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Conversion of tropical forests into oil palm plantations reduces the habitats of many species, including primates, and frequently leads to human–wildlife conflicts. Contrary to the widespread belief that macaques foraging in the forest–oil palm matrix are detrimental crop pests, we show that the impact of macaques on oil palm yield is minor. More importantly, our data suggest that wild macaques have the potential to act as biological pest control by feeding on plantation rats, the major pest for oil palm crops, with each macaque group estimated to reduce rat populations by about 3,000 individuals per year (mitigating annual losses of 112 USD per hectare). If used for rodent control in place of the conventional method of poison, macaques could provide an important ecosystem service and enhance palm oil sustainability.

Submitted by Gizele Lima (gizele.lima@inpa.gov.br) on 2017-06-19T13:53:15Z No. of bitstreams: 2 2016_10_18_Dissertação_LuizaCosme.pdf: 1416222 bytes, checksum: 54f85e213133bb0455bb2a8d4098f181 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-19T13:53:15Z (GMT). No. of bitstreams: 2 2016_10_18_Dissertação_LuizaCosme.pdf: 1416222 bytes, checksum: 54f85e213133bb0455bb2a8d4098f181 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-05-31 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Environmental filters act directly on the distribution and composition of species. However, it is not known how soil and belowground hydric conditions are related to hydraulic characteristics of the xylem, branches and of the whole plant on a local scale. We examined wood density and anatomy, height, leaf area, specific leaf area, and the leaf area:sapwood area ratio at the branch level in valleys and plateaus of the terra-firme forest in Central Amazonia. These environments present contrasting table water depths and soil textures. We measure 20 traits related to branches, stem, and whole plant in 28 congeneric species pairs from 12 genera, each containing one valley and one plateau species. Species associated with the plateaus or valleys showed trait differences that indicate distinct investments in prevention against hydraulic failure and driving efficiency, respectively. On plateaus, species had higher wood density, lower averages of vessel size and hydraulic diameter of the vessel, smaller stem sapwood area and smaller specific leaf area. Some correlations between traits change according to the contrasting environmental conditions, demonstrating that species have different investments in traits according to the water conditions in the soil. The maximum adult stature in contrast environments was associated with different investing in conductivity efficiency through the xylem anatomy.We conclude that even in a fine scale, with few meters separating contrasting soil texture and water table depth conditions, environmental filters may impose ecological restrictions on trees that could explain species complementary distribution in Central Amazonia. These filter may be stronger in phylogenetically closely related species, which show more similarities and compete for the same resources. Thus, contrasting soil texture and water table depth conditions may be important determinants of species composition and diversity . Thus, we suggest that hydraulic attributes and their relationships with the environment must be better understood, especially on a local level. / Filtros ambientais atuam diretamente sobre a distribuição e composição de espécies. No entanto, não se sabe como solo e as condições hídricas abaixo do solo estão relacionados às características hidráulicas do xilema. Nós examinamos a densidade da madeira e anatomia da madeira, altura, área foliar, área foliar específica e a razão entre área foliar:área de xilema ativo no nível do ramo em espécies de árvore que ocorrem no baixio e platôs em uma floresta de terra-firme. Esses ambientes apresentam diferenças na profundidade do lençol freático e textura do solo. Nós medimos 20 traços funcionais em 28 pares de espécies congenéricas de 12 gêneros. Cada par com uma espécie associada a baixio e uma espécie associada platô. Espécies associadas aos platô ou baixios mostraram diferenças que indicam investimentos distintos na prevenção contra a falha hidráulica e eficiência de condução, respectivamente. Em platôs, as espécies apresentaram maior densidade da madeira, as médias mais baixas de diâmetro do vaso e diâmetro hidráulico do vaso, menor área de xilema ativo no caule e menor área foliar específica. A relação entre alguns atributos se alterou nas condições ambientais contrastantes, e espécies de diferentes alturas nos diferentes ambientes parecem investir em eficiencia e segurança hidráulica de maneiras distintas. Concluímos que mesmo em uma escala fina, com poucos metros separando ambientes com condições contrastantes de textura do solo e profundidade do lençol freático, filtros ambientais podem impor restrições ecológicas em árvores que poderiam explicar espécies de distribuição complementar na Amazônia Central. Estas restrições podem ser mais fortes em espécies filogeneticamente relacionadas, que mostram mais semelhanças e competem pelos mesmos recursos. Sugerimos que os atributos hidráulicos e suas relações com o meio ambiente devem ser melhor compreendidos, especialmente a nível local.

The Panama Canal Watershed (PCW) represents a special opportunity for studies related to seed dormancy in the tropics with both applied and basic research objectives. There is a clear need for seed information for nursery planning in restoration projects that involves use of a large number of local species. Moreover, the strong rainfall gradient along the 60 km of continuous lowland forest in the PCW represents an excellent opportunity to understand dormancy and its role as an adaptive trait that evolved in response to environmental factors. This study presents useful seed information for 100 tree species native to the PCW. For each species, it includes collection system, fruiting time, seed mass, seed moisture content, germination, and longevity in storage at 20??C. For the first time, an attempt is made to classify (to class sensu Baskin andamp; Baskin 2004) the class of dormancy in seeds of the PCW. An analysis of the relationship between class of dormancy and seed mass, moisture content, longevity, germination patterns, and seasonality is presented. The relationship between class of seed dormancy and longevity and geographical distribution of species within the watershed based on the rainfall gradient was investigated.

Factors relating to natural regeneration and tree community recovery after slash and burn agricultural practices were investigated in secondary seasonally dry tropical forests (SDTF) of varying land use intensity and post-disturbance management. Patterns and processes of regeneration were explored by collecting community composition data at secondary and primary sites, by conducting seedling experiments, and by investigating existing forest rehabilitation efforts in both Lao PDR (Laos) and Vietnam. In the forests surveyed in Laos, forest recovery in terms of the composition of primary forest tree species juveniles in fallow forests was high at most sites regardless of previous land use intensity. While community compositional studies indicated significant differences between primary and secondary communities, little or no significant differences were found in terms of primary tree species or family diversity, evenness, or dominance of regenerating juveniles. Significant differences appeared to be due to changes in the relative abundances of different species rather than the absence of primary forest obligate species in the secondary communities. This effect is expected to be due to the relatively common resprouting ability of SDTF species, the wide range of ecological conditions that these species can persist under, and the mosaic pattern of land-uses across the landscape. Evidence of environmental filtering affecting composition patterns in secondary communities was found for two plant traits; dispersal syndrome and plasticity of specific leaf area (SLA). Ecological strategies of primary SDTF tree species were investigated in two ways. Within the narrow range of species capable of regenerating within the primary forest environment, evidence of different life history strategies was found, indicated by significant correlations between continuous plant traits of seed size, fruit size, maximum tree height, SLA, leaf size and wood density. The correlations found largely mirrored patterns found in similar studies in Neotropical forests. Evidence of different seedling regeneration strategies was investigated by comparing species of two different successional preference groups in a seedling/light experiment. Seedlings of non-pioneer later successional species responded differently than species more associated with disturbed environments (long-lived pioneers) when exposed to both increasing absolute light treatments, and to light received under various sunfleck treatments. Earlier successional species demonstrated greater plasticity of SLA, leaf area ratio (LAR), stem elongation, and root mass ratio to increasing light. Regeneration under minimally managed monoculture and pair-wise plantations of both native and exotic species at the Laos field site was not significantly different when compared with nearby remnant primary forest in terms of diversity, evenness, and richness. Therefore, plantation overstoreys did not appear to be suppressing the regeneration of primary forest species. Seedlings grown in enrichment designs nearby had survival rates of approximately 50%, and diameter increments of less than 0.2 cm/yr after 6 to 9 years of growth. The performance of seedlings in such plantings is expected to be sufficient for conservation aims but is unlikely to encourage private investment for forestry purposes due to long expected rotation lengths. At Hai Van Pass in central Vietnam, the combination of a fast growing exotic species to capture a degraded site and ameliorate site conditions, followed by enrichment planting of native species was demonstrated to be a successful approach to reforesting degraded land, whilst funding itself through the sale of timber. The results indicate the high regeneration potential of the studied secondary forests, both in terms of observed patterns of regeneration in slash and burn fallow forests, and in terms of the general regenerative abilities of SDTF species. Decisions regarding future land-uses and secondary forest management should have consideration of this possible high level of recovery, and simple diversity sampling techniques should be included in any related processes to confirm the regeneration potential of a particular secondary forest.

Made available in DSpace on 2014-06-11T19:32:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-09Bitstream added on 2014-06-13T19:22:48Z : No. of bitstreams: 1 klein_dk_dr_botib.pdf: 427517 bytes, checksum: 69b36be9a11ed0b66d6a420111b90ee9 (MD5) / Para um melhor entendimento dos processos que determinam a dinâmica das florestas tropicais, estudos que investigam tanto a vegetação (parte aérea) como o banco de sementes do solo, são necessários. Através de estudos de banco de semente pode-se avaliar, por exemplo, a capacidade de regeneração natural de uma dada vegetação, a viabilidade das sementes existentes no solo e sua influência na estrutura da vegetação. No entanto, pouco se sabe sobre os processos que podem provocar variações na estrutura do banco de sementes, especialmente em florestas semideciduais. O presente estudo teve como objetivo conhecer a composição do banco de sementes do solo em um trecho de Floresta Estacional Semidecídual, bem como investigar possíveis processos capazes de gerar variações em sua estrutura. Além disso, determinou-se o grau de similaridade entre a parte aérea e o banco de sementes. Primeiramente, a densidade (número de plântulas), a riqueza, a diversidade e a composição de espécies foram comparadas entre áreas em diferentes estágios sucessionais, bem como entre diferentes profundidades do solo e estações do ano (chuvosa e seca). Em seguida, a similaridade entre o banco de sementes e a vegetação local foi comparada. Constatou-se que a principal fonte de variação do número de plântulas, da riqueza e da diversidade de espécies presentes no banco de sementes foi a profundidade na qual as sementes foram amostradas. De forma geral, as amostras obtidas da serrapilheira continham, significativamente, um maior número de plântulas, uma maior riqueza e maior diversidade de espécies do que as amostras provenientes das profundidades de 0-10cm e 10-20cm, tanto na estação chuvosa como seca. Comparações da riqueza e da diversidade de espécies entre a estação seca e chuvosa... / For a better understanding of the processes that determine tropical forest dynamics, studies that investigate vegetation both above and below ground are needed. By studying seed banks it is possible to determine, for example, the natural regeneration capacity of vegetation, the viability of the soil seed bank as well as its influence at structuring plant communities. However, little is known about the processes that can generate variation in the seed bank structure, particularly in semideciduous forests. The main aim of this study was to know the soil seed bank composition in a semideciduous seasonal forest fragment, and also to investigate some processes that may generate variations in this structure. Besides, it was determined below (seed bank) and above ground (vegetation) similarity. Firstly, the density (seedling numbers), the richness, and the diversity and species composition were compared among areas of different sucessional stages, and among different soil depths and season (rainy and dry season). After that, the similarity between the soil seed bank and local vegetation was compared. It was observed that the main source of variation of seedling numbers, richness, and species diversity was the depth at which seed samples were obtained. In overall, samples from the litterfall had significantly higher seedling numbers, species richness and diversity than the other depths (0-10cm and 10-20cm); this difference occurred at both in the rainy and dry season. Comparisons of species richness and diversity between the rainy and dry season showed that both significantly differed between seasons, and higher values were observed in the rainy season. Seedling numbers did not differ between seasons. Species composition was more similar between pairs of samples from depths near to each other; for example, for both seasons... (Complete abstract click electronic access below)

Tropical forests are extremely important ecosystems which play a substantial role in the global carbon budget and are increasingly dominated by anthropogenic disturbance through deforestation and forest degradation, contributing to emissions of greenhouse gases to the atmosphere. There is an urgent need for forest monitoring over extensive and inaccessible tropical forest which can be best accomplished using spaceborne satellite data. Currently, two key processes are extremely challenging to monitor: forest degradation and post-disturbance re-growth. The thesis work focuses on these key processes by considering change indicators derived from radar remote sensing signal that arise from changes in forest structure. The problem is tackled by exploiting spaceborne Synthetic Aperture Radar (SAR) and Interferometric SAR (InSAR) observations, which can provide forest structural information while simultaneously being able to collect data independently of cloud cover, haze and daylight conditions which is a great advantage over the tropics. The main principle of the work is that a connection can be established between the forest structure distribution in space and signal variation (spatial statistics) within backscatter and Digital Surface Models (DSMs) provided by SAR. In turn, forest structure spatial characteristics and changes are used to map forest condition (intact or degraded) or disturbance. The innovative approach focuses on looking for textural patterns (and their changes) in radar observations, then connecting these patterns to the forest state through supporting evidence from expert knowledge and auxiliary remote sensing observations (e.g. high resolution optical, aerial photography or LiDAR). These patterns are descriptors of the forest structural characteristics in a statistical sense, but are not estimates of physical properties, such as above-ground biomass or canopy height. The thesis tests and develops methods using novel remote sensing technology (e.g. single-pass spaceborne InSAR) and modern image statistical analysis methods (wavelet-based space-scale analysis). The work is developed on an experimental basis and articulated in three test cases, each addressing a particular observational setting, analytical method and thematic context. The first paper deals with textural backscatter patterns (C-band ENVISAT ASAR and L-band ALOS PALSAR) in semi-deciduous closed forest in Cameroon. Analysis concludes that intact forest and degraded forest (arising from selective logging) are significantly different based on canopy structural properties when measured by wavelet based space-scale analysis. In this case, C-band data are more effective than longer wavelength L-band data. Such a result could be explained by the lower wave penetration into the forest volume at shorter wavelength, with the mechanism driving the differences between the two forest states arising from upper canopy heterogeneity. In the second paper, wavelet based space-scale analysis is also used to provide information on upper canopy structure. A DSM derived from TanDEM-X acquired in 2014 was used to discriminate primary lowland Dipterocarp forest, secondary forest, mixed-scrub and grassland in the Sungai Wain Protection Forest (East Kalimantan, Indonesian Borneo) which was affected by the 1997/1998 El Niño Southern Oscillation (ENSO). The Jeffries- Matusita separability of wavelet spectral measures of InSAR DSMs between primary and secondary forest was in some cases comparable to results achieved by high resolution LiDAR data. The third test case introduces a temporal component, with change detection aimed at detecting forest structure changes provided by differencing TanDEM-X DSMs acquired at two dates separated by one year (2012-2013) in the Republic of Congo. The method enables cancelling out the component due to terrain elevation which is constant between the two dates, and therefore the signal related to the forest structure change is provided. Object-based change detection successfully mapped a gradient of forest volume loss (deforestation/forest degradation) and forest volume gain (post-disturbance re-growth). Results indicate that the combination of InSAR observations and wavelet based space-scale analysis is the most promising way to measure differences in forest structure arising from forest fires. Equally, the process of forest degradation due to shifting cultivation and post-disturbance re-growth can be best detected using multiple InSAR observations. From the experiments conducted, single-pass InSAR appears to be the most promising remote sensing technology to detect forest structure changes, as it provides three-dimensional information and with no temporal decorrelation. This type of information is not available in optical remote sensing and only partially available (through a 2D mapping) in SAR backscatter. It is advised that future research or operational endeavours aimed at mapping and monitoring forest degradation/regrowth should take advantage of the only currently available high resolution spaceborne single-pass InSAR mission (TanDEM-X). Moreover, the results contribute to increase knowledge related to the role of SAR and InSAR for monitoring degraded forest and tracking the process of forest degradation which is a priority but still highly challenging to detect. In the future the techniques developed in the thesis work could be used to some extent to support REDD+ initiatives.

Submitted by LAURA CAROLINA BELLO LOZANO (caro.bello58@gmail.com) on 2018-09-13T18:59:34Z No. of bitstreams: 1 Tese Carolina Bello new version.pdf: 7168608 bytes, checksum: f47469d76b0f113d4401a511c5b9c908 (MD5) / Rejected by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: - Capa: deve seguir o modelo da seção de pós-graduação. Verificar (Modelo de capa) no site http://ib.rc.unesp.br/#!/pos-graduacao/secao-tecnica-de-pos/programas/ecologia-e-biodiversidade/normas/ - Página de rosto: retirar a informação da Comissão Examinadora e os membros - Nome: o seu nome deve estar completo na capa, na página de rosto e na ficha catalográfica - Título: o título deve seguir a folha de aprovação, ou seja, somente o título em inglês. Alterar o título da capa, da página de rosto e da ficha catalográrica. - Ficha catalográfica: solicitar alteração do seu nome e do título no site da biblioteca Agradecemos a compreensão. on 2018-09-14T11:36:38Z (GMT) / Submitted by LAURA CAROLINA BELLO LOZANO (caro.bello58@gmail.com) on 2018-09-14T15:22:10Z No. of bitstreams: 1 Bello teses versao imprimir OK grafica.pdf: 7240972 bytes, checksum: 78f64ec47aed13ae323c0ead8ce43294 (MD5) / Approved for entry into archive by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br) on 2018-09-14T16:34:34Z (GMT) No. of bitstreams: 1 bello-lozano_lc_dr_rcla.pdf: 6995897 bytes, checksum: 3eab07c5fa5a3be2ac3b78242a7a7f8e (MD5) / Made available in DSpace on 2018-09-14T16:34:35Z (GMT). No. of bitstreams: 1 bello-lozano_lc_dr_rcla.pdf: 6995897 bytes, checksum: 3eab07c5fa5a3be2ac3b78242a7a7f8e (MD5) Previous issue date: 2018-07-27 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A extinção de animais é uma ameaça silenciosa nas florestas tropicais. As florestas tropicais estão se tornando ecossistemas defaunados, especialmente de animais de grande porte. No entanto, a defaunação vai além da perda de animais carismáticos, o que estamos perdendo são interações fundamentais que modulam a funcionalidade da floresta e, portanto, dos serviços ecossistêmicos associados. A defaunação tem efeitos sobre a dispersão de sementes, a ciclagem de nutrientes, a qualidade da água, a manipulação de matéria fecal, entre outros serviços ecossistêmicos. Nesta tese, exploramos os efeitos da defaunação de grandes animais no serviço ecosistêmico de estoque de carbono em florestas tropicais. Nós encontramos que o serviço ecossistêmico de armazenamento de carbono está sustentado pelos animais de grande porte, isso porque frugívoros grandes são os principais dispersores de árvores com sementes grandes e, as árvores com sementes grandes tendem a ser altas e com madeira densa, armazenando assim grandes quantidades de carbono. Portanto, a remoção de árvores de sementes grandes das florestas, devido à perda de dispersão induzida pela falta dos grandes frugívoros, pode reduzir o potencial do estoque de carbono da floresta. No entanto, a redução não é direta porque os frugívoros menores podem compensar parcialmente a perda dos grandes frugívoros. Além disso, a perda de grandes predadores de sementes também pode afetar o potencial estoque de carbono. Em comunidades fortemente defaunadas, pequenos roedores tendem a aumentar a sua abundância e a predação de sementes grandes, reduzindo assim o recrutamento deste tipo de árvore. Finalmente, nós exploramos o impacto da relação entre defaunação e o armazenamento potencial de carbono em programas de conservação. Nós mostramos que os projetos de restauração estão promovendo ecossistemas defaunados porque estes são dominados por árvores anemocóricas ou árvores de sementes pequenas que não irão fornecer recurso alimentar suficiente para animais grandes. Além disso, observamos que a falta de animais de grande porte pode produzir impactos econômicos nos mercados de carbono. Enfatizamos a necessidade urgente de integrar o papel dos animais em estratégias de restauração e mitigação das mudanças climáticas. O impacto econômico da defaunação no orçamento de carbono é um bom argumento para inserir os animais neste tipo de programas. Logo, devemos concentrar esforços no desenvolvimento de novas políticas nacionais e internacionais para proteger as florestas das "frentes de defaunação" assim como se tem feito com as “frentes de desmatamento." / Animal loss is a silent threat of forest ecosystem. Tropical forests are becoming defaunated ecosystems, especially defaunated of large animals. The loss of animals goes beyond than the loss of charismatic animals, what we are losing are key interactions that modulate the functionality of the forest and therefore of the associated ecosystem services. For instance, defaunation have effects over seed dispersal, nutrient cycling, water quality and dung removal among others ecosystem services. In this thesis, we explore the potential effects of defaunation of large animals in carbon stock ecosystem services of tropical forest. We found that the carbon stock ecosystem service is supported by large animals due to large frugivores are the main dispersers of large-seeded trees and, large-seeded trees tend to be tall trees with dense wood, therefore, store high quantities of carbon. Hence, the removal of large-seeded trees from the forest, because of diminished dispersal induced by the lack of large frugivores, reduce the carbon stock potential of the forest. However, the reduction is not straightforward because smaller frugivores can partially compensate for the loss of large frugivores. Moreover, strong defaunation effects in the seed predators communities can also affect the carbon stock potential of the forest. In strongly defaunated communities small rodents tend to increase their abundance and the predation pressure over large seeds, reducing their recruitment. In addition, we explore the impact of defaunation and carbon stock relation in conservation programs. We show that restoration projects are promoting defaunated ecosystems because they are dominated by abiotic trees or small-seeded trees, which will not provide enough food to large animals. Besides we observed that the lack of large animals can produce economic impacts in the carbon markets. Therefore, we argue the urgent necessity of integrating the animal role in restoration and climate mitigation strategies to. The economic impact of animal defaunation on carbon budget is a good argument to introduce animals in REED+ markets and forest restoration strategies. Within this evidence, we claim for the development of new national and international policy frames to protect forests from ‘defaunation fronts’ as well as has been done with ‘deforestation fronts’. / La extinción de animales es una amenaza silenciosa en los bosques tropicales. Los bosques tropicales se están convirtiendo en ecosistemas defaunados, especialmente despoblados de grandes animales. Esta pérdida de animales va más allá de la pérdida de animales carismáticos, lo que estamos perdiendo son interacciones clave que modulan la funcionalidad del bosque y, por lo tanto, de los servicios ecosistémicos asociados. Por ejemplo, la defaunación tiene efectos sobre la dispersión de semillas, el ciclo de nutrientes, la calidad del agua, la eliminación de excrementos, entre otros servicios de los ecosistemas. A través de esta tesis, exploramos los efectos potenciales de la defaunación de animales grandes en el servicio ecosistémico de almacenamiento de carbono de los bosques tropicales. Encontramos que el almacenamiento de carbono es soportado por animales grandes debido a que los frugívoros grandes son los principales dispersores de árboles con semillas grandes y, los árboles con semillas grandes tienden a ser árboles altos con madera densa, y consequentemente, almacenan altas cantidades de carbono. En consecuencia, la eliminación de árboles de semilla grande del bosque, debido a la dispersión disminuida inducida por la falta de grandes frugívoros, puede reducir el potencial de reserva de carbono del bosque. Sin embargo, la reducción no es directa debido a que los frugívoros más pequeños pueden compensar parcialmente la pérdida de frugívoros grandes. Además, los fuertes efectos de defaunación en las comunidades de depredadores de semillas también pueden afectar el potencial de reserva de carbono del bosque debido a que, en las comunidades fuertemente defaunadas los pequeños roedores tienden a aumentar su abundancia y la presión de depredación sobre las semillas grandes, reduciendo su reclutamiento. Finalmente, exploramos el impacto de la relación entre la defaunación y el potencial de carbono de los bosques tropicales en los programas de conservación. Mostramos que los proyectos de restauración están promoviendo ecosistemas defaunados porque están dominados por árboles abióticos o árboles de semilla pequeña, que no proporcionarán suficiente alimento a los animales grandes. Además, la falta de animales grandes puede producir impactos económicos en los mercados de carbono. Por lo tanto, recalcamos la necesidad urgente de integrar el papel de los animales en las estrategias de restauración y mitigación del cambio climático. El impacto económico de la defaunación de animales en los mercados de carbono es un buen argumento para introducir los animales en los proyectos REED+ y las estrategias de restauración forestal. A partir de estas evidencias, reivindicamos la necesidad de desarrollar nuevos marcos de políticas nacionales e internacionales para proteger los bosques de los "frentes de la defaunación", así como se ha hecho con los "frentes de deforestación". / FAPESP: 2013/22492-2 / FAPESP: 2015/23770-1

Orientador: Marcelo Nogueira Rossi / Coorientador: Renata Cristina Batista Fonseca / Coorientador: Vera Lex Engel / Banca: Maria Tereza Grombone Guaratini / Banca: Wesley Augusto Conde Godoy / Banca: Rita de Cássia S. Maimoni Rodella / Banca: João Nakagawa / Resumo: Para um melhor entendimento dos processos que determinam a dinâmica das florestas tropicais, estudos que investigam tanto a vegetação (parte aérea) como o banco de sementes do solo, são necessários. Através de estudos de banco de semente pode-se avaliar, por exemplo, a capacidade de regeneração natural de uma dada vegetação, a viabilidade das sementes existentes no solo e sua influência na estrutura da vegetação. No entanto, pouco se sabe sobre os processos que podem provocar variações na estrutura do banco de sementes, especialmente em florestas semideciduais. O presente estudo teve como objetivo conhecer a composição do banco de sementes do solo em um trecho de Floresta Estacional Semidecídual, bem como investigar possíveis processos capazes de gerar variações em sua estrutura. Além disso, determinou-se o grau de similaridade entre a parte aérea e o banco de sementes. Primeiramente, a densidade (número de plântulas), a riqueza, a diversidade e a composição de espécies foram comparadas entre áreas em diferentes estágios sucessionais, bem como entre diferentes profundidades do solo e estações do ano (chuvosa e seca). Em seguida, a similaridade entre o banco de sementes e a vegetação local foi comparada. Constatou-se que a principal fonte de variação do número de plântulas, da riqueza e da diversidade de espécies presentes no banco de sementes foi a profundidade na qual as sementes foram amostradas. De forma geral, as amostras obtidas da serrapilheira continham, significativamente, um maior número de plântulas, uma maior riqueza e maior diversidade de espécies do que as amostras provenientes das profundidades de 0-10cm e 10-20cm, tanto na estação chuvosa como seca. Comparações da riqueza e da diversidade de espécies entre a estação seca e chuvosa... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: For a better understanding of the processes that determine tropical forest dynamics, studies that investigate vegetation both above and below ground are needed. By studying seed banks it is possible to determine, for example, the natural regeneration capacity of vegetation, the viability of the soil seed bank as well as its influence at structuring plant communities. However, little is known about the processes that can generate variation in the seed bank structure, particularly in semideciduous forests. The main aim of this study was to know the soil seed bank composition in a semideciduous seasonal forest fragment, and also to investigate some processes that may generate variations in this structure. Besides, it was determined below (seed bank) and above ground (vegetation) similarity. Firstly, the density (seedling numbers), the richness, and the diversity and species composition were compared among areas of different sucessional stages, and among different soil depths and season (rainy and dry season). After that, the similarity between the soil seed bank and local vegetation was compared. It was observed that the main source of variation of seedling numbers, richness, and species diversity was the depth at which seed samples were obtained. In overall, samples from the litterfall had significantly higher seedling numbers, species richness and diversity than the other depths (0-10cm and 10-20cm); this difference occurred at both in the rainy and dry season. Comparisons of species richness and diversity between the rainy and dry season showed that both significantly differed between seasons, and higher values were observed in the rainy season. Seedling numbers did not differ between seasons. Species composition was more similar between pairs of samples from depths near to each other; for example, for both seasons... (Complete abstract click electronic access below) / Doutor