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Programa de Pós-Graduação em Ciências Ambientais - PPGCA/IG

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2854

O Programa de Pós-Graduação em Ciências Ambientais (PPGCA) integra o Instituto de Geocências (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) iniciou suas atividades em 2005 com o Mestrado Acadêmico e em 2011 com o Doutorado Acadêmico.

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Acesso aberto (Open Access)
Uma estrada na reserva: impactos sócioambientais da PA-136 em Mãe Grande, Curuçá, (PA)
(Universidade Federal do Pará, 2007) FIGUEIREDO, Elida Moura; FURTADO, Lourdes Gonçalves; http://lattes.cnpq.br/1828475659148260; CASTRO, Edna Maria Ramos de; http://lattes.cnpq.br/4702941668727146
The ambiental changes of the Amazonia, are going along a certain seria of factors and performances who demonstrate certain complexity of interests who go since any substitution from the forest to pasture and for agroindustry, until a superexploration of the fishing recourses, the construction of hidrelectrical units and exploration of minerals, among others. Despite an continued criction of Conservation Unids for the sense to maintain integrity as an part of the forest, it’s perceble that the devastation continued with alarmant numbers in each new year ho comes along. This canary, as roads have a fundamental paper. The arise ant expansion of roads in Amazonia are an great vectors of these changes, originating farther devastation, social changes, ambiental, economic and cultural, allowing conflicts and various tensions. On this mather, this work identifies and analisaises the social-ambiental impacts of the PA-136, road who connect the municipality as Castanhal to the community São João do Abade, area moun legally sinse 2000 as Extrativism Reserve Marina Mãe Grande, of the municipality Curuça, northeast of Para Stat.
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)
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.
Acesso aberto (Open Access)
Hidroquímica dos lagos Bolonha e Água Preta, mananciais de Belém-Pará
(Universidade Federal do Pará, 2007) SODRÉ, Silvana do Socorro Veloso; SANTOS, Maria de Lourdes Souza; http://lattes.cnpq.br/1604134738302499; ROCHA, Edson José Paulino da; http://lattes.cnpq.br/2313369423727020
Water for Belem’s Metropolitan Area is supplied by COSANPA (Companhia de Saneamento do Pará), which uses the water source of the lakes Utinga, Bolonha and Água Preta. These lakes are considered the most important in the region, and are responsible for the provision of water to 75% of that population. These water sources receive continuously a contribution of waters from Guamá River in order to maintain their water level. The period of study was 12 months (feb/2006 to jan/2007), using 12 sampling points (surface and bottom), being 11 points in Água Preta Lake (point 1 to 11) and 1 point in Bolonha Lake (point 12). All samples were obtained using a hydrologic bottle (Niskin). The objective of this research is to study abiological parameters such as temperature, turbidity, apparent color, electric conductivity, pH, dissolved oxygen, nitrate, N-amoniacal, phosphate, solids in suspension and the water’s transparency, in order to evaluate it’s behavior related to the lake’s seasonality and hydrology. The hydrological variables studied were input and output water flow, precipitation, water level variation and variation in the volume of waters. The batimetry in Água Preta Lake was accomplished to obtain current mean depth data.. A statistical treatment was applied to the results in order to evaluate the relationship between the studied parameters. Turbidity, apparent color and solids in suspension parameters reached higher concentrations in the period of minor precipitation and they presented values varying between 4 and 59 UNT; 15 to 550 mg L-1 Pt Co and 1 to 57 mg L-1, respectively. The electric conductivity presented a similar distribution when compared to the analyzed physical parameters, with higher concentrations in the period of minor precipitation, and it varied from 35,40 μ S / cm - 1 to 149,70 μ S / cm -1. The studied nutrients (nitrate, N-amoniacal and phosphate) presented the maximum values of 1,4 mg L-1, 1,34 mg L-1 and 1,6 mg L-1, respectively.
Acesso aberto (Open Access)
Balanço de água em área de cultivo de soja no Leste da Amazônia
(Universidade Federal do Pará, 2007) BISPO, Carlos José Capela; RIBEIRO, Aristides; http://lattes.cnpq.br/8652338930029697; ROCHA, Edson José Paulino da; http://lattes.cnpq.br/2313369423727020
The expansion of the agricultural frontier, driven mainly by soy cultivation (Glycine max (L) Merrill), covers a large regional extent and is highly important to understanding the changing face of Amazonia. A field observation experiment was established to study water balance components of the soy agriculture ecosystem and analyze the impact of the water balance associated with forest conversion. The experiment also evaluated the crop’s need for water according to its development phase. For the water balance study, the BRS Candeia cultivar was used along with its respective phenological phases. The experiment measured soil water storage, precipitation, plant cover water interception, superficial drainage of soil water, evapotranspiration (Etc), and water content retained by the soy plant. Water infiltration in the soil was also measured. Interception and superficial drainage were 45,9% and 1% of the precipitation, respectively. The greatest evapotranspiration occurred during the flowering phase (R1-R2) with a gradual decline in values until crop harvest and a cycle average of 3,80mm.day-1, which was very similar to that found in forest. The period between the vegetative phase (V) and fruiting (R3-R4) was when the plant presents the greatest percentage of water, declining gradually during the grain-forming phase (R5). Overall, no water deficiency occured in the mean soil water balance. Precipitation was greater than the amount necessary to compensate for evapotranspiration and supply adequate water storage, creating a surplus of water in the soil.
Acesso aberto (Open Access)
A representação social de áreas verdes em cidades: o caso Bosque Rodrigues Alves – Jardim Botânico da Amazônia
(Universidade Federal do Pará, 2007) CORRÊA, Homero Vilar; NASCIMENTO, Ivany Pinto; http://lattes.cnpq.br/6649004854958284; SANTOS JÚNIOR, Roberto Araújo de Oliveira; http://lattes.cnpq.br/9355107718329833
It was studied the importance of the Rodrigues Alves Botanical Garden for visitors. So, the history, the influence and the feelings about its green area preservation were consulted. For this interpretation, botanical garden visitors’s quiz was executed like research instrument. Like that, it was relating environment opinion about Rodrigues Alves Botanical Garden and social representation. In general, this work indicated botanical garden meaning for visitors and importance of the results to government.
Acesso aberto (Open Access)
Incidência de malária no Estado do Pará e suas relações com a variabilidade climática regional
(Universidade Federal do Pará, 2007-11-23) PARENTE, Andressa Tavares; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685
The objective of the present work is to approach a diagnostic study on the malaria incidence in four different regions over the Pará state in the eastern Amazon, seeking its relationships with the regional climate variability, with the population growth and rates of deforestation. Time series containing 35 years of annual data (1970-2005) and 14 years of monthly data are used. The percentiles technique was employed in order to establish five categories or classes of the malaria incidence rates and precipitation for each municipal district.Results based on the analyses using annual data showed that the cities present different factors that contribute to the endemic profile. The growth of the population has direct relationship with the increased malaria incidence in Anajás, Itaituba and Santana do Araguaia. In Anajás, the precipitation was not a decisive factor in the occurrence of the parasitosis. In Santana do Araguaia and Viseu the highest rates of the malaria incidence occurred in years with rainfall deficit. For Viseu, the normal precipitation pattern also categorized high malaria incidence. Concerning the deforestation rates from 1988 until 1995, the curves of malaria incidence follow the deforestation rates. From 1995 onwards, it was evidenced consecutive years of high rates of malaria incidence just after the years characterized with higher deforestation rates, as observed during 1995, 2000 and 2004. Composites analyses based on objective selection of the indices of malaria occurrence categorized by the percentiles, allowed to define annual features of the regional climate variability in each city. In general, years with higher malaria indices area associated with the Pacific El Niño and warmer than normal oceanic conditions over the north Atlantic basin, while the years with lower malaria indices are related to the Pacific La Niña and no significant signal in the tropical Atlantic Ocean. Results obtained from monthly data base, using composites based on objective selection of climate events observed over Pacific and Atlantic Oceans, it was investigated the response of such mechanisms on the monthly evolution of the malaria incidence over the Pará state. The El Niño composites revealed "negative" impacts, i.e., systematic and significant increase in cases of malaria occurring in a sequence of months in Itaituba and Santana do Araguaia. For Anajás and Viseu, the El Niño scenario is associated with "positive" impacts i.e., malaria incidence in the medium and low categories. Concerning La Niña composites, a widespread response over most of Pará state is verified, with predominance of higher malaria incidence in the four cities and processing persistently during the consecutive months from December to May. The composites for the positive dipole events in the intertropical Atlantic showed intra-regionally differentiated 11 malaria indices over the state, with Anajás and Itaituba presenting predominance of increased cases, while in Santana do Araguaia and Viseu presented several months with normal rates and below than average. Except for Itaituba, composites for the negative dipole events in the intertropical Atlantic evidenced malaria incidence in the medium and low categories, evolving from November to May.
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)
Regimes térmico e hídrico em solos sob ecossistemas naturais e área agrícola no Leste da Amazônia
(Universidade Federal do Pará, 2007-12-14) CARVALHO, Saulo Prado; SOUZA, José Ricardo Santos de; http://lattes.cnpq.br/2797414407717271
Soils temperature and moisture are variables whose knowledge is required to Determine the energy and water budgets in the biosphere. The thermal and hydric regimes of soils beneath each ecosystem, present considerable variations, according to their mineralogy, the local climate and vegetation. In this context, soil temperatures and moistures were measured under three ecosystems existing over the eastern portion of the Amazon Region, namely: native forest (Caxiuana's National Forest, 01° 42' 30" S and 51° 31' 45" W), pasture area (Soure, 00° 43' 25" S and 48° 30' 29" W) and cultivated area (Igarape-Acu, 01° 07' 59" S and 47° 36' 55" W). Field data at the forest and pasture sites were collected between December, 2001 and February, 2005; while at the cultivated area, the monitoring was limited to the August, 2003 to February, 2005, period. These observations of soil physical variables were analyzed taken into consideration the simultaneously measured meteorological variables such as the incoming solar radiation flux and pluviometric precipitation, which directly impacted the soil variables at each site selected for study. The soil temperatures were monitored by means of thermal sondes at 0.05, 0.2 and 0.5 m depths. Heat fluximeters, measured heat flux at 0.05 and 0.2 m depth levels. The upper 0.3 m soil layer bulk moisture was measured by double probe Time Domain Reflectometer (TDR) sondes at each site. Analyses were made, considering the soil responses during the local dry and rainy seasons at these three representative ecosystems of eastern Amazonia. Apparent thermal diffusivity estimates were made by the amplitude and phase methods, using the daily heating pulse propagation data in these soils. The results showed quite different values. However, the first approach seemed to be more reliable and suitable to numerical modeling. As expected, considering their small vegetation cover, the soil temperatures at the upper levels, presented larger variations at the pasture and cultivated sites. Unexpectedly, the temperatures at 0.5 m depth beneath the forest showed larger amplitude variations than at 0.2 and 0.05 m depths. The numerical modeling of time variations of temperature, as function of depth, for each soil was made through the harmonic method. The results showed that the first harmonic represented over 90% of the total variation of the observed daily pulse of temperature for the pasture and cultivated areas at 0.2 and 0.05 m depths. Similar performance of the modeling was observed for the forest at 0.05 and 0.20 m levels. The magnitude of heat fluxes beneath the pasture and cultivated sites reached values six times larger than those observed beneath the soil of the forest. The results also show that, for the upper 0.30 m layer of soils, the bulk moisture beneath the forest is larger than under the other ecosystems studied in this work. This result apparently is due to the forest's protection against the soils surface evaporation. An analysis of the seasonal and daily behavior of the soils temperature and moisture in response to the incoming solar radiation and precipitation are presented. Case studies of the rate of soil moisture losses after significant water recharge by precipitation events were also analyzed. Some estimates of daily water depletion and even, night recharge of moisture by rising water from lower layers to the 0.30 m layer were made. This work analyzed the largest time series of soil temperature and moisture data taken at high sampling rates, available so far, for eastern Amazonia. It was possible to characterize the differences of these physical variables regimes, beneath three important ecosystems in this Region. Further studies of the minerals and organic materials in these soils, as well as the foliar area and biomass indexes of their vegetation covers, would improve the comprehension of the regimes described in this work.
Acesso aberto (Open Access)
Eventos extremos da zona de convergência intertropical sobre o Atlântico durante o período chuvoso da Amazônia oriental
(Universidade Federal do Pará, 2008) FERREIRA, Douglas Batista da Silva; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685
This work reports an observational analysis of the climatological characteristics (period of 1985-2007) associated with the ITCZ extreme events, observed over the equatorial Atlantic Ocean, establishing its influences on the pluviometric variability over eastern Amazon, during the months of February, March and April. These events were selected objectively through Empirical Orthogonal Functions analysis, and the ocean-atmosphere patterns associated with ITCZ events, as well as, its impacts on eastern Amazon rainfall, were investigated through monthly composites. The results showed some monthly differences in the dynamical pattern related to the 200 hPa atmospheric circulation and configuration of vertical tropospheric motion, associated with the equatorial Hadley cell. Basically, the dynamic structure of the ocean-atmosphere patterns observed in February, March and April, showed that the ITCZ is formed over the equatorial Atlantic Ocean in a region of confluence between northeasterly and southerly winds that is coincident with areas of abnormally hotter SST, upward vertical air motion associated with the Hadley cell, and divergent outflow at high levels. The impacts of such events in the precipitation variability over the eastern Amazon, showed that the states affected by ITCZ are mainly Amapá, Pará and Maranhão. Additionally, it were reported some socio-environmental impacts (floods, falling trees, proliferation of diseases, among others) that occurred in the metropolitan area of Belém, associated with the occurrence of extreme weather events ITCZ selected in this work, associated to the presence of ITCZ over the region.
Acesso aberto (Open Access)
Comunidades macrobentônicas da Reserva Biológica do Lago Piratuba (Amapá – Brasil)
(Universidade Federal do Pará, 2008) ALMEIDA, Mayk Ferreira de; ROSA FILHO, José Souto; http://lattes.cnpq.br/3223362071251898; ALBERNAZ, Ana Luisa Kerti Mangabeira; http://lattes.cnpq.br/1220240487835422
The structure of the macrobenthic communities was characterized in different climatic periods and areas of the Reserva Biológica do Lago Piratuba (Amapá-Brazil). The samplings occurred on June and November of 2005 (Meridional belt lake - lakes Comprido de cima, Bacia, Lodão, Grande, Comprido de Baixo, Canal Tobaco and estuary of the river Araguari) and of 2006 (eastern belt lake - lakes Piratuba, Jussara, Escara, Trindade, Maresia, Boiado and the Duarte stream and seven places in the coast (areas vegetated and not vegetated). At each site four samples had been collected, with a corer (0.0079 m2) buried 20 cm in the sediment. After collection samples were passed in a 0.3 mm mesh and the retained organisms were fixed in formalin 5%. The structure of the communities varied seasonally, with severe modifications in density, specific composition, richness, eveness and diversity among sampling occasions and environments (lakes/coast). A total of 54 taxa had been identified belonging to phyla: Annelida, Arthropoda, Mollusca and Nemertea. In the rainy seasonal it was recorded 36 taxa, and in the dry seasonal 42 taxa were recorded. Annelida was the most abundant taxon, representing always more than 48% of total organisms. In the lakes Insecta larvae, Mollusca and Oligochaeta were the dominant taxa. In the coast, Polychaeta and Crustacea were dominant. It was recorded 32 taxa in the lakes and mean density of 667 ind.m-2. In the coast 34 taxa were recorded and 1353 ind.m-2. The coastal non-vegetated area was richer and denser and showed the higher eveness. Benthic fauna from the Meridional belt lake and the Eastern belt lake behavioured distinctively among seasons. Three sub-environments had been identified based on the benthic fauna: freshwater environment - majority of the lakes of the Eastern belt, dominated by insects; transition environment (freshwater/coast) with mixed fauna (Polychaeta and Insecta); and coastal environment, with Polychaeta and Crustacea. The environmental characteristics best correlated with spatialtemporal changes in the benthic communities structure were water pH, electric conductivity and turbidity.
Acesso aberto (Open Access)
A influência do Arco do Desmatamento sobre o ciclo hidrológico da Amazônia
(Universidade Federal do Pará, 2008) BELTRÃO, Josivan da Cruz; GANDU, Adilson Wagner; http://lattes.cnpq.br/8491359374260645; COHEN, Júlia Clarinda Paiva; http://lattes.cnpq.br/0293299378753887
This study aimed to quantify the changes in the hydrological cycle of the Amazon due the deforestation, mainly in area called "Arc of Deforestation". Thus, experiments were performed using the BRAMS (Brazilian Regional Atmospheric Modeling System) model include the submodel of dynamic vegetation GEMTM (General Energy and Mass Transport Model). We investigated the impacts caused by the actual Arc of Deforestation compared to intact forest, as well as future changes, caused by the increase of deforestation up to 2050. As surface boundary conditions we used scenarios from empirical models of deforestation for 2002 and 2050. The increase in the Arc of Deforestation showed a complex interaction on variable analysed. For example, the precipitation showed heterogeneous distribution with positive and negative anomalies that were consistent with the anomalies of other variables, such as evapotranspiration and divergence of moisture. Also, we found the influence of the great rivers and topography on precipitation distribution. The balance of radiation and energy has been affected by deforestation, mainly over area which the forest was substituted by pastures due the surface albedo had been changed. The impact of current deforestation to intact forest showed changed only over areas most affected by deforestation, while to deforestation in the future (2050) the hydrological cycle change reaches whole the Amazon region.
Acesso aberto (Open Access)
Avaliação da exploração florestal de impacto reduzido em atributos físicos e químicos do solo e na regeneração natural em Paragominas, PA
(Universidade Federal do Pará, 2008) HIRAI, Eliana Harumi; SILVA, José Natalino Macedo; http://lattes.cnpq.br/0479038232182214; CARVALHO, Cláudio José Reis de; http://lattes.cnpq.br/5976057799163293
This work was carried out at Fazenda Rio Capim, property of the Cikel Brasil Verde Madeiras Ltda., in the municipality of Paragominas, State of Pará, Brazil. The main objective was to study the effect of logging on the physical and chemical properties of the soil and on natural regeneration in three Working Units logged in 2000, 2003 and 2006., The treatments were gap center, primary and secondary skid trails, logging landing and one control plot. The diameter of each individual was measured at approximately 1,30 m of the ground; all species were identified and calculated the species richness, abundance, diversity Index, evenness and floristic similarity. Samples of litterfall were collected in same the locations of soil plots. For physical analysis (granulometry, texture, soil bulk density, resistance to the penetration, porosity and volumetric humidity) soil samples were collected at 0-5, 5-10, 10-20, 20-30 cm depth, and for the chemical analysis (pH, carbon stock and nitrogen, C/N) the samples were at 0-10 cm depth. In the primary skid trails it was considered its beginning, middle and end of the extension, and both for primary and secondary skid trails, the marks of the wheels of the machinery (RM), the place between the wheels (ER), and the edges of the trail (BT). Felling gaps were randomly measured and classified with areas <600m2 and> 600m2. The soil of the study areas is Yellow Latosol with very clay texture. The soil bulk density and porosity varied significantly among years and between treatments (p <0,001); no significant differences were found at 20-30 cm depth. Main and secondary skid trails and logging landings were the most affected treatments. Gaps had no influence on bulk density. It was verified that ER and BT did not differ statistically. The comparison among beginning, middle and end of the skid trails showed ere no significant differences for any of the comparisons. Results for to resistance to penetration were very similar to the bulk density and porosity. Volumetric humidity varied according to the combination year x treatment (p <0,001). Average pH values varied between 4,72 to 5,92. Litterfall decreased as time elapsed since logging. Average contents of C varied between 25,94 to 42,59 g.kg-1 and the contents of N between 2,23 to 3,35 g.kg-1, both considered as high values. For carbon stock of (Mg.ha-1) it was not found significant difference for any of the interactions (year, season and treatment). The relationship C/N for logged forest showed values between 10,37 and 15,42, indicating mineralization of the soil inorganic nitrogen. The three studied WUs presented high diversity and evenness. WUs logged in 2000 and 2003 showed the highest similarity (35,93%), followed by the WUs logged in in 2003 and 2006 (33,46%), and WUs logged in 2000 and 2006 (26,93%). It has been concluded that it is necessary a long observation period for evaluation of the effects of soil compaction on the growth of the regeneration. Indicators for good forest management practices should consider soil attributes (physical, chemical and biological) for a better understanding of the system and choice of other indicators that can give answers on the equilibrium of the forest ecosystem. The studied parameters can be used as indicators of environmental quality.
Acesso aberto (Open Access)
Análise espacial das mudanças na cobertura e uso da terra em Santarém e Belterra, Pará, Brasil
(Universidade Federal do Pará, 2008) CASTRO, Williams Martins; VENTURIERI, Adriano; http://lattes.cnpq.br/8968863324073508; BATISTELLA, Mateus; http://lattes.cnpq.br/1337579164863601
Through a case study, this work tests how the delimitation of the study area may influence the results of multiscale analyses in spatial processes of land-use and landcover change in the Amazon. Within the municipal limits of Santarém and Belterra in western Pará State, three levels of analysis were defined. The first level encompasses a rectangular region that was arbitrarily defined as the Santarém subregion. The second level, which encompasses part of the first level, corresponds to an established agricultural settlement, defined by the set of limits of property lots designed by INCRA in the 1970’s. The third level corresponds to the zones of influence of four different roads located within the established agricultural settlement, subdivided into sub areas North and South, comprising a total of eight sub areas within the second level of delimitation. For each level of analysis, landscape metrics were calculated based on land-use and land-cover thematic maps for 1986, 1997, and 2005, also analyzed with basis on field surveys. The results show that the peculiarities of the occupation dynamics in each level allow for a better identification of patterns and processes revealed by the landscape structure. In particular, it is clear there is a continuation of processes of landscape fragmentation and expansion of intensive agriculture at different rates in distinct portions of the study area. The results obtained for the three levels of analysis are complementary, allowing for a better understanding of land-use and land-cover changes as well as their driving forces.
Acesso aberto (Open Access)
Análise e modelagem hidrometeorológica na Bacia do Rio Tocantins em Marabá-PA
(Universidade Federal do Pará, 2008) SANTOS, Daniel Meninéa; SOUZA, Everaldo Barreiros de; http://lattes.cnpq.br/6257794694839685; ROCHA, Edson José Paulino da; http://lattes.cnpq.br/2313369423727020
The objectives of the present work is to develop a statistical model to predict discharge or flow in Marabá-PA, as well assess the atmospheric dynamic structure associated with the extreme hydrological regime observed in the Tocantins river basin. The hydrological model based on multiple linear regressions uses time series derived from fluviometric and pluviometric stations which are obtained from ANA database. Validation tests of the statistical model with Nash coefficient above 0.9 and standard error of 1.5% and 5% during flood and drought periods, respectively, allow generating predictions of discharge with antecedence of 2 to 4 days (3 to 5 days) for the flood (drought) period. Through composites technique considering all years with record of above/very above discharge and below/very below discharge in Marabá, obtained from percentiles method, it was investigated the precipitation characteristics in basin scale and the dynamic aspects observed in each month (November to April). The composites of years with above/very above discharge showed that the rainfall on the basin was above normal in all months, and the large-scale patterns indicated a configuration associated with La Niña phenomenon over Pacific and cooling conditions over South Atlantic; intensification of both zonal/meridional ascending branch of the Walker/Hadley cell; intensification of the Bolivian High anomalously placed eastward and negative ROL anomalies associated with the joint occurrence of ZCAS and ZCIT. Conversely, the composites of years with below/very below discharge showed a predominance of precipitation below normal throughout basin, which was associated with the conditions of warming (El Niño) over Pacific, and also warm TSM anomalous over South Atlantic, cell of Walker and Hadley with weak upward movement, the positioning of the High Bolivia westward with positive ROL anomalies indicating inhibition of tropical convective activity. Additionally, a quantitative analysis of the socio-economic impacts in the main centers of Marabá revealed that approximately 10 thousand (5% of the population) people are affected by Tocantins river floods with costs in the flooding operations above R$ 500.000,00, considering the 2005 case.
Acesso aberto (Open Access)
Aspectos observacionais e numéricos da interação floresta-atmosfera na Amazônia oriental: fenômenos turbulentos noturnos
(Universidade Federal do Pará, 2008) NOGUEIRA, Daniele Santos; GANDU, Adilson Wagner; http://lattes.cnpq.br/8491359374260645; SÁ, Leonardo Deane de Abreu; http://lattes.cnpq.br/0107976161469463
This study identified two nocturnal turbulent phenomena above Caxiuanã region, in the eastern Amazonia, during its dry season: low level jets (LLJ) and wind gusts, using data from the field campaigns CiMeLA (dry season of 2003) and COBRA-PARÁ (dry season of 2006). Both of them were analyzed observationally, considering aspects such as time of occurrence, intensity, height and duration, as well as their nocturnal evolution. It was verified that most of the LLJ events were accompanied by a drop in equivalent potential temperature. It was also found that the wind gusts had an important influence over the forest-atmosphere exchanges. The genesis of these phenomena was also investigated. It was noted, using the mesoscale model BRAMS, that the origin of the jets is possibly associated to the sea breeze and the intensification of the northeasterly winds. These results were based on sensibility tests, which included the removal of the rivers, the ocean-continent interface, the effects of downdrafts and the deforestation of the region. It was observed that the origin of the wind gusts is associated to the existence of Caxiuanã bay, which resembles a lake, and to the local convective activity. Furthermore, it was found that both phenomena did not exist simultaneously, except for one single night. This can be explained by a shear-sheltering effect that impedes that propagation of the turbulence downward, to the surface. This effect is generated by the presence of strong LLJs. This research reflects the importance and complexity of the atmospheric phenomena near the coast of Pará.
Acesso aberto (Open Access)
Estudo comparativo da distribuição espaço-temporal da precipitação na Amazônia Oriental
(Universidade Federal do Pará, 2008) GOMES, Nilzele de Vilhena; MOTA, Galdino Viana; http://lattes.cnpq.br/8821024246942574
This work used precipitation data during January 2000 to September 2007 from the gauge on the micrometeorological tower located in the Ferreira Pena Scientific Station in the Caxiuanã forest. This data was compared with the 3B42 algorithm, an estimate based on microwave to ajust infrared measurements. Additionally, the comparisons were extended do the Eastern Amazonia using five algorithms: The Geostationary Environmental Satellite Precipitation Index (GPI); the 3B42; 3A12 and 3A25 that are based on the sensors of microwave and radar from the Tropical Rainfall Measuring Mission (TRMM) satellite; and the Global Precipitation Climatology Center (GPCC), from January 1998 to December 2007.The comparison between the 3B42 estimates with the gauge showed that the 3B42 algorithm overestimates the precipitation from the gauge for all period. The rainy trimonthly periods were in March-April-May (MAM) and December-January-February (DJF) and the less rainy periods were September-October-November (SON) and June-July-August (JJA), This seasonality of precipitation is caused by the different meteorological systems over the region, especially the Intertropical Convergence Zone (ITCZ) which modulates the rainy season over the region. The seasonal analyses showed that the 3B42 algorithm overestimates (underestimates) the rainfall compared with the gauge in MAM and JJA (DJF and SON); and DJF is the quarter what the estimates of precipitation is closer regarding the gauge measure in micrometeorology tower of Caxiuanã. In the monthly averages, the 3B42 algorithm underestimates the rainfall from October to January and overestimates from Mach to August compared to the gauge. The 3B42 algorithm overestimated (underestimated) the nocturnal (the morning and the afternoon) precipitation compared to the gauge in the six grids around Caxiuanã Reservation. However, both data showed the maximum period of precipitation of the diurnal cycle around 18:00 local time (LT). Also, the analysis of diurnal cycle seasonal average indicate what in DJF to 0900 LT, 1500 LT and 1800 LT have a precipitation estimated for 3B42 algorithm closer to gauge measured punctually in Caxiuanã.. The months of November to February have a major maximum of precipitation in the afternoon in both datasets. In the period from may to July the maximum of precipitation becomes nocturnal and in the early morning, changing the diurnal cycle compared to the other months. The comparisons between the five algorithms over the Eastern Amazonia showed different behaviors among the estimators. The GPI algorithm underestimated the precipitation compared to the other algorithms in the Amapá state and French Guyana; and overestimated in central area of Amazonia. Both estimators from TRMM satellite the 3A12 and 3A25 algorithms, presented less precipitation than the other algorithms. The 3B42 algorithm presented similar pattern of precipitation as that showed by Figueroa e Nobre (1990). However, the GPCC estimator showed less details in the spatial distribution of rainfall in the Northwest of Pará state. The differences between the algorithms here considered might be related to the characteristics of each algorithm and/or the methodology used. The comparison between a locally data from the gauge with the averaged data from satellites might be the explanation for the discrepancies in the seasons or in the diurnal cycle. However, the differences could be due to the differences of the nature of precipitation among the subregions; as systems modulating the diurnal cycle of rainfall over the Eastern Amazonia.
Acesso aberto (Open Access)
Dinâmica do amônio e nitrato em solos consorciados com plantios de Paricá (Schizolobium Amazonicum) em Aurora do Pará, Pará
(Universidade Federal do Pará, 2008) DIAS, Joelma Dezincourt; CARVALHO, Cláudio José Reis de; http://lattes.cnpq.br/5976057799163293
To obtain knowledge of the dynamics of nitrogen in soil in the forms of mineral-N: ammonium and nitrate from 3 different areas cultivated with paricá, paricá x freijó (PF), mahogany x paricá (PM), paricá x curauá x freijó (PCF) and secondary forest, was estimated rates of net mineralization and nitrification, stocks of carbon and nitrogen, pH, urease, basal respiration and physical parameters (density and total porosity). The study was conducted in northeastern Para in the city of Aurora do Para, in the farm business Tramontina SA, in October and November of 2007, representing the dry season, while January and march representing the rainy season. In all areas of the farm cultivated samples for chemical and physical analysis were taken at depths of 0-10, 10-20 and 20-30 cm. For net mineralization of the highest values occurred in the dry season, this result was observed for all areas of cultive. For net nitrification of the highest values occurred in October 2007 in the areas of secondary forest and paricá x curauá x freijó and the month of March in the areas of mahogany x paricá (PM) and paricá x freijó (PF). The values for the rates of net nitrification showed that there was significant interaction between treatment and season. The values of carbon stocks for all areas in the dry season varied from 11-17 Mg/ha and in the rainy season of 15-25 Mg/ha. The values for the storage of nitrogen varied from 0,78-1,80 Mg/ha in the dry season and 0,76-1,47 Mg/ha in the rainy season. The relation C/N for all systems was around 15/1 indicating a rapid process of decomposition of organic matter in soils.
Acesso aberto (Open Access)
Estudo comparativo do uso da terra em unidades de produção familiar no Nordeste Paraense
(Universidade Federal do Pará, 2008) MOREIRA, Aninha Melo; VENTURIERI, Adriano; http://lattes.cnpq.br/8968863324073508
The historical context of territorial formation of the Paraense Northeast, is related with the several occupation periods that the Amazonian area suffered, from the origins of the colonization, going by the migratory flows, starting from the decade of 1950, until his/her current configuration. The Paraense Northeast is composed by Salgado's microrregiões, Bragantina, Cametá, Guamá and Tomé-Açu, occupying about 135 thousand squared kilometers, in other words, 10,6% of the state surface, including 49 municipal districts, possessing 1,8 million inhabitants, 27% of the state population. After almost a century of use the virgin forest areas are part of the past. The pattern of use of the earth bases on the handling of portions of secondary forest, in rotation with annual cultures and the implantation of perennial cultures and of pastures. In this context this work aimed at to understand the dynamics of the use of the earth in units of family production, for like this to subsidize alternatives for the planning of the properties. The research was accomplished in thirty three units, disposed in the municipal districts of Bragança (it presents an older occupation, with different occupation reports and use of the earth, approximately 300 years), Capitão Poço (it represents an occupation and use middlemen, 60 years) and Garrafão do Norte (with a process of more recent occupation about 20 years). the methodology based on the direct observation, in the application of questionnaires, semi-structured interviews, photographic registrations, elaboration of mental maps and use of the System of Geographical Information, for construction of thematic maps and analysis of the satellite images. It can be observed that the use pattern if it doesn't differentiate in the three areas, because it is not the atmosphere only that it will influence in the established practices, but each farmer's culture, in other words, his/her cultural load that it is printed on the territory. It was verified that the landscape of a property will be more or less fragmented in function of the number of people that you/they make use of her. The secondary vegetation is an important element in this dynamics, because his/her presence or absence will contribute more or less to a property to be resilient the pressures of markets, in other words, the existence of this forest resource, together with other productive systems, they allow that property to have a variety of products to be made available in the sphere of the family and to the market. It is like this necessary that strategies of planning of the property are elaborated, to guarantee the social and environmental sustainability.