varias enfermedades neurodegenerativas: el no aumento en los niveles de Tau total, y la posible hiperfosforilación de sólo Tre181. Fue importante lograr aislar Tau desde el LCR para futuros estudios de MS / The neurological disorder known as tropical spastic paraparesis / HTLV-I-associated myelopathy (TSP/HAM) is characterized by axonal degeneration of the cortico-spinal tracts. Although the selectivity of HTLV-I towards the longest axons of the central nervous system (CNS) is not fully understood, the main candidate is the secreted viral protein Tax from lymphocytes T-CD4+ that shows a stimulatory activity of transcriptional factors acting through several signaling pathways is the main candidate. This protein, chronically present in CSF, could extracellularly alter axonal transport. The longest axons are mainly affected because they are more vulnerable. In vitro studies on Tax protein have shown the binding of this protein to many cellular proteins that regulate transcription and cytoskeleton related pathways including phosphatases and kinases, therefore an imbalance in the level of cytoskeleton phosphorylated/unphosphorylated proteins could be involved in this pathogeny. Levels of total Tau and/or phospho-Tau in the CSF have been proposed as biomarkers of various neurodegenerative diseases. Hence, the aims of this investigation were to compare Tau phosphorylation present in CSF of TSP/HAM patients and control subjects, to elucidate if these proteins are involved in the pathogeny of this disease, and to isolate Tau protein from CSF for further proteomic studies of its phosphoforms. Levels of Tau in CSF and evaluation of the molecular pattern of phosphorylation of selected residues such as Thr181, Ser199, Thr205, Thr231, Ser262, Ser356, Ser396, Ser404 and Ser422 were performed by immunowestern blot, using monospecific polyclonal antibodies. With all the antibodies tested we observed a main band with 52 kDa. The CSF levels of Tau in TSP/HAM were not significantly different from those of controls. Only an abnormal hyperphosphorylation on Thr181, although it was not significantly different (p = 0.06), could be suggested in TSP/HAM patients. If a high phosphorylation level in Thr181 is confirmed by working with a larger number of patients or other more reliable methods, it would suggest an increase in activity or over-expression of two Ser/Thr-pro-directed kinases GSK3-α and β, and Cdk5. A complete characterization of Tau phosphorylation sites in CSF from control and TSP/HAM patients required the use of the additional analytical technique of Mass Spectrometry (MS). Therefore, we tried to isolate Tau from CSF samples using the phosphopeptide affinity column with Ga(III), and two immunoprecipitation methods, one using protein A/G-coupled agarose beads and a second one with covalently bound antibodies (Sepharose activated with CNBr). Neither the Ga(III) column nor the first immunoprecipitation method were adequated for MS analysis. After demonstrating by SDS/PAGE that the method that used covalently bound antibodies showed a main band of 52 kDa, the sample was eluted, trypsinized and analyzed in a Mass Spectrometer MALDITOF. This preliminary study suggested the presence of Tau and of some other cytoskeleton associated proteins that could have been coimmunoprecipited with Tau. The low “score” obtained did not allow reach confirmatory results. In conclusions, two of the results showed differences with various neurodegenerative diseases: lack of changes in Tau levels in CSF, and possible hyperphosphorylation of only threonine 181. It was important to have been able to isolate a Tau form from CSF for further studies of MS

A estabilização de solos com adição de cal, que é uma técnica comumente empregada em países das zonas temperadas, tem encontrado muita dificuldade de aplicação no Brasil e no domínio tropical em geral. Os mecanismos envolvidos nessa estabilização são pouco conhecidos, mas citam-se normalmente a capacidade de troca, floculação e aglomeração das argilas e as reações pozolânicas como as responsáveis pela alteração e melhora das propriedades geotécnicas das misturas solo-cal. Com o objetivo de contribuir para o avanço do conhecimento da estabilização com adição de cal em materiais tropicais, selecionou-se 3 solos e 2 alteritas, expressivos em termos de área e que apresentam dificuldades de emprego na construção rodoviária, nas regiões sul e sudeste do país: o Latossolo Roxo, a Terra Roxa estruturada, o Latossolo Vermelho Escuro orto, as alteritas de granito e de gnaisse. Optou-se por uma abordagem pedológica e geoquímica, utilizando como instrumentos de pesquisa as técnicas mineralógicas e micromorfológicas, além dos ensaios mecânicos que funcionaram como controle das variações de comportamento hídrico e mecânico dos materiais antes da adição de cal. Os materiais foram estudados sob três condições diferentes: natural, compactado sem tratamento prévio e compactado após adição de cal. Os solos são de textura argilosa, constituídos por caolinita, oxi-hidróxidosde ferro e gibbsita (esta última ausente na TER). As alteritas são siltosa a silto-arenosas, constituídas basicamente por caolinita, mica (biotita alterada), quartzo e feldspatos (pouco). A adição de cal confere a todos os materiais um aumento na capacidade de suporte, redução na expansão e na contração, com intensidades variáveis em função da natureza do material envolvido. A análise mineralógica mostrou que a cal afeta os minerais da fração argila, promovendo uma \"amorfização\" na gibsita e caolinita. Nas alteritas é a caolinita que é afetada ) preferencialmente, enquanto que amica (biotita alterada) não mostra sinais de ataque. Os produtos neoformados são entretanto, mais difíceis de serem detectados pelas técnicas de difração de raios-X e análise termo diferencial. Os estudos micromorfológicos, por outro lado, revelam a existência dos produtos de neossíntese, a sua distribuição e as relações que mantêm com os constituintes do plasma. Mostram, ainda, que a compactação destrói parcial ou totalmente a organização natural dos materiais, dando origem a um novo arranjo, onde são visíveis sinais deinstabilidade: orientações plasmáticas estriadas e fissuras que em geral delimitam lamelas. Estes indícios são observados principalmente nos solos. As misturas solo-cal compactadas exibem arranjos diferentes destes, onde os sinais de instabilidade são atenuados ou suprimidos, dependendo do material utilizado. Em conclusão, verifica-se que tanto a mineralogia quanto a organização original dos materiais influenciam o resultado da estabilização. / The soil stabilization with lime is a well known technic in countries of temperate zone, but its utilization in Brazil and the Tropical countries as a general, has been rather problematic. The mechanisms involved in the stabilization are not well known and cation exchange capacity, clay flocculation and agglomeration and pozzolanic reactions have been mentioned as responsible for the alteration and improvement of the geotechnical properties of the soil lime mixture. In order to contribute to the better acknowledgement of the soil stabilization with lime addition, 3 soils types and 2 alterites were selected on the basis of their extensive occurrence and their bad quality as road construction materials. The soils selected were a LR, a TRE and a LE of a granite and a of gnaisse. The methods of study were mainly pedological and geochemical based on mineralogical and micromorphological analysis associated with mechanical tests in order to control the hydric and mechanical behaviour of the materials before and after the lime treatment. The material were studied within 3 different condition: natural, compacted without treatment and compacted with treatment. The soils present a clay texture and are constituted by kaolinite, iron oxydes and hydroxydes and gibbsite (the latter not present in TRE). The alterites present a silty to sandy silt textures and are formed mainly by kaolinite, mica (weathered biotite), quartz and few feldspar. The lime addition to these materials represents an increase in the bearing capacity and a reduction of expansion and contraction, a different intersities according to the nature of these material. The mineralogical analysis has shown that lime affects the clay fraction, leading to a \"amorphization\" of gibbsite and kaolinte. In the alterites, the kaolinite is the most affect while the mica remains nearly antouched. Nevertheless, the newly formed materials are rather difficult to be detected by XRDA and ATD. On the other hand, the micromorphological studies, sow the presence of the products of neosintesis and its distribution and relationship with the plasma constituents. It is also shown that the compactness destroyes partially or totally the natural organization of the material, given origin to a new one were signs of instability are rather clear: plasmic orientation and parallel fissures limiting lamellae. These evidences are better observed in the soils. The compacted soil-lime mixture show different organizations, where the signs of instability are attenuated or suppressed, depending on the material. As a conclusion, it can be said that mineralogy as well as the original organization of the materials has influence on the stabilization result.

Cacao (<i>Theobroma cacao </i>L.) is an ancestrally cultivated crop that has been the source of one of the most beloved commodities, chocolate. Its worldwide demand has shaped the history of its cultivation. In Chapter 1, the center of origin of cacao, its center of domestication, the most outstanding movements of germplasm from the Pre-Columbian to the Republican era, the appearance and discovery of major diseases, among other important economic, agricultural and social aspects regarding cacao cultivation are reviewed. The following chapters focus on one of the major pathogens of cacao in the Americas, <i>Moniliophthora roreri</i> causing frosty pod rot disease. Chapter 2 presents evidence that the center of origin of <i>M. roreri </i>is not limited to the Magdalena Valley in Colombia, as other studies have suggested, but extends to Ecuador and the Peruvian Upper Amazon. Chapter 3 focuses on the <i>A </i>and <i>B </i>mating type loci diversity of <i>M. roreri </i>and reports a new <i>A </i>mating allele in Colombia and new mating types in Colombia, Ecuador and infers the presence of even more mating types in Ecuador and the Peruvian Upper Amazon. Additionally, Chapter 3 introduces rapid approaches to collect <i>M. roreri </i> and to diagnose mating types. Finally, Chapter 4 touches the genomic aspect of <i>M. roreri </i>and its close relatives within the Marasmiineae suborder. It presents the most complete genome of a <i>Moniliophthora </i>species generated so far and describes the evolution of predicted effectors and other proteins that might be involved in pathogenicity in this suborder. It also releases a custom program called SyLOCAL that evaluates synteny of a cluster of genes between two genomes.

A hipótese principal deste trabalho é que as anomalias de precipitação na ZCIT com períodos de 20 a 50 dias e dimensão zonal de 1000 a 1500 km, causadas remotamente por Ondas de Instabilidade Tropical (OITs) e/ou Ondas de Rossby Curtas (ORCs) podem causar anomalias de salinidade da superfície do mar. Para responder à hipótese, o presente trabalho quantifica a influência dos padrões propagantes da temperatura da superfície do mar sobre variáveis atmosféricas na escala das ORCs e OITs. Os coeficientes de regressão do vapor dágua integrado verticalmente e da precipitação revelam que a influência da temperatura superficial na atmosfera se dá remotamente à região de domínio das ondas, alcançando a ZCIT. A distribuição das anomalias do divergente do vento corrobora a ideia de aceleração dos ventos sobre águas quentes e desaceleração sobre águas frias. A carência de correlações estatisticamente significativas entre a precipitação e a salinidade superficial, devido à baixa qualidade dos dados, não permitiu que a hipótese principal fosse avaliada. Entretanto, fica evidente a influência destas ondas em variáveis atmosféricas que alteram o balanço de evaporação e precipitação que tem influência direta na salinidade superficial. Denominamos ORCs as oscilações com período de _49 dias e comprimento de onda de _1500 km e OITs os padrões com _21 dias e _1000 km. A identificação dinâmica destas ondas foi feita através da teoria linear de ondas equatoriais no modelo de águas rasas quase-geostrófico para um oceano invíscido de 1,5 camadas. Os dados de anomalia da altura da superfície do mar revelaram apenas a existência de ORCs, enquanto que a temperatura da superfície do mar apresentou o sinal de ambas as ondas, sendo as OITs dominantes até 6_ do Equador. A principal contribuição deste trabalho é a confirmação da hipótese de que OITs e ORCs coexistem, são distinguíveis e geram alterações no vento por mecanismos similares. Até o presente momento, desconhecemos outro estudo que alie a separação teórica dos padrões oceânicos propagantes obtidos por satélites à quantificação da variabilidade atmosférica associada às anomalias de TSM em bandas do espectro zonal-temporal características de ondas dinamicamente distintas / We hypothesize that rainfall anomalies with 2050 days and 10001500 km on the Intertropical Convergence Zone (ITCZ) can induce sea surface salinity anomalies. We argue that these precipitation anomalies are remotely caused by Tropical Instability Waves (TIWs) and Short RossbyWaves (SRWs). We have quantified the sea surface temperature influence on atmospheric fields at the TIWs and SRWs spectral bands through regression analysis. In that, wind anomalies are larger over temperature anomalies. Winds tend to accelerate over positive temperature anomalies and slow down over negative anomalies. Changes on water vapor and rainfall occur predominantly on the ITCZ, far from the strongest temperature anomalies near the equator. However, we couldnt address the main hypothesis due to the lack of significant correlation between rainfall and sea surface salinity anomalies. We speculate that this is a consequence of the low quality of the salinity data used in this study. We have identified TIWs as the waves with _21 days and _1000 km and SRWs as the oscillations with _49 days and _1500 km. The identification of the dynamics was made according to equatorial long waves theory based on a linear, quasi-geostrophic, 1.5 layers, inviscid ocean model. Sea surface height anomalies could only reveal SRWs. Sea surface temperature anomalies show both type of waves, with TIWs dominating within 6_ from the equator. Our main contribution was to show that TIWs and SRWs coexist, can be isolated and change wind field through similar mechanisms. We do not know any other study that linked theoretical identification of dynamically different oceanic waves to the atmospheric variability in a quantitative fashion

Only a small body of work currently exists regarding the geomorphology of humid tropical montane rivers. The research that does exist reports rapid geomorphic processes and high sediment loads compared to other montane rivers. This research applies traditional field survey methods combined with new applications of remote sensing techniques to examine the geomorphology and sediment dynamics of the montane portions of the Rio Pacuare in Costa Rica. A suite of geomorphic components (channel slope and width, lateral contributions and planform) are examined and a model presented that illustrates the complexity of the Rio Pacuare’s geomorphology and how the distribution of alluvial sediment varies in relation to geology (tectonics and lithology) and flow hydraulics (stream power). Next, average annual bedload sediment transport capacity is estimated using fifty-one years of daily discharge data at six different locations within the study area, including the temporal (monthly) variability of sediment flux due to dry versus wet season discharge regimes. Then, a time-step hydraulic model is created that simulates observed (modern) and potential future discharge scenarios based on regional climate change model results. The simulated discharge data for two locations within the study area is then integrated into the sediment transport model to examine how sediment flux, and thus channel geomorphology, is likely to change in response to changes in the river’s discharge regime.

Submitted by Gizele Lima (gizele.lima@inpa.gov.br) on 2016-08-29T13:15:09Z No. of bitstreams: 2 Dissertação_Victor_Santos_2016_CFT.pdf: 1826823 bytes, checksum: 77718c6aef8adc0ebf3bd0ea0ad75475 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-29T13:15:09Z (GMT). No. of bitstreams: 2 Dissertação_Victor_Santos_2016_CFT.pdf: 1826823 bytes, checksum: 77718c6aef8adc0ebf3bd0ea0ad75475 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-09 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The reduction of water availability in severe drought conditions, e.g. El Niño, can influence the photosynthesis of tree species in the canopy and understory of tropical forests through changes in steps associated with the assimilation of CO2 (e.g. diffusive and photochemical step). However, it is also known that changes in the availability of irradiance along the vertical profile of rainforests can lead to tree species develop different mechanisms of harvesting and use of this resource. Were investigated in trees species of canopy and understory of a Central Amazonian rain forest the seasonality effects in an El Niño year over photosynthetic leaf traits (Chapter 1) and, the mechanisms of irradiance harvesting and use which allowing complementarity in use of this resource in canopy and understory (Chapter 2). In the chapter 1 were investigated photosynthetic leaf traits related to gas exchange (PNmax - light saturated photosynthesis; gs - stomatal conductance; E - leaf transpiration e Rd - leaf dark respiration), leaf chlorophyll concentration, photochemical performance (Fv/Fm - maximal quantum yield of photosystem II; PIABS - performance index, PItotal - total performance index) and leaf contents of nitrogen, phosphorus and potassium, during four seasonal precipitation periods, wet (April), wet/dry transition (July), dry (September) and dry/wet transition (November) in the 57 plants belonging to 52 tree species in the forest canopy and understory environments. PNmax reduced during the dry season due to a strong stomatal limitation. The maintenance of photochemical performance and chlorophyll concentration may have favored the PNmax recuperation during the rainfall events in dry/wet transition season. With respect to leaf nutrients contents, the phosphorus was more related to photosynthesis, while higher potassium accumulation was observed in the understory during the dry season. In the chapter 2, the canopy and understory tree species were compared with respect to mechanisms of irradiance harvesting and use. Therefore, were investigated morphoanatomical (LMA – leaf mass area, leaf tissue thickness) and functional leaf traits (leaf chloroplastid pigments, phosphorus and nitrogen content, chlorophyll a fluorescence parameters and gas exchange). Higher photosynthesis values were related with higher leaf mass area, palisade thickness, leaf nitrogen and phosphorus content and photochemical performance in electron transport steps associated with photosystem I. In the other hand, in the understory a higher chloroplastid pigment concentration, chlorophyll nitrogen partition and maximal quantum efficiency for primary photochemistry improve the irradiance harvesting. These traits together with a reduced leaf dark respiration, provided low light compensation point. In summary, the chapter 1 highlights the dry season photosynthesis reduction primarily provided by stomatal conductance limitation and the maintenance of photosynthetic apparatus even in severe dry conditions. The chapter 2 provides evidence for concluding that tree species in the canopy efficiently use the high available irradiance, while in the understory the irradiance harvesting efficiently and reduced leaf dark respiration ensure the positive carbon budget maintenance. / A redução da disponibilidade hídrica em condições de seca severa, por exemplo El Niño, pode influenciar a fotossíntese em espécies arbóreas no dossel e sub-bosque de florestas tropicais mediante alterações em etapas associadas à assimilação de CO2 (e.g. etapa difusiva e fotoquímica). Mas, sabe-se também que a variação na disponibilidade de irradiância ao longo do perfil vertical de florestas tropicais pode levar as espécies arbóreas a desenvolverem diferentes mecanismos de captação e uso desse recurso. Assim, foram investigados em espécies arbóreas no dossel e sub-bosque de uma floresta ombrófila densa na Amazônia Central os efeitos da sazonalidade, em ano de ocorrência de El Niño, sobre as características fotossintéticas (Capítulo 1) e os mecanismos de captação e uso da irradiância que permitem a complementariedade no uso desse recurso nos ambientes dossel e sub-bosque (Capítulo 2). No capítulo 1 foram investigadas as características fotossintéticas foliares relacionadas às trocas gasosas (PNmax - fotossíntese máxima; gs - condutância estomática; E - transpiração e Rd - respiração foliar no escuro), concentração foliar de clorofila, desempenho fotoquímico (Fv/Fm - eficiência quântica máxima do fotossistema II; PIABS - índice de desempenho na base ABS, PItotal - índice de desempenho total) e os conteúdos foliares de nitrogênio, fósforo e potássio, durante quatro períodos sazonais de precipitação, chuvoso (abril), transição chuvoso/seco (julho), seco (setembro) e transição seco/chuvoso (novembro) em 57 plantas pertencentes a 52 espécies arbóreas nos ambientes de dossel e sub-bosque florestal. PNmax reduziu durante o período seco em função de uma forte limitação estomática. A manutenção do desempenho fotoquímico e concentração de pigmentos cloroplastídicos, ao longo do período seco, pode ter favorecido a recuperação dos valores de PNmax após o retorno da precipitação durante o período de transição seco/chuvoso. O fósforo esteve mais relacionado à fotossíntese ao longo dos períodos investigados, enquanto o maior acúmulo de potássio foi observado no sub-bosque durante o período seco. No capítulo 2, os mecanismos de captação e uso da irradiância foram comparados em espécies arbóreas no dossel e sub-bosque. Para tanto, foram investigadas características morfoanatômicas (MFE - massa foliar específica; espessura de tecidos foliares) e funcionais foliares (teores foliares de pigmentos cloroplastídicos, fósforo e nitrogênio; parâmetros do transiente polifásico de fluorescência da clorofila a e trocas gasosas). Maiores valores de fotossíntese no dossel foram relacionados com maiores valores de massa foliar específica, espessura do parênquima paliçádico, conteúdo foliar de nitrogênio e fósforo e, principalmente, eficiência fotoquímica nas etapas do transporte de elétrons associadas ao fotossistema I. Por sua vez, no sub-bosque uma maior concentração de pigmentos cloroplastídicos, alocação de nitrogênio para clorofilas e eficiência quântica máxima do fotossistema II aprimoraram a captação da irradiância. Essas características, juntamente com reduzida respiração foliar no escuro, proporcionaram menores valores de irradiância no ponto de compensação. Em síntese, o capítulo 1 destaca a redução na fotossíntese durante o período seco em ano com ocorrência de forte El Niño primariamente proporcionada pela redução na condutância estomática, mas com a manutenção da funcionalidade e estrutura do aparato fotossintético mesmo em condições de seca severa. O capítulo 2 fornece evidências que permitem concluir que espécies arbóreas no dossel possuem traços anatômicos e funcionais associados a eficiente utilização da elevada irradiância disponível, enquanto no sub-bosque a eficiência na captação da irradiância dispersamente disponível e a reduzida respiração foliar asseguram a manutenção do balanço positivo de carbono.

Submitted by Gizele Lima (gizele.lima@inpa.gov.br) on 2016-08-29T19:17:18Z No. of bitstreams: 2 Tese final_bianca maíra de paiva ottoni boldrini.pdf: 2022038 bytes, checksum: 912be076443ed0fbe32d6a6d5a84b784 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-29T19:17:18Z (GMT). No. of bitstreams: 2 Tese final_bianca maíra de paiva ottoni boldrini.pdf: 2022038 bytes, checksum: 912be076443ed0fbe32d6a6d5a84b784 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-08-28 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The leaf decomposition in aquatic systems is a process that involves both physical and chemical aspects of the environments and riparian vegetation as ecological relationships between aquatic communities. In small shaded streams, this process becomes the link between different ecological compartments, providing energy and matter for the survival of species that inhabit these aquatic systems. Thus, this ecological process is critical to maintaining these ecosystems and hence for the survival of their species. This thesis aimed to evaluate the leaf decomposition process in Amazonian streams, emphasizing the community of aquatic invertebrates and fungal biomass. The first chapter has the fungal biomass and colonization patterns of aquatic invertebrates along the leaf decomposition process in eight Amazonian streams. Two plant species with differences in their physical and chemical characteristics were used in these experiment of decomposition. The results showed that the decomposition process is influenced by plant species, the stream in which it develops, by time and interaction between time and plant species. However, the influence of these factors is different in each ecological compartment. For example, fungal biomass, density and composition of aquatic invertebrates are not influenced by plant species. The results allowed the observation that decomposition time and the stream influencing the decomposition process (decomposition rates, invertebrates and aquatic fungi). The second chapter of this thesis evaluated the influence of the density of aquatic invertebrates in relation to leaf decomposition rate in Amazonian streams. For three months (November 2012 to January 2013) the leaf decomposition of 30 plant species was followed to obtain the leaf decomposition rates and the density of aquatic invertebrates associated with the process. The experiment was conducted in three streams of small order of the Ducke Reserve (Manaus / AM) and leaves of the plant species used in the experiment are found in riparian area of these streams. The data shows that there is a strong influence of the density of aquatic invertebrates on leaf decomposition rates, independent of the trophic group of these invertebrates. These results do not corroborate previous discussing the little influence of invertbrates on the leaf decomposition process in tropical regions. In this chapter, aiming to cooperate with future studies of leaf decomposition, was proposed a leaf decompisiton speeds classification based on the values obtained for the plant species studied. The last chapter of the thesis was to analyze the differences in the decomposition process of green and senescent leaves in Amazonian streams. To achieve this goal, we performed a leaf decomposition experiment with 14 plant species, where 18 packages of green leaves and 18 senescent leaves of each plant species were submerged in three streams of small order located in the Ducke Forest Reserve (Manaus / AM). The experiment was conducted between November 2012 and January 2013, with 6 packs of green leaves and 6 senescent removed after 15, 30 and 60 days of incubation. The results demonstrated that foliar decomposition speed is faster in green leaves compared to packages with senescent leaves. However, only fungi and aquatic biomass density of aquatic invertebrates have been influenced by the leaf state. / A decomposição foliar em sistemas aquáticos é um processo que envolve tanto os aspectos físicos e químicos do ambiente quanto às relações ecológicas entre as comunidades aquáticas. Em pequenos riachos sombreados, esse processo torna-se o elo entre diferentes compartimentos ecológicos, fornecendo a energia e a matéria inorgânica para as espécies que habitam esses sistemas aquáticos. Dessa forma, esse processo ecológico é fundamental para a manutenção desses ecossistemas e, consequentemente, para a sobrevivência de suas espécies. Esse estudo teve como objetivo avaliar o processo de decomposição foliar em riachos amazônicos, dando ênfase à comunidade de invertebrados aquáticos e à biomassa fúngica. O primeiro capítulo aborda os padrões de biomassa de fungos e colonização dos invertebrados aquáticos ao longo do processo de decomposição foliar em oito riachos amazônicos. As espécies vegetais Pourouma minor e Protium sp. foram utilizadas no experimento de decomposição por apresentarem diferenças em suas características físicas e químicas. Os resultados demonstraram que o processo de decomposição é influenciado pela espécie vegetal, pelo riacho em que se desenvolve, pelo tempo e pela interação entre tempo e espécie vegetal. No entanto, a influência desses fatores será diferente em cada compartimento ecológico. Por exemplo, a percentagem de massa remanescente é influenciada pela espécie vegetal, porém isso não foi observado para a biomassa de fungos, densidade e composição de invertebrados aquáticos. Os resultados também permitiram observar que tempo de decomposição e o riacho influenciam o processo de decomposição (taxas de decomposição, invertebrados e fungos aquáticos). O segundo capítulo avaliou a influência da densidade de invertebrados aquáticos em relação a velocidade de decomposição foliar em riachos amazônicos. Durante três meses (novembro 2012 a janeiro de 2013) a decomposição foliar de 30 espécies vegetais foi acompanhada visando obter os coeficientes de decomposição foliar e a densidade de invertebrados aquáticos associados ao processo. O experimento foi realizado em três riachos de pequena ordem da Reserva Florestal Ducke (Manaus/AM) e as espécies vegetais utilizadas são encontradas na zona ripária desses riachos. Os dados permitem concluir que há uma forte influência da densidade de invertebrados aquáticos sobre as taxas de decomposição foliar, independente do grupo trófico de alimentação desses invertebrados. Esses resultados não corroboram com os anteriores que discutem a pouca influência dos invertebrados no processo de decomposição foliar em regiões tropicais. Nesse capítulo, visando colaborar com estudos futuros de decomposição foliar, foi proposta uma classificação de velocidades de decomposição foliar com base nos valores obtidos para as espécies vegetais estudadas. O último capítulo da tese teve como objetivo analisar as diferenças no processo de decomposição de folhas verdes e senescentes em riachos amazônicos. Para alcançarmos esse objetivo, foi realizado um experimento de decomposição foliar com 14 espécies vegetais, onde 18 pacotes de folhas verdes e 18 de folhas senescentes de cada espécie vegetal foram submersos em três riachos de pequena ordem localizados na Reserva Florestal Ducke (Manaus/AM). O experimento foi realizado entre novembro de 2012 e janeiro de 2013, sendo 6 pacotes de folhas verdes e 6 de senescentes retirados após 15, 30 e 60 dias de incubação. Os resultados demonstraram que a velocidade de decomposição foliar é mais rápida em pacotes de folhas verdes quando comparado com folhas senescentes. No entanto, somente a biomassa de fungos aquáticos e a densidade de invertebrados aquáticos foram influenciadas pelo estado foliar.

Endophytic fungi live within tissues of plant hosts without causing symptoms of disease. These fungi are broadly split into the taxonomically and ecologically cohesive Clavicipitaceous endophytes, which infect grasses, and the taxonomically diverse non-Clavicipitaceous endophytes, which are found in nearly all plants and have diverse ecological strategies. My dissertation has two sections: Section A investigates the intersection of Clavicipitaceous endophyte ecology with other ecological theory, including invasion ecology (Chapter II) and community ecology and climate change (Chapter III); Section B investigates the ecology of one group of non-Clavicipitaceous endophytes, the Xylariaceae, using a culture-based study in Ecuador (Chapter IV) and a next-generation sequencing based endophyte survey in Taiwan (Chapter V). Section B is centered on testing the Foraging Ascomycete (FA) hypothesis—the idea that some decomposer fungi may adapt an endophytic lifestyle to escape limitations in primary substrate in both time and space. In Chapter II, I utilized a host-specific Epichloë endophyte present ubiquitously in the European native range of the Pacific Northwest (PNW) invasive grass Brachypodium sylvaticum to test theories of invasion. In Chapter III, I examined the grass Agrostis capillaris in the context of a climate manipulation experiment in prairies in the PNW to elucidate patterns of interaction between multiple symbionts (Epichloë endophytes, dark septate root endophytes, and arbuscular mycorrhizal fungi) within single hosts across climatic variation. In Chapter IV, I began to test the FA hypothesis by examining spatial relationships of Xylaria endophytic fungi in the forest canopy with Xylaria decomposer fungi on the forest floor in a remote Ecuadorian cloud forest. In Chapter V, I build on the results from the previous study, using a novel technique to examine spatial ecology of the Xylariaceae, pairing traditional mycological collection with the preparation of a next-generation sequencing metabarcode library of endophytes over a much greater area. This dissertation includes previously published and unpublished coauthored material.