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Registros recuperados: 239 | |
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Lu,Dengsheng; Batistella,Mateus. |
Many texture measures have been developed and used for improving land-cover classification accuracy, but rarely has research examined the role of textures in improving the performance of aboveground biomass estimations. The relationship between texture and biomass is poorly understood. This paper used Landsat Thematic Mapper (TM) data to explore relationships between TM image textures and aboveground biomass in Rondônia, Brazilian Amazon. Eight grey level co-occurrence matrix (GLCM) based texture measures (i.e., mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment, and correlation), associated with seven different window sizes (5x5, 7x7, 9x9, 11x11, 15x15, 19x19, and 25x25), and five TM bands (TM 2, 3, 4, 5, and 7) were analyzed.... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Texture; Aboveground biomass; TM image; Correlation; Amazon. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672005000200015 |
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Thatcher,Vernon E.. |
Two new genera and species of Paramphistomidae (Tremadota, Digenea) are described from freshwater fish of the Brazilian Amazon. Anavilhanatrema robustagen. et sp. nov. is characterized as having a cylindrical body with an anterior expansion, small suckers, a small cirrus sac, large lobate testes, a lobate ovary, long ceca and extensive vitellaria. Pacudistoma turgidagen. et sp. nov., on the other hand, is distinguished by having a stout, cylindrical body, a large oral sucker with internal diverticula, a large genital sucker, smaller lobate testes, a spherical ovary, long ceca and relatively extensive vitellaria. Both species appear to be host specific with A. robustafound in Pristobrycon striolatus(STEINDACHNER) while P. turgidaoccurus in Hyleus... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amphistome; Trematode; Amazon; Fish parasite.. |
Ano: 1992 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59671992000400609 |
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FIGUEIREDO,Symone Maria de Melo; VENTICINQUE,Eduardo Martins; FIGUEIREDO,Evandro Orfanó; FERREIRA,Evandro José Linhares. |
Species distribution modeling has relevant implications for the studies of biodiversity, decision making about conservation and knowledge about ecological requirements of the species. The aim of this study was to evaluate if the use of forest inventories can improve the estimation of occurrence probability, identify the limits of the potential distribution and habitat preference of a group of timber tree species. The environmental predictor variables were: elevation, slope, aspect, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). To estimate the distribution of species we used the maximum entropy method (Maxent). In comparison with a random distribution, using topographic variables and vegetation index as... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Modeling; Maxent; Forest inventory; Modeflora; Amazon. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672015000200167 |
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ARIANO,Ana Paula Ramos; SILVA,Ivone Vieira da. |
ABSTRACT Leaves have a variety of morphological and anatomical characters mainly influenced by climatic, edaphic and biotic factors. The aim of this study was to describe the anatomical leaf traits of Qualea parviflora from three phytophysiognomies. The studied phytophysiognomies were Amazon Savannah on rocky outcrops (ASR), Transition Rupestrian Cerrado (TRC), and Cerradão (CDA). Freehand sections of the leaf blade were made and stained with 0.5% astra blue and with basic fuchsin. From the adaxial and abaxial leaf surface, freehand paradermal sections were made for epidermis analysis. The Jeffrey´s method, with modifications, was used in the epidermis dissociation process. The samples from the TRC phytophysiognomy had relatively smaller ordinary epidermal... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adaptations; Amazon; Cerrado; Environmental conditions. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672016000200119 |
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ADIS,Joachim; PAARMANN,Wilfried; AMORIM,Maristela A.; ARNDT,Erik; FONSECA,Claudio R. V. da. |
Over a seven year period from 1991 to 1997, 22 species of tiger beetles, representing nine genera, were recorded near Manaus, Brazil. In the Whitewaterfloodplains along the Rio Solimões-Amazonas (Ilha de Marchantaria), three diurnal species inhabit inundation forests and six species (two diurnal, four nocturnal) live in open areas. Data on their natural history and adaptation to living conditions in floodplains are presented. Fifteen species were located on non-flooded uplands (Reserva Florestal A. Ducke). Five diurnal species inhabit the forest floor, two species are canopy dwellers, and eight species (seven diurnal, one nocturnal) live in open areas on whitesand or laterite. Only one species, Pentacomia lacordairei, was found in both floodplain and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tiger beetles; Floodplains; Várzea; Terra firme; Amazon; Neotropics. |
Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59671998000300247 |
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PAARMANN,Wilfried; ADIS,Joachim; LÜDECKE,Kirsten; TOBASCHUS,Nicole; FONSECA,Claudio R. V. da. |
The spatial and temporal distribution of a guild of eight diurnal tiger beetle species was studied on a 105 m long transect near the field station of the Reserva Florestal A. Ducke near Manaus (AM), Brazil. The transect followed a path that included both shaded and an open areas. Five of the species, restricted to primary forest, occurrred only in shaded areas of the transect, and three species occurred in open areas. Of all eight species only two of the open habitat species showed no clear seasonality in adult activity. In six species the activity of adults was limited to the rainy season. The most pronounced annual rhythm was found in Pentacomia ventralis, an open habitat species. Activity of adults was limited to October/November. First in-star larvae... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Tiger beetles; Guild structure; Terra firme; Amazon. |
Ano: 1998 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59671998000300331 |
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Santos ARRAES,Débora Regina; Albuquerque CUNHA,Helenilza Ferreira; TAVARES-DIAS,Marcos. |
The purpuse of this study was to investigated the influence of anthropogenic impacts on Podocnemis unifilis nesting on a stretch from Falsino river, with two forest reserves, and one urban area on the Araguari river, state of Amapá, eastern Amazon (Brazil). A total of 180 nests were found, being 89.4 % in the forest reserves and only 10.6 % in urban areas. On Falsino river, we observed a spawning pattern, because the number of nests was correlated to the length and width of the nesting locations. On Araguari river, the P. unifilis nests were generally found in areas with surrounding vegetation up to 5 meters in height, minimum distance of 120 meters from residences and immediately or after places of higher exploration of pebbles. Females from Falsino river... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Eggs; Freshwater turtle; Neonates; Nests. |
Ano: 2016 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2016000200009 |
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Brito,Eliete da Silva; Ilkiu-Borges,Anna Luiza. |
This study aims to investigate the richness and ecological aspects (ecosystem and substrate) of mosses and liverworts at two municipalities on Marajó Island, in the state of Pará, Brazil. The study area (6615 km²) encompasses the municipalities of Soure and Cachoeira do Arari. Bryophytes were collected from the 10th to the 16th of January, 2007, during random visits along existing trails or during the forging of new trails, from all possible types of vegetation, regardless of the type of substrate. The ecosystems visited in the study area were capoeira (secondary vegetation, growing on land that has been burned or cleared), teso (vegetation growing on areas of land at an elevation slightly higher than the water line during flood season), floodplain forest,... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bryophyta; Marchantiophyta; Bryophytes; Amazon; Neotropics. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000100013 |
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Sá,Natália de Paula; Absy,Maria Lúcia; Soares,Emílio Alberto Amaral. |
ABSTRACT The core PD-67 of 160 cm depth was collected from the delta of Lake Cabaliana situated on the Solimões River. Seventeen samples were removed for palynological and sedimentological analysis and three for radiocarbon analysis. Two dry periods, both in the Late Holocene, were observed (2800-2550 cal yr BP, 1450-550 cal yr BP) separated by a wetter phase (2550-1450 cal yr BP). In 2800-2550 cal yr BP, varzea forests of Alchornea, Symmeria, Cecropia, Alternanthera and Asteraceae were predominant. Beginning in 2,550-1450 cal yr BP, the varzea was characterized by pioneer elements, such as Cassia, Laetia, Mabea, Symmeria and Cecropia, and by the expansion of Poaceae, Cyperaceae, Sagittaria, Montrichardia and Asteraceae. In 1450-550 cal yr BP the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Pollen; Quaternary; Rainfall; Terra firme forest. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062016000300473 |
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Quaresma,Adriano C.; Piedade,Maria Teresa F.; Feitosa,Yuri Oliveira; Wittmann,Florian; Steege,Hans ter. |
ABSTRACT Research focusing on assemblages of vascular epiphytes in the Amazon are scarce. This is especially true for Amazonian floodplain forests, for which only two previous studies have been published. We compared composition, richness and structure of epiphyte assemblages in white-water and black-water floodplains (várzea and igapó) in Central Amazonia in order to close knowledge gaps concerning the distribution and richness of epiphytes. We established sixteen 25x25 m plots in each forest type, and counted and identified all species of vascular epiphytes occurring on trees with a diameter at breast height (DBH) ≥10 cm. We observed a clear distinction in epiphytic species composition (r2=0.83, p=0.001) and diversity (t=3.24, P=0.003) between the two... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Biodiversity; Floodplains; Igapó forests; Várzea forests. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062017000400686 |
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Silva,Mayra Nina Araujo; Absy,Maria Lúcia; Latrubesse,Edgardo M.; Albuquerque,Patrícia Maia Correia de. |
ABSTRACT Morphological descriptions were made for pollen grains and spores extracted from samples from three sedimentary sections - Chandless 1, Purus 10 and Purus 30 - from fluvial terraces on the Chandless and Purus rivers, Acre State, Brazil. Level CH1-12 at Chandless 1 was C14-dated to 4861 - 5050 cal yr BP, P10-3 of Purus 10 was dated through the OSL method at 8200 +/- 65 yr BP, while P30-6 at Purus 30 was C14 dated to 7845 - 7998 cal yr BP. For pollen analysis, 2 cm3 of each sample was removed, treated with potassium hydroxide (KOH) and acetolysed, followed by palymorph separation with bromoform/alcohol density 2.0 solution. A total of 49 palynomorphs were morphologically described (39 pollen types and 10 Pteridophyte spores). The most frequent... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acre; Amazon; Chandless; Palynomorphs; Purus. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000100017 |
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Pimentel,Alyne Daniele Alves; Absy,Maria Lucia; Rech,André Rodrigo; Abreu,Vanessa Holanda Righetti de. |
ABSTRACT Insect pollination has influenced the evolution and diversification of angiosperms. Consequently, knowing plants used as food sources by bees, the most important pollinator group, is the first step toward understanding how their ecological relationships works. Pollen source information is also highly relevant for bee management and associated fruit and seed production. Accordingly, to improve understanding of the trophic ecology of these bees and their relationships with native Amazonian plants the current study identified, quantified and compared pollen stored in nests of Frieseomelitta stingless bees along the Rio Negro, Amazonas, Brazil. A total of 31 pollen pots were sampled and found to contain 65 pollen types distributed across 52 genera and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon; Feeding behavor; Meliponicultura; Stingless bees; Trophic resources. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062020000200371 |
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Registros recuperados: 239 | |
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