Three experiments carried out in the southeast of Mexico (Yucatan) are reported. In the first, yield of P. purpureum increased from 3,760 to 14,526 kgDM/ha with age 6 weeks (young) and 28 weeks (mature). Maturity increased lignin from 43 to 108g/kgDM. Potential degradabilities of leaf and stem were 788g & 782g/kgDM with young, and 725 & 403g/kgDM with mature. Young yielded more potentially degradable DM (70 & 35kgDM/ha/d) than mature. In the second, molasses urea block (MUB) supplementation of bulls grazing during the dry season, did not improve the potential degradability of pasture (525g/kgDM). Estimated pasture intake was 68gDM/kgW0.75 /d, and measured rumen pool size of grazing bulls was 79 gDM/kgW 0.75. Intake of MUB was low (236gDM/d) and only increased rumen NH 3-N from 100 to 128mg/l. Availability of pasture was 255kg DM/animal. It is suggested that need of supplementation could be low if there is sufficient pasture to allow selective grazing. In the third, hay diets of young or mature P. purpureum were studied in six zebu (Bos indicus) bulls fed ad libitum. Intakes were, 91 and 44gDM/kgW0.75/d, digestibilities, 591 and 453g/kgDM, estimated energy intakes 768 and 307kJME/kgW0.75/d and Metabolizable Protein, 4.1 and 1.3g/kgW0.75/d with young and mature forages respectively. Forage maturity resulted in negative N balance (352 vs -113mgN/kgW0.75/d), decreased potential (756 vs 568g/kgDM) and fractional rate (0.07 vs 0.03%) of rumen DM degradation, but gave higher DM degradabilities of the non-soluble fraction (378 vs 283g/kgDM). Forage maturity reduced rumen outflow rates of liquid (0.09 vs 0.05%), and solid (0.038 vs 0.015%) phases, increasing mean retention times of digesta (22 vs 65h), and the rumen pool size (84 vs 120gDM/kgW0.75) and reduced the eating (380 vs 273min) and rumination daily times (433 vs 398min). The Purine Derivatives (PD) excretion in urine reflected differences between diets (651 vs 354mMol/kgW0.75/d). However, rumen Microbial N Supply estimated by the PD method was very low in comparison with estimates from digestibility and N balance measurements. It is suggested this effect could be explained by greater recycling of PD to the rumen and a lower endogenous excretion by zebu cattle.

No description available.

Genetic variation in Calamus subinermis was investigated in a provenance cum progeny trial and a study on some quantitative morphological traits. These studies show that variation occurs within and among populations of the species. Genetic gain was estimated for provenance and family selection at a range of selection intensity based on some economic traits. A karyomorphological study on C. subinermis and C. caesius reveals little variation in the chromosome morphology between and within species. The flowering and fruiting phenology of C. subinermis, C. caesius, C. manan and C. trachycoleus was elucidated. Except for the relatively opportunistic C. subinermis, in which floral initiation occurred at about four-month intervals, flowering and fruiting of the Calamus species investigated exhibited a regular annual pattern. Unravelling of the pollination mechanism and floral biology of C. subinermis and C. caesius in this project enables understanding of the breeding system and is important in breeding programmes. Pollination mainly by small noctuid and pyralid moths, which have small foraging ranges, partly accounts for the observed divergence among geographically isolated populations of C. subinermis. The discovery of andromonoecy in C. subinermis, together with the potential bisexuality in the other generally dioecious calamoid genera, calls for modification in the present system of classification for the tribe Calameae, and has implications for natural and artificial pollination. Several rattan mensuration techniques were developed. Growth and yield models based on the Richards function were constructed for C. caesius. These techniques and models will contribute to the conservation with wise use of rattan resources. Recommendations for further research are given for attaining the goal of the project.

Submitted by Gizele Lima (gizele.lima@inpa.gov.br) on 2017-02-13T19:56:09Z No. of bitstreams: 2 dissertacao_diogorosa_CFT-INPA_vFINAL_ATA.pdf: 2457370 bytes, checksum: 46f25127228559590ba550bc46553215 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-02-13T19:56:09Z (GMT). No. of bitstreams: 2 dissertacao_diogorosa_CFT-INPA_vFINAL_ATA.pdf: 2457370 bytes, checksum: 46f25127228559590ba550bc46553215 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-06-13 / Fundação de Amparo à Pesquisa do Estado do Amazonas - FAPEAM / The objective of this study was to investigate the structural differences of the canopy and its seasonal variation in four environments of terra firme in the Central Amazon. Structural attributes of the forest canopy were obtained, using a rangefinder LiDAR, which provides the distance to the last return for each of 1,000 pulses per second. The sensor was aimed upwards and held 1m above the forest floor to obtain 150m long forest canopy profiles at a constant walking speed. Each of four different forest types that comprise a toposequence (catena) was profiled, with six replicates (total 900m of transect per type) at monthly intervals for a full year. From the highest to the lowest, the catena compartments were: plateau on well drained clay-loam; upper slope on well drained clay-loam; gentle lower slope on white sand (tall campinarana forest); and seasonally waterlogged riparian zone on white sand (baixio forest). For each 150m transect, the canopy structure profile was represented by a 2D point cloud containing the positions (x, z) of ~ 345,000 LiDAR last-returns. The main features extracted were: (1) top-of-canopy height in each 1m horizontal interval; (2) the mean and standard deviation (roughness) of these 150 maximum heights per transect; (3) canopy openness; (4) vertical profiles of leaf area density (LAD); (5) the fraction of the total leaf area index (LAI) contained in the highest 5m and in the highest 10m of the canopy and in the highest 6m and in highest 11m of the understory; and (6) the average LAI per transect and the LAI of each 1m horizontal interval, the latter used to construct frequency histograms. From the baser of the catena toward the plateau, top-of-canopy height and top-of-canopy roughness both increase. Vertical profiles of the leaf area density are bimodal in all four forest types, with higher concentrations of leaves in the lower understory and in the upper canopy. The upper canopy leaf density mode gradually decreases from the riparian forest toward the plateau, as expected from the increasingly irregular topof-canopy surface. The lower understory´s leaf density is greatest in the waterlogged riparian forest and lowest in the tall white-sand forest. The first 5m of upper canopy (below the highest return at each horizontal transect interval of 1m) contains 54-60% of the leaf area of the forest. The first 10m of upper canopy contain 79-86% of the leaf area. Canopy openness and the LAI (using six transect averages per forest type) do not vary between the four forest types. Over the full year, three significant changes in LAI were detected when all four forest types were lumped (repeated-measures analysis of the 24 transects per month). First, there was an LAI increase of 2.9% from 15/Mar to 15/Aug/2015 (wettest month to first dry month); then a drop of 2.0% from 15/Aug to 15/Oct (two driest months of the 2015 El Niño); and finally there was an LAI increase of 3.7% as precipitation gradually increased from 15/Oct/2015 to 15/Jan/2016. Over the full year (15/Mar/2015- 15/Mar/2016) there was a small but significant increase in the LAI (3% ± 2%). There was no seasonal change of the LAI in the understory (1 to 5/11m above the ground). When lumping all forest types, seasonal amplitude of LAI (between the smallest and largest of the 13 monthly averages) was only 4.8%, indicating that LAI alone should have little influence on the seasonality of the forest canopy photosynthetic capacity, even in a severe El Niño year. However, the frequency histograms of the LAI classes, obtained for 900 intervals of 1m from the six transects of each of the four forest types, had a truncated upper tail in every month, indicating saturation in the detectability of high values of LAI. Therefore, the seasonal variation of LAI was probably underestimated. Saturation may also impede detecting LAI differences between the forest types / O objetivo deste estudo foi investigar as diferenças estruturais do dossel e sua variação sazonal em quatro ambientes de terra firme na Amazônia Central. Foram obtidos atributos estruturais do dossel florestal, utilizando um LiDAR tipo rangefinder, que fornece a distância até o último retorno de cada pulso, na frequência de 1.000 pulsos por segundo. O sensor foi orientado para cima e mantido 1m acima do chão. Foram percorridos mensalmente, em velocidade constante, seis transectos de 150m em cada um de quatro ambientes florestais (total de 900m de transecto por tipologia). Do mais alto para o mais baixo na topossequência, estes foram: platô argiloso e bem drenado; vertente superior argiloso e bem drenado; vertente inferior com areia branca (campinarana); e faixa ripária sazonalmente encharcada sobre areia branca (baixio). O perfil de estrutura de cada transecto foi representado por uma nuvem bidimensional contendo a posição (x, z) de ~345.000 últimos retornos. Os principais atributos extraídos foram: (1) a altura máxima em cada intervalo de 1m horizontal; (2) a média e o desvio padrão (rugosidade) destas 150 alturas máximas por transecto; (3) a abertura do dossel; (4) perfis verticais da densidade de área foliar (LAD); (5) a fração do índice de área foliar (LAI) que é contida nos 5m e nos 10m de dossel superior e nos 6m e 11m de altura no sub-bosque; e (6) o LAI médio de cada transecto e de cada intervalo de 1m horizontal, este último para avaliar histogramas de frequência. Do ambiente ripário em direção ao platô, a altura e a rugosidade do dossel aumentam. O perfil vertical da densidade de área foliar mostrou-se bimodal em todos os ambientes, com uma concentração de folhas no subbosque e outra no dossel superior. A concentração das folhas em uma faixa específica de altura no dossel superior se atenua gradualmente do baixio para o platô, o que é consistente com o aumento de rugosidade. O sub-bosque é mais denso no baixio e menos denso na campinarana alta. Os primeiros 5m de dossel superior (abaixo do retorno mais alto em cada incremento horizontal de 1m) contêm 54-60% da área foliar da floresta. Os primeiros 10m de dossel superior contêm 79-86% da área foliar. A abertura do dossel e o LAI (médias por transecto de 150m) não variam entre os quatro ambientes. Ao longo do ano, ocorreram três mudanças significativas no LAI quando os ambientes foram analisados em conjunto. Primeiro, houve aumento de 2,9% de 15/Mar a 15/Ago/2015 (mês mais chuvoso até o primeiro mês seco); depois houve queda de 2,0% de 15/Ago a 15/Out/2015 (os meses mais secos do El Niño de 2015); e finalmente houve aumento de 3,7% durante a retomada das chuvas no período 15/Out/2015 a 15/Jan/2016. Entre março de 2015 e março de 2016 houve um aumento pequeno, mas significativo do LAI (3% ±2%). Não houve mudança sazonal do LAI no sub-bosque (1 a 6m e 1 a 11m do chão). O conjunto dos 24 transectos dos quatro ambientes, a amplitude temporal do LAI entre a menor e a maior das 13 médias mensais foi apenas 4,8%, indicando que o LAI, sozinho, teria pouca influência sobre a sazonalidade da capacidade fotossintética do dossel, mesmo neste ano de El Niño severo. O histograma de frequências de classes de LAI, obtido para os 900 intervalos de 1m ao longo dos seis transectos de cada ambiente, teve cauda superior truncada em todos os ambientes e todos os meses, indicando saturação na detectabilidade de valores altos de LAI. Portanto, a variação sazonal de LAI foi provavelmente subestimada. Esta saturação também pode impedir a detecção de diferenças LAI entre os ambientes.

The general aim of this thesis was to investigate the mechanisms that determine variation in Al accumulation among tropical woody plants. The focus of the study variation among populations of the well-studied Al accumulator Melastoma malabathricum, but this was coupled with sampling 50 tree species growing on the 50 ha forest dynamics plot at Pasoh Forest Reserve in Peninsular Malaysia in order to gain a perspective on Al accumulation at a community scale. I sampled mature leaves and seeds of M. malabathricum from 20 populations growing in six habitats across Peninsular Malaysia. Concentrations of Al, N, P, K, Ca and Mg were determined in air-dried leaves and the soil from each site. The seeds were used to generate cohorts of seedlings that were grown in hydroponic solutions amended with Al in the form of 1.0 mM AlCl3. Foliar Al concentrations varied significantly among populations, but were not consistently different among plants growing in different habitats and showed no relationship to total or exchangeable Al concentrations in soils collected at the 20 sites. Similarly, foliar Al concentrations in seedlings grown in the presence of Al differed significantly among source populations, but values did not correlate with foliar Al concentrations in wild plants from parent populations. Mean foliar Al concentration in wild plants was positively correlated with foliar Ca concentration, and with total soil Ca and Mg concentrations, across the 20 populations. Furthermore, total dry mass and relative growth rates were significantly greater for seedlings that had received Al in the growth medium than for seedlings that had received no Al. The growth response to Al addition varied among populations of M. malabathricum, and relative growth rate in response to Al addition was greater for populations that accumulated higher foliar Al concentrations. In a further experiment, increasing Al concentrations from In a further experiment, increasing Al concentrations from 0 to 2.0 mM in the nutrient solution increased rates of growth, but growth declined at 5.0 mM Al. The responses to Al addition varied among populations for growth, photosynthesis, respiration, carbon allocation, and foliar P, Ca, and Mg concentrations. The rates of photosynthesis and respiration, and total nonstructural carbohydrate concentrations, were higher for seedlings grown in the presence of 2.0 mM Al in the nutrient solution than in the absence of Al, while lignin concentration in roots decreased. These results suggest that Al addition stimulate growth stimulation by increasing rates of photosynthesis and respiration, resulting in higher non-structural carbohydrate concentrations. Increased allocation of photosynthate to root systems coupled with their lower lignification results in enhanced nutrient uptake (particularly P, Ca and Mg), which contributes to enhanced whole-plant growth. To test the prevalence of Al accumulation at the community scale I sampled 50 tree species growing on the 50 ha Forest Dynamics Plot at Pasoh Forest Reserve in Peninsular Malaysia. Twenty two species possessed foliar Al concentrations that exceeded a value of 2.3 mg g-1 Al dry mass, which is a suitable threshold for detecting Al accumulators in Southeast Asian forests. A phylogenetic signal was detected for foliar concentrations of Al and other elements, suggesting that more closely related species have more similar values of these traits. A canonical correspondence analysis (CCA) revealed that soil Al concentrations have limited influence on the fine-scale distribution of the tree species sampled at Pasoh. I conclude that the distribution of differences in the expression of Al accumulation among populations of M. malabathricum and the distribution of Al accumulator species within a tree community growing at one site are uncoupled from soil Al concentrations, but may be linked to other soil properties such as Ca and Mg concentrations. When supplied in nutrient solutions, Al promotes the growth of the Al accumulator M. malabathricum through a physiological mechanism that includes up-regulation of photosynthetic and respiration rates. The functional significance of this growth response for plants growing under natural conditions in the field requires further investigation.

In tropical algebras we substitute min or max for the typical addition and then substitute addition for multiplication. A dot product representation of a graph assigns each vertex of the graph a vector such that two edges are adjacent if and only if the dot product of their vectors is greater than some chosen threshold. The resultS of creating dot product representations of graphs using tropical algebras are examined. In particular we examine the tropical dot product dimensions of graphs and establish connections to threshold graphs and the threshold dimension of a graph.

Mechanisms of tropical Pacific climate variability and change are studied in numerical experiments of future anthropogenic global warming (AGW), the Last Glacial Maximum (LGM) 21,000 years ago, and decadal variability (PDV). According to these mechanisms the equatorial Pacific does not become either El Niño- or La Niña-like as the tropics warm up in response to increasing greenhouse gases. Because humidity increases much faster than precipitation as the tropical atmosphere warms up, theory and models anticipate a slowing-down of the Walker circulation in order to keep a balanced flow of water vapor into areas of convection. On long time scales characteristic of climate change, ocean dynamics oppose these changes in the Walker circulation. First, equatorial adjustment theory indicates that changes in the Walker circulation are not amplified via the Bjerknes feedback, as during El Niño or La Niña events. Second, during AGW, the ocean becomes more thermally stratified resulting in enhanced cooling of the equatorial cold tongue opposing the warming there. These ideas can be applied to interpret proxies of the LGM for which El Niño and La Niña analogies have been made. However, the LGM tropics are not an opposite analogue to future AGW because the Walker circulation is also sensitive to changes in the geography of the Maritime continent associated with lower sea level. Models simulate a stronger Walker circulation when the tropics cool in order to compensate for the decrease in moisture due to a cooler/drier atmosphere. However, this response is opposed by a weakening of the ascending branch of the Walker circulation because convection is suppressed over vast areas of the Maritime Continent exposed due to lower sea level. In general, the patterns of warming or cooling for AGW and LGM are not El Niño- or La Niña-like because of the opposing mechanisms presented here. As such, adherence to an ENSO analogy for interpreting tropical Pacific climate change can lead to serious misconceptions. However, proxies of the thermocline tilt can provide unequivocal evidence of changes in the Walker circulation because the pressure gradient associated with the thermocline tilt has to be in balance with the trade winds at all timescales.

Bulls of various breedtypes including Angus (Bos taurus), Bonsmara (Sanga X Bos taurus), Brahman (Bos indicus), Romosinuano (Criollo), Tuli (Sanga) and Wagyu (Japanese Bos taurus) were utilized to evaluate the influence of tropical adaptation on adrenal and testicular function. The objectives were to determine if tropical adaptation influenced: a) response to management stressors, b) organ and gland weights, adrenal and testis StAR and P450 content and total adrenal, medullary and cortical areas, c) basal and hCG-induced testosterone and d) testis and epididymal sperm concentrations. Blood samples were obtained within 5 min before and after transportation and during restraint every 15 min for 6 h to evaluate cortical response. Angus, Brahman and Romosinuano bulls were slaughtered following sexual maturity. Cortical responses to transportation and restraint were not influenced by tropical adaptation. Response to these stressors could be categorized into high responders (Angus, Brahman), intermediate responders (Romosinuano, Tuli) and low responders (Wagyu, Bonsmara). Tropically-adapted breedtypes were not categorized into a single group; therefore, cortical responses to management stressors were influenced by breedtype, but not by tropical adaptation. Most organ and gland weights (actual weight and weight corrected for BW) and the steroid precursors, StAR and P450, were not influenced by tropical adaptation, but were by breedtype. Paired adrenal gland weight, total adrenal area, medullary and cortical areas were influenced by tropical adaptation. Tropically-adapted breedtypes had lighter glands and smaller areas than the temperate Bos taurus breedtypes. All breedtypes except Wagyu had similar basal concentrations of plasma testosterone prior to hCG administration; therefore, basal testosterone was not influenced by tropical adaptation, but only by breedtype. Wagyu had greater basal concentrations of testosterone than other breedtypes. Testosterone concentrations following hCG administration was similar between adaptation groups and breedtypes. As expected, testis and epididymal sperm concentrations were influenced by tropical adaptation. Tropically-adapted breedtypes had greater testicular and epididymal sperm concentrations than the temperate Bos taurus breedtypes during the summer months. In summary, adrenal weight and area and testicular and epididymal sperm concentrations were influenced by tropical adaptation. Cortical response to management stressors, basal testosterone and StAR and P450 content were influenced by breedtype, not tropical adaptation.

Convective clouds in the tropics can be grouped into three categories: shallow clouds with cloud-top heights near 2 km above the surface, mid-level congestus clouds with tops near the 0°C level, and deep convective clouds capped by the tropopause. This trimodal distribution is visible in cloud data from the Geoscience Laser Altimeter System (GLAS), carried aboard the Ice, Cloud, and land Elevation Satellite (ICESat), as well as in precipitation data from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). Fractional areal coverage (FAC) data is calculated at each of the three levels to describe how often optically thick clouds or precipitation are seen at each level. By dividing the FAC of TRMM PR-observed precipitation by the FAC of thick GLAS/ICESat-observed clouds, the fraction of clouds that are precipitating is derived. The tropical mean precipitating cloud fraction is low: 3.7% for shallow clouds, 6.5% for mid-level clouds, and 24.1% for deep clouds. On a regional basis, the FAC maps created in this study show interesting trends. The presence of nonphysical answers in the PCF graphs, however, suggest that greater study with more precise instruments is needed to properly understand the true precipitating cloud fraction of the tropical atmosphere.

Convective clouds in the tropics can be grouped into three categories: shallow clouds with cloud-top heights near 2 km above the surface, mid-level congestus clouds with tops near the 0°C level, and deep convective clouds capped by the tropopause. This trimodal distribution is visible in cloud data from the Geoscience Laser Altimeter System (GLAS), carried aboard the Ice, Cloud, and land Elevation Satellite (ICESat), as well as in precipitation data from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). Fractional areal coverage (FAC) data is calculated at each of the three levels to describe how often optically thick clouds or precipitation are seen at each level. By dividing the FAC of TRMM PR-observed precipitation by the FAC of thick GLAS/ICESat-observed clouds, the fraction of clouds that are precipitating is derived. The tropical mean precipitating cloud fraction is low: 3.7% for shallow clouds, 6.5% for mid-level clouds, and 24.1% for deep clouds. On a regional basis, the FAC maps created in this study show interesting trends. The presence of nonphysical answers in the PCF graphs, however, suggest that greater study with more precise instruments is needed to properly understand the true precipitating cloud fraction of the tropical atmosphere.