Dissertações em Ciências Ambientais (Mestrado) - PPGCA/IG

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2855

O Mestrado Acadêmico em Ciências Ambientais teve início em 2005 e funciona no Programa de Pós-Graduação em Ciências Ambientais (PPGCA) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA) em parceria com o Museu Paraense Emílio Goeldi (MPEG) e a Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA/Amazônia Oriental).

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Acesso aberto (Open Access)
Dinâmica do carbono dissolvido no Rio Acre: variações espaciais e sazonais
(Universidade Federal do Pará, 2007) SOUSA, Eliete dos Santos; SALIMON, Cleber Ibraim; http://lattes.cnpq.br/4353834821288043; FIGUEIREDO, Ricardo de Oliveira; http://lattes.cnpq.br/2388049759708934
The main objective of this study was to study the dissolved carbon dynamics along a reach of the Acre River, evaluating the influence of Rio Branco city urban area and of the discharge from three of its tributaries (Riozinho do Rola, igarapé Judia and igarapé São Francisco), as well as the influence of hydrological seasonal changes. Samples were taken monthly, between December 2006 and September 2007, at five sites in Acre River and one site at the tributaries mouths. Each sample consisted of 1 liter of river/tributary water, which was submitted to filtering and aliquots withdrawn for dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and major ions (Ca2+, Mg2+, K+, Na+, NH4 +, HCO3 -, Cl-, SO4 2-, NO3 -, NO2 -, e PO4 3-) analysis. Electrical conductivity, pH, dissolved oxygen and water temperature measurements were also made. Mean annual pH in Acre River varied from 6.46 to 6.54 between sites and electrical conductivity presented mean values from 69.93 to 77.84 μS cm-1. In the tributaries, the mean annual pH ranged from 6.10 to 6.51 and electrical conductivity presented annual means from 54.08 and 153.03 μS cm-1. Na+ and Ca2+ were the dominant cations for both Acre River and its tributaries, while main anions were Cland SO4 2-. The mean annual DOC concentration in Acre River ranged from 4.62 to 5.17 mg l-1, with no significant difference among sampling sites. The tributaries’ mean annual DOC concentrations varied from 3.55 to 6.55 mg l-1. The concentrations were significantly higher in the high water period, with averages that ranged from 6.26 to 6.39 mg l-1 in Acre River sites. igarapé São Francisco was the only tributary that did not present differences between the seasons. Mean annual DIC concentration in Acre River ranged from 527.91 to 598.18 μM, with no significant difference among sampling sites. The higher concentrations were observed in the dry season, ranging from 816.31 to 998.52 μM. Mean annual DIC concentration in the tributaries ranged from 248.54 to 986.50 μM. Mean annual CO2 partial pressure (pCO2) in Acre River sites ranged from 3559 and 4059 ppm, with no significant differences among sites and with higher values in high waters. Based on these results, we conclude that the dissolved carbon dynamics in Acre River have not presented significant variations due to the tributaries discharge or due to the sewage discarded. On the other hand, hydrological seasonal changes are the most important drivers for changes in carbon dynamics.
Acesso aberto (Open Access)
Dinâmica do carbono em pequenas bacias de drenagem sob uso de agricultura familiar na Amazônia Oriental
(Universidade Federal do Pará, 2007) ROSA, Maria Beatriz Silva da; FIGUEIREDO, Ricardo de Oliveira; http://lattes.cnpq.br/2388049759708934
This research was designed to evaluate carbon dynamics in Eastern Amazon, where the main land use is small holder farming, and was conducted in three small catchments. Carbon dynamics was evaluated considering hydrological and biogeochemical measurements in Cumaru, Pachibá and São João streams from June 2006 to May 2007. Aquatic environment and fluvial hydrogeochemistry were characterized through in situ measures of electrical conductivity, temperature, pH and dissolved oxygen concentration. Water samples were collected and analyzed to determine dissolved organic carbon (DOC) concentrations and carbon dioxide partial pressures (pCO2). Concentrations of dissolved inorganic carbon (DIC) were calculated from pCO2 values. Despite being calculated from pCO2 values, CO2 fluxes were also measured in situ. Instantaneous discharge was measured in each month field campaign and used to calculate DOC annual fluxes. Soil and land use characterization in the study watersheds, as well as precipitation and discharge rates, were considered for results interpretation. Main results were: 1) Stream water physic-chemical characteristics in the study catchments respond to the acid soils, riparian vegetation, and the hydrological and biogeochemical processes in the terrestrial and aquatic ecosystems, and present some seasonal variation. 2) Dissolved carbon concentrations was correlated with pH and dissolved oxygen in stream water; 3) DOC fluxes weighted by area were higher than in other Amazonian watersheds and even higher during rainy season; 4) DOC fluxes and CO2 evasion seem to respond positively to riparian vegetation and mature forest, and negatively to agriculture; 5) CO2 evasion rates were higher than in other Amazonian rivers corroborating the hypothesis that small catchments are important sources of atmospheric CO2 in the region.
Acesso aberto (Open Access)
Efeitos do processamento artesanal de raízes de mandioca (Manihot esculenta Crantz) e plantas de malva (Urena lobata L.) sobre a hidrobiogeoquímica de microbacias do Nordeste do Pará
(Universidade Federal do Pará, 2011) PIRES, Camila da Silva; FIGUEIREDO, Ricardo de Oliveira; http://lattes.cnpq.br/2388049759708934
Cassava and caesar weed are among the mainly products of the familiar agriculture in the Northeast of the Pará State. To treat these products the small farmers used to sink amounts of cassava and caesar weed in small streams (regionally named as "igarapés"), to make peal softer and remove its toxic compounds, in the case of cassava, or to promote defibrating in the case of the caesar weed. The effects of these practices to the stream water quality are poor known. In this context, this study aimed to evaluate the potential impacts of these practices to the fluvial hydrobiogeochemistry in the "igarapés" of these region. We adopted the strategy of collect stream water samples before the washing point of these products, in the washing point, and ten meters after this point. For a clearer understanding of the feasible alterations of the water chemistry due to cassava and caesar weed washing it was conducted besides the field monitoring a controlled input and output discharge tank experiment. In both approaches it was measured in the dissolved material the following hydrobiogeochemical: pH, electric conductivity, dissolved oxygen, calcium, magnesium, potassium, sodium, chloride, sulfate, phosphate, nitrate, ammonium, as well as total nitrogen total and organic and inorganic carbon. Our results point out that these cassava and caesar weed washing processes contribute to alter the fluvial hydrobiogeochemistry of these small streams only locally. However, some of the observed local alterations remained along at least ten meters downstream the products washing points. In the tank experiments the alteration were observed clearer and a cluster analysis confirmed the hypotheses that these rude treatments of the studied agriculture products contributes to change the fluvial hydrogeochemistry of the monitored small streams. The study recommends some precautions regarding to the evaluated products treatments and also the adoption of some parameters measurements to monitor these impacts.
Acesso aberto (Open Access)
Estrutura de comunidades de peixes de igarapés de três pequenas bacias de drenagem sob uso de Agricultura Familiar no Nordeste Paraense
(Universidade Federal do Pará, 2007-11-26) CORRÊA, Jean Michel; GERHARD, Pedro; http://lattes.cnpq.br/5621269098705408; FIGUEIREDO, Ricardo de Oliveira; http://lattes.cnpq.br/2388049759708934
Stream fish species can be distributed in space and time and in an organized pattern, which can be observed on the association of groups of species and their relationship to certain habitats. The reduced number of studies and the scarce knowledge on the aquatic fauna in Amazon contribute to the under-estimation of the magnitude of impacts upon lotic habitats and stream fish fauna. The Bragantina Region, in the northeast portion of Pará, is an example of an old agricultural frontier in the Amazon. Smallholder farming in the area is expressive, the main cultures are corn, caupi, and cassava, and semi-perennial cultures, such as “maracujá” (passion fruit) and “pimenta-do-reino” (black pepper). The areas of familiar production are a dominant feature of the landscape, thus contributing to most of the soil and aquatic ecosystem degradation. Aiming at the description of stream fish communities and its relations to environmental variables, a two-year study was carried out in eight reaches of three streams located in this region: Cumaru, São João and Pachibá streams. After nine monthly collections, 2.117 fishes were collected, distributed in seven orders, 13 families, 27 genera and 43 species. The most abundant species in all samples was Hypessobrycon heterorhabudus, totalling 337 individuals, followed by Bryconops caudomaculatus, with 326 individuals. The species richness was highest in a Pachibá stream reach (IGPA-B), with 21 species. Simpson’s diversity index showed the highest species dominance in a Cumaru stream reach, while Shannon’s diversity index showed that the IGPA-B had the greatest diversity. Iguanodectes spirulus was the most constant species, occurring in 50% of samples. The similarity between the environments showed that the distribution of species followed a longitudinal pattern instead of a geographic pattern. Land use, specially small farms, did not affect the ichthyofauna, since the low intensification of this activity still permit some integrity to aquatic ecosystem. However, as agriculture system intensification increases in the future, we do not know what will be the ecosystem response.
Acesso aberto (Open Access)
Fluxos hidrogeoquímicos em águas fluviais de microbacias do nordeste paraense e a sua relação com o uso da terra
(Universidade Federal do Pará, 2011) BARROSO, Daniel Fernandes Rodrigues; FIGUEIREDO, Ricardo de Oliveira; http://lattes.cnpq.br/2388049759708934
The Northeast of Pará is characterized by the Amazonian old settlements, where the slash and burn small farming and large pastures are predominant. Its landscape is dominated by secondary vegetation at a widely succession stage and very few mature forest remnant, which are generally situated along the rivers and streams. In this context, the present study was conducted in fourteen small catchments under different land use and four other small catchments in forested areas under low anthropic impact, with the objective of evaluating the fluvial hydrogeochemistry to support two mesobasins management in the studied region. It was detected that the chemical composition of the evaluated small stream waters is being affected by the agriculture practices adopted in their drainage areas. Hydrogeochemical changing signals were observed for the small catchments where the predominant land uses are: slash-and-burn small farming; crops with irrigation and agrochemical; and cattle farming. Moreover, we observed the importance of the forested catchments for nitrate, chloride and sodium inputs to the studied stream ecosystems. In addition, it was verified a seasonal fluvial hydrogeochemistry variation and strong effects of agriculture systems, especially cattle farming, to the monitored physic-chemical parameters, as the dissolved oxygen concentration decrease, besides the increasing of temperature, pH and electric conductivity. By the results of the present research we can infer that riparian forest is indispensable to mitigate the impacts of the agriculture systems to the water resources, and should be pointed as an important tool in the watershed management, as well as the substitution of slash-and-burn for more sustainable agriculture practices as chop-and-mulching for instance. Finally, we suggest that some of the analyzed parameters can be recommended, according to the focused land use, as environment sustainable indicators of the agriculture systems along the local watershed management in the region.
Acesso aberto (Open Access)
Relações entre os sistemas de produção agropecuários adotados e a qualidade da água em igarapés amazônicos de duas bacias hidrográficas na região de Paragominas (PA)
(Universidade Federal do Pará, 2007) GONÇALVES, Sabrina Forte e Silva; MONTEIRO, Maurílio de Abreu; http://lattes.cnpq.br/8077335023133373; FIGUEIREDO, Ricardo de Oliveira; http://lattes.cnpq.br/2388049759708934
Concerning water scarcity the Brazilian Amazon is a privileged region as Amazon Basin presents high precipitation rates and is the largest river basin in the world (6,925,000 km2), in which almost 63% of the area is situated in Brazil. However, its water quality is in dangerous nowadays, due to an accelerated process of occupation of Eastern Amazon that was initiated in 1958 with the building of Belém- Brasília highway, and that has promoted great landscape changes related to timber and agriculture activities. Considering the significant differences in the water resources use and environmental impacts on them, related to different social agents, specifically those of cattle farm and grain crops in Eastern Amazon, we designed a research to identify and evaluate the conditioning factors which influence farmers behaviors of Cinquenta e Quatro and Sete streams catchments in Paragominas (PA). In this context, we tried to verify if this social actors use appropriated agriculture practices in the production systems that they have adopted, including the soil management, and if they have any proactive worry for the Amazonian streams conservation that run through their lands, especially water quality maintenance. Secondary data of water quality and land use dynamic in these watersheds has supported this work research by being related to agriculture practices and soil management adopted in the studied farms. Some conditioning factors that influence farm management have been identified as those that promoted land use and land cover changes in the studied small catchments resulting in different level of impacts to water stream quality. These factors are: (1) land occupation and farm management patterns adopted by the different social agents in the watersheds; (2) the disobedience to environmental law that says about natural resources preservation policies, especially water resources; (3) the economic interests that prioritizes fast productivity and profitability over the sustainability of natural capital water; and (4) the called conservationist agriculture techniques that do not stimulate a integrated vision among the different landscape components and that do not consider impacts to water resources. We conclude that water quality in Cinquenta e Quatro and Sete streams catchments is mainly threatened by the agriculture practices and land management that have being done by the farmers. Among the identified factors we highlighted that the adoption or no adoption of conservationist techniques, when these ones are not coupled with an integrated vision of environmental compartments, have little influence to water resources in the studied catchments, as in a general way law conservation areas are not being respected. Through environmental Brazilian law view, the observed consequence is that the multiple water use in these catchments is threatened.

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