Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The destruction and fragmentation of habitats for expansion of agricultural crops have contributed to the loss of diversity across the planet. One of the main consequences of fragmentation is the formation of artificial borders, which modify the microclimate and can trigger changes in biological processes. Such changes are termed edge effects and their magnitude depends on factors such as distance from the edge, size fragment, canopy structure, logging, vegetation matrix and taxonomic group. Lichenized fungi are sensitive to microclimate changes and are good predictors of human-induced disturbances. While edge effects in wet forest ecosystems are well studied, their impact on natural habitats of the Caatinga biome are still little explored. Thus, the aim of this study was to investigate whether the richness and species composition of corticicolous lichens changes over a edge-interior gradient resulting from forest fragmentation. The study was conducted in a remnant located in the Green Well municipality in the state of Sergipe, in Santa Maria da Lage. A total of 972 samples of corticicolous lichens were collected, distributed over 80 phorophytes corresponding to different distances from the edge (0 to 330 m). Among the samples, 182 species were identified, belonging to 16 families and 57 genera. There was no significant correlation between distance from the edge and species richness, but statistical analysis showed a significant difference in species composition related to edge distance. However, species richness was correlated with relative light intenity (canopy openness and diffuse transmittance). This work emphasizes the importance of the study of lichens in relation to the edge effect in the Caatinga, reinforcing the inclusion of these organisms in strategies for biodiversity conservation in this environment. / A destruição e fragmentação dos habitats para expansão de cultivos agrícolas têm contribuído com a perda de diversidade no mundo. Uma das principais consequências da fragmentação é a formação de bordas artificiais, que modificam o microclima, desencadeando modificações em processos biológicos. Essas alterações são consideradas efeitos de borda e podem ter sua intensidade e magnitude aumentada a depender de fatores como distância da borda, tamanho do fragmento, estrutura do dossel, tempo de corte, matriz e grupo taxonômico. Os fungos liquenizados são organismos sensíveis às modificações microclimáticas e bons preditores das perturbações antrópicas. Embora os efeitos de borda sobre os ec ossistemas florestais sejam bem estudados, as suas consequências para o bioma Caatinga ainda são pouco exploradas. Dessa forma, o objetivo deste trabalho foi investigar se a riqueza e composição de espécies de liquens corticícolas mudam ao longo de um gradiente de borda-interior. O estudo foi realizado em um remanescente localizado na Fazenda Santa Maria da Lage , município de Poço Verde, Sergipe. Foram coletadas 972 amostras de liquens corticícolas distribuídas em 80 forófitos em diferentes distâncias de bo rda (0 a 330 m da borda). Dess e total, foram identificadas 182 espécies, distribuídas em 1 6 famílias e 57 gêneros. As análises estatísticas mostr aram uma diferença significativa em relação à composição de espécies de liquens entr e as distâncias no gradiente borda-interior. Por outro lado, não houve resultado significativo em relação à riqueza de espécies. Dentre os fatores abióticos, apenas o fator de luminosidade (transmitância difusa) obteve resultado significativo em relação à riqueza de espécies de liquens corticícolas. O presente trabalho enfatiza a importância do estudo de liquens em relação ao efeito de borda na Caatinga, reforçando a inclusão destes organismos em estratégias para conservação da biodiversidade neste ambiente.

Tree growth influences forest community dynamics and responses to environmental variations, but currently is not well understood. Tree growth in highly diverse wet tropical forests have been well studied and characterised compared to the species-poor dry tropical forests. Thus, it is not clear if growth rates and community dynamics of dry forests are similar to those of wet forests, given the longer dry season, greater rainfall variability, more open canopy and lower number of species in dry forests. This thesis focuses on identifying important factors that influence tree diameter growth rates in the dry tropical forest at Mudumalai, southern India, and also compares growth patterns at this dry forest with those at moister forests. The thesis thus contributes towards closing the gap in understanding of tree growth patterns across the tropics. An initial analysis involving matrix-based population projections of four common canopy species at Mudumalai showed that variations in diameter growth have the potential to drastically modify population trajectories of dominant species. Thus the main focus of this thesis is aimed at identifying the important intrinsic and extrinsic factors affecting growth in this dry forest, as this information could be useful for future management of the forest. The second important aim of the thesis was to find out if growth rates are influenced by different sets of factors in tropical dry versus moist forests. A large permanent 50ha plot vegetation monitoring plot was set up in 1988-89 in the Mudumalai dry deciduous forest, and was subsequently monitored annually by staff of the Centre for Ecological Sciences. Data used in this thesis represent a 12-year interval between 1988 and 2000. Girth measurements were obtained from all woody tree stems ≥1cm in diameter every four years during this 12 year interval, which provided three census intervals of diameter increment data on >13,000 trees. For the comparison between dry and moist deciduous forests, data were obtained from a similar large plot maintained and monitored at the Barro Colorado Island (BCI) in Panama. Influences of the intrinsic factors, tree size, individual identity, species identity and growth form, were examined using t-tests, Wilcoxon signed ranks tests, linear regressions, analysis of variance (ANOVA), principal components analysis (PCA) and cluster analysis. Among the intrinsic factors tested, species identity explained approximately 20% of growth rates at the community level, while tree diameter explained less of growth variation, and growth form had a minor influence on growth. Growth rates also were examined for variations across the three census intervals, and for relationships with rainfall and survival from fire. Statistical tests included t-tests, Wilcoxon and other non-parametric sign tests, logistic regression and ANOVA. Most species and individuals showed significant reductions of growth in the second census interval (1992-1996), and growth rates of most trees were positively related to rainfall. Growth rate variations generally were not related to survival from fire, and few species were capable of escaping fire mortality by fast growth. Spatial environmental influences were tested in the commonest fifteen species, using five habitat categories, local elevation, slope, aspect, and the biotic neighbourhood variables of local conspecific and heterospecific density. Statistical tests included analysis of covariance, multiple linear regression and redundancy analysis. The tests were quadrat-based or individual-based, and species' growth responses were tested at different levels of distance and spatial scale. Topographic features and habitat categories had ephemeral effects on species growth. Only the most dominant species, Lagerstroemia microcarpa, showed consistent conspecific neighbour density effects. Redundancy analysis using a subset of common species and environmental factors did not reveal common growth responses to spatial environmental factors. Comparison of factors influencing growth at Mudumalai versus at BCI using multiple factor ANOVA and multiple linear regressions showed a similar influence of temporal variation at the two sites, but stronger and more widespread influence of tree size (diameter) at BCI. The greater influence of tree size at BCI may be related to greater light limitation in this dense moist forest. Spatial environmental factors had weak influences at both plots. Species were less differentiated from each other at the more diverse BCI plot compared to the relatively species-poor Mudumalai plot, suggesting that species' growth niches may be weakly related to diversity across tropical forests. Overall the results showed that among the factors tested species identity and census intervals were the most important influences on diameter growth at the Mudumalai dry deciduous forest. Tree diameter was less important and less consistent in affecting growth at the Mudumalai dry forest, contrary to expectations based on moist tropical forests where this relationship has been established previously. When comparing Mudumalai and BCI, the relative importance of different factors was different at the two sites, and the most important difference was a dominant influence of light limitation at the wetter forest in Panama. In terms of management applications, this study showed that fires at Mudumalai might be an inescapable source of mortality for many vulnerable species, and improved fire management is crucial for long term survival of species in this dry forest. At a larger scale, light and other environmental variables were found to influence growth differently at Mudumalai compared to BCI. This suggests that location-specific responses may be important for projections of tree biomass and carbon sequestration, especially under future climatic change scenarios.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The successional processes in tropical forests follow a progression of stages during which forests have a gradual enrichment of species and an increase in structural and functional complexity. Stochastic actions resulted from the behaviour of the population s components and species define forest succession, where biotic and abiotic factors lead the ecological diversity strategies in a community according to local and regional environmental filters. Lichens are organisms with complex relationship within successional forest because they respond to spatial and temporal factors, and at the same time, are bioindicators of environmental quality. In this context, the present study aims to investigate the richness and species composition of corticicolous lichens along a gradient of forest succession in the Caatinga biome, and verify the possibility of using functional traits of lichens as indicators of successional stages of this type of vegetation. The study was undertaken in three areas of different successional stages in the Caatinga from Sergipe semiarid, in two municipalities. A total of 1460 samples were collected, distributed between the initial, intermediate and advanced stage areas. After the analysis, 119 species were identified, comprising 17 families and 47 genera. The richness differs between stages of succession, where the highest values are for the initial stage, followed by intermediate and later stages. Among the sampled environmental factors, the pH of the rainy season is the one that significantly affects species richness. Regarding species composition, there is a clear separation of stages, where the advanced stage differs from the initial and intermediate and are influenced by parameters such as bark pH, DAP of the tree, brightness, and elevation. The beta diversity is higher for the advanced stage, which has a more heterogeneous composition than the initial and intermediate, which share species among themselves. The functional traits presents a noticeable variation in the abundance and are bioindicators of stages of succession. Results show that the community of lichens respond to natural succession and is influenced by biotic and abiotic factors. Therefore, it is expected that this work will contribute to enhance the ecological knowledge of lichens in the Caatinga, serving as the starting point for complementary and innovative research that contributes to the conservation of this ecosystem. / Os processos sucessionais em florestas tropicais seguem uma progressão de estágios durante os quais as florestas apresentam um enriquecimento gradual de espécies e um aumento em complexidade estrutural e funcional. Ações estocásticas resultadas do comportamento dos componentes das populações e espécies definem a sucessão florestal, onde fatores bióticos e abióticos em uma comunidade conduzem as estratégias ecológicas de diversidade de uma determinada comunidade de acordo com filtros ambientais locais e regionais. Os liquens são organismos que possuem uma complexa relação sucessional dentro da floresta, pois respondem a fatores espaciais e temporais, e ao mesmo tempo, são bioindicadores de qualidade ambiental. Neste sentido, o presente estudo tem como objetivo analisar a riqueza e a composição de espécies de liquens corticícolas ao longo de um gradiente de sucessão florestal na Caatinga, e verificar a possibilidade da utilização de atributos funcionais de liquens como indicadores dos estágios de sucessão florestal neste tipo de vegetação. O trabalho foi realizado em três áreas de diferentes estágios sucessionais na Caatinga do Alto Sertão Sergipano, em dois municípios do estado. Foram coletadas 1460 amostras, distribuídas entre as áreas inicial, intermediária e avançada. Desse total, 119 espécies foram identificadas, compreendendo 17 famílias e 47 gêneros. A riqueza difere entre os estágios de sucessão, onde os maiores valores estão para o estágio inicial, seguidos pelo avançado e intermediário. Dentre os fatores ambientais amostrados, o pH do período chuvoso é o único que afeta a riqueza. Com relação à composição, há uma clara separação dos estágios, onde o estágio avançado se diferencia do inicial e intermediário e são influenciados pelos fatores pH, DAP, luminosidade, elevação. A diversidade beta é maior para o estágio avançado, que possui uma composição mais heterogênea em relação ao inicial e intermediário, os quais compartilham espécies entre si. Com relação aos atributos funcionais, é perceptível a variação da abundância e a correlação bioindicadora dos estágios de sucessão. Os resultados demonstram que a comunidade de liquens responde à sucessão natural e é influenciada por fatores bióticos e abióticos. Logo, espera-se que este trabalho venha contribuir para ampliar os conhecimentos ecológicos sobre os liquens na Caatinga, servindo como ponto inicial para pesquisas complementares e inovadoras que contribuam para a conservação deste bioma.

Made available in DSpace on 2014-07-29T12:05:37Z (GMT). No. of bitstreams: 1 Tese Potira Hermuche.pdf: 2991051 bytes, checksum: c339e425379e980c3d0328785a889e09 (MD5) Previous issue date: 2010-12-10 / Current dry forests in the Vão do Paranã region, northeastern Goiás State, Brazil, are strongly fragmented mainly because of intense cattle ranching activities. This affects the ecological dynamics of flora and fauna since the connectivity among remaining fragments is reduced. The objectives of this study was: a) to map dry forests occurrences in the study area; b) to determine the relevant geoenvironmental indicators that control dry forest occurrences in the landscape; c) to find areas with high pressure in terms of human occupation of remaining fragments; and d) to propose an operational strategy for dry forest conservation. The map of dry forest occurrences was obtained from the image interpretation of multitemporal LANDSAT satellite scenes. The environmental controllers analyzed were climate, topography, geology and soils. The human occupation pressure in the remaining fragments was analyzed based on the metrics obtained from land use and land cover map, environmental data and social and economical data. The proposal for conservation strategy of dry forests was based on the idea of using tree species such as the Aroeira (Myracroduon urundeuva) found in cultivated pastures as living fences before they are cut as invasors by the farmers. Results indicated the presence of approximately 190,000 hectares of dry forests in the study area. The largest fragments were mostly found in the central and northern parts of Vão do Paranã. It was found that there was a strong relationship between lithology (carbonatic rocks) and the presence of dry forests, both in plain areas and in rocky outcrops. A detailed qualitative analysis indicated the main controls for the establishment of the dry forests: strong water table variation in the soil-bedrock profile, the soil eutrofism and the climatic seasonality, allowing a hierarchy that can be described as: strong water table variation in the soil-bedrock profile > soil eutrofism > lithology > climatic seasonality > rainfall > soils > hipsometry > slope. As the most remaining fragments are located in hilly areas with limestone outcrops, only 1% presented high and very high tendencies for land occupation, though they are facing strong wood selective loggings. The substitution of dead fences for living fences and the increment of isolated trees indicated an increase of permeability of matriz and of conectivity among remaining vegetation fragments. The simulation of a scenery based on three test sites indicated that such substitution would result, for the entire Vao do Paranã region, in 338,520 trees saved (4.2 km2) and 5,077,800 new trees planted in form of living fences (63,5 km2). Regarding isolated trees, in the case of all pasture areas present an average of 310 trees per km2, this would represent 42 km2 of vegetation cover. / Atualmente, a Floresta Estacional Decidual (FED) na região do Vão do Paranã, nordeste do estado de Goiás, encontra-se bastante fragmentada principalmente em função da intensa atividade pecuária, fato que compromete a dinâmica ecológica da flora e da fauna por meio da alteração na conectividade entre os fragmentos remanescentes. O objetivo da presente tese foi: a) mapear as áreas de ocorrência atual de FED na área de estudo; b) determinar os principais controles geoambientais relacionados com o seu estabelecimento na paisagem; c) indicar as áreas com forte tendência de ocupação dos fragmentos remanescentes; e d) apresentar uma estratégia operacional para sua conservação na região. O mapeamento das áreas de ocorrência de FED foi obtido com base na análise de imagens multitemporais do satélite LANDSAT, enquanto os principais controles geoambientais analisados foram clima, topografia, geologia e solos. As tendências de ocupação dos fragmentos remanescentes foram analisadas com base nas métricas obtidas de mapas de uso e cobertura da terra, dados ambientais e dados socioeconômicos. A sugestão de estratégia de conservação da FED foi baseada na proposta de utilizar espécies arbóreas como a Aroeira (Myracroduon urundeuva) que rebrotam em áreas de pastagens cultivadas na produção de cercas vivas. Os resultados indicaram a presença na região de aproximadamente 190.000 hectares de FED. Os fragmentos maiores dessa fitofisionomia encontram-se distribuídos essencialmente na região centro-norte do Vão do Paranã. Verificou-se a existência de uma forte relação entre a litologia (rochas carbonáticas) e a presença de FED, tanto em áreas planas como em afloramentos rochosos. A análise qualitativa detalhada indicou como principais controles para o estabelecimento da FED a variação hídrica do perfil solo-rocha, o eutrofismo dos solos e a sazonalidade climática, permitindo uma hierarquização que pode ser descrita como : variação hídrica do perfil solo-rocha> eutrofismo dos solos> litologia > sazonalidade climática > total pluviométrico > classes de solos > hipsometria > declividade. Como a maioria dos fragmentos remanescentes está localizada nas áreas de relevo acidentado com presença de afloramentos de calcário, apenas 1% apresentou tendências alta e muito alta de uso e ocupação, apesar de sofrerem com intensa exploração seletiva de madeira. A substituição das cercas mortas por cercas vivas e o incremento de árvores isoladas indicou aumento na permeabilidade da matriz e na conectividade entre os fragmentos de vegetação remanescentes. A simulação de um cenário baseado em três áreas-teste indicou que essa substituição resultaria, para todo o Vão do Paranã, em 338.520 árvores poupadas (4,2 km2) e 5.077.800 novas árvores plantadas em forma de cercas vivas (63,5 km2). No que diz respeito às árvores isoladas, caso todas as áreas de pastagem apresentassem uma média de 310 árvores isoladas por km2, essas representariam 42 km2 de cobertura vegetal.

<div>Biodiversity loss is the silent crisis of the 21st century. Human activities are drastically altering the diversity of life on Earth, yet the extent of this transformation is shrouded by our limited information on biodiversity and how it is changing. Emerging technologies may be suited to fill this information gap, and as a result increase our capacity to measure and manage natural systems. Acoustic monitoring is a remote sensing technique that is rapidly reshaping the temporal and spatial scales with which we can assess animal biodiversity. Through recording and analyzing soundscapes—the collection of sounds occurring at a given place and time—we can assess biodiversity, habitat condition, and environmental change. However, the relationships between soundscapes and these three ecological dimensions are still in the early phases of categorization, especially in aquatic systems. </div><div><br></div><div>This dissertation investigates how soundscapes can be used to measure biodiversity, habitat condition, and environmental change in aquatic habitats. It addresses several knowledge gaps: First, I develop a framework for classifying unknown sounds within a soundscape, which I use to measure the acoustic diversity and dynamics within a tropical freshwater wetland. Second, I demonstrate that soundscapes can reflect the resilience of animal communities following disturbance events. Altered soundscapes revealed that Hurricane Maria, which swept through Puerto Rico in September 2017, impacted dry forest animal communities more than adjacent coral reef communities. Third, in kelp forest habitats off the coast of California, USA, I showed that soundscape variables correlated with ecological variables associated with regime shift in kelp forests, including urchin density, kelp cover, and fish diversity. Overall, this dissertation demonstrates that soundscape recording and analysis is a promising way to assess the ecological conditions of aquatic systems. </div>

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