Teses em Geologia e Geoquímica (Doutorado) - PPGG/IG
URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/6341
O Doutorado Acadêmico pertence ao Programa de Pós-Graduação em Geologia e Geoquímica (PPGG) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA).
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Navegando Teses em Geologia e Geoquímica (Doutorado) - PPGG/IG por Assunto "Ecologia dos manguezais"
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Tese Acesso aberto (Open Access) Análise da dinâmica das áreas de manguezal no litoral Norte do Brasil a partir de dados multisensores e hidrossedimentológicos(Universidade Federal do Pará, 2016-12-16) NASCIMENTO JUNIOR, Wilson da Rocha; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252The objective of this research is to analyze the dynamics of the mangrove areas in the north coast of Brazil from images of remote orbital sensors and hydrosedimentological data (flow and suspened sediment concentration). We tried to understand the existence of causality between the expansion or retraction of the mangroves with the suspened solid discharge calculated from the data of flow and suspened sediment concentration. The mangroves were mapped, using the object oriented classification technique, in the years 1975, 1996 and 2008 based on data from microwave sensors (RADAM / GEMS, JERS-1, ALOS / PALSAR). The data of fluviometric stations and sediments of the National Water Agency were used to calculate the solid discharge in suspension in the rivers Araguari, Gurupi, Pindaré, Grajaú and Mearim seeking to relate the addition and erosion in the areas of mangrove with the sedimentary load of the rivers that drain On the coast. The flow variations reflect the precipitation in the sub-basins of the analyzed rivers and presented a strong and moderate correlation with the temperature anomalies on the surface of the Pacific Ocean evidencing a relation of the El Niño and La Niña phenomena with the precipitation regimes in the Amazon. The variations of suspended sediment concentration were not related to the fluviometric variation suggesting that the annual mean oscillations are reflections of other phenomena (coverage and land use). The results show that the drainage areas of the sub-basins most impacted by the anthropic action contribute with a higher sediment load to rivers that have a higher concentration of native forest. Native vegetation contributes to containment of soil erosion and exposed soil and pasture areas are more vulnerable to soil erosion. The Gurupi, Pindaré, Grajaú and Mearim Rivers presented solid suspended load higher than or equal to the Araguari River. Analyzing the mangroves in the estuaries we noticed the addition of mangroves along the estuaries of the Gurupi and Mearim rivers (Baia de São Marcos) and the reduction of mangrove areas in the Araguari estuary. The Amazon coastal zone is subject to natural processes of great magnitude, but atrophic activities influence the natural dynamics of the region by implementing unsustainable economic practices.Tese Acesso aberto (Open Access) Desenvolvimento da vegetação e morfologia da foz do Amazonas-PA e rio Doce-ES durante o Quaternário tardio(Universidade Federal do Pará, 2013-11-05) FRANÇA, Marlon Carlos; PESSENDA, Luiz Carlos Ruiz; http://lattes.cnpq.br/0425441943533975; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228This work compares the vegetation and morphological changes occurred along the littoral of the Marajó Island, Amazonian littoral, and the coastal plain of the Rio Doce, southeastern Brazil, during the Holocene and late Pleistocene/Holocene, respectively, focused specifically on the response of mangroves to sea-level fluctuations and climate change, which have been identified in several studies along the Brazilian coast. This integrated approach combined radiocarbon dating, description of sedimentary features, pollen data, and organic geochemical indicators (δ13C, δ1₵N and C/N). On coastal plain of the Doce River between ~47,500 and ~29,400 cal yr BP, a deltaic system was developed in response mainly to sea-level fall. The post-glacial sea-level rise caused a marine incursion with invasion of embayed coast and broad valleys, and it favored the evolution of a lagoonal/estuary system with wide tidal mud flats occupied by mangroves between at least ~7400 and ~5100 cal yr BP. Considering the Marajó Island during the early and middle Holocene (~7500 and ~3200 cal yr BP) mangrove area increased over tidal mud flats with accumulation of estuarine/marine organic matter. It was a consequence of the marine incursion caused by post-glacial sea-level rise, further driven by tectonic subsidence. Dry conditions in the Amazon region during this time led to a rise is tidal water salinity and contributed to mangrove expansion. Therefore the effect of relative sea-level (RSL) rise was determinant to the mangrove establishment in the southeastern and northern region. During the late Holocene (~3050 – 1880 cal yr BP) the mangroves in both regions were retracted to a small area, with some areas replaced by freshwater vegetation. This was caused by the increase in river discharge associated to a wet period recorded in the Amazon region, and considering the coastal plain of the Doce River (southeastern Brazil), the mangroves shrank in response to an increase in fluvial sediment input associated to a sea-level fall.Tese Acesso aberto (Open Access) Dinâmica de nutrientes e da matéria orgânica no manguezal do Igarapé Nunca Mais - Ilha de São Luís (MA)(Universidade Federal do Pará, 2002-11-22) MELO, Odilon Teixeira de; LIMA, Waterloo Napoleão de; http://lattes.cnpq.br/1229104235556506It is well known that the State of Maranhão has more than fourty percent of the Brazilian mangroves covering an área with almost 4800km2 and along of 640km of coastline. These mangrove swamps border a number of tidal channels, bays, gulfs, and others estuarine systems, where the macro-tidal system gives a singular condition to this environment, that it is different from the others Brazilian áreas. The exportation of macro-particles from the mangroves to the coastal waters is well known. However, there is a discussion if the mangroves import or export micro-particles and dissolved nutrients to the coastal areas. Few studies have been developed in this subject due to the methodological complexities of the flow calculations. The choice of the pilot-area for this study is the igarapé Nunca Mais, a tidal channel surrounded by an area of 1.22km2 of mangrove ecosystem, situated in the Northeastern portion of the São Luís Island. This choice is due bay the fact that in this area occurs exchanges with the coastal waters from the Maranhão Gulf take place. This tidal channel is the main transport pathway between the mangrove and the coastal waters. During the spring tides this mangrove is completly flooded. The main aim of this study was to evaluate the role of a mangrove region — Maranhão Gulf — in a macro-tidal area in exchanging of materials with the coastal waters. The characterization and quantification of the dissolved inorganic nutrients and the organic matter were the main focuses of this study. For this purpose were utilized flows calculations from "Eulerian" method. During the period of 13 months (from April 2000 to April 2001), in the neap and spring fluxes of the dissolved inorganic nutrients (ammonium, nitrite, nitrate, phosphate, and silicate) and those of the organic matter (organic carbon, organic nitrogen, and organic phosphorus) were determined along 52 tidal cycles. For the characterization of organic matter were used elemental ratio C/N, isotopes 13C and 15N ratio, and by the identification of dissolved humic substances as tracers for organic matter sources. The differences on day clear and orvernight show average values from 0960 for the pH and salinity, positive values of 5, 6, 8 and 11%, respectively, for nitrate, phosphate, ammonium, and silicate, and negative values for the oxygen (-10%), and for the dissolved and particulate organic matter (-1% to -6%). The dissolved nutrients and organic matter varies such as tidal ranges showing maximum values in the low tile, indicating flow from intersticial water of the mangrove for the tidal channel. Particulate organic matter values show variations relationships with current velocity showing resuspension and sediment transport. This fact confirms that the biological processes, such as nutrient consumption and organic matter deposition, in the tidal channel, and the tidal dynamics were relevants in the lief variations. The results obtained in this study show a seasonal variation with minium values in the dry season, except for the silicate, and maximum values in the rainy season, showing the raro precipitation influence in the transport from mangrove for the coastal waters. In addition, in the dry period, occurs maximum consumption of nutrient by phytoplancton, as well as, observed on primary production. It was evidencied also lower values in the concentration of particulate organic matter during this dry season due the lower fluxes values from the mangrove. The net exportation of inorganic nutrients and the organic matter in the mangroves of the São Luís Island (Maranhão State, Brazil), in the tidal channel Igarapé Nunca Mais, is evidencied in this study by interpretation of the flows calculations and the values from C/N. rations, elemental and isotopic. The isotopes of C and N used here as tracers lead to the identification of the primary sources of the organic matter in the tidal channel, i.e., the originated from mangroves, the coastal waters, and the resulting from allochthonous production. During the rainy period there are dominance of the organic matter (dissolved and particulate) transported from the mangrove, while in the dry period the marine and autochthonous sources are more considerables. The photosynthesis of the phytoplancton, in the tidal channel, justifies the autochthonous production. The net exportation of the dissolved organic matter for the coastal waters is slightly superior to the particulate organic matter (DOM, 14mM-2.day-1; POM, 20mM.m.-2.day-1). Perhaps this difference is due a fast sedimentation in the intermediary zune of the tidal channel that have the biggest profundity; this fact leads a minor quantity of particulates exported for coastal waters. It infers that this organic matter is constititued, dominantly, by humic substances because they are more refractory to the bacterial activity and consequently they can be transported by tidal currents for the adjacent coastal waters. Of course, the tidal amplitude ranges and pluviometric precipitation are relevant factors in these exportation processes. By this exposition, this study confirms the important role of mangrove for the fertilization of the coastal waters of Maranhão Gulf.