Forests are a critical biome but are under threat from unprecedented global change. The need to understand forest dynamics across spatial, temporal and biological scales has never been greater. Critical to this will be understanding how the demographic rates of individuals translate into patterns of species diversity, biomass and carbon turnover at much larger scales. In this thesis, I present a modelling framework focussed on demography. In Chapter 2, I introduce methods for translating forest inventory data into population models that account for the size-dependency of vital rates and persistent differences in individual performance. Outbreaks of forest pest and pathogens are increasing in frequency and severity, with consequences for biodiversity and forest structure. In Chapter 3, I explore the impact of ash dieback on the community dynamics of a British woodland, describing a spatially explicit individual based model that captures the effect of an opening of the canopy on local competitive interactions. Chapter 4 introduces methods to infer the impact of historical deer herbivory on the juvenile survival of forest trees. The approach is generalisable and could be applied to any forest in which patterns of regeneration and community structure have been impacted by periodic disturbance (e.g. forest fires). Finding meaningful ways of incorporating species diversity into global vegetation models is increasingly recognised as a research priority. In Chapter 5, I explore the diversity of demographic rates in a tropical forest community and identify groups of species with similar life history strategies. I discuss the potential of integrating demographic and physiological traits as a way to aggregate species for inclusion in global models. In summary, translating measurements of individuals into population dynamics provides opportunities to both explore small-scale community responses to disturbance events, and to feed into much larger scale vegetation models.

No description available.

Climate models predict changes to the frequency and intensity of extreme events, with large effects on tropical forests likely. Predicting these impacts requires understanding how landscape configuration and land-use change influence the susceptibility of forests to disturbances such as wind, drought, and fire. This is important because most tropical forests are regenerating from anthropogenic disturbance, and are located in landscape mosaics of forest, agriculture, and other land use. This dissertation consists of four chapters that combine remote sensing and field data to examine causes and consequences of disturbance and land-use change in tropical second-growth forests. In Chapter 1, I use satellite data to identify factors associated with permanence of second-growth forest, and assess how estimates of carbon sequestration vary under different assumptions about second-growth forest permanence. I show that most second-growth forest is cleared when young, limiting carbon sequestration. In Chapter 2, I combine data from weather stations, remote sensing, and landowner surveys to model fire activity on 732 farms in the study area over ten years. The relative importance of these factors differs across scales and depending on the metric of fire activity being considered, illustrating how implications for fire prevention and mitigation can be different depending on the metric considered. Chapter 3 combines Landsat imagery and field data to map wind damage from a severe convective storm, providing strong empirical evidence that vulnerability to wind disturbance is elevated in tropical forest fragments. Finally, in Chapter 4 I integrate annual forest census data with LiDAR-derived topography metrics and tree functional traits in a hierarchical Bayesian modeling framework to explore how drought, topography, and neighborhood crowding affect tree growth, and how functional traits modulate those effects. The results from these studies demonstrate innovative approaches to understanding spatial variation in forest vulnerability to disturbance at multiple scales, and the results have implications for managing forests in a changing climate.

Este trabalho objetivou analisar a dinâmica da regeneração natural de duas áreas de Floresta Ombrófila Densa (FOD) com idades diferentes de regeneração, sendo uma de FOD Submontana de oito anos (A1- Miracatu) e outra FOD das Terras Baixas de 33 anos (A2-Peruíbe), degradadas para implantação da bananicultura. A caracterização da regeneração foi feita por meio de levantamento florístico e fitossociológico realizado pelo método de parcelas, onde em cada área foram implantadas cinco parcelas de 10 x 25 m, totalizando 2.500 m². O material botânico de todos os indivíduos de porte arbustivo-arbóreo 1 m de altura foi coletado e foram registrados a altura e o perímetro do caule a 1,3 m do solo. Após a identificação das espécies foram classificadas as suas síndromes de dispersão, assim como foram estabelecidos os grupos sucessionais aos quais pertenciam. A estrutura florestal foi estudada através do cálculo dos parâmetros de densidade e dominância, tanto absoluta quanto relativa, além do valor de cobertura (VC), realizados com o Fitopac, e também os índices de similaridade de Jaccard (ISj), de diversidade de Shannon (H) e equabilidade (J). Na A1 foram levantados 1.440 indivíduos de 149 espécies e 59 famílias e na A2 foram levantados 1.023 indivíduos de 172 espécies e 56 famílias. As famílias de maiores riquezas de espécies da A1 foram Melastomataceae (29), Myrtaceae (15), Fabaceae (10), Rubiaceae (9) e Asteraceae (6), e na A2 foram Myrtaceae (29), Piperaceae (19), Fabaceae (18), Melastomataceae (13) e Rubiaceae (11), onde na A1 predominaram as espécies pioneiras e secundárias iniciais (36,91%) e na A2 as tardias e de sub-bosque (38,96%) e a síndrome de dispersão predominante em ambas as áreas foi a zoocoria para 54,36% das espécies de A1 e 65,11% em A2. As espécies com maiores valores de VC da A1 foram Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia, Piptocarpha macropoda, Vernonanthura discolor e Myrsine coriacea que somaram 64,8% de VC. Na A2 as espécies com os maiores valores de VC foram Euterpe edulis, T. pulchra, Hyeronima alchorneoides, Bathysa australis, Ficus insipida, Cyatheaceae sp.1, Piper gaudichaudianum e Psychotria nuda perfazendo 58,12% do VC. Na A1 as espécies com maiores densidades foram L. variabilis (DeA=2.568 ind./ha e DeR=24,21%), T. pulchra (DeA=1.360 ind./ha e DeR=12,82%), M. cinnamomifolia (DeA=1.088 ind./ha e DeA=10,26%) e H. alchoneoides (DeA=408 ind./ha e DeA=3,85%). A2 possui uma floresta com estrutura mais complexa, apresentou flora similar a quatro estudos realizados nas regiões do Vale do Ribeira e Baixada Santista, e A1 apresentou baixa similaridade. Na A1 as espécies pioneiras destacaram-se na estrutura e na A2 o papel das espécies dos diferentes grupos sucessionais foi mais equilibrada. O componente da vegetação amostrado em A1 apresentou H= 3,330 nat. ind-1 e J = 0,666 e em A2 H= 3,919 nat. ind-1 e J = 0,761. A regeneração natural mostrou-se capaz de promover a erradicação de 95,45% a 100% das bananeiras em A1 enquanto em A2, após 33 anos, nenhuma bananeira remanescente foi observada. / This work aimed to analyze the dynamics of natural regeneration of two areas with physiognomies and different ages of regeneration, with a Dense Ombrophilous Forest (DOF) Submontane (A1-Miracatu-8 years) and another on DOF lowland (A2-Peruíbe-33 years), degraded to deployment of the banana plantation. The characterization of the regeneration was made by using floristic and phytosociological survey, which was performed by methods of plots. Were deployed five 10 x 25 m plots in each area, totaling 2,500 m². The botanical material of all individuals to carry shrub-tree 1 m tall was collected and have been registered, the height and circumference at breast height to 1.3 m above the ground. After the identification of the species have been classified their dispersal syndromes, as well as successional groups to which they belonged were established. The forest structure was studied by calculating the parameters of density and dominance, both absolutely and relative, in addition to the coverage value (VC), performed with the Fitopac, and also the indexes of similarity of Jaccard (ISj), Shannon diversity (H \') and equability (J \'). In A1 were raised 1,440 individuals of 149 species and 59 families and A2 were surveyed 1,023 individuals of 172 species and 56 families. The families of most species richness of A1 were Melastomataceae (29), Myrtaceae (15), Fabaceae (10), Rubiaceae (9) and Asteraceae (6), and A2 were Myrtaceae (29), Piperaceae (19), Fabaceae (18), Melastomataceae (13) and Rubiaceae (11), where the A1 predominated the pioneer and early secondary species (36.91%) and A2 late and understory (38.96%) and predominant dispersion syndrome in both areas was zoochory to 54.36% of the species A1 and 65,11% in A2. The species with the highest values of VC the A1 were Tibouchina pulchra, Leandra variabilis, Miconia cinnamomifolia, Piptocarpha macropoda, Vernonanthura discolor and Myrsine coriacea totaling 64.8% of VC.. In A2 the species with higher VC were Euterpe edulis, T. pulchra, Hyeronima alchorneoides, Bathysa australis, Ficus insipida, Cyatheaceae 1, Piper gaudichaudianum and Psychotria nuda totaling 58,12% of VC. A1 in the species with the highest densities were L. variabilis (DeA = 2.568 ind./ha and DeR = 24.21%), T. pulchra (DeA = 1,360 ind./ha and DeR = 12.82%), M. cinnamomifolia (DeA = 1,088 ind./ha and DeA = 10.26%) and H. alchoneoides (DeA = 408 ind./ha and DeA = 3.85%). A2 has a forest with more complex structure showed similar flora to four studies conducted in regions of the Ribeira Valley and Santos Lowland, and A1 showed low similarity. In A1 pioneer species stood out in the structure and A2 the role of species of different successional groups was more balanced. The vegetation component sampled at A1 presented H\' = 3,330 nat. ind-1 and J\' = 0,666 and A2 H\' = 3,919 nat. ind-1 and J\' = 0.761. Natural regeneration has been shown to promote the eradication of 95.45 to 100% of the banana trees in A1 while in A2 after 33 years, any remaining banana was observed.

Os métodos de amostragem por conveniência procuram maximizar o volume das amostras e podem, neste sentido, ser bastante eficazes, porém, o esperado é que venham a comprometer a acurácia e a precisão na representação de espécies em sub-bosque floretal. Isto se deve ao fato dos pesquisadores, usualmente, alocarem as redes-neblina em locais conhecidos por atrair uma maior abundância de animais e onde estes apresentariam uma redução em sua habilidade para detectar e se esquivar à rede-neblina, como em rotas de voo, fontes alimentares e abrigos. A alocação determinística das redes pode, desta forma, resultar em um elevado viés amostral, caracterizado pela superamostragem de algumas espécies que, frequentemente, utilizam estes espaços, em detrimento daquelas que, ao contrário, estariam sendo sub-representadas por não os utilizarem na mesma proporção. Baseado nisto, este estudo teve por principal objetivo o desenvolvimento de método padronizado, que pudesse elevar a acurácia e a precisão na obtenção de dados populacionais de quirópteros em sub-bosque florestal, com foco na amostragem sistemática. Como procedimentos metodológicos, uma área amostral de 8,82 ha foi delimitada em três fragmentos florestais, no interior do estado de São Paulo, dos tipos vegetacionais cerradão (22º15\'S e 47º39\'W), floresta estacional semidecidual (22º09\'S e 47º33\'W) e eucalipto (22º11\'S e 47º39\'W), para o que um conjunto móvel de doze redes-neblina foi utilizado na captura e recaptura dos quirópteros, no período de jul/2009 a jun/2010, totalizando um esforço amostral de 155.520 h.m2. A taxa de detecção das redes-neblina foi estimada, através de observações em tempo real, e utilizada na correção das estimativas populacionais. A habilidade de detecção e esquiva à captura foi elevada, porém, não diferiu do observado nas rotas de voo, anteriormente demonstrado por estudos comportamentais. O resultado disto foi o registro de quatorze espécies e, pela correção das estimativas, Desmodus rotundus foi a dominante na região e no eucalipto, enquanto que Micronycteris microtis foi a espécie mais abundante no cerradão e, Glossophaga soricina, na floresta estacional semidecidual. A abundância da Carollia perspicillata não foi corrigida, devido a sua elevada taxa de recaptura atribuída à redução na habilidade para detectar as redes, levando a uma redução de sua importância, dentre as espécies dominantes, na região e nos fragmentos de vegetação nativa. De forma inovadora, foi possível estimar o índice de densidade e o padrão de distribuição populacionais, e, ainda, dada a padronização espacial, compreender a influência de aspectos como a altitude e a declividade do solo, a densidade da vegetação, a presença e a altura do dossel florestal, sobre as populações de quirópteros. Assim, foi concluído que a amostragem sistemática pode ser mais acurada e precisa para os estudos populacionais por reduzir os vieses amostrais dos métodos de amostragem por conveniência, aumentar nossa compreenção sobre os parâmetros populacionais e a forma com que os quirópteros interagem com o ecossistema florestal, e potencializar a comparação de dados em diferentes situações e localidades. / Bats population convenience sampling methods mostly focus on maximizing sample volumes. This method can be highly effective in delivering significant number of samples, but on the other hand can potentially compromise accuracy and precision in representation of species potentially available in understory forests. This is due to the fact that researchers tend to position mist-nets according to known places by attracting greater abundance of bats and where its might be less attentive to the presence of mist-nets, such as bats flyways, food sources and shelters. However, the deterministic approach for mist-nets placement allocation may lead to a misrepresentation of the species in specific habitats and result in oversampling of the species that usually occur in those places. Based on this, the key objective of this study was to develop an standardized protocol that enhances accuracy and precision when collecting bat samples in understory forest, with focus on the evaluation of the systematic sampling. An sample area of 8.82 ha was delimited in three forest fragments within São Paulo State. These were of the vegetation types of cerradao (22º15\'S to 47º39\'W), semideciduous florest (22º09\'S to 47º33\'W) and forestation of eucalyptus (22º11\'S to 47º39\'W). A mobile set of twelve mist-nets was used to capture and recapture of bats from the Jul/2009 to Jun/2010, totaling a sampling effort of 155,520 h.m2. The detectation rate of mist-net of bats was estimated by observations in real time and was used to obtain correct population estimates. The ability of bats to detect and evade capture was hight, but consistent with observed for the flyways, earlier demonstrated by behavioral studies. The result of this was fourteen species recorded in the understory of the different forest fragments, and through the correctness of the estimates, the Desmodus rotundus was dominant in the region and in eucalyptus, while Micronycteris microtis was the most abundant specie in the cerradao and Glossophaga soricina in the semideciduous forest. The abundance of the Carollia perspicillata has not been corrected, due to its hight rate of recapture what was possibly the result of a reduced ability to detect the mist-net, leading to a reduction in your importance amoung the dominant species in the region and fragments of native vegetation. The proposed systematic design innovated and led to enhanced accuracy and precision, beyond to enable the estimate density level and the population distribution patterns. Thus, the spatial standardization in allocation mist-nets provides far representation of the influence of all habitat conditions on the bat populations, such as altitude and slope soil, vegetation density, presence and height of the forest canopy. Therefore, the overall conclusion was that the systematic sampling can be more accurate and precise for bats population studies by reduce convenience sampling methods biases, increase the understanding bats interaction with the forest ecosystem and the potentiate data comparation in different situations and localizations.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-11T12:15:06Z No. of bitstreams: 1 2009 - Luiz Santana do Nascimento.pdf: 2500157 bytes, checksum: 032a65fbfdb3472167b24e484317dd31 (MD5) / Made available in DSpace on 2017-05-11T12:15:06Z (GMT). No. of bitstreams: 1 2009 - Luiz Santana do Nascimento.pdf: 2500157 bytes, checksum: 032a65fbfdb3472167b24e484317dd31 (MD5) Previous issue date: 2009-08-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The pre-dispersal seed predation by insects has great importance for seed production. The germination is affected due to damage caused by insects in larval development inside the seed. If this damage occurs in the cotyledons, it mainly affects the performance and survival of seedlings, otherwise, if it occurs directly in the embryonic axis, the seed mortality is unavoidable. There are few studies about species of Albizzia lebbeck (L.) Benth. in urban trees, especially when it comes to ecology and behaviour of insect predators of their seeds. In this context, this study aims to evaluate and quantify the damage in seeds, the occurrence and population fluctuation of insects on pods and seeds with emphasis mainly on the stage of pods ripening at different levels of human disturbance and air pollution caused by motor vehicles. The samples of pods were carried out on mother trees of A. lebbeck located on the campus of UFRRJ (Serop?dica), km 32 of old road Rio-S?o Paulo (Nova Igua?u) and km 47 (Serop?dica), Rio de Janeiro and the pods analyzed at the Laboratory of Forest Entomology, DPF, IF, UFRRJ. It was observed low levels of insect infestation in prematurely ripening pods which should be linked to the low number of specimen in oviposition on the first pods. However, for late ripening pods, especially those collected at sites with high levels of human disturbance and influence of air pollution, it was observed an increase in insect infestation. The same was observed in the final processing of seeds in pods of quarantine. In general, 9% of the seeds presented intact (healthy), 31% aborted and 60% damaged. 83% of damaged seeds were from the mother trees located in central reservation of Highway (Km 32), 43% of its margin (km 47) and 42% in the conservation area of Universidade Federal Rural do Rio de Janeiro Botanical Garden. Percentage of 92.68 was found of insect seed predators distributed in the following species: Bruchidius sp. (57.39%), Merobruchus paquetae (33.98%), Stator limbatus (0.27%), an unidentified species of Lepidoptera (1.04%) and the rest of emerging insects (7.32%) belonging to Order Hymenoptera. Specimen of Bruchidius sp. presented emergency period with well-defined peak in mid-September (approximately 135 days after observation of the first ovipositions in the field) and species M. paquetae average occurrences rather homogeneous, with low numbers of specimen and few variations throughout the period of emergency quarantine on pods. The largest number of bruchids was recorded in an area of high human disturbance, being the species Bruchidius sp. predominant in pods of trees placed in central reservation of the highway and the species M. paquetae on mother trees located beside of the highway. The number of bruchids in seeds of A. lebbeck was reduced with decreasing levels of human disturbance in urban trees which resulted in a lower percentage of damaged seeds and higher number of healthy seeds / A preda??o pr?-dispers?o de sementes por insetos ? de suma import?ncia para a produ??o de sementes, uma vez que o potencial germinativo ? afetado devido a danos provocados pelos insetos em desenvolvimento larval em seu interior. Quando este ataque acontece somente nos cotil?dones, as reservas energ?ticas do embri?o s?o drasticamente reduzidas afetando o desempenho e sobreviv?ncia das pl?ntulas, enquanto que, diretamente ao eixo embrion?rio, a mortalidade das sementes. H? poucos trabalhos na literatura sobre a esp?cie Albizzia lebbeck (L.) Benth. em arboriza??o, principalmente em se tratando da ecologia e comportamento dos insetos predadores de suas sementes. Neste contexto, este trabalho teve como objetivo avaliar e quantificar os danos em sementes, a ocorr?ncia e flutua??o populacional dos insetos em frutos e sementes com ?nfase, principalmente, ? fase de matura??o dos frutos em diferentes n?veis de antropiza??o e polui??o do ar provocada por ve?culos automotores. As amostragens de frutos foram realizadas em matrizes de A. lebbeck localizadas no Campus da UFRRJ (Serop?dica), Km 32 da antiga Estrada Rio-S?o Paulo (Nova Igua?u) e Km 47 (Serop?dica), Estado do Rio de Janeiro e analisadas no Laborat?rio de Entomologia Florestal, DPF, IF, UFRRJ. Foram observados baixos n?veis de infesta??o por insetos em frutos de matura??o prematura o que deve estar associado ao baixo n?mero de indiv?duos em oviposi??o nos primeiros frutos. J? para frutos de matura??o tardia, sobretudo aqueles coletados em locais com maior n?vel de antropiza??o e influ?ncia da polui??o do ar, foi observado aumento na infesta??o por insetos. O mesmo foi verificado no beneficiamento final das sementes em frutos de quarentena. No total, 9% das sementes apresentaram-se intactas (sadias), 31% abortadas e 60% danificadas sendo estas ?ltimas 83% provenientes de matrizes localizadas no canteiro central da Rodovia (Km 32), 43% ? sua margem (Km 47) e 42% em ?rea de conserva??o do Jardim Bot?nico da UFRRJ. Foi encontrado percentual de 92,68 de insetos predadores de sementes distribu?dos nas seguintes esp?cies: Bruchidius sp. (57,39%), Merobruchus paquetae (33,98%), Stator limbatus (0,27%), uma esp?cie de Lepidoptera n?o identificada (1,04%) e, o restante dos insetos emergentes (7,32%), pertencentes ? Ordem Hymenoptera. Os indiv?duos da esp?cie Bruchidius sp. apresentaram per?odo de emerg?ncia bem definida com pico em meados de setembro (cerca de 135 dias ap?s a observa??o das primeiras posturas no campo) e a esp?cie M. paquetae m?dias de ocorr?ncias bastante homog?nea, com baixo n?mero de indiv?duos e poucas varia??es ao longo de todo o per?odo de emerg?ncia em frutos de quarentena. O maior n?mero de bruqu?deos foi registrado em ?rea de elevada antropiza??o, sendo a esp?cie Bruchidius sp. predominante em frutos de matrizes localizadas no canteiro central e a esp?cie M. paquetae em matrizes localizadas ? margem da rodovia. O n?mero de bruqu?deos em sementes de A. lebbeck foi reduzido com a diminui??o do n?vel de antropiza??o local em matrizes em arboriza??o o que refletiu em menor taxa de sementes danificadas e maior n?mero de sementes sadias.

The effect of contiguous forested habitat area on local avian diversity and species richness in the Tualatin Mountain area of northwestern Oregon was investigated. Observations of eight forested stands representing seven area values (1, 2, 7, 14, 18, 24 and 40 hectares) were made during the spring and summer of 1991 and 1992. The variables measured were chosen in an attempt to show possible relationships between vegetation factors, spatial patterns and bird communities. Kendall's rank correlation coefficients were used to analyze the data. Avian species richness and diversity were significantly correlated with forest stand (patch) size. The only significant correlation between avian species richness and diversity and vegetation measures was with percent shrub layer cover. It seems likely that avian diversity and richness are increased due to the presence of species that can utilize the interior and edges of forest stands along with species which depend upon true forested interior. When forested patch size drops below a critical area, the patch becomes all edge. Interior species are absent due to increased predation and the inability to compete with interior-edge species. Edge effect may be a contributing factor to variation in diversity of birds. The correlation of percent shrub layer cover with avian measures is accompanied by a correlation of percent shrub layer cover with distance from edge. This suggests further investigation is required to assess this relationship. Studies conducted in the northeastern and north central United States have shown a similar relationship between bird communities and forest patch size.

acase@tulane.edu

No description available.

Typescript. Copies of two papers co-authored by the author, in back cover pocket. Bibliography: leaves 128-143.