Environmental determinants for natural regeneration of gallery forest at the Cerrado/Amazonia boundaries in Brazil

Natural regeneration and structure and their relationship to environmental variables were studied in three sections of a gallery forest, in Eastern Mato Grosso, Brazil (14º43′S and 52º21′W). The assumption was that natural regeneration is constrained by environmental determinants at all stages of development of the tree community. The objective was to analyse the forest structure and to verify the relationship between species distribution and abundance at different stages of regeneration and environmental variables. In each section, 47 contiguous (10x10m) permanent plots were established to sample trees (gbh≥15cm), following a systematic design. Seedlings (0.01 to 1m height), saplings (1.01 to 2m) and poles (from 2.01m height to gbh<15cm) were sampled in sub-plots of 1x1m, 2x2m and 5x5m, respectively. In each plot, soil properties, gaps projection, bamboos, rocky cover, declivity and depth of ground watertable were determined. The relationships between the environmental variables with trees and seedling communities were assessed by canonical correspondence analysis. In spite of the sections being near to each other, they presented large differences in floristics, structure and site conditions. The forest soil presented a low cation exchange capacity and a high level of Al saturation. The occurrence of bamboos and gaps and the depth of ground watertable limited the occurrence of poles and trees. The high degree of structural heterogeneity for each regeneration category was related primarily to a humidity gradient; but soil fertility (Ca+Mg) was also a determinant of seedling and sapling communities.

New record of a very specialized interaction: myrcidris epicharis Ward 1990 (Pseudomyrmecinae) and its myrmecophyte host Myrcia madida McVaugh (Myrtaceae) in Brazilian Meridional Amazon

In this study we present a new record of a plant-animal interaction: the mutualistic relationship between the specialist plant-ant Myrcidris epicharis Ward, 1990 (Pseudomyrmecinae) and its myrmecophyte host Myrcia madida McVaugh (Myrtaceae). We observed more than 50 individuals of M. madida occupied by M. epicharis in islands and margins of the Juruena River, in Cotriguaçu, Mato Grosso, Brazil (Meridional Amazon). We discuss a possible distribution of this symbiotic interaction throughout all the riparian forest of the Amazon River basin and its consequence to coevolution of the system.

Composição e riqueza de Odonata (Insecta) em riachos com diferentes níveis de conservação em um ecótone Cerrado-Floresta Amazônica

A retirada ou a substituição da vegetação ripária provoca uma alteração no ambiente físico, no fluxo sazonal e na qualidade química da água. Essas modificações podem causar a diminuição da riqueza pela extinção local de espécies. O objetivo deste trabalho foi avaliar o efeito do distúrbio da integridade ambiental sobre a riqueza e composição de espécies de Odonata adultos em córregos com diferentes níveis de conservação, na Bacia do Rio Suiá-Missu, Mato Grosso, Brasil. As modificações nos sistemas aquáticos afetaram a comunidade de Odonata, provavelmente devido às exigências ecofisiológicas e comportamentais relacionadas a adultos e larvas. Anisoptera, que necessitam de ambientes com maior incidência de sol devido ao tamanho do corpo, apresentaram maior riqueza de espécies em ambientes com menor cobertura vegetal. Por outro lado, os Zygoptera geralmente habitam riachos com cobertura vegetal mais densa, e por isso, apresentaram um decréscimo de sua riqueza em locais alterados, devido à maior entrada de luz e/ou variação do calor. Assim, para as duas subordens, as alterações ambientais não precisam ser severas para produzir modificações significativas na composição, indicando que os serviços ecossistêmicos poderiam ser perdidos, mesmo com alterações parciais do meio físico.

Reproductive biology of Amasonia obovata Gleason (Laminaceae)

Floral mechanisms that ensure seed production via autogamy are more likely to occur in species growing in environments where pollination is scarce. Amasonia obovata was studied in the State of Mato Grosso-Brazil, from 2009 to 2012, to analyze the morphological and reproductive characteristics, aside from investigating the association of the reproductive success with the pollinator frequency and identity. The flowering and fruiting of A. obovata was concentrated in a period of five months during the rainy season. The dichogamy in flowers of A. obovata is not clearly defined, since the sexual functions were overlapped in the male and female phases. The species is self-compatible and not apomictic. The fruiting percentage obtained by hand self-pollination did not differ from cross-breeding (F = 0.74, P =0.39). In the observations from 2010 to 2012, a hummingbird (Thalurania furcata) legitimate visited 20-100% of the flowers in the male and female phases on different A. obovata plants. Due to the high frequency, this hummingbird was considered the single potential pollinator of the species. These findings show that a limited availability of pollinators may select for floral traits and plant mating strategies that lead to a system of self-fertilization.

Use of anatomical root markers for species identification in Catasetum (Orchidaceae) at the Portal da Amazônia region, MT, Brazil

Orchidaceae is one of the largest botanical families, with approximately 780 genera. Among the genera of this family, Catasetum currently comprises 166 species. The aim of this study was to characterize the root anatomy of eight Catasetum species, verifying adaptations related to epiphytic habit and looking for features that could contribute to the vegetative identification of such species. The species studied were collected at the Portal da Amazônia region, Mato Grosso state, Brazil. The roots were fixed in FAA 50, cut freehand, and stained with astra blue/fuchsin. Illustrations were obtained with a digital camera mounted on a photomicroscope. The roots of examined species shared most of the anatomical characteristics observed in other species of the Catasetum genus, and many of them have adaptations to the epiphytic habit, such as presence of secondary thickening in the velamen cell walls, exodermis, cortex, and medulla. Some specific features were recognized as having taxonomic application, such as composition of the thickening of velamen cell walls, ornamentation of absorbent root-hair walls, presence of tilosomes, composition and thickening of the cortical cell walls, presence of mycorrhizae, endodermal cell wall thickening, the number of protoxylem poles, and composition and thickening of the central area of the vascular cylinder. These traits are important anatomical markers to separate the species within the genus and to generate a dichotomous identification key for Catasetum. Thus, providing a useful tool for taxonomists of this group

Chemical and physical attributes and calcium, magnesium, potassium, and phosphorus in the soil of murundu fields in Brazil

Fields of murundus (FM) are wetlands that provide numerous ecosystem services. The objectives of this study were to evaluate the chemical [organic carbon (OC), P, K+, Ca2+, Mg2+, Al3+ and H+Al] and physical [texture and bulk density (Bd)] soil attributes and calculate the organic matter (OM) and nutrient stock (P, Ca, Mg, and K) in soils of FM located in the Guapore River basin in Mato Grosso. Thirty-six sampling points were selected, and soil samples were collected from two environments: the murundu and plain area surrounding (PAS). At each sampling point, mini trenches of 0.5 × 0.5 × 0.4 m were opened and disturbed and undisturbed soil samples were collected at depths of 0-0.1, 0.1-0.2, and 0.2-0.4 m. In the Principal Component Analysis the variables H+Al (49%) and OM (4%) were associated with the F1 component and sand content (47%) with the F2 component. The FM had lower pH values and higher concentrations of K+, P, and H+Al than PAS at all depths (p < 0.05). Additionally, FM stocked up to 433, 360, 205, and 11 kg ha-1 of Ca, Mg, K, and P, respectively, for up to a depth of 0.2 m. The murundu stored two times more K and three times more P than that in the PAS. Our results show that the FM has high sand content and Bd greater than 1.5 Mg m-3, high acidity, low OC content, and low nutrient concentrations. Thus, special care must be taken to preserve FM such that human intervention does not trigger environmental imbalances.

Litterfall production in intact and selectively logged forests in southern of Amazonia as a function of basal area of vegetation and plant density

Nutrient recycling in the forest is linked to the production and decomposition of litter, which are essential processes for forest maintenance, especially in regions of nutritionally poor soils. Human interventions in forest such as selecttive logging may have strong impacts on these processes. The objectives of this study were to estimate litterfall production and evaluate the influence of environmental factors (basal area of vegetation, plant density, canopy cover, and soil physicochemical properties) and anthropogenic factors (post-management age and exploited basal area) on this production, in areas of intact and exploited forest in southern Amazonia, located in the northern parts of Mato Grosso state. This study was conducted at five locations and the average annual production of litterfall was 10.6 Mg ha-1 year-1, higher than the values for the Amazon rainforest. There were differences in litterfall productions between study locations. Effects of historical logging intensity on litterfall production were not significant. Effects of basal area of vegetation and tree density on litterfall production were observed, highlighting the importance of local vegetation characteristics in litterfall production. This study demonstrated areas of transition between the Amazonia-Cerrado tend to have a higher litterfall production than Cerrado and Amazonia regions, and this information is important for a better understanding of the dynamics of nutrient and carbon cycling in these transition regions.

Predation of bat (Molossus molossus: Molossidae) by the centipede Scolopendra viridicornis (Scolopendridae) in Southern Amazonia

Centipedes are opportunistic carnivore predators, and large species can feed on a wide variety of vertebrates, including bats. The aim of this study was to report the third record of bat predation by centipedes worldwide, the first record in the Amazon region, while covering aspects of foraging, capture and handling of prey. We observed the occurence in a fortuitous encounter at Cristalino State Park, located in the Amazon region of the state of Mato Grosso, Brazil. The attack took place in a small wooden structure, at about three meters from the floor, and was observed for 20 minutes. During the observation, the centipede stung the neck and abdominal region of the bat several times, grabbing the prey with its 15 pairs of front legs while hanging from the ceiling with its hind legs. This type of observation suggests that vertebrates can be important preys for invertebrates such as giant centipedes, both for its nutritional composition and for the amount of energy available in a single prey.

Diet and ecomorphology of Leporinus reticulatus (Characiformes: Anostomidae) from the upper Rio Juruena, MT, Brazil: ontogenetic shifts related to the feeding ecology

The conservation of diverse and well-distributed fish taxa, as the genus Leporinus, relies intrinsically on the knowledge of the ecological attributes of its representatives. Aiming to increase this knowledge, studies on diet and ecomorphology are ideal to provide important information about species ecology. Thus, this study aimed to analyze aspects of feeding ecology of L. reticulatus, from the upper Rio Juruena, Mato Grosso State, Brazil. The diet of specimens in different ontogenetic stages was compared, as well as their teeth morphology and ecomorphological attributes. Leporinus reticulatus presented omnivorous diet, with higher consumption of invertebrates by smaller specimens (younger ones), and gradual introduction of plant items in larger specimens (older ones). The items consumed by the individuals and the ecomorphological attributes indicated that the species is generalist and opportunistic, besides its association with the river bottom, evidencing a benthic feeding behavior. This species presents a gradual ontogenetic modification in teeth shape and mouth positioning, ranging from a terminal mouth with tricuspid teeth, in smaller specimens, to an inferior mouth with spatula shaped teeth with no cusps, in larger specimens.The ecomorphological attributes indicate an increasing swimming efficiency, and ability for performing vertical displacements, along the ontogenetic development, which in addition to the morphological ontogenetic alterations in the buccal apparatus, contributes to a better ability to explore another niches.

Tendência do risco de morte por doenças circulatórias, cerebrovasculares e isquêmicas do coração em treze Estados do Brasil, de 1980 a 1998

OBJETIVO: Analisar tendências do risco de morte por doenças circulatórias (DC) em 13 estados do Brasil, no período de 1980 a 1998. MÉTODOS: Dados de mortalidade por DC, isquêmicas do coração (DIC) e cerebrovasculares (DCbV) nos 13 estados foram obtidos do Ministério da Saúde. Estimativas das populações, de 1980 a 1998, foram calculadas por meio de interpolação, pelo método de Lagrange, com base nos dados dos Censos de 1970, 1980, 1991 e contagem populacional de 1996. As tendências foram analisadas pelo modelo de regressão linear múltipla. RESULTADOS: A mortalidade por DC mostrou tendência de queda na maioria dos estados. Observou-se aumento, nos homens, em Pernambuco, para todas as faixas etárias, em Goiás, a partir de quarenta anos e na Bahia e Mato Grosso, a partir dos cinqüenta anos. Nas mulheres, aumento em Mato Grosso, a partir dos trinta anos, em Pernambuco, a partir dos quarenta anos, e em Goiás, nas faixas etárias entre trinta e 49 anos. Em Goiás, nas outras faixas etárias, o aumento foi discreto. Para as DIC, aumento da mortalidade para todas as faixas etárias em Mato Grosso e Pernambuco, e a partir dos quarenta anos, na Bahia, Goiás e Pará. Para as DCbV, aumento da mortalidade para todas as faixas etárias em Mato Grosso e Pernambuco, e a partir dos quarenta anos na Bahia e em Goiás. CONCLUSÃO: Observou-se importante aumento do risco de morte para as doenças circulatórias nos estados menos desenvolvidos do Brasil.

Índice de massa corporal e hipertensão arterial em indivíduos adultos no Centro-Oeste do Brasil

FUNDAMENTO: O excesso de peso e a obesidade constituem importante problema de saúde pública na sociedade, devido ao crescimento em todas as faixas etárias e por sua associação a várias doenças crônicas, especialmente a hipertensão arterial. OBJETIVO: Investigar possíveis fatores associados às alterações no índice de massa corporal (IMC). MÉTODOS: Estudo desenvolvido em Nova Andradina - Mato Grosso do Sul, com 369 indivíduos cadastrados no programa Estratégia Saúde da Família no ano de 2007. Os dados foram coletados nos domicílios, por meio de entrevista semiestruturada e avaliação antropométrica. Na análise dos dados, foram utilizados os testes qui-quadrado e Mantel Haensel, para respostas categóricas, e ANOVA e Tukey, para as contínuas. RESULTADOS: As prevalências de sobrepeso e obesidade foram de 33,3% e 23,0%, respectivamente. Em sua maioria, os indivíduos apresentavam as seguintes características: sexo feminino (85,4%), inativos (89,7%), relação cintura-quadril (RCQ) inadequada (83,7%) e portavam algum problema de saúde crônico (31,9%), especialmente a hipertensão arterial. Os fatores de risco para sobrepeso e obesidade podem ser relacionados às variáveis estado civil viúvo, RCQ inadequada, renda mais baixa e problemas de saúde. Já a hipertensão arterial pode ser associada apenas à obesidade. CONCLUSÃO: O percentual de pessoas que se encontravam acima do peso e daquelas que não praticavam atividade física em Nova Andradina indica que essas questões constituem desafio importante para o setor saúde também nas pequenas cidades. Por isso, é premente a implantação de programas de intervenção multidisciplinares no âmbito da atenção básica.

Biologia de Rolepa unimoda (Dognin,1923) (Lepidoptera, Lymantriidae) em folhas de Tabebuia avellanedae Lor. ex-griseb (Bignoniaceae) e observações sobre inimigos naturais

Este trabalho trata do estudo da biologia de Rolepa unimoda (Dognin,1923) (Lepidoptera, Lymantriidae), cujas lagartas são desfolhadoras em plantios ornamentais de Tabebuia avellanedae Lor. ex-Griseb (Bignoniaceae). Ataca também T. caraiba (Mart.) Burm. Os insetos foram criados em condições de laboratório (Temperatura 27±2°C; UR: 70 ± 15%, Fotoperíodo de 12 h), na Seção de Entomologia do Centro de Ciências Agrárias da Fundação Universidade Federal de Mato Grosso, em Cuiabá, MT. Foram estudados os seguintes parâmetros: período e viabilidade das fases de ovos,lagarta, pré-pupa e pupa; número e duração dos ínstares larvais e consumo foliar da fase de lagarta; longevidade dos adultos e proporção quanto ao sexo; inimigos naturais; plantas hospedeiras e ocorrência do inseto nos Estados de Mato Grosso e Mato Grosso do Sul.