Artigos Científicos - FBIO/IECOS

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Acesso aberto (Open Access)
Virological and serological diagnosis of rabies in bats from an urban area in the brazilian Amazon
(Universidade Federal do Pará, 2015-12) OLIVEIRA, Rubens Souza de; COSTA, Lanna Jamile Corrêa da; ANDRADE, Fernanda Atanaena Gonçalves de; UIEDA, Wilson; MARTORELLI, Luzia Fatima Alves; KATAOKA, Ana Paula de Arruda Geraldes; ROSA, Elizabeth Salbé Travassos da; VASCONCELOS, Pedro Fernando da Costa; PEREIRA, Armando de Souza; FERNANDES, Marcus Emanuel Barroncas; CARMO, Antônio Ismael Barros do
The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005, in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a priority area for studies on this zoonosis. Given this, the present study provides data on this phenomenon in an urban context, in order to assess the possible circulation of the classic rabies virus (RABV) among bat species in Capanema, a town in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and dry seasons. Samples of brain tissue and blood were collected for virological and serological survey, respectively. None of the 153 brain tissue samples analyzed tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum samples analyzed were seropositive. Artibeus planirostris was the most common species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31 52.60%). Statistically, equal proportions of seropositive results were obtained in the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95% CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested positive for infection, the high proportion of seropositive specimens indicates that RABV may be widespread in this urban area.
Acesso aberto (Open Access)
Licófitas e monilófitas das Unidades de Conservação da Usina Hidroelétrica - UHE de Tucuruí, Pará, Brasil
(2012-06) FERNANDES, Rozijane Santos; ROSÁRIO, Sebastião Maciel do; PIETROBOM, Marcio Roberto
This work presents a survey of lycophytes and monilophytes in the Conservation Unit named Zonas de Preservação da Vida Silvestre da Usina Hidrelétrica de Tucuruí, Pará State, Brazil. This Conservation Unit is located at southeastern Pará and comprises about 29,700 ha, composed mainly of tropical rainforest. Our results recorded 18 families, 37 genera and 82 species. The richest family is Pteridaceae, with 21 species, and Adiantum is the richest genus, with 14 species. Three species are new records for Pará State: Didymoglossum ovale, Danaea nodosa, and Pecluma hygrometrica. Furthermore, two new species were identified. One has already been described, Thyelypteris amazonica. The other new species belongs to the genus Adiantum and shall be published soon. The floristic richness of the area, associated with the taxonomic novelties, attests for its biological importance and for the necessity of increasing the efforts on research and conservation of the study area.
Acesso aberto (Open Access)
Cyatheales (Polypodiopsida) do Corredor de Biodiversidade do Norte do Pará, Brasil
(2014-09) GÓES NETO, Luiz Armando de Araújo; PIETROBOM, Marcio Roberto
This paper is part of a series where the lycophyte and fern species of the Biodiversity Corridor ofnorthern Pará State are presented, produced under the project "Diagnóstico da Biodiversidade das Unidades de ConservaçãoEstaduais do Mosaico Calha Norte, Estado do Pará". In this manuscript the taxonomic treatment of Cyatheales is presented with identification keys, illustrations, distribution, descriptions, and comments to the studied taxa. Two families (Cyatheaceae and Metaxyaceae), three genera (Cnemidaria, Cyathea, and Metaxya), eight species, and one variety are registered. Cyathea is the most representative genus with seven species.
Acesso aberto (Open Access)
Indução de calos em espécies amazônicas do gênero Theobroma
(2006-04) SILVA, Marivana Borges; RAMOS, Alessandra de Rezende; VENTURIERI, Giorgini Augusto
Many works have been done on cocoa (Theobroma cacao) in vitro culture, with few studies being published for other species of the same genus, as cupuassu (T. grandiflorum), whose planted area is increasing expressively, and others that could be used as a source of genes for those with recognized economical importance. Protocols to obtain in vitro somatic embryos from T. cacao,T. grandiflorum,T. speciosum and the hybrid T. grandiflorum x T. obovatum from two sources of explants, staminodes and petals (formed by ligues and cogules) were evaluated, using a primary callus growth medium made of DKW salts, supplemented with 20 g l-1 of sucrose, 250 mg l-1 of glutamine, 200 mg l-1 of myo-inositol, 0.2 mg l-1 of thyamine-HCl; 0.1 mg l-1 of nicotinic acid; 0.2 mg l-1 of glycine; 2 mg l-1 of 2,4-D; 2.2 g l-1 of Gelrite® and the pH adjusted to 5.8. To this media was added different concentrations of thidiazuron (0; 5 and 10 µg l-1). Cultures were maintained at dark for 14 days, at a temperature of 25 ± 2 ºC, and so transferred for the secondary callus growth, made with WPM salts, Gamborg vitamins, 20 g l-1 of sucrose, 2 mg l-1 of 2,4 D; 0.3 mg l-1 of cinetin, 50 ml l-1 of coconut milk, 2.2 g l-1 of Gelrite® and the pH adjusted to 5.8. Callus formation occurred in all species. Somatic embryos were obtained only for T. cacao. Callus formation was influenced by genotype and was higher on staminodes.
Acesso aberto (Open Access)
Genetic variation in native and farmed populations of Tambaqui (Colossoma macropomum) in the Brazilian Amazon: regional discrepancies in farming systems
(2013) AGUIAR, Jonas da Paz; SCHNEIDER, Horacio; GOMES, Maria de Fátima; CARNEIRO, Jeferson Costa; SILVA, Simoni Santos da; RODRIGUES, Luis Reginaldo Ribeiro; SAMPAIO, Maria Iracilda da Cunha
The tambaqui, Colossoma macropomum, is the most popular fish species used for aquaculture in Brazil but there is no study comparing genetic variation among native and farmed populations of this species. In the present study, we analyzed DNA sequences of the mitochondrial DNA to evaluate the genetic diversity among two wild populations, a fry-producing breeding stock, and a sample of fish farm stocks, all from the region of Santarém, in the west of the Brazilian state of Pará. Similar levels of genetic diversity were found in all the samples and surprisingly the breeding stock showed expressive representation of the genetic diversity registered on wild populations. These results contrast considerably with those of the previous study of farmed stocks in the states of Amapá, Pará, Piauí, and Rondônia, which recorded only two haplotypes, indicating a long history of endogamy in the breeding stocks used to produce fry. The results of the two studies show two distinct scenarios of tambaqui farming in the Amazon basin, which must be better evaluated in order to guarantee the successful expansion of this activity in the region, and the rest of Brazil, given that the tambaqui and its hybrids are now farmed throughout the country.
Acesso aberto (Open Access)
Feeding and larval growth of an exotic freshwater prawn Macrobrachium equidens (Decapoda: Palaemonidae), from Northeastern Pará, Amazon Region
(2014-09) GOMES, Jean Neves; ABRUNHOSA, Fernando Araujo; COSTA, Anne Karoline Ribeiro; MACIEL, Cristiana Ramalho
In the present study, we carried out experiments on the diet of the freshwater prawn Macrobrachium equidens. We tested which type of food and which density of food is suitable for larval development. For the experiment on the type of food, eight treatments were carried out: (I) starvation, (AL) microalgae, (RO) rotifers, (AN) Artemia, (RO + AN) rotifers + Artemia, (AL + RO) microalgae + rotifers, (AL + AN) microalgae + Artemia, (AL + RO + AN) microalgae + rotifers + Artemia. For the experiment on the density of food, we used the type of food, which had resulted in a high survival rate in the previous experiment. Three treatments were carried out: 4, 8 and 16 Artemia nauplii /mL. The rate of feeding during larval development was observed. The survival, weight and percentage of juveniles of each feeding experiment were determined. We found that larvae are carnivores; however, they have requirements with respect to the type of food, because larvae completed their cycle from the zoeal to the juvenile stage only when Artemia nauplii were available. We also verified that the larvae feed mainly during the day-time, and are opportunistic with respect to the density of food offered.
Acesso aberto (Open Access)
Aspleniaceae (Polypodiopsida) do corredor de biodiversidade do norte do Pará, Brasil: um fragmento do Centro de Endemismo Guiana
(2012-06) GÓES NETO, Luiz Armando de Araújo; PIETROBOM, Marcio Roberto
This paper is part of a series that will treat the lycophyte and fern species of the Northern Pará Biodiversity Corridor, and is part of the project "Diagnóstico da Biodiversidade das Unidades de Conservação Estaduais do Mosaico Calha Norte, Estado do Pará". Aspleniaceae are treated in this article, and an identification key, illustrations, geographic distributions, brief descriptions, and taxonomic comments are provided. There are eight species of Aspleniaceae in this region (Asplenium angustum Sw., A. auritum Sw., A. cruegeri Hieron., A. delitescens (Maxon) L.D. Gómez, A. juglandifolium Lam., A. salicifolium L., A. serratum L. and A. stuebelianum Hieron.). The majority of the species are epiphytes that grow on decaying trunks inside the forest. For this family, the registered species correspond to 35% of the species in the Brazilian Amazon, and 40% of species in Pará State.
Acesso aberto (Open Access)
Spatial distribution of the amazon river prawn Macrobrachium Amazonicum (Heller, 1862) (Decapoda, Caridea, Palaemonidae) in two perennial creeks of an estuary on the northern coast of Brazil (Guajará Bay, Belém, Pará)
(2011-11) SILVA, Bianca Bentes da; MARTINELLI-LEMOS, Jussara Moretto; SILVA, Leiliane Souza da; CAVALCANTE, Danielle Viveiros; ALMEIDA, Morgana Carvalho de; ISAAC, Victoria Judith
Macrobrachium amazonicum is the most frequently consumed freshwater crustacean by river communities of the Amazon. Despite its relative abundance and vast knowledge on the species from data on cultivated specimens, little is known regarding its biology in the natural environment, especially its use of creeks that are strongly influenced by the tide. Specimens of Macrobrachium amazonicum were collected in September 2006 (dry season) and March 2007 (rainy season) from two perennial creeks of the Guajará Bay in the state of Pará (northern Brazil), using traps similar to the matapis used by local fishermen to identify the spatial distribution of the species. Shrimps of all sizes use the tidal creeks in both seasons, including for breeding purposes. The greatest abundance of the species occurred in headwater areas and in the dry season. It is suggested that abundant allochthonous organic matter and the preference for protected areas may explain the abundance and breeding activity of this species in the headwaters of the creeks.
Acesso aberto (Open Access)
Food categories reconstruction and feeding consumption estimates for the Sciaenid Macrodon ancylodon (Bloch & Schneider), and the congeneric fishes Stellifer rastrifer (Jordan) and Stellifer naso (Jordan) (Pisces, Perciformes) in the Caeté Estuary, Northern Coast of Brazil
(2004-03) CAMARGO-ZORRO, Mauricio; ISAAC, Victoria Judith
A quantitative method to estimate fish feeding consumption and energy intake from different food categories through the reconstruction of ingested preys based on hard not digestible body structures is presented. In order to establish the equations of the functional relationships between preys weight and body structures, stomachs of 1.086 specimens of Macrodon ancylodon (Bloch & Schneider, 1801), Stellifer rastrifer (Jordan, 1889), and Stellifer naso (Jordan, 1889) fish species were dissected. Consequently, preys reconstruction enabled a quantitative evaluation of food categories consumption. Results indicate a marked difference in diet composition and energy requirements according to fish species ontogenetic development.
Acesso aberto (Open Access)
Comparative morphology of the first zoea of twelve brachyuran species (Crustacea: Decapoda) from the Amazon region
(2013-06) SOUZA, Adelson Silva de; COSTA, Rauquírio André Albuquerque Marinho da; ABRUNHOSA, Fernando Araujo
The laboratory-hatched first zoeal stage of twelve brachyuran species collected in the estuarine area of the Caeté River in the Amazonian region are described and illustrated in the present study: P. americanus Saussure, 1857, Eurytium limosum (Say, 1818), Sesarma curacaoense De Man, 1892, S. rectum Randall, 1840, Armases rubripes (Rathbun, 1897), Aratus pisonii (H. Milne Edwards, 1837), Ocypode quadrata (Fabricius, 1787), Uca rapax (Smith, 1870), U. maracoani (Latreille, 1802), U. thayeri Rathbun, 1900, Ucides cordatus (Linnaeus, 1763) and Pachygrapsus gracilis (Saussure, 1858). Through intraspecific comparisons of the respective larval stage, an identification key was generated and provided. Most of the studied species presented morphological differences (e.g. type and presence or absence of setae) when compared to the same species previously described in the literature.
Acesso aberto (Open Access)
Mangrove vegetation in Amazonia: a review of studies from the coast of Pará and Maranhão States, north Brazil
(Instituto Nacional de Pesquisas da Amazônia, 2008) MENEZES, Moirah Paula Machado de; BERGER, Uta; MEHLIG, Ulf
The present study is a compilation of the literature about vegetation of mangrove forest of the north coast of Brazil. It synthesizes the knowledge about this important ecosystem and lists the currently available literature. The study focuses on the coast of Pará and Maranhão states, which are covered by a continuous belt of mangroves. The mangrove flora comprises six mangrove tree species and several associated species. Mangrove tree height and stem diameter vary as a function of abiotic local stand parameters. Seasonal variation in rainfall and salinity affect the species' phenology and litter fall. Local population use products derived from mangrove plants for different purposes (e.g. fuel; medicinal; rural construction). The increase in the coastal population has given rise to conflicts, which impact on mangrove forest.
Acesso aberto (Open Access)
Tide distortion and attenuation in an Amazonian tidal river
(2012-12) FREITAS, Paulo Tadeu Amorim; SILVEIRA, Odete Fátima Machado da; ASP NETO, Nils Edvin
The present study seeks to evaluate tidal propagation in the Guamá-Capim river system, in the Amazonian region, considering hydrodynamic and geomorphological aspects. Available data sets on fluvial discharge and water level variations were considered, besides several methods of measuring the tides (currents, water levels and discharges) recorded at different stations and in different periods. The main point argued is that fluvial discharge is the key-factor in tidal distortion and tidal bore formation in the system investigated, whereas the low relief of the area would be the main factor contributing to landward tidal incursion. The results show an impressive upward tidal incursion of more than 200 km, including substantial distortion -increasing upstream -of the tidal wave, of which the ebb phase lasts up to 5 hours longer than the flood, including higher flood current velocities as far as 161 km upstream. Generally, only hyposynchronous tidal response was observed. Seasonally, the fluvial discharge varies about 10 times in the Guamá and 4 times in the Capim River. The increase of the fluvial discharge results in an increasing distortion of the tide, besides a weak increase of the attenuation. During high fluvial discharge periods in conjunction with equinoctial tides (e.g. March-April), a tidal bore occurs in the system, also increased by the generally low relief. Therefore, the conclusions include: low relief and the distortion related to high fluvial discharges are the main factors controlling tidal propagation along the system and tidal bore formation. Furthermore, the system could be classified as a tidal river, in which massive regional fresh water input results in virtually non-existent salinity throughout the Guamá-Capim system.
Acesso aberto (Open Access)
Plantas nativas úteis na Vila dos Pescadores da Reserva Extrativista Marinha Caeté-Taperaçu, Pará, Brasil
(2010-12) CARNEIRO, Diogo Borges; BARBOZA, Myrian Sá Leitão; MENEZES, Moirah Paula Machado de
This study identifies the native plant species used by the inhabitants of Vila dos Pescadores, Caeté-Taperaçu Marine Extractive Reserve, Bragança, Pará, Brazil. By means of semi-structured interviews with 30 inhabitants, a socio-economic profile of the people interviewed was done; useful plant species and their respective usage were recorded. A total of 23 species were cited. Of these, 20 species are native to mangrove or sand dune (restinga) ecosystems. The remaining 3 species are considered "native" by village inhabitants, although they are in fact introduced exotic species. Most of the restinga species are used for food, while most mangrove species are employed in a broad range of usage types, mainly associated with "construction" and "technical applications" categories. The fishing profession was evident in plant species usage, especially for the mangrove species. The Shannon diversity index was high (H'=2.3) due to the large number of reported uses of mangrove species. The results indicate that, due to the great utility of native plant species, the management, use and preservation policies of Marine Extractive Reserves should pay more attention to the exploitation of plant resources, especially those from mangrove forests.
Acesso aberto (Open Access)
The dynamics of a frictionally-dominated Amazonian estuary
(2012-09) ASP NETO, Nils Edvin; SCHETTINI, Carlos Augusto França; SIEGLE, Eduardo; SILVA, Marcio Sousa da; BRITO, Roney Nonato Reis de
A hidrodinâmica, morfologia e sedimentologia do estuário do Taperaçu foram investigadas. Este é um entre vários estuários do litoral amazônico que integram a maior extensão contínua de manguezais do mundo, apresentando uma descarga de água doce muito reduzida, atípica para a região. Os resultados revelam grandes bancos arenosos que ocupam em grande parte a porção central do estuário. Areias muito finas e bem selecionadas de origem marinha prevalecem. Fases de enchente mais curtas, com velocidades de corrente substancialmente mais altas, são observadas na porção superior do estuário, como esperado para um estuário raso e dominado por fricção. Por outro lado, uma vazante mais intensa poderia ocorrer como resultado de grandes áreas de manguezais associadas e intenso preenchimento estuarino, sendo que ambas as condições são observadas no Taperaçu. Neste caso, a prevalência da enchente parece estar associada à ausência de uma descarga fluvial efetiva. Além disso, alguns canais de maré conectam o Taperaçu com seu vizinho estuário do Caeté, o que contribuiria para o domínio de enchente. Como um todo, os resultados demonstram uma complexa interação de aspectos de configuração (fricção, drenagem fluvial, conexões com estuários vizinhos, preenchimento e grandes áreas intermareais) na determinação dos padrões hidrodinâmicos, contribuindo para o entendimento dos estuários da região amazônica.
Acesso aberto (Open Access)
Mangrove sedimentary characteristics and implications for crab Ucides cordatus (Crustacea, Decapoda, Ucididae) distribution in an estuarine area of the Amazonian region
(2013-12) GOMES, José Diego; ABRUNHOSA, Fernando Araujo; SIMITH, Darlan de Jesus de Brito; ASP NETO, Nils Edvin
At the coastal zone sediments, water and organisms interact intensely. At equatorial tidal-dominated coast mangroves are abundant. These areas are well-known for their ecological importance. Considering the mangroves of Atlantic South America, the mangrove crab, Ucides cordatus has ecological and economic prominence. High densities of this crab are found on the Amazon coast. This study investigates the sediment distribution of the Bragança mangrove area (Amazon coast, Brazil) and its correlations with vegetation and mangrove crab distribution. Sediments of 47 sites, as well as crabs from sites with different sediment and vegetation, were sampled. Results show that surface sediment of the area is mainly composed by silt (59%), with 21% sand and 20% clay. Variations in sorting and skewness are the product of local variations in clay and sand content. The vegetation type was significantly correlated to mangrove crab characteristics, abundance and weight/size. Sediment characteristics are also substantially different according to the vegetation type. Areas where Avicennia germinans prevails have more sand and clay than areas of Rizophora mangle, in which silt is dominant and crabs were significantly heavier. The present results have showed that the distribution of sediments, crabs and vegetation at mangrove areas are strongly correlated. Thus, they should be studied in conjunction.
Acesso aberto (Open Access)
The coastal restinga vegetation of Pará, Brazilian Amazon: a synthesis
(2010-12) SILVA, Rachel Macedo da; MEHLIG, Ulf; SANTOS, João Ubiratan Moreira dos; MENEZES, Moirah Paula Machado de
The present article reviews studies (some unpublished) of the vegetation of coastal sandy soils (restinga) along the coast of Pará State, northern Brazil. A total of 411 higher plant species are reported; Fabaceae, Poaceae, Cyperaceae, Rubiaceae and Myrtaceae are the most species-rich families. Nearly half of the restinga species (48%) are terrestrial herbs; palms, trees and shrubs account for 39% of the species, the remainder being lianas and epiphytes. Species are frequently wide-spread and occur in coastal areas of Southeastern Brazil as well as at inland sites in the Amazon region. Only two species appear to be exclusively coastal; whereas other species appear to exhibit a preference for sandy soils. Plant assemblages are commonly classified by means of "formations" associated with certain habitats but current data do not allow the description of well-defined plant associations. The species composition at different sites along the Pará coast does not show any clear regional grouping pattern. Seasonal changes in the composition of restinga vegetation are most probably linked to variation in ground water level. Restinga forest is mostly low and open; among the dominant tree species are Humiria balsamifera Aubl., Pouteria ramiflora (Mart.) Radlk., Anacardium occidentale L., Byrsonima crassifolia (L.) Kunth, and Tapirira guianensis Aubl.
Acesso aberto (Open Access)
Wave refraction and longshore transport patterns along the southern Santa Catarina coast
(2007-06) SIEGLE, Eduardo; ASP NETO, Nils Edvin
Based on the wave climate for the southern Brazilian coast, wave refraction has been modelled in order to obtain the refracted wave heights and directions along the southern Santa Catarina coast, providing the needed information for potential longshore drift estimates. According to its coastline orientation, different sectors of the coast present varying longshore drift patterns. Estimates have been made for the yearly-averaged wave climate as well as for each season, showing thereby the longshore drift patterns along the year. Based on the results of the potential longshore drift intensities and directions and on the shoreline outline in plan, it has been possible to identify a strongly drift-dominated coast in the south turning to a mixed drift and swash dominated coast towards the north of the studied area. Contrasting patterns of longshore drift between the southern and northern portion of the coastline indicate a sediment surplus in the central portion, making sediment available for cross-shore transport processes, either on- or offshore. Considering long-term aspects, the longshore drift patterns are in agreement with the coastal infilling process which has mainly been driven by persistent surplus from littoral sediment drift.
Acesso aberto (Open Access)
Innovative molecular approach to the identification of Colossoma macropomum and its hybrids
(2012-06) CUNHA, Maria de Fátima Gomes; SCHNEIDER, Horacio; BARROS, Maria Claudene; SAMPAIO, Dioniso de Souza; HASHIMOTO, Diogo Teruo; PORTO-FORESTI, Fábio; SAMPAIO, Maria Iracilda da Cunha
Tambaqui (Colossoma macropomum) is the fish species most commonly raised in the Brazilian fish farms. The species is highly adaptable to captive conditions, and is both fast-growing and relatively fecund. In recent years, artificial breeding has produced hybrids with Characiform species, known as "Tambacu" and "Tambatinga". Identifying hybrids is a difficult process, given their morphological similarities with the parent species. This study presents an innovative molecular approach to the identification of hybrids based primarily on Multiplex PCR of a nuclear gene (α-Tropomyosin), which was tested on 93 specimens obtained from fish farms in northern Brazil. The sequencing of a 505-bp fragment of the Control Region (CR) permitted the identification of the maternal lineage of the specimen, all of which corresponded to C. macropomum. Unexpectedly, only two CR haplotype were found in 93 samples, a very low genetic diversity for the pisciculture of Tambaqui. Multiplex PCR identified 42 hybrids, in contrast with 23 identified by the supplier on the basis of external morphology. This innovative tool has considerable potential for the development of the Brazilian aquaculture, given the possibility of the systematic identification of the genetic traits of both fry-producing stocks, and the fry and juveniles raised in farms.
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)
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.