Navegando por Assunto "Manguezal"

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Análise espaço-temporal dos manguezais degradados de Bragança, com base em imagens de satélite e modelos de elevação digital
(Universidade Federal do Pará, 2022-02-22) MOLANO CÁRDENAS, Sergio Mauricio; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The Bragança Peninsula occurs at the northern littoral of Brazil, in the state of Pará. It is characterized by the largest continuous mangrove belt in the world. The construction of the PA- 458 road in the ‘70s changed the hydrodynamics of the peninsula, causing the degradation of a considerable portion of the mangroves in the central region of the peninsula. Recently, degraded areas are being colonized by mangrove trees, mainly by the Avicennia germinans specie. This study intends to identify changes in the degraded areas of the tidal flats in topographically higher sectors during the last 35 years. To reach that objective, we used the following techniques: a) manual mapping of the degraded areas with mid spatial resolution satellite imagery; b) object-based classification of the degraded areas and mangrove species, using high spatial resolution satellite imagery; c) photogrammetry of drone imagery; d) digital elevation models; and e) topographic validation with theodolite and GNSS GPS “Antenna Catalyst”. From 1986 to 2019, there was a reduction in the degraded areas of 247.96 ha according to the mid-resolution “dataset” quantification. However, high-resolution data showed a reduction in the degraded areas of 211.65 ha between 2003 and 2019. The degraded areas quantification presents fluctuations in the regeneration trend; it is related to significant climatic phenomena such as “El Niño” and “La Niña”, accompanied by periods of drought and high rainfall, respectively. Overall accuracy and Kappa index values for the high-resolution data generally exhibited values above 0.9. Producers’ and users’ accuracy and Kappa per class values showed the difficulties separating mangrove species due to the lack of radiometric resolution of the analyzed images. The digital terrain model representing the tidal flat showed two topographically differentiated regions in the degraded areas, separated by the PA-458 road, which are mainly influenced by the Caeté’s and Taperaçú’s characteristics. This same difference was found in the vegetation height model, where the largest trees are located toward the SE side of the road, reaching 25 m, while at the NW side of the road, the tree heights oscillated mainly between 5 and 15 m. The sea-level rise specifically controls regeneration rates. This relocated the intertidal zone to topographically higher areas, increasing tidal flushing processes, essential for the mangrove forests development.
Acesso aberto (Open Access)
Crescimento de mudas de mangue sob diferentes níveis de sombreamento na península de Ajuruteua, Bragança, Pará
(Instituto Nacional de Pesquisas da Amazônia, 2013-09) LOPES, Elaine Cristina; ARAÚJO, Erneida Coelho de; COSTA, Rejane Silva da; DAHER, Rogerio Figueiredo; FERNANDES, Marcus Emanuel Barroncas
The purpose of this study was to evaluate the influence of different levels of shading on the development of seedlings of three mangrove species (Avicennia germinans (L.) Stearn., Rhizophora mangle L. and Laguncularia racemosa (L.) Gaertn. f.). The experiment was conducted at the community of Tamatateua, Ajuruteua peninsula, Bragança, PA, Brazil. For seedling production, the propagules and seeds of the mangrove species were planted in polyethylene bags (17 x 27 cm), filled with a typical mangrove substrate. The seedlings of the three species were grown under full sun (0), 30% and 60% shading, in a completely randomized design, a 3 x 3 factorial (three species and three shading levels), with eight seedlings per replication. After nine months under shading, plant samples were taken. The variables evaluated were: the shoot/height ratio, stem diameter, shoot dry matter, stem mass, root dry matter, total dry mass matter and morphological indices. Growth of seedlings of R. mangle occurred at all light levels. Seedlings of A. germinans grew faster at full sun and at 30% shading. Whereas, seedlings of L. racemosa were able to grow at 30 and 60% shading, but they also grew faster at full sunlight.
Acesso aberto (Open Access)
dinâmica da vegetação durante o quaternário tardio no limite continental da península bragantina, litoral amazônico
(Universidade Federal do Pará, 2022-11-25) MACIEL, Giordana Leticia Monteiro; ASP NETO, Nils Edvin; http://lattes.cnpq.br/7113886150130994; https://orcid.org/0000-0002-6468-6158; FRANÇA, Marlon Carlos; http://lattes.cnpq.br/8225311897488790; https://orcid.org/0000-0002-3784-7702
The eastern Amazonian region is dominated and shaped by a macrotidal regime, harboring environments such as muddy plains colonized by mangroves, estuaries associated with tidal channels, floodplains, and macrotidal beaches, among others. To understand the vegetation dynamics and carry out the paleoenvironmental reconstitution in an Amazonian floodplain, palynological, sedimentary, and C-14 dating data were integrated based on a subsurface sedimentary profile collected in the region of the Taperaçu’s herbaceous fields, in the Bragança peninsula (PA), on the Amazon coast. The present study identified three fácies associations and four pollen zones that occurred during the Late Pleistocene and Holocene. The first facies association is defined as an alluvial deposit, which presented pelite facies, flaser heterolithic bedding with a coarsening upward sequence. The vegetation was predominantly typical of trees and shrubs, marked by the presence of Rubiaceae, Agavaceae, and Annonaceae families and with low herbaceous vegetation dominated by the Araceae family developed around 41,200- 39,975 cal years BP. The second facies association identified showed typical characteristics of a tidal channel, with a well-delimited erosive surface, which marks a transition in the processes operating over this environment; it comprises gravel, massive sand, and wavy-marked mud facies. Toward the Taperaçu’s tidal channel, herbaceous vegetation was developed, represented by Cyperaceae and Ulmaceae, and the presence of trees and shrubs, such as Arecaceae, Malphighiaceae, and Rubiaceae. During the early and mid-Holocene (6000-5915 cal years BP), at a depth of 6.45 m from the surface, the results revealed the formation of a tidal flat. The main pollen result during this phase was the establishment of mangroves, colonized by Rhizophora and Avicennia, in addition to the presence of herbaceous vegetation, which currently occupies the studied region, marking the late Holocene.
Acesso aberto (Open Access)
A dinâmica dos manguezais subtropicais no litoral norte de Santa Catarina durante o Holoceno tardio.
(Universidade Federal do Pará, 2019-06-28) PINHEIRO, Vanessa da Conceição; FRANÇA, Marlon Carlos; http://lattes.cnpq.br/8225311897488790
The goal of this work is identifying the establishment and expansion of mangroves on the northern coast of Santa Catarina during the Late Holocene. For this work, pollen data, 14C dating, organic geochemical (δ13C, C:N, TN and TOC) and results of sedimentary analyzes were integrated. These data were obtained from the analyses carried out from two sedimentary cores (SF7 and SF8) collected using a Russian sampler in the Babitonga Bay, northern coast of Santa Catarina. The data reveals a typical tidal channel and tidal plain deposits throughout the records. The tidal channel deposit was accumulated between > 1692 cal yr BP to ~ 667 cal yr BP, close to the bottom of the cores. This deposit is formed by fine-to-medium sand with parallel laminated sand (Sp facies), cross lamination (facies Sc), low angle planar lamination (Sb facies) and massive sand (Sm facies). The sedimentary deposit is characterized as a tidal plain around ~ 1223 cal yr BP, constituted by facies flaser heterolithic bedding (Hf), wavy heterolithic bedding (Hw), lenticular heterolithic bedding (H1) and parallel mud (Mp). The pollen content preserved along the tidal channel deposits reveals predominance of trees, shrubs, herbs and palms surroundings of the channel and on topographically higher regions. Only SF8 core was found mangroves pollen while the isotopic data revealed δ13C (-24.4 to -21.47 ‰), C/N ratio (4.77 to 20.81) with a strong contribution of marine organic matter and C3 terrestrial plants. The tidal channel was clogged and allowed the beginning of the deposition of the tidal plain. The deposit of the tidal plain has a large amount of plants fragments and pollen content characterized by predominance of herbs, trees, shrubs, palms and mangroves. The results of δ13C (-22.48 to -21.18 ‰) and C:N ratio (11.49 to 19.89) indicated the contribution of C3 terrestrial plants as well as contribution of marine organic matter. In addition, the mangroves beginning from approximately ~1692 cal yr BP with the genus Laguncularia and Avicennia, still at the edge of the tidal channel. Around ~586 cal yr BP was observed the mangrove development with a Rhizophora genus. The Laguncularia and Avicennia were initially established in sandy substrates and then also occupied in silty sandy soil. In the tidal plain environment, the genus Rhizophora was established in mud substrate. The mangroves of this region settled in the topographically higher regions and later expanded to the lower and closest regions of the Babitonga bay, possibly due to the decrease of the relative sea level recorded during the late Holocene as well as the migration and filling of the tidal channels. The occurrence of Rhizophora pollen close to the surface probably was a result of the temperature rise during the Late Holocene.
Acesso aberto (Open Access)
Os efeitos dos manguezais e das intervenções humanas na dinâmica sedimentar das praias de SalinópoliS, PA
(Universidade Federal do Pará, 2025-03-07) PÉREZ MARTINEZ, Julián David; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
Salinópolis, on the coast of Pará, has become an important tourist hub, expanding its infrastructure along the coastal zone. This area is considered sensitive to sea-level rise. Therefore, identifying the area most vulnerable to coastal erosion is extremely important, especially due to the growth of coastal urban areas, which can interfere with sediment balance, intensifying erosion processes. This master's thesis aims to identify the effects of mangroves and coastal urban expansion on sediment balance along the beaches of Salinópolis. This study was carried out through a spatio-temporal analysis based on satellite (2003 – 2023) and drone data (2019-2024). The data revealed that the urban area expanded (627 ha), while the mangrove area fluctuated, increasing from 3630 ha to 3889 ha between 2003 and 2023. Erosion was identified along the beaches, particularly at Praia do Farol Velho (erosion = 432,625 m³, sedimentation = 217,259 m³). Praia do Atalaia (erosion = 115,415 m³, sedimentation = 462,630 m³) and the Maçarico/Corvina beaches (erosion = 640,389 m³, sedimentation = 801,670 m³) showed a trend of sediment accumulation. Erosion has predominantly occurred in the lower intertidal zone, while sedimentation has occurred in the supratidal zone and the upper intertidal zone. Residences, particularly in Farol Velho, may accentuate this process and Praia do Atalaia, which are currently located in the intertidal and supratidal zones in front of the mangroves. The walls built to protect these residences from waves and current action have also functioned as a barrier to retain sediments at the upper intertidal/supratidal transition. In much of Praia do Farol Velho, without these walls, there has been erosion in the intertidal zone, with a retreat of the coastline by about 100 meters between 2009 and 2023. However, the Maçarico/Corvina beaches have mangroves in front of the urban infrastructure, with sediment accumulation predominantly in the supratidal zone and the upper part of the intertidal zone. Human interventions on these beaches have not impacted the sedimentary dynamics until 2023. This beach provides a good example of how coastal infrastructure projects should be planned, using mangroves as protection against the action of waves and currents. However, the construction of beach access walkways in 2024 altered the hydrodynamic flow of a tidal channel, trapping tidal waters and creating muddy intertidal zones with porewater salinities close to 70 ‰. This process has already killed approximately 7 ha of mangrove. These data provide valuable insights to guide more efficient public and private investments, avoiding construction in high-risk areas or those that harm the mangroves, offering crucial information about coastal erosion and its impacts on urban infrastructure in the beaches of Salinópolis, especially in the face of sea-level rise.
Acesso aberto (Open Access)
Estudo comparativo dos índices de reflectância da vegetação de manguezal e várzea-de-maré do litoral paraense através de sensoriamento remoto e técnicas espectrofotométricas
(Universidade Federal do Pará, 2009-10-08) SILVA, Jadson Queiroz da; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The present work delimited the main littoral vegetations of the Pará State through the differences in the reflectance levels obtained by Landsat images and in situ by a spectrophotometer. This study indicated that the mangrove leaves present lower values of reflectance than others vegetations, mainly in the visible interval of the electromagnetic spectrum.This may be related to the strong absorption developed by the photosynthesis pigments of the mangrove trees. Among its leaves, the Avicennia presented higher reflectance values than Rhizophora. Besides, the reflectance of mangrove leaves changed between the studied areas, mainly the Rhizophora that in Curuçá presented higher values. This can be associated to the stress conditions found in the Bragança and Mosqueiro, since the environmental changes affects the spectral reflectance of leaves. In the case of the mangrove, adverse salinity conditions may hinder the plants development. The tidal water salinity in Mosqueiro presents low values. This factor allows a wider ecological competition between the mangrove species and others vegetations that together with the sediment type, may produce an increase in the stress to the mangrove. It may justify the low height of the trees, and the relatively high reflectance values. Thus, the relationship between the tree height and spectral values of the Rhizophora and Avicennia indicates an inverse relation. This may be attributed to the development of chlorophyll in the initial periods of vegetation growth that allows a elevated amount of energy reflected in the visible interval until the leaves reach its typical green color with relatively lower reflectance. Based on the reflectance data was possible to elaborate maps with the following vegetation units: mangrove, terra firme vegetation, tidal varzea, transition zones mangrove/varzea and herbaceous field.
Acesso aberto (Open Access)
Estudo dos manguezais degradados da costa oeste da Flórida durante os últimos 20 anos baseado em imagens de satélite e dados Lidar.
(Universidade Federal do Pará, 2024-05-31) CARDENAS RUIZ, Diana Paola; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The Gulf of Mexico presents one of the longest mangrove belts in southern Florida. This continuous mangrove strip has an approximate area of 2200 km2. Natural stressors such as hurricanes, storms, and other anthropogenic factors such as oil spills or pollution can trigger the dieback of the mangrove on the southwest coast of Florida. The dieback of the mangrove refers to the phenomenon where the mangrove forests experience a loss in the canopy that can lead to the decline or death of the trees. The effects of the dieback occasionally leave a scar of degradation in the mangrove forest. In the last century, with urban development in southwest Florida, the adverse effects of dieback seem to be gaining permanence. The present study identified the possible causes of the permanence of mangrove degradation associated with dieback over the last two decades. To identify these causes, the following methodology was used: a) classification of vegetation cover along the west coast of Florida, b) identification of dieback points in high-resolution satellite images, c) spatiotemporal analysis of dieback areas, and d) digital models of surface elevation and vegetation height. 86 dieback points (PD) were found grouped into 6 regions: Crawl Key, Key West, Marco Island, Pine Island, Charlotte, and Terra Ceia. 75% of the PD appeared between 2004 and 2007, coinciding with hurricane activity. In 2020, the total dieback area in southwest Florida was 119,69 ha. For the periods of 2014-2016 and 2009-2011, the areas of dieback recorded values of 116,47 and 127,89 ha, respectively, evidencing a dynamic of regeneration and degradation. The digital terrain models for Pine Island and Marco Island showed changes in the height of the tidal flat with variations between -2 to 45 cm. These variations may be linked to sedimentation processes, dissolution of carbonates in the tidal flat, or peat collapse associated with the mangrove soil. The mangrove trees reduced their height after the passage of hurricanes, particularly in the PD. Even though the PD showed regeneration, this process was slow, leaving a scar exposed to the tidal flat. This study revealed a direct relationship between hurricanes and the appearance of dieback.
Acesso aberto (Open Access)
A evolução dos manguezais nos litorais Nordeste e Sul brasileiros durante o Holoceno
(Universidade Federal do Pará, 2020-09-30) FREIRE, Neuza Araújo Fontes; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
It is possible that climate changes and sea level fluctuations (allogenic processes) are and will cause major changes in mangrove dynamics. However, other driving forces may be significantly affecting this system. Distinguishing allogenic and autogenic influence on mangroves is a challenging question, because mechanisms related to the natural dynamics of depositional environments (autogenic processes) have strong influences on the establishment and degradation of mangroves. Thus, impacts on mangroves caused by autogenic processes may be erroneously attributed to allogenic mechanisms. Therefore, it is imperative to identify the ‘fingerprint’ of global changes in modern mangrove dynamics. This thesis integrates palynological, geochemical, sedimentological data, 14C dating of sedimentary organic matter, geomorphological and vegetation data in order to evaluate the influence of autogenic and allogeneic processes on Brazilian mangroves during the Holocene. Tropical estuaries from Rio Grande do Norte and southern Bahia, and subtropical estuaries in northern and southern Santa Catarina estates with different climatic, geomorphological and oceanographic characteristics were studied. The Relative Sea-Level (RSL) along the Rio Grande do Norte reached modern level and stabilized at about 7,000 cal yr BP, allowing the mangrove establishment at the edges of the Ceará-Mirim River estuary until the nowadays. However, changes in the spatial distribution of mangroves have occurred since then due to channels dynamics in the region (autogenic processes). Considering the mangroves of the Jucuruçu River in southern Bahia, their horizontal and vertical distribution were controlled by the interactions of the changes in the RSL and fluvial discharge. Therefore, the dynamics of these estuarine mangroves during the Holocene was mainly controlled by changes in sea level and precipitation that affected fluvial discharge. These allogeneic mechanisms were the main drivers of the dynamics of these mangroves. However, during the last 600 years, factors intrinsic to the depositional system gained relevance by controlling the establishment and migration of mangroves by deposition and erosion of muddy tidal flats, abandonment and reactivation of channels (autogenic processes). In the case of Santa Catarina mangroves, the RSL rise up to the middle Holocene was decisive for the establishment of tidal flats appropriate for the expansion of saltmarshes. However, mangroves did not tolerate the Holocene low temperatures in the southern littoral of Santa Catarina. The pollen data indicate the establishment of mangroves with Laguncularia around 1,700 cal yr BP, followed by Avicennia and lastly Rhizophora trees, a cold less tolerant genus, around 650 cal yr BP in São Francisco do Sul, north of Santa Catarina. The mangroves of Laguna, south of Santa Catarina, composed of Laguncularia and Avicennia, were established in the current southern limit of the South American mangroves only in the last decades. No evidence was found for the presence of mangroves in Laguna during the Holocene. The establishment of these mangroves in the region probably started during the Anthropocene, as a consequence of the increase in minimum winter temperatures in southern Brazil. Considering changes in precipitation rates over drainage basins that feed mangrove estuaries, as well as trends in RSL rise and temperatures until the end of the 21st century, tropical estuarine mangroves will likely migrate to higher topographically sectors in the interior of the river valleys, where its extension will depend on the volume of river discharge interacting with the RSL rise. Subtropical mangroves are expected to expand to more temperate zones as minimum winter temperatures increase. This process should cause an increase in the diversity of mangrove species, such as the introduction of the Rhizophora genus in the current southern limit of the mangroves, positioned in Laguna-SC. However, in the case of high rates of RSL rise, the relatively new subtropical mangroves are also expected to migrate to topographically higher sectors of the coast.
Acesso aberto (Open Access)
Forçantes naturais e antrópicas sobre os manguezais de Salinópolis - Pará.
(Universidade Federal do Pará, 2023-10-05) SERRÃO, Izabelle Caroline Goes; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
Mangroves stand out for their resilience and important role in environmental balance. Still, globally, mangrove areas have suffered losses of around 35% between 1980 and 2000, caused by changes in salinity gradients, wave and current action, relative sea level changes and urban expansion. The Brazilian coastal zone is distributed in 395 municipalities, among them Salinópolis, located on the Paraense coast, with a wide occurrence of mangroves that have also presented degradation. A spatial-temporal analysis based on Landsat, Quickbird and drone images was used to investigate the main forces driving the natural and anthropogenic mangrove dynamics in Salinópolis. These data allowed for individualizing the vegetation and geomorphology units between 2009 and 2019. An aerial photogrammetric survey based on drone data between Feb / 2019 and Sep / 2019 enabled the identification of changes in the topography of the tidal flats and cliffs. These data indicated an increase in mangrove areas of around 104 ha between 2009 and 2017 in the study area. However, there was a loss of this forest of approximately 52.3 ha between 2017 and 2019, when there was an increase in unregulated urbanization of coastal areas. The area comprising the so-called “Praia do Maçarico” presented losses of mangroves of around 15.2 and 28.8 ha in 2010 - 2017 and 2017 – 2019 periods, respectively. In the Atalaia area, there was a loss of about 23.5 ha between 2017 and 2019. The expansion of the mangroves occurred over higher coastal plains (~2.8 m above mean sea level), distant from human intervention, and probably caused by a relative sea level rise. However, the retraction of mangrove areas occurred mainly due to unregulated urban expansion over the higher tidal flats. In addition, the spatio-temporal analysis indicated erosion on the Maçarico cliff, with a retreat from the top of the cliff of up to 20 m between Feb / 2019 and Sep / 2019. In the year 2022 there were urban infrastructure works in this area with new sediment input to try to stabilize the cliff. It should be highlighted that the eroded material from the cliff caused an increase of up to 1 m on the tidal flat near the base of the cliff, where some mangroves occur, causing the burial of their roots and the death of these trees. The data showed that interventions on the coast with mangroves have caused losses in these forest areas that tend to migrate to topographically higher sectors due to the relative sea level rise, characterizing a conflict between the current expansion trend of this ecosystem and anthropogenic interventions on the coast. The coast of Salinópolis, with a vulnerability degree between very high (4,6) and high (3,6) requires the inclusion of projects with a quali-quantitative analysis of the interaction of the main coastal characteristics (e.g. geomorphology, topographic gradients of the coast, tidal range, vegetation, angle and speed of currents and surface runoff) before implementing works on the Salinópolis coast.
Acesso aberto (Open Access)
Influência da dinâmica atmosférica na produção de serapilheira em um manguezal da costa amazônica.
(Universidade Federal do Pará, 2019-02-19) SOUZA, Hyago Elias Nascimento; VITORINO, Maria Isabel; http://lattes.cnpq.br/2313369423727020
This work aimed to investigate the influence of atmospheric dynamics on litterfall production in the Cuiarana mangrove, Salinópolis, Amazon Coast. The seasonal rainfall variation was analyzed along with the precipitating systems on the Amazon coast and its influence on the variability of litterfall production. It was also characterized the temporal variation of the direction and speed of the wind and its influence on the spatiotemporal production of litterfall. In a mangrove forest, 3 sample plots were delineated with 3 mangrove species Rizophora mangle, Avicennia germinans and Laguncularia racemosa. In each plot, 4 traps 1 m2 were randomly installed. Meteorological data were obtained from the Micrometeorological Tower of the UFRA located in the study area. The main statistical methodologies used were two-way and one-way ANOVA, linear regression analysis (p <0.05) and Principal Components Analysis (PCA). The results show that the temporal variation of precipitation is modulated by different meteorological systems, where the months of March, April and May appear as the region's rainiest quarter. The annual distribution of wind direction showed predominance in the eastern (E), frequency of winds with higher velocity were recorded in the second semester. In the litterfall production there was a significant difference between the values of monthly production and between the fractions. The annual total litter production was 9.4 ± 0.06 Mg ha-1 year-1, where 67% was composed by the leaf fraction. Leaves had negative trends with precipitation, but woody and reproductive material had positive trends. The ACP shows in 4 components negative correlation with reproductive material and positive correlation with wood associated with the temporal variation of winds and rainfall.
Acesso aberto (Open Access)
Influências das flutuações do nível do mar e mudanças climáticas na dinâmica dos manguezais do litoral Sul de Santa Catarina durante o Holoceno.
(Universidade Federal do Pará, 2019-06-10) ROCHA, Denise Oliveira Souza; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The objective of this work was to identify the main factors controlling the mangrove dynamics in the southern limit of this ecosystem in the South American continent, in the Laguna - Santa Catarina region. This study was based on the integration of sedimentary facies, isotopes (δ13C and δ15N), elementary organic matter (C/N), and pollen data with 14C dates obtained from core RP4 (S 28°29'18.41 " and W 48°50'47.01) with 2 meters depth sampled from a tidal flat near the Santo Antônio Lagoon, 8 km away from the present coastline, west of the town of Laguna. Three facies associations were identified: facies Herbaceous Floodplain, Fluvial channel and tidal flat with Spartina. The Herbaceous Floodplain is characterized by massive mud with benthic tubes, fragments of shells and roots. The facies association of Fluvial Channel presents sand with crossed stratification and massive. The top of the studied core presents the facies association Tidal Flat with Spartina represented by mud silt with roots fragments. The integration of these data suggests an increase in the relative sea-level during the Holocene, when the low river courses were flooded and it favored the formation of lagoon systems that are well represented along the Santa Catarina littoral, especially in the study area. A gradual Holocene marine transgression would have favored the mangrove expansion on tidal flat flats. Considering the physicochemical and hydrodynamic, probably the sedimentary environment was favorable for the establishment and expansion of mangroves over the last centuries, when occurs a strong contribution of organic matter sourced from estuary in the study site and development of tidal flats. The absence of mangrove pollen grains along the studied core (<9000 years AP) indicates, besides the low relative sea-level stand, another factor must have prevented mangrove establishment in the study area. The presence of Laguncularia and Avicennia shrubs/trees nowadays in the study area and the absence of mangrove pollen grains in the studied stratigraphic profile indicates that these genus were established only during the last decades. Probably, the temperatures during the Holocene winters on the modern austral limit of the South American mangroves prevented the mangrove establishment during that period the sediments of the core RP4 were accumulated. Probably, the increase in minimum winter temperatures during the last decades has allowed the expansion of the southern limit of the southern American mangroves into temperate zones.
Acesso aberto (Open Access)
Mineralogia e geoquímica dos sedimentos dos manguezais de Marapanim (litoral do Estado do Pará), e suas influências sobre a Rhizophora mangle, carangueijos (ucides cordatus) e cabelo humano
(Universidade Federal do Pará, 2006-05-23) VILHENA, Maria do Perpetuo Socorro Progene; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302; https://orcid.org/0000-0002-0134-0432
The estuarine region of the Marapanim River, located in the northeast of the State of Pará, Eastern Amazonian, is rich in mangroves closer to coastal zone areas, from where crustaceans are extracted by the local population, for consumption and provisioning of neighboring cities. In general the mangroves sediments have the capacity to absorb heavy metals whether in the organic matter, loamy fraction or sulfide minerals. In order to contribute for the knowledge of the distribution of these metals through several compartments of the mangroves and man as final consumer of its products, grain size analysis, mineralogical determinations and whole chemical and trace element analysis were carried out in sediments, vegetation, crab and human hair in order to evaluate the transference of metals in the chain sediment-vegetation-crabman. Two transects with the collection of sediments, vegetation (leaves of Rhizophora mangle) and crabs (Ucides cordatus) were established. Human hair was collected in inhabitants around the periphery of the city of Marapanim and rivershore of the Marapanim River. Salinity, pH and Eh (mV) directly measured in sediments were in the field. Grain size analyses considered the sand, silt and clay fractions, and the mineral identification were carried out by XRD and SEM/EDS and whole sediment chemistry and trace element and heavy metal analyses were conducted by ICP-MS, ICP-OES, and AAS. The samples of vegetation leaves, crabs and human hair were also analyzed by those methods and the MO by humid way. Mangroves sediments are silt-loamy, constituted by quartz, kaolinite, illite, smectite, Kfeldspars, goethite, pyrite, jarosite and halite. Quartz, kaolinite and goethite, and some illite, come from weathered sediments of Barreiras Formation, as source area of mangrove sediments and smectite, pyrite, K-feldspars and jarosite have been formed inside of the deposited sediments, as authigenic minerals. Salinity and pH increase with depth, the positive values of Eh indicate the oxidation of Fe 2+ and S 2- found in the sulfide minerals and organic matter. A second zone is characterized by acid pH (average 6,5) and negative Eh values which preserves sulfides and organic matter. Mangroves sediments contain high contents of SiO2, Al2O3 and Fe2O3 that reflect their main minerals, quartz, kaolinite, smectite and pyrite, showing the close relationship to the Barreiras Formation and their soil-derived material. The expressive contents of Na, K, Ca, and Mg found mainly as K-feldspars, illite, smectite and halite reflect the marine contribution to mangrove environment. The bioavailability of the elements in mangroves sediments is low, in general below to 1% of the total concentration of each element, except for As that displays high bioavailability. The leaves of Rhizophora mangle concentrate Mg, Ca and P, besides Zn, Sr, Zr, As, and Hg. These values are inside the normal range found in non impacted environments and reflect their very low concentration in mangrove sediments and indirectly in the Barreiras Formation sediments. Crabs show that the largest concentrations of Fe, Al, Mg, and Si in the hepatopancreas of the females, whereas Ca, K and Na in the muscles of females, Zn concentrates either in the muscles of females or males, however, with higher concentration in the muscles of females. Se and As also concentrate on the hepatopancreas of males and females but, the hepatopancreas of males concentrates more Se and the females, As. The transference of the elements in the sediments to the plants can be seen through the biological absorption coefficient (BAC), and Hg is the one that accumulated in the leaf tissue the best. The BAC plant-crab shows high values for Fe that concentrates either in the hepatopancreas as of males or females; Zn in the muscles of males and Sr in muscles and hepatopancreas of females. The contents of Hg, Se and As in human hair are very low, below the limits recommended by WHO for environments without anthropic influence. The human hair “mineral analyses” indicate that the nutritious elements are in the normal range, in the same way for so called toxic and additional “minerals”(chemical elements). The data obtained in sediments, in leaves and in crabs of the mangroves of Marapanim, show that leaves of Rhizophora mangle and crabs picture the chemical nature and indirectly the mineralogy of the mangrove sediments, and they reveal low values of transference of the chemical composition of the sediments to mangroves leaves to the crabs. The chemical composition of the sediments of the mangroves of Marapanim allows visualizing its affinity with the sediments of the Barreiras Formation, as source area, with a parge marine contribution, and it indicates that the mangroves, in fact don't present any natural geochemical anomaly nor indications of environmental impact. Thus crabs are important in the alimentary diet of the Marapanim region, constituting are appropriate food source because it doesn't present any evidence of contamination by heavy metals.
Acesso aberto (Open Access)
Reconstituição paleoambiental da vegetação costeira na foz dos rios Santa Maria da Vitória e Jucu durante o holoceno médio e tardio, Estado do Espírito Santo, Brasil
(Universidade Federal do Pará, 2025-03-13) PANTOJA, NISYA ROBELLY CARDOSO; FRANÇA, Marlon Carlos; http://lattes.cnpq.br/8225311897488790; https://orcid.org/0000-0002-3784-7702
Climate and sea level changes may have caused significant alterations in coastal morphology and mangrove distribution on the central coast of Espírito Santo State, Brazil. Therefore, this study aims to identify the dynamics of coastal vegetation during the middle and late Holocene, in the Santa Maria da Vitória and Jucu rivers. For this purpose, 14C dates, sedimentary data and pollen data were used, obtained from two sedimentary cores, called RSMV (340 cm) and JUCU (190 cm). During the middle Holocene, around 7245-7368 cal years BP, the relative sea level (SSL) was above the current level, resulting in the development of mangroves in the RSMV core region. However, around 2699-2787 cal years BP, with the regression of the SSL, the mangrove area moved to topographically lower regions. Another determining factor for the reduction of these areas during this period to date was human intervention. In the JUCU core region, mangrove forests were identified between 2188-2332 cal yr BP, initially colonized by Laguncularia. Thus, in this context, the dynamics of vegetation and sediments are associated with fluctuations in relative sea level and climate change throughout the Holocene.
Acesso aberto (Open Access)
Os saberes tradicionais dos pescadores de caranguejo-uçá e o manguezal: o caso de Tamatateua Bragança - Pará, costa Amazônica brasileira
(Universidade Federal do Pará, 2019-12) OLIVEIRA, Francisco Pereira de; SOUZA, Gamaliel Tarsos de; SILVA, Klayton Luiz Campelo; FERNANDES, Marcus Emanuel Barroncas
This study focuses on the empirical knowledge and environmental perceptions of Uçá crab (Ucides cordatus) fishermen from the Tamatateua region, municipality of Bragança, northeast of Pará. The main objective is to describe the fishermen's traditional knowledge on this resource focusing on the ecological knowledge from their perceptions and close relationship with the mangrove ecosystem. used the qualitative research approach, in which the technique and the research instrument were carried out using interviews from a questionnaire designed with semi-structured questions, respectively. Data collection took place between 2017 and 2018, with 14 (fourteen) fishermen of Uçá crab, aged between 22 and 62 years, in which the analytical process made use of content analysis. The results demonstrate that the fishermen have elaborated ecological knowledge about the Uçá crab specimen, as well as the natural and environmental phenomena. They perceive the connection between the human being and the mangrove as a synonym of food, marketing, culture, religiosity, among others, which, in some way, directly influence the knowledge passed on from generation to generation through non-formal and informal education. It was also found that the management of the Uçá crab resource is due to the learning process that occurs daily between kinship (father, son, grandson, uncles and others), as well as in the process and socialization (sharing) between friends of the “ mangrove". On the other hand, it was identified that even using predatory practices and arts, such as the hook, the fishermen recognize them as such, but reveal the idea of maintaining the resource when arguing about the respect in the reproduction periods of the specimen.
Acesso aberto (Open Access)
Variação sazonal do carbono e um ecossistema de manguezal na Amazônia Oriental: florística, clima e economia
(Universidade Federal do Pará, 2019-02-25) RODRÍGUEZ, Nelson Antonio Castellón; JARDIM, Mário Augusto Gonçalves; http://lattes.cnpq.br/9596100367613471; VITORINO, Maria Isabel; http://lattes.cnpq.br/4813399912998401
This interdisciplinary research aims at investigating the seasonal and economic dimensions of the mangrove forest, in relation to the capture, storage and carbon emissions, from spatial variation of floristic, physical-chemical, biological and climatic variables for the period of 2016 and 2017 in the Eastern Amazon. The study area is located at the Experimental Site of UFRA / UFPA in the village of Cuiarana, Salinópolis-PA. The floristic inventory method consisted of transects and plots, with DBH measures ≥ 2.5cm, monthly precipitation data generated by the CMORPH technique and the tide of the Salinopólis Fundeadouro. The stock of organic carbon, CO2 emissions and physico-chemical and biological variables were measured through seasonal sampling in nine 20x20m plots in three mangrove strata. Socioeconomic data are based on the combination of carbon dioxide fluxes measured by a micrometereological tower installed in the study area and interviews with residents of Cuiarana Village. Spatially, the main results show that for the three mangrove strata the dominance of Rhizophora mangle (L) was observed, with the highest values of phytosociological indices. The species Avicennia germinans (L.) Stearn presented a higher positive correlation (0.72) with organic carbon during the rainy season. The largest stocks and emissions of organic carbon in the soil occurred in the adult mangrove in the rainy season when compared to the young / dwarf and intermediate strata. In the socioeconomic context, the villagers identified nine mangrove properties of which the main ones are the consumption and the sale of the crab in the less rainy season. However, services for carbon capture and storage in the soil presented higher income in the rainy season. The incomes estimated by mangrove goods and services were R $ 92,660.50 per hectare per year.