Navegando por Assunto "Ecologia dos manguezais"

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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/3282736820907252
The 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.
Acesso aberto (Open Access)
Atributos químicos do solo e interação com folhas de serapilheira em manguezais da ilha de Itarana e comunidade Caranã, São João de Pirabas, Pará, Brasil
(Universidade Federal do Pará, 2013-04-26) SOUZA, Marina Lopes de; MOTA, Maria Aurora Santos da; http://lattes.cnpq.br/5817549281617240; RUIVO, Maria de Lourdes Pinheiro; http://lattes.cnpq.br/9419564604488031
Mangroves are coastal ecosystems situated in the land-sea interface, under constant influence of the dynamics of the tides. It is known that this ecosystem is considered one of the most productive in the world, due to the large amount of organic matter that is produced and fed into other environments. This productivity, in turn, has its origin both in litterfall produced within the system itself, the inputs of nutrients arising tidal and storm water. The nutrient dynamics in mangroves is linked to factors such as the frequency of flooding by tides, the seasonal period, the topography and biogeochemical processes. In this context, this study aims to evaluate the soil chemical properties and verify the interaction between soil and leaf litterfall in mangroves in northeast Pará, in the rainy and less rainy season. For this, samples of soil and leaf litterfall were collected in different seasonal periods, for analyses of pH, Eh, interstitial salinity, C, N, S, P, Fe, Na +, K +, Ca + 2, Mg + 2 and Al + 3. The results of soil chemical properties show that seasonality exerted greater influence on the results of Na +, K + and interstitial salinity. The intertidal mangrove presented nutrient content of higher soil when compared to the supramaré mangrove. In general, there was a relation to the concentration of the soil nutrients with the concentration of nutrients in leaf litterfall, more evident in the high carbon concentration, as well as the lifting conditions content of some nutrients in leaf litterfall of supramaré mangrove during the rainy season.
Acesso aberto (Open Access)
Costa de manguezais de macromaré da Amazônia: cenários morfológicos, mapeamento e quantificação de áreas usando dados de sensores remotos
(2005-12) SOUZA FILHO, Pedro Walfir Martins e
De acordo com o Atlas de Manguezais, este ecossistema representa 8% de toda a linha de costa do planeta e um quarto da linha de costa da zona tropical, perfazendo um total de 181.077 km2. Este trabalho objetiva quantificar a extensão dos manguezais de macromaré da costa nordeste do Pará e noroeste do Maranhão, aqui denominada de Costa de Manguezais de Macromaré da Amazônia (CMMA). O reconhecimento das áreas de manguezais e sua quantificação foram realizados a partir da utilização de imagens Landsat-7 ETM+, adquiridas em 1999 e 2000 e de um sistema de informações geográficas (SIG). A integração dos dados de sensores remotos, dados geológicos e oceanográficos permitiu o reconhecimento de cinco setores geomorfológicos, que abrangem uma superfície total de 7.591 km2 de manguezais. Esta área representa a maior faixa de manguezais contínuos do planeta e corresponde a 56,6% dos manguezais do Brasil. Medidas prioritárias de conservação dos manguezais da Amazônia devem ser tomadas e pesquisas que busquem a melhor compreensão deste complexo e importante ecossistema devem ser financiadas e desenvolvidas.
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/8809787145146228
This 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.
Acesso aberto (Open Access)
A dinâmica das florestas alagadas durante o holoceno no litoral de Calçoene, Amapá
(Universidade Federal do Pará, 2008-02-25) GUIMARÃES, José Tasso Felix; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The integration of palynological and spectrophometric data with radiocarbon dating of sediment cores has allowed to propose developing model and vegetation dynamic according to climatic and relative sea-level changes during the Late Holocene in the Calçoene Coastal Plain- Amapá. Thus, this work suggests three periods characterized by marine influence between 2000- 800, 500-300, e 80 years BP - modern, as well as, two fluvial periods between 800-500 years BP and 300-80 years BP. The analysis of current patterns of geobotanical units distribution and palaeovegetation indicate a mangrove (311 Km 2 ) and várzea forest (684 Km 2 ) migration on inundated field (1.021 Km 2 ) positioned in elevated topographically areas of this coastal plain, which may be related to a local relative sea-level rise.
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/1229104235556506
It 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.
Acesso aberto (Open Access)
Estimativa da produção anual de serapilheira dos bosques de mangue no Furo Grande, Bragança-Pará
(2007-10) FERNANDES, Marcus Emanuel Barroncas; NASCIMENTO, Antonia Aparecida Monteiro do; CARVALHO, Muzenilha Lira
It is well known that environmental conditions of a determined place can influence the productivity of mangroves. So, the present study estimated the total and components litter production in Furo Grande, Bragança-PA. This study comprised four annual cycles (July/2000 to August/2004) at three sites. Seven traps were placed at each site along a 140 m transect, with 20 m intervals. Each trap had a useful area of 1 m2, with 1 mm2 mesh, suspended above the spring tide level. Accumulated material in the traps was collected on a monthly basis, sorted manually into leaves, flowers, fruits, stipules, twigs, and miscellaneous and then oven-dried to constant weight at 70ºC. The mean production of four years was 9.85 t.ha-1.year-1 at site 1, 6.41 t.ha-1. year -1 at site 2, and 5.99 t.ha-1. year -1 at site 3, with significant difference between sites 1 and 3 (H=7.53; df=2; p<0.05). Overall, the results showed that leaf was the most productive component, and together with flower, had peak in the dry season, which seems to favor energy saving to invest in reproduction, whereas fruit peak in the wet season, providing propagule dispersion and hence the renewal and maintenance of these forests.
Acesso aberto (Open Access)
Estimativa do fluxo de metano e dióxido de carbono em áreas de manguezais do município de São Caetano de Odivelas - PA.
(Universidade Federal do Pará, 2019-12-03) MARTINÉZ CASTELLÓN, Saúl Edgardo; SILVA, José Francisco Berrêdo Reis da; http://lattes.cnpq.br/1338038101910673; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; CATTANIO, José Henrique; http://lattes.cnpq.br/1518769773387350
Mangroves are considered environmentally and socioeconomically productive ecosystems because of their contribution to mitigating climate change, capturing and storing CO2 in the aerial and underground biomass, and a large fraction of carbon is escaped from soil and water into the atmosphere. The mangrove areas are important contributors to greenhouse gases (GHG). The study highlights the monthly measurements of fluxes methane (FCH4) and carbon dioxide (FCO2) flows in mangrove forest at the soil-atmosphere interface (Macaca Island), and water-atmosphere interface (Mojuim Estuary). The measurements included the temporal (dry period: July to December 2017 and rainy: January to June 2018) and spatial, (high topography: 2.5 m and low: 2.0 m) scale. Flows are measured by the dynamic chamber method associated with an infrared gas analyser. Additionally, parameters were recorded. A) environmental, air temperature, relative humidity, wind speed. B) physical and chemical water, water temperature, dissolved oxygen and pH. C) soil physical and chemical, soil temperature, soil moisture, organic matter, pH, organic total carbon, total nitrogen, and C/N ratio, microbial carbon, microbial nitrogen. The FCH4 in the soil varied in means of 0.1874 g m-2 d-1 and 0.0711 g m-2 d-1 between dry and rainy season. The FCO2 varied in means of 6.3607 g m-2 d-1, and 7.0542 g m-2 d-1 between dry and rainy season. The FCH4 ranged from 0.2360 g m-2 d-1 to 0.0271 g m-2 d-1 between low and high topography. The FCO2 ranged from 5.4383 g m-2 d-1, and 7.079 g m-2 d-1 between low and high topography. This could be related to the lower amount of organic matter, oxidized environment and good soil aeration in the high topography favoring FCH4 anoxia. The FCH4 in the estuary varied between season dry and rainy from 0.039 to 0.050 g m-2 d-1. The FCO2 varied between season dry and rainy from 10.474 g m-2 d-1 to 28.985 g m-2 d-1. The FCO2 present difference (p < 0.05) between the dry and rainy season, and may be influenced by the salubrious sea water in the tide and fresh water from the Mojuim River into the ebb. In this study it was observed that the highest FCH4 and FCO2 occur in the rainy season, and minimal variation of FCO2 in the soil.
Acesso aberto (Open Access)
Formas de relevo e dinâmica costeira em São Caetano de Odivelas (PA)
(Universidade Federal do Pará, 2013-05-22) PICANÇO, Maria do Socorro Monteiro; FRANÇA, Carmena Ferreira de; http://lattes.cnpq.br/5723672412810714
The present research was conducted on the northern part of municipality of São Caetano de Odivelas (PA), which had as objectives identify the relief units, analyze the distribution of these units from the physiographic conditions, verify the variation of multitemporal position of the coastline, identify the geoindicators and analyze the consequences for the vegetation and the morphology that area of study. The methodological procedures of the research included the bibliographical survey and literature review, cartographic base survey and products from remote sensors; treatment and digital processing of orbital images, thematic mapping and field work. Among the morphological units, in this area of study, are the tabuleiros that totals of 52.7 km ² and are located in the center of this area of study, in the shape of isolated blocks with a wavy soft relief, where the altimetry ranges from 6 to 30 meters; The plains of muddy tidal add up to 95.9 km ² and will position themselves as sites parallel to the coastline and along the lower course of rivers, have a flat topography, in which his altimetry goes 2 to 6 meters; muddy banks of intertidal have 7.3 km ², are positioned so as planes parallel to the coastline, with slightly angled relief that goes 0 to 2 meters; the sand ridges subatual add up to 2.2 km ² and are positioned in the shape of arrows arranged as meaning of the present coastline, with flat topography, with a altimetry 6 to 12 meters; alluvial plains have 10.7 km ² and are situated in contact with mangrove areas and along some river channels, with flat topography, above 6 meters; alluvial plains presenting species of Avicennia sp. have 1.1 km ², feature a flat topography that goes 2 to 6 meters and are found the interior plains of muddy tidal; alluvial plains with vegetation fields add up to 4.4 km ², are located shaped places of the narrow valley floors with a flat topography ranges from 4 to 10 meters; the sandy bars have 17.3 km ², are located as deposits elongated in the sense of the mouths of estuaries and feature a flat topography, which ranges from 0 to 2 meters. The geomorphological indicators identified are the advance and retreat of the coastline; the emergence and growth of sandy bars; approach and retraction of sandy bars in relation to the coastline; the biological indicators relates to formation and destruction of neossolos mangrove soil; the increase of mangrove area and development of the standard "Escada"; reduction mangrove area and pattern formation "Paliteiro". The morphological changes can be classified in their majority as acrecionais because in 24 years there was an increase in mangrove area of 3.85 km ², which responsible for 4.19% of the total area plus in addition to have occurred in this period, installing two new islands, the Nova and Peruru. The dynamic that occurs in this municipality cause changes in soil and morphology due to installation of neossolos and formation of mangrove ecosystem, besides the occurrence of patterns "Escada" and "Paliteiro".
Acesso aberto (Open Access)
A influência dos parâmetros biofísicos da vegetação de mangue em regeneração no retroespelhamento de imagens radarsat-2 multipolarizada na Amazônia, Brasil
(Universidade Federal do Pará, 2013-09-05) COUGO, Michele Ferreira; SILVA, Arnaldo de Queiroz da; http://lattes.cnpq.br/1682623730626187; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The main goal of this work is to understand the relationship between backscattering (σ°, β° e γ) of a multipolarized Radarsat-2 Fine Beam band C image with biophysical parameters of mangrove vegetation in regeneration. The study site was the Bragança peninsula (northeast of Pará State) far from the Amazon River mouth about 380 km (southeast). 30 years ago it was built a highway causing disturbances in the hydrological regimes and vegetation death, then it was deforested and currently the natural regeneration is incipient. Field data was taken in 17 stands of 10 square meters and it was delimited and positioned with a DGPS (Differential Global Positioning System) and a total station. Structural characterization of the sampling units was made with the following field data: CBH (circumference at breast height), height and specie in 3090 specimen and then it were estimated values of DBH (diameter at breast height) and BA (basal area). A cluster analysis of the sample units has defined four groups of vegetation in different regeneration stages: pioneer stage, initial regeneration, intermediate regeneration and advanced regeneration. Fromard et al. (1998) equation was used to biomass estimation. It was used a SLC (Single Look Complex) multipolarized image (Radarsat-2) from June 11th, 2010. VIMAGE/Focus/PCI software was used to retrieve backscattering values of SAR (Synthetic Aperture Radar) image, using as reference the limits of the parcels. Statistical models of simple and multiple regressions were used in the analysis of the relationship between vegetation structure and backscattering values of the SAR image. Results shown that linear sigma backscattering with cross-polarization (VH) had the strongest relationship with all vegetation structure analyzed. Although the function of multiple linear regression with HH, VH and VV polarization got the best adjustments with the biophysical parameters mean height, DBH and Biomass (R2 values were respectively 0,81, 0,79 and 0,79). Backscattering values of the image with adjusted functions were used to generate maps of these three biophysical variables and it was coherence with field data, mainly mean height and DBH maps. Biomass map got a low amplitude variation suggesting saturation of the sign, in mangroves in regeneration, less than indicated in the literature to band C in homogeneous mangrove areas.
Acesso aberto (Open Access)
Manguezais do Pará: fauna de galerias perfuradas por teredo em toras de Rhizophora
(Universidade Estadual de Campinas, 1989-11-29) FERREIRA, Clara Pantoja; AMARAL, Antonia Cecília Zacagnini; http://lattes.cnpq.br/4597417616952392
In view of the large area the mangroves occupy in the State of Para’s coast their well-known importance and with the purpose to investigate their plant composition and to demonstrate the importance of the galleries bored in the logs as an habitat to several populations, periodic collects of Rhizophora lags were conducted. Measurements of temperature, pH, salinity and dissolved oxigen were accomplished. The study region was divided into 2 AREAS. The first one located at the Igarape-Curumbá mangrove (Ananindeua), where the collects were carried cut from April 1985 through January 1986 and the second in the Municípios of Benevides, Belém (Mosqueiro Island), Vigia and São Caetano de Odivelas, in which collects were carried out in July 1987 and January 1988. The mangrove stands from both AREAS are well-developped, specially those from Vigia and São Caetano de Odivelas, that are structurally the most developped. Rhizophora wangle was the dominant species in the 2 AREAS. A total of 45 species and 5022 individuals was recorded from the galleries of the 40 Rhizophora logs analysed. CRUSTACEA was the dominant taxon both for individuals and species numbers in almost all Subareas. The amphipode Grandidierella bonnieroides was the dominant species in the fauna composing 43,5% of the total number of individuals. The high in the AREA I reflects the high proport of common species among Subareas. The low values among the species of the Subareas from AREA II indicates that the composition of the fauna found inside the galleries is affected both by the physical and biological conditions to which the Rhizophora logs are submitted. The relatively high species diversity values of the 2 AREAS suggests the existence of stable conditions inside the galleries, allowing biological adaptations and interactions.
Acesso aberto (Open Access)
Mapeamento dos parâmetros florísticos e estruturais de floresta de mangue com dados LIDAR e SRTM
(Universidade Federal do Pará, 2014-06-24) ABREU, Maria Rafaela Braga Salum de; FERNANDES, Marcus Emanuel Barroncas; http://lattes.cnpq.br/8943067124521530; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
This study estimated the floristic and structural parameters (height, diameter at breast height - DBH and biomass) of mangrove from remote sensing data Laser Detection and Range (LIDAR), Shuttle Radar Topography Mission SRTM and orthophoto on Guarás Island, located 30 km from the mouth of the Amazon River. It was used data from LIDAR, SRTM and ortophotos during overflights. With the orthophoto data it was produced a map of Geobotanic units including only the mangrove area. It was performed the orthometric height correction and the point clouds was interpolated by nearest neighbor Technique, generating Digital Elevation Model (DEM) LIDAR (full points) with RMSE of 0.88 cm and using a computer language it was statistically separated the information of the last pulse of the surface as known as ground points. Thus data was interpolated by kriging method which was subsequently subtracted from the DEM. With Digital Model Height (DMV) values it was defined and selected the study sites and it was measured the trees in three categories: upside, intermediate and emerging trees. Than it was measured DBH and height in these places. 212 samples were collected and it was calculated the RMSE between the heights of the LIDAR and field, that resulted in a RMSE of 1.10 m. The chosen model to cross the information of LIDAR and field was the linear model whit R 2 = 91% and RMSE = 0.98 cm and for DBH and height field it was chosen the logarithmic model with R 2 = 74.1%. In the results of calibration of SRTM data the logarithmic model was also the most appropriate, in the relation of average height with SRTM there was a R 2 = 91% and RMSE of 2.2 m and to avarage DAP with SRTM the R 2 value was 88% and RMSE of 2.2 cm. With an inventory, biomass per specie data was estimated from field and it was produced maps of biomass per species from LIDAR, corrected SRTM and ortophotos.
Acesso aberto (Open Access)
Quantificação e caracterização de matéria orgânica em sedimentos de mangue, visando estudo geoquímico (Baía de Inajá, São João de Pirabas NE do Pará)
(Universidade Federal do Pará, 2002) ALCÂNTARA, Bianca Delamare Passinho; LIMA, Waterloo Napoleão de; http://lattes.cnpq.br/1229104235556506
The good functioning of the ecosystem depends on important vital factors, among which, one includes the soil stability, the salinity and an adequate supply in fresh- water and nutrients. The selected physiografic area is the Inajá Bay, situated in the municipal district of São João de Pirabas, in Northeast of Pará. Mangrove sediments sampling was accomplished at Itarana's island, located in this bay, and receiving direct influence of the Atlantic Ocean waters. Analytical results showed seasonal variation in the transportation of the fixed material in mangroves or exported to coastal waters. While pH are close to 7 in the rainy period, it to can reach values higher to 8 (maximum of 8,55) in the dry period; also specific conductivity (maximum in 33,9 ms.cm –1 in the rainy period) can reach 50 ms.cm –1 in the dry period, revealing an elevated electrolytic content due to the influence of oceanic waters. The suspended particulate material exhibits higher concentrations in the rainy period (maximum of 178 mg.L –1), in concordance with turbidity (maximum of 150 UNT) and with the index of colour (maximum in 60 UC). Organic matter, however was lower in the dry period (maximum content observed in 2,06 mg C/ L), it was higher in the rainy period (maximum in 3,4 mg C/L) , suggesting larger material contribution transposed by the rivers. While silicate contents are higher in the rainy period (maximum in 1,63 mg SiO2 / L) , the total organic and inorganic phosphate reached a maximum (1,46 mg PO4 3- /L) in the dry period, revealing probable oceanic influences in the middle of Inajá Bay, where, fishing captures take place. The ratios C / N, C / P and N / P (maximum at 126,7, 1039 and 83,2; minimum at 1,75, 101 and 17,2, respectively) suggest deficiency of N and P and enrichment in cellulose decomposition material, of vegetation origin. Else, the carbonous material of “furo” Grande exhibits a C/N ratio of 126,7 that indicates long period of maturation. The interpretation of the absorption spectra in the infrared region can identify the hydrophilic groups (OH alcoholic and phenolic); of functional groups methyl ( -CH3 ) and methylene ( -CH2 - ) of aliphatic chains; of carboxylic and/or carbonyl groups; and their derivatives (carboxylate and complexes, more probably with Fe and Al) ; and they confirm geopolymer presence through the identification bands owed to silicate. These considerations to come suggest to the occurrence of humic material whether in the water (perhaps more recent) or in the sediments. Being of more refractory material, these humic substances can be aggregated to the geological sediments and promote the necessary sedimentation to facies formation, mostly in the carbonic material collected in the “furo” Grande (15,29 % of organic matter ) and in the material collected in the Pilões sandstone (9, 62% of organic matter ). Samples with higher organic matter content (15,29% and 9,62%) showed higher CEC (30,12 meq/100g and 35,66 meq/100g) respectively. The large quantity of organic matter in the environment of this study seems to be much more associated with the tidal cycle, with the poor drainage in the sediment (whether in mangrove or in the sandstone), elevated bioturbation (plant detrius, marine organisms action) and drainage of ground water, that originate humics substances in podzol soils, that is to say, the organic matter is from two origins: one, alloctonous – material transported by the rivers; and other, authoctonous – resultant of the incorporation of roots, spineless microorganisms and perhaps mostly of the litter resultant of mangrove metabolism.
Acesso aberto (Open Access)
Radiação solar na regeneração natural de manguezais do nordeste paraense
(Universidade Federal do Pará, 2016-05-23) FERNANDES, Desirée Antéia Jastes; VITORINO, Maria Isabel; http://lattes.cnpq.br/4813399912998401
This work was done to characterize the weather, the weather configuration of global radiation and radiation balance and evaluate the effects of these variables on the spatial and temporal dynamics of natural regeneration in a mangrove forest in the city of Salinópolis, northeast coast of Para. the work was divided into three chapters that cover: I. Theoretical Foundation; II. Climatology, the radiation balance setting and the influence on the spatiotemporal distribution of the original vegetation of the mangrove forest and; III. The effects of the quantity of solar radiation in the spatiotemporal dynamics of mangrove species in natural and controlled environments. The climate characterization was performed using a series of 32 years of longwave radiation data from NCEP/NOAA. The weather variability of global radiation was obtained with a series of 5-year data, from the microclimatic towers of UFRA and UFPA. The monthly net radiation was determined by empirical methods applied to Wave Swing components Short and Long. In Experimental Site mangrove forest of Cuiarana, Cuiarana Village – Salinópolis, five plots were installed where four were kept under natural conditions and was covered with polyethylene shading (50%), which were determined the floristic composition and horizontal structure through identification, quantification and calculation of phytosociological density and frequency parameters relative and natural regeneration on. The spatio-temporal variability of abundance of species in relation to global radiation was determined by Factorial Principal Component Analysis and Tukey test and Student's t test at 95% confidence. The study was conducted between the months of November/2014 to October/2015 with monthly monitoring of weather and floristic variables. The weather has rainy and less rainy periods which concentrate 45.5% and 54.5% of the annual net radiation, respectively. The weather configuration of global radiation study period revealed to be under the influence of El Niño. The spatiotemporal variability shows that the high intensity of global radiation received, recruited Avicennia germinans individuals positively expressive in natural environments, indicating that environmental faces, provide different degrees of global radiation interception, favoring the photosynthetic processes and promoting warmer temperatures in the soil in the densest areas in vegetation, while Laguncularia racemosa requires less solar radiation than Avicennia germinans, evidenced by the increase in number of individuals in controlled lighting environments, with tolerance to 50% of sunlight retention.
Acesso aberto (Open Access)
Use of synthetic aperture radar for recognition of Coastal Geomorphological Features, land-use assessment and shoreline changes in Bragança coast, Pará, Northern Brazil
(2003-09) SOUZA FILHO, Pedro Walfir Martins e
Synthetic Aperture Radar (SAR) images are being used more extensively than ever before for geoscience applications in the moist tropics. In this investigation, a RADARSAT1-1 C-HH SAR image acquired in 1998 was used for coastal mapping and land-cover assessment in the Bragança area, in the northern Brazil. The airborne GEMS 1000 X-HH radar image acquired in 1972 during the RADAM Project was also used for evaluating coastal changes occurring over the last three decades. The research has confirmed the usefulness of RADARSAT-1 image for geomorphological mapping and land-cover assessment, particularly in macrotidal mangrove coasts. It was possible to map mangroves, salt marshes, chenier sand ridges, dunes, barrier-beach ridges, shallow water morphologies and different forms of land-use. Furthermore, a new method to estimate shoreline changes based on the superimposition of vectors extracted from both sources of SAR data has indicated that the shoreline has been subjected to severe coastal erosion responsible for retreat of 32 km2 and accretion of 20 km2, resulting in a mangrove land loss of almost 12 km2. In an application perspective, orbital and airborne SAR data proved to be a fundamental source of information for both geomorphological mapping and monitoring coastal changes in moist tropical environments.