Genetic improvement has been an integral part of loblolly pine plantation forestry in southern United States for about 60 years with focus on improving timber yield, wood quality, and pest and disease resistance. Advances in techniques of genetic selection, breeding, and propagation of planting material have made it possible to achieve genetic gains that are likely to result in significant changes in loblolly pine stand dynamics. Height-age relationships, height and diameter relationships and distributions, and intraspecific competition were investigated in second generation open-pollinated, controlled-pollinated, and clonal loblolly pine with an objective of characterizing the nature and magnitude of changes in these characteristics due to genetic improvement and clonal forestry. Genetic improvement and/or clonal forestry had no practical effect on parameters of the height-age and height-diameter relationships beyond the effect on the asymptote parameter of the Chapman-Richards and Korf equations that were used to model these relationships. Genetic improvement resulted in an increase in the mean of height distribution without a corresponding increase in the mean of the diameter distribution, but had no effect the variance and skewness of the distributions. Thus, growth and yield models in which basal area is a function of height at a specific age (site index) are likely to over predict genetic gains in basal area growth and volume yield. Increase in stand density resulted in an increase in variance of the diameter distribution of non-clonal stands but had no effect on the variance of the diameter distribution of clonal stands. Thus, diameter distribution of clonal stands may differ from that of non-clonal stands after crown closure despite the distributions not being different before and during early stages of crown closure. This study also evaluated methods that may be used to predict height growth of new genetic varieties and those that may be used to asses intraspecific competition in forest stands. Mixed-model approach of calibrating a height-age relationship to a new loblolly pine clone gave biased estimates for clones that were at the extremes of the distribution of the groups. The use of maximum likelihood with simulated annealing (MLSA) to evaluate competitive interactions among trees in loblolly pine stands gave non-unique estimates of optimum competitor selection radius. A simpler technique that uses Pearson correlations was proposed and was found to work better than MLSA. / Ph. D.

Doenças como a dengue, chikungunya, Zika e febre amarela urbana são causadas por patógenos transmitidos pela picada de fêmeas infectadas de Ae. aegypti e Ae. albopictus. Fatores bióticos, como a competição na fase larval, e abióticos, como a variação da temperatura, provocam alterações no ciclo de desenvolvimento dessas espécies. O presente estudo avaliou os efeitos da competição intraespecífica e da temperatura na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus. Os objetivos do trabalho foram: comparar o tamanho das fêmeas de Ae. aegypti e Ae. albopictus oriundas de criadouros com baixa e alta competição intraespecífica; avaliar o efeito da competição intraespecífica na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, à 25ºC e analisar o padrão da atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, sob diferentes temperaturas (20ºC, 25ºC e 30ºC). As colônias dos mosquitos utilizados nos experimentos são provenientes da FIOCRUZ-RJ. Para o experimento de competição, larvas de ambas as espécies foram criadas sob condições de alta (100 larvas) e baixa (20 larvas) densidades. Para isso, foram utilizadas 14 bacias preenchidas com 500 ml de água e 0,2 g de ração para peixes. Após a competição, as fêmeas oriundas de cada densidade foram transferidas para incubadoras para a realização da análise da atividade locomotora. Após a atividade, verificou-se o tamanho dos adultos oriundos de cada densidade larvária, por meio da medição das asas de cada fêmea. Para a análise da atividade locomotora sob diferentes temperaturas, as fêmeas utilizadas foram desenvolvidas em ambiente com quantidade de ovos similares. Foi utilizado o mesmo procedimento para análise da atividade do experimento anterior, porém, cada experimento ocorreu sob diferentes temperaturas: 20°C, 25°C e 30°C. Para a análise dos dados obtidos foram utilizados os testes T e ANOVA multifatorial. Para o experimento de competição, fêmeas de ambas as espécies oriundas de competição de baixa densidade foram maiores do que as oriundas de desenvolvimento sob alta densidade larvária. A atividade das fêmeas de Ae. aegypti e Ae. albopictus de ambas as densidades foi muito semelhante, sugerindo que fêmeas menores tem atividade equivalente à de fêmeas maiores. Já no experimento que avaliou a atividade das fêmeas sob faixas térmicas distintas, notou-se que, em Ae. aegypti, houve diferença significativa na atividade total sob 20°C quando comparadas a 25°C e 30°C, demonstrando que a temperatura mais baixa foi limitante para a atividade desta espécie. Houve diferenças em algumas médias avaliadas na atividade de Ae. albopictus, porém, esta espécie pareceu ter sido menos influenciada com a variação da temperatura. Análises estatísticas confirmaram que as fêmeas de Ae. aegypti respondem de forma distinta das fêmeas de Ae. albopictus quando as temperaturas foram modificadas. O presente estudo ajuda a esclarecer alguns aspectos relacionados ao comportamento dos mosquitos Ae. aegypti e Ae. albopictus, que são considerados de grande importância para a saúde pública. / Diseases such as dengue, chikungunya, Zika and urban yellow fever are caused by pathogens transmitted by the bites of infected females of Ae. aegypti and Ae. albopictus. Biotics factors essentially competition on larval stages, and abiotics factors, for instance, temperature variation, occasion adjustments on development cycle of these species. The present study evaluated the effects of intraspecific competition and temperature on locomotor activity of Ae. aegypti and Ae. albopictus. The aims of this study were: to compare the size of females Ae. aegypti and Ae. albopictus from breeding sites with low and high intraspecific competition; to evaluate the effect of intraspecific competition on locomotor activity of virgin females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark at 25°C and to analyze the pattern of the locomotor activity of virgins females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark, under different temperatures (20ºC, 25ºC e 30ºC). The mosquitoes colonies used on experiment are from FIOCRUZ-RJ. For the competition experiment, larvae from both species were raised under conditions of high (100 larvae) and low (20 larvae) densities. For this 14 containers filled with 500 ml of water and 0,2 g of fish food were used. After the competition, the females from each density were transferred to incubators to perform locomotor activity analysis. After the activity, the size of adult from each larval density, were verified by wings measurement of each female. For the analysis of the locomotor activity under different temperatures, the females used were developed in an environment with similar amount of eggs. The same procedure was used to the analyze the activity of the previous experiment, however, each experiment happened under different temperatures: 20°C, 25°C e 30°C. For the analysis of the obtained data were applied T tests and ANOVA multivariate. For the competition experiment, females of both species from low density of competition were longer than females from competition under high larval density. The activity of females of Ae. aegypti and Ae. albopictus from both densities was very similar, suggesting that smaller females have equivalent activity to that of larger females. In the experiment that evaluated the activity of females under different thermal bands, it was noticed that in Ae. aegypti there was significant difference in total activity under 20°C when compared with 25°C and 30°C degrees, demonstrating the lower temperature was limiting to activity for this species. There were differences in some averages evaluated in Ae. albopictus activity, however, this species seemed to have been less influenced with the temperature variation. Statistical analysis confirmed that females of Ae. aegypti respond differently than females of Ae. albopictus when the temperatures were modified. The present study helps to clarify some aspects about the behavior of mosquitoes Ae. aegypti and Ae. albopictus which are considered of great concern for public health.

Doenças como a dengue, chikungunya, Zika e febre amarela urbana são causadas por patógenos transmitidos pela picada de fêmeas infectadas de Ae. aegypti e Ae. albopictus. Fatores bióticos, como a competição na fase larval, e abióticos, como a variação da temperatura, provocam alterações no ciclo de desenvolvimento dessas espécies. O presente estudo avaliou os efeitos da competição intraespecífica e da temperatura na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus. Os objetivos do trabalho foram: comparar o tamanho das fêmeas de Ae. aegypti e Ae. albopictus oriundas de criadouros com baixa e alta competição intraespecífica; avaliar o efeito da competição intraespecífica na atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, à 25ºC e analisar o padrão da atividade locomotora de fêmeas virgens de Ae. aegypti e Ae. albopictus, sob regime de 12 horas de claro e 12 horas de escuro, sob diferentes temperaturas (20ºC, 25ºC e 30ºC). As colônias dos mosquitos utilizados nos experimentos são provenientes da FIOCRUZ-RJ. Para o experimento de competição, larvas de ambas as espécies foram criadas sob condições de alta (100 larvas) e baixa (20 larvas) densidades. Para isso, foram utilizadas 14 bacias preenchidas com 500 ml de água e 0,2 g de ração para peixes. Após a competição, as fêmeas oriundas de cada densidade foram transferidas para incubadoras para a realização da análise da atividade locomotora. Após a atividade, verificou-se o tamanho dos adultos oriundos de cada densidade larvária, por meio da medição das asas de cada fêmea. Para a análise da atividade locomotora sob diferentes temperaturas, as fêmeas utilizadas foram desenvolvidas em ambiente com quantidade de ovos similares. Foi utilizado o mesmo procedimento para análise da atividade do experimento anterior, porém, cada experimento ocorreu sob diferentes temperaturas: 20°C, 25°C e 30°C. Para a análise dos dados obtidos foram utilizados os testes T e ANOVA multifatorial. Para o experimento de competição, fêmeas de ambas as espécies oriundas de competição de baixa densidade foram maiores do que as oriundas de desenvolvimento sob alta densidade larvária. A atividade das fêmeas de Ae. aegypti e Ae. albopictus de ambas as densidades foi muito semelhante, sugerindo que fêmeas menores tem atividade equivalente à de fêmeas maiores. Já no experimento que avaliou a atividade das fêmeas sob faixas térmicas distintas, notou-se que, em Ae. aegypti, houve diferença significativa na atividade total sob 20°C quando comparadas a 25°C e 30°C, demonstrando que a temperatura mais baixa foi limitante para a atividade desta espécie. Houve diferenças em algumas médias avaliadas na atividade de Ae. albopictus, porém, esta espécie pareceu ter sido menos influenciada com a variação da temperatura. Análises estatísticas confirmaram que as fêmeas de Ae. aegypti respondem de forma distinta das fêmeas de Ae. albopictus quando as temperaturas foram modificadas. O presente estudo ajuda a esclarecer alguns aspectos relacionados ao comportamento dos mosquitos Ae. aegypti e Ae. albopictus, que são considerados de grande importância para a saúde pública. / Diseases such as dengue, chikungunya, Zika and urban yellow fever are caused by pathogens transmitted by the bites of infected females of Ae. aegypti and Ae. albopictus. Biotics factors essentially competition on larval stages, and abiotics factors, for instance, temperature variation, occasion adjustments on development cycle of these species. The present study evaluated the effects of intraspecific competition and temperature on locomotor activity of Ae. aegypti and Ae. albopictus. The aims of this study were: to compare the size of females Ae. aegypti and Ae. albopictus from breeding sites with low and high intraspecific competition; to evaluate the effect of intraspecific competition on locomotor activity of virgin females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark at 25°C and to analyze the pattern of the locomotor activity of virgins females of Ae. aegypti and Ae. albopictus, under regime of 12 hours of light and 12 hours of dark, under different temperatures (20ºC, 25ºC e 30ºC). The mosquitoes colonies used on experiment are from FIOCRUZ-RJ. For the competition experiment, larvae from both species were raised under conditions of high (100 larvae) and low (20 larvae) densities. For this 14 containers filled with 500 ml of water and 0,2 g of fish food were used. After the competition, the females from each density were transferred to incubators to perform locomotor activity analysis. After the activity, the size of adult from each larval density, were verified by wings measurement of each female. For the analysis of the locomotor activity under different temperatures, the females used were developed in an environment with similar amount of eggs. The same procedure was used to the analyze the activity of the previous experiment, however, each experiment happened under different temperatures: 20°C, 25°C e 30°C. For the analysis of the obtained data were applied T tests and ANOVA multivariate. For the competition experiment, females of both species from low density of competition were longer than females from competition under high larval density. The activity of females of Ae. aegypti and Ae. albopictus from both densities was very similar, suggesting that smaller females have equivalent activity to that of larger females. In the experiment that evaluated the activity of females under different thermal bands, it was noticed that in Ae. aegypti there was significant difference in total activity under 20°C when compared with 25°C and 30°C degrees, demonstrating the lower temperature was limiting to activity for this species. There were differences in some averages evaluated in Ae. albopictus activity, however, this species seemed to have been less influenced with the temperature variation. Statistical analysis confirmed that females of Ae. aegypti respond differently than females of Ae. albopictus when the temperatures were modified. The present study helps to clarify some aspects about the behavior of mosquitoes Ae. aegypti and Ae. albopictus which are considered of great concern for public health.

This collection of studies was designed to understand the mechanisms and consequences of competition among early life stages of red drum (Sciaenops ocellatus), with a special attention to asymmetric competition and multiple-breeding strategy of parents. The overall hypotheses were that (1) red drum larvae show behavioral interactions, and the magnitude of these interactions is explained by the sizes of the competing individuals, (2) red drum larvae compete for food and habitat use, and the competition is asymmetric as determined by size and behavioral interactions, and (3) the parents can reduce negative effects of competition among larvae and increase larval survival by altering their multiple-spawning traits. The laboratory experiments showed the existence of sociality in red drum larvae. The magnitudes of aggressive behavior, vigilant behavior and shoaling behavior were explained by a combination of absolute and relative phenotypes of competing individuals, such as body lengths and body condition. A new method of combining the laboratory experiments and the foraging theory disentangled interference competition for food from exploitative competition, revealing that both absolute and relative body lengths of competing individuals influence feeding efficiencies. In addition, vigilant behavior decreased feeding efficiency regardless of body sizes. The competitor size and behavioral interactions between individuals had different effects on competition for habitat use: the existence of larger individuals prevented the newly settled larvae from entering preferred habitats, whereas the aggressive behavior from the occupants of preferred habitats moved newly settled larvae to the unpreferred habitats. Finally, computer simulations using an individual-based model revealed that as interference competition among larvae increased, the number of spawning events and the spawning interval of the parents increased to lessen competition and maximize total survival of offspring. / text

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-24T12:56:34Z No. of bitstreams: 2 Dissertação - Tainã Lucas Andreani - 2017.pdf: 3737114 bytes, checksum: b4362aa48e6eb415bd815100d5261817 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-04-24T12:57:17Z (GMT) No. of bitstreams: 2 Dissertação - Tainã Lucas Andreani - 2017.pdf: 3737114 bytes, checksum: b4362aa48e6eb415bd815100d5261817 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-04-24T12:57:17Z (GMT). No. of bitstreams: 2 Dissertação - Tainã Lucas Andreani - 2017.pdf: 3737114 bytes, checksum: b4362aa48e6eb415bd815100d5261817 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / During the reproductive season, the anurans crowd in sites where they can constitute vocalization assemblies. Different social contexts occur during these occasions, where the male individuals modify actively their behavior between attracting the female individuals and defending their territory and resources. Of huge importance for the social interaction of anurans, their vocalization acts as a tool for studies about sexual selection and aggressive interactions. Thereby, we aimed to evaluate the temporal variation of the advertisement and aggressive calls of Hypsiboas goianus over the course of 10 reproductive seasons that amount 18 years of time-lapse in a population and the acoustic answer of focal males in repeated interactions with conspecific competitors. The records were performed in Floresta Nacional de Silvânia, city of Silvânia, Goiás, Brazil. For temporal analysis, five advertisement calls and five aggressive calls – at most – of each individual were analyzed. Temporal parameters (duration of call, number and duration of pulses, call and pulse repetition rate) and a spectral parameter (dominant frequency) were extracted. To analyze the competitive interactions, the repetition rates of the advertisement, aggressive and total calls were considered as a response to the conspecific advertisement calls offered in 10 periods of playback. The acoustic parameters do not diverge inside the temporal lapse that was analyzed. The individuals modified their acoustic behavior with the simulation of the arrival of a new competitor during the first interactions with the playback (playback 1 e 2), afterward, the repetition taxes of calls were similar to those observed in the pre-playback period were, once again, emitted. / Na estação reprodutiva, os anuros se aglomeram em sítios onde formam assembléias de vocalização. Diferentes contextos sociais ocorrem nessas ocasiões, onde os machos modificam ativamente seus comportamentos entre atrair fêmeas e defender seus territórios e recursos. Por exercerem grande importância para as interações sociais de anuros, suas vocalizações apresentam uma ferramenta para estudos envolvendo seleção sexual e interações agressivas. Dessa forma, o presente trabalho objetivou avaliar a variação temporal dos cantos de anúncio e agressivos de Hypsiboas goianus ao longo de 10 estações reprodutivas que perfazem 18 anos de intervalo temporal em uma população e a resposta acústica de machos focais em seguidas interações a um competidor coespecífico. As gravações foram realizadas na Floresta Nacional de Silvânia, município de Silvânia, Goiás, Brasil. Para a análise temporal, foram analisados, no máximo, cinco cantos de anúncio e cinco cantos agressivos de cada indivíduo. Foram extraídos parâmetros temporais (duração do canto, número e duração de pulsos, taxa de repetição de cantos e de pulsos) e um parâmetro espectral (frequência dominante). Para as análises das interações competitivas, as taxas de repetição dos cantos de anúncio, agressivos e total foram consideradas em repostas a cantos coespecíficos de anúncio ofertados em 10 períodos de playback. Os parâmetros acústicos não diferiram dentro do intervalo de tempo analisado. Os indivíduos alteraram seu comportamento acústico com a simulação da chegada de um novo competidor durante as primeiras interações com o playback (playback 1 e 2), posteriormente voltando a emitir taxas de repetição de cantos similares à aquelas observadas no período pre-playback.

Orientador: João Frederico da Costa Azevedo Meyer / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-23T13:46:24Z (GMT). No. of bitstreams: 1 Santos_CarlosFrankLimados_M.pdf: 3104358 bytes, checksum: a690d16041a50b1c06291d1d64615b29 (MD5) Previous issue date: 2013 / Resumo: O propósito deste trabalho é desenvolver uma modelagem matemática que descreverá computacionalmente o convívio entre duas espécies competidoras sem característica migratória diante da variação de densidade de vegetação. As equações utilizadas nesta modelagem incluíram os fenômenos de difusão de vegetação, processos de dispersão populacional, dinâmicas vitais e um decaimento proporcional a variação de densidade de mata, no sentido de que quanto maior a densidade de mata menor o decaimento populacional quanto menor a densidade de mata maior a mortalidade populacional. Para as espécies competidoras usaremos as clássicas modelagem do tipo Lotka-Volterra (não- linear) combinado a equação diferenciais parciais de difusão-advecção. Primeiramente faremos a descrição do modelo matemático e a descrição do domínio visando o uso do método de diferenças finitas para o espaço combinados a um modelo de Crank-Nicolson no tempo. Em seguida, desenvolveremos um algoritmo em ambiente MATLAB , que aproxima as soluções relativas a difusão de vegetação e a cada população em cada ponto e ao longo do tempo considerado nas simulações. Por fim, foram obtidos resultados gráficos que foram analisados o efeito da recuperação da mata no convívio das espécies competidoras consideradas. De modo que se disponha de ferramentas mais acessíveis a profissionais e pesquisadores ligados aos estudos de ecologia matemática e meio ambiente, bem como aos responsáveis pelas adoções de medidas de emergências e contingências de áreas destruídas pelas ações antrópicas / Abstract: The main objective of this work is that of obtaining an adequate mathematical model and, consequently, a computational algorithm to describe the interaction between two competing species in face of a density variation in vegetation. Population dispersal and dynamics and the presence of a term relating the loss of vegetation density to higher mortality for both competing species must be considered, as well as the inverse: a raise in vegetation density is bound to increase the survival of species. In order to describe the interaction between vegetation and animals, a classic Lotka-Volterra system is used, coupled with the use of the diffusion-reaction partial differential equation for all three participants considered in the model: vegetation density and both animal species. For the interacting animal species, no migration is considered, although the possibility of a preferential direction similar to an advective component is permitted in the dispersal of plants. Numerical discretization include centered finite differences in order to obtain second order approximations in space variables, as well as a Crank-Nicolson method, also second order, for approximations in time. In order to qualitatively analyze possible results, a MATLAB environment was used, with the possibility of exhibiting graphical results based on the numerical ones. This is done in order to create a numerical auxiliary tool which can be used by researchers and professional agents in the evaluation of ecological and environmental policies and decisions, as well as the description of some of the effects of anthropic a actions / Mestrado / Matematica Aplicada / Mestre em Matemática Aplicada

1. The success of invasive species is often thought to be due to release from natural enemies. This hypothesis relies on the assumption that species are regulated by top-down forces in their native range and implies that species are likely to be regulated by bottom-up forces in the invasive range. Neither of these assumptions has been consistently supported with insects, a group which include many highly destructive invasive pest species. 2. Winter moth (Operophtera brumata) is an invasive defoliator in North America that appears to be regulated by mortality in the larval stage in its invasive range. To assess whether regulation in the invasive range is caused by top-down or bottom-up forces, we sought to identify the main causes of larval mortality. 3. To measure the importance of different sources of winter moth larval mortality, we used observational and manipulative field studies to measure dispersal, predation, parasitism, disease. We measured the response of larval dispersal in the field to multiple aspects of foliar quality, including total phenolics, pH 10 oxidized phenolics, trichome density, total nitrogen, total carbon, and carbon-nitrogen ration. We also used manipulative laboratory studies to measure the presence of cannibalism and dispersal. 4. Tree-level declines in density were driven by density-dependent larval dispersal of early instars with very little mortality caused by other factors. Later instar larvae dispersed at increased rates from previously damaged vs. undamaged foliage, and field larval dispersal rates were related to proportion of oxidative phenolics in 2015, suggesting that larval dispersal may have been mediated by an induced decline in foliar quality. 5. We conclude that winter moth population densities are regulated in New England by density-dependent larval dispersal possibly mediated by phenolic oxidative capacity. The suggested role of host plant quality in mediating dispersal means that winter moth population densities in New England appear to be regulated by bottom up forces, aligning with the assumptions of the natural enemy release hypothesis. This is the first study known to the authors presenting data showing a negative effect on insect herbivore performance from pH 10 oxidized phenolics.

Many researchers have highlighted the dire prospects for biodiversity in fragmented agricultural landscapes and stressed the need for increasing the area of, and connectivity between, natural ecosystems. Some have advocated the use of naturally regenerating forest ecosystems for sequestering atmospheric carbon, with opportunities for dual restoration and carbon benefits. However, no studies have explicitly explored the feasibility of obtaining such dual benefits from a regenerating woody ecosystem. This thesis aims to provide a detailed assessment of the restoration and carbon potential of Brigalow regrowth, an extensive naturally regenerating ecosystem throughout the pastoral regions of north eastern Australia. It combines observational, experimental and modelling techniques to describe the agricultural legacy of pastoral development, identify constraints to restoration and explore methods to remove these constraints. A review of existing ecological knowledge of Brigalow ecosystems is provided in chapter 3, along with discussion of policy and socio-economic issues that are likely to influence how and to what extent regrowth is utilised for restoration and carbon purposes in the Brigalow Belt. The review found restoring regrowth is likely to have benefits for a wide range of native flora and fauna, including the endangered bridled nailtail wallaby. Knowledge gaps exist relating to the landscape ecology of Brigalow regrowth and the impacts of management and climate change on carbon and restoration potential. Also, a conflict exists between short-term carbon sequestration and long-term restoration goals. Regional demand for high biomass regrowth as a carbon offset is likely to be high but ambiguities in carbon policy threaten to diminish the use of natural regrowth for reforestation projects. A large cross-sectional study of regrowth is presented in chapter 4. Data were analysed using multi-level / hierarchical Bayesian models (HBMs). Firstly, we found that repeated attempts at clearing Brigalow regrowth increases stem densities and densities remain high over the long term, particularly in high rainfall areas and on clay soils with deep gilgais. Secondly, higher density stands have slower biomass accumulation and structural development in the long term. Spatial extrapolations of the HBMs indicated that the central and eastern parts of the study region are most environmentally suitability for biomass accumulation, however these may not correspond to the areas that historically supported the highest biomass Brigalow forests. We conclude that carbon and restoration goals are largely congruent within regions of similar climate. At the regional scale however, spatial prioritisation of restoration and carbon projects may only be aligned in areas with higher carbon potential. Given the importance of stem density in determining restoration and carbon potential, an experimental thinning trial was established in dense Brigalow regrowth in southern Queensland (chapter 5). Four treatments were applied in a randomised block design and growth and mortality of a subset of stems was monitored for two years. Data were analysed using mixed-effects models and HBMs and the latter were subsequently used to parameterise an individual-based simulation model of stand structural development and biomass accumulation over 50 years. The main findings of this study were that growth and mortality of stems is influenced by the amount of space available to each stem (a neighbourhood effect) and that thinning accelerates structural development and increases woody species diversity. The examination of neighbourhood effects is taken further by considering drought-related mortality in a Eucalyptus savanna ecosystem (chapter 6). For this work a multi-faceted approach was employed including spatial pattern analyses and statistical models of stem survival to test three competing hypotheses relating to neighbourhood effects on drought related tree mortality. The main finding of this study was that neighbour density and microsite effects both influence drought-related mortality and the observed patterns can readily be explained by an interaction between these two factors. As a whole, this thesis contributes the following scientific insights: (1) restoration and carbon goals may be aligned for naturally regenerating woody ecosystems, but the degree of goal congruence will vary across the landscape in question, (2) while some woody ecosystems retain an excellent capacity to regenerate naturally, the agricultural legacy may still have long term effects on restoration and carbon potential, (3) neighbourhood effects that operate at the stem scale strongly influence dynamics at the ecosystem scale.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Decreased variability in the distribution of plants on line and increased nitrogen fertilization efficiency are important order management for high yields in corn. The objective of this study was to evaluate the quality of sowing provided by two types of planting the spatial arrangement of plants and quantify the effect of spacing error between plants in plant vigor and productivity of maize and also the efficient use of dose nitrogen variable (DVN) in the different cultivation systems. The study was conducted in Carazinho-RS in the agricultural years 2012/13 (Experiment I) and 2013/14 (Experiment II) with the treatments: a) mechanical seeder feeder with horizontal discs (SM); b) air seeder and seeds organizer (SP); c) air seeder and seeds organizer coupled to tractor with autopilot and RTK signal (SPP). The study was conducted in macro plots of 6,600 and 990m2 for the experiments I and II respectively and in micro plots for the study plant to plant with plots of 5.4 m2. Still, a case study was directed in the form of transects of 5 plants which investigated the effect of spacing error between plants vigor and productivity of the crop. The evaluation of DVN efficiency was held in Experiment II area, the main tracks for cultivation systems, the DVN and the fixed dose of nitrogen (DFN) divided into the main tracks. The sowing quality was affected by the type of seed feeder and had no effect on the use of the autopilot, and the best distribution obtained in treating SP, with a CV of 25.4 and 19.7% for the experiments I and II respectively. The best spatial arrangement of plants in the SP in relation to MS, with a reduction of approximately 16% in the CV spacing between plants in both experiments in the macro share resulted in an increase of 12.5 and 6.8% in productivity, respectively. Furthermore, the use of autopilot and RTK signal (SPP) increased by 7% relative to the productivity SP in the first experiment. In the study of micro plots, which was evaluating the individual productivity of plants in the planting line, the SP there was only 2% of plants with lower productivity at 8,500 kg ha-1 for the first trial and 10% below 6500 kg ha-1 to II. Already, in the SM the frequency of plants below these productivity was approximately 18% in both experiments, and these results attributed to higher occurrence of dominated plants, which was justified in force assessments plant by NDVI through the uniformity of assessment and of the highest rates in the SP relative to the SM. In the study of DVN in Experiment II, the negative effect that has an unusual distribution of plants was minimized by DVN, however when associated with a more uniform distribution of plants in an environment with greater productive capacity, even in a year with restrictions water productivity is enhanced. In the investigation of error in the distribution of plants through the case study, it was found that the NDVI indices and grain yield are negatively affected for every 10% increase in CV, and the decrease in productivity of 1,356 and 815 kg ha -1 for experiment I and II, respectively, demonstrating the importance of the distribution of the plants near the equidistance lines. / A diminuição da variabilidade na distribuição de plantas na fileira e o aumento da eficiência da fertilização nitrogenada são importantes visando o manejo para altas produtividades na cultura do milho. Objetivou-se com este trabalho avaliar a qualidade de semeadura proporcionada por dois sistemas de semeadora no arranjo espacial de plantas e quantificar o efeito do erro de espaçamento entre plantas na fileira no vigor de planta e na produtividade do milho e ainda a eficiência da utilização da dose variável de nitrogênio (DVN) nos diferentes sistemas de semeadora. O estudo foi desenvolvido em Carazinho-RS nos anos agrícolas 2012/13 (Experimento I) e 2013/14 (Experimento II) sendo os tratamentos: a) semeadora com sistema mecânica e dosador em discos horizontais (SM); b) semeadora com sistema pneumática e organizador de sementes (SP); c) semeadora com sistema pneumático e organizador de sementes acoplado a trator com piloto automático e sinal RTK (SPP). O estudo foi conduzido em parcelas principais de 6.600 e 990m2 para os experimentos I e II, respectivamente e em sub parcelas visando o estudo planta a planta com parcelas de 4,05 m2. Ainda, um estudo de caso foi direcionado na forma de transectos de 5 plantas onde investigou-se o efeito do erro de espaçamento entre plantas na fileira no vigor e na produtividade da cultura. A avaliação da eficiência da DVN foi realizada na área do Experimento II, sendo as faixas principais para os sistemas de semeadora e a DVN e a dose fixa de nitrogênio (DFN) subdividas nas faixas principais. A qualidade de semeadura foi afetada pelo sistema da semeadora não tendo sido observado efeito da utilização do piloto automático, sendo a melhor distribuição obtida no tratamento SP, com um CV de 25,4 e 19,7 % para os experimentos I e II, respectivamente. O melhor arranjo espacial de plantas no SP em relação ao SM, com uma redução de aproximadamente 16 pontos percentuais no CV do espaçamento entre as plantas para os dois experimentos na parcela principal, resultou em incremento de 12,5 e 6,8% na produtividade, respectivamente. Além disso, o uso de piloto automático e sinal RTK (SPP) incrementou em 7 % a produtividade em relação ao SP no primeiro experimento. No estudo em sub parcelas, no qual foi avaliando a produtividade individual de plantas ao longo da fileira de semeadura, no SP observou-se apenas 2% das plantas com produtividade inferior a 8.500 kg ha-1 para o experimento I e 10% abaixo de 6.500 kg ha-1 para o II. Já, no SM a frequência das plantas abaixo destas produtividades foi de aproximadamente 18% para os dois experimentos, sendo estes resultados atribuídos a maior ocorrência de plantas dominadas, o que se justificou nas avaliações de vigor de planta pelo índice de vegetação por diferença normaliza (NDVI), através da uniformidade das avaliações e dos maiores índices no SP em relação ao SM. No estudo da DVN no Experimento II, o efeito negativo que se tem com uma distribuição irregular de plantas foi minimizado pela DVN, no entanto quando associado a uma distribuição de plantas mais uniforme em um ambiente com capacidade produtiva maior, mesmo em um ano com restrições hídricas a produtividade é potencializada. Na investigação do erro na distribuição de plantas através do estudo de caso, constatou-se que os índices de NDVI e a produtividade do milho são afetados negativamente para cada 10% de aumento no CV, sendo o decréscimo na produtividade de 1.356 e 815 kg ha-1 para o experimento I e II, respectivamente, demonstrando-se a importância da distribuição das plantas próximo da equidistância nas fileiras.

Orientador: Márcio Silva Araújo / Resumo: A variação individual no uso de recursos alimentares pode depender de fatores ecológicos como a competição intra e interespecífica, predação, além da diversidade e abundância de recursos. O objetivo deste trabalho foi identificar as causas da variação individual no uso de recursos alimentares em populações do peixe Characidium schubarti, conh’ecido como “charutinho” e descrito como insetívoro bentônico. O estudo foi realizado em riachos de Mata Atlântica no Parque Estadual Carlos Botelho, núcleo São Miguel Arcanjo, região sudeste do Estado de São Paulo. Os charutinhos foram coletados ao longo de transectos em 11 riachos diferentes. Foram coletadas amostras da comunidade de invertebrados bentônicos em cada riacho para a obtenção de estimativas da diversidade e abundância de recursos alimentares. Identificamos e quantificamos todas as possíveis espécies de peixes competidoras (insetívoros bentônicos). Nossos resultados sugerem significativa variação na dieta dos indivíduos de todas as populações, porém com baixo grau de especialização individual. Nós não encontramos efeito significativo da oportunidade ecológica (diversidade de recursos), produtividade secundária (biomassa de recursos) e competição (densidade de charutinhos e competidores) sobre o grau de variação na dieta nas populações estudadas. / Abstract: Individual variation in food resource use can depend on ecological factors such as intra and interspecific competition, predation, and the diversity and abundance of resources. Our main goal in this study was to identify the ecological causes of individual variation in the use of food resources in natural populations of the fish Characidium schubarti, part of a group popularly known as “South American darters”, described as benthic insectivores. The study was conducted in Atlantic Forest streams at the Carlos Botelho State Park, at São Miguel Arcanjo, in the southeast of the state of São Paulo. Specimens were collected along transects in 11 streams. We collected samples from the benthic invertebrate community in each stream to estimate the diversity and abundance of food resources. We identified and quantified all possible competing species of fishes (benthic insectivores). Our results suggest significant variation in the diet of individuals from all populations, however, with a low degree of individual specialization. We found no significant effect of ecological opportunity (resource diversity), secondary productivity (resource biomass) and competition (density of charutinhos and competitors) on the degree of dietary variation in the studied populations. / Mestre