Ciências do ambiente: conceitos básicos em ecologia e poluição

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Influência da matéria orgânica dissolvida alóctone e autóctone sobre o balanço de carbono em sistemas aquáticos: um experimento em mesocosmos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Efeitos individuais e interativos da diversidade de detritos, contexto e variabilidade ambiental sobre a magnitude e estabilidade do processo de decomposição

Studies on the effects of changes in biodiversity and ecosystem functioning have been a central theme in ecology over the past two decades. Several studies have showed that the diversity of plant debris differently affects the decomposition process in aquatic and terrestrial environments, but we know very about the effects of detritus diversity on decomposition under fluctuating environmental conditions. We tested whether and how the environmental contexts, as well as the dynamic of their alternation, influence the effects of detritus diversity on the decomposition process. We performed a field experiment where we manipulate the litter diversity of 8 species of terrestrial plants decomposing (litterbags) in single and in mixture containing the eight species together in three different environmental contexts: the terrestrial environment (T), aquatic (A) and interface (I) - experimental treatment that simulates variation in flooding regime. We measured the rate of decomposition through the loss of mass of the community and each individual detritus in monocultures and mixtures. Species richness and environmental variability had no effects on the magnitude and stability of the decomposition process. However, there were significant diversity effects on the decomposition of an individual alien species, F. benjamina. Environmental context had significant effects on the magnitude and variability of decomposition. Detritus decomposition was faster and more variable on aquatic, interface and terrestrial conditions, respectively. Our results demonstrate that the diversity of plant detritus has minor effects to the decomposition across disparate environmental conditions and suggest that it is necessary to consider the potential of other abiotic factors in affect the magnitude and variability of the decomposition processes

Saturação em CO2 e regulação metabólica do bacterioplancton em ecossistemas aquáticos de baixa latitude

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Análise de desempenho de sistemas de comunicação sem-fio para monitoramento de unidade de produção de poços petrolíferos terrestres

The greater part of monitoring onshore Oil and Gas environment currently are based on wireless solutions. However, these solutions have a technological configuration that are out-of-date, mainly because analog radios and inefficient communication topologies are used. On the other hand, solutions based in digital radios can provide more efficient solutions related to energy consumption, security and fault tolerance. Thus, this paper evaluated if the Wireless Sensor Network, communication technology based on digital radios, are adequate to monitoring Oil and Gas onshore wells. Percent of packets transmitted with successful, energy consumption, communication delay and routing techniques applied to a mesh topology will be used as metrics to validate the proposal in the different routing techniques through network simulation tool NS-2

Colêmbolos (arthropoda: hexapoda: collembola) numa área de caatinga do nordeste brasileiro

Edaphic ecosystems are the basis for the production of terrestrial biological resources and their dynamics affect not only the natural environment but also society and their economic activities. In Caatinga biome, the semi-arid climate associated with an inadequate soil management has increased the degradation and loss of productive potential of the soil. In this context, the study of soil fauna, including springtails, becomes an important indicator of soil quality. This study aimed to evaluate the fauna of Collembola in an area of Caatinga of Rio Grande do Norte State and the influence of biotic and abiotic factors, such as soil, vegetation and climate characteristics, on the structure of the taxocenosis. The environmental variables which were used were the following ones: granulometry (represented by the proportion of sand), quantity of organic matter and soil pH, richness, density and aerial biomass of the vegetal structure, and necromass. We used pitfall traps intending to collect specimens of the epiedaphic fauna of Collembola in 30 points located on Cauaçu Farm, João Câmara, RN, in July (rainy season) and November (dry season) 2011. We collected 5513 individuals of 15 species distributed in 13 genera and 9 families of Collembola. Five of the recorded species are new to science, confirming the expected high degree of endemism for Caatinga biome, and the highest abundance was recorded in the rainy season, which suggests Collembola sensitivity to low humidity. Four species were more abundant in the dry season, all of them belonged to the Order Entomobryomorpha. Results of statistical analyzes suggest that plant species richness, aerial biomass of vegetal structure, proportion of sand in the soil, pH and humidity are the main influences to the abundance of Collembola in the region studied

Efeitos de detritos e nutrientes alóctones sobre estrutura e dinâmica trófica de ecossistemas lacustres tropicais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior