Made available in DSpace on 2015-04-17T14:55:23Z (GMT). No. of bitstreams: 1 ArquivoTotalAlexandre.pdf: 4361037 bytes, checksum: 30d0dbe76d670583e9a0738af171e654 (MD5) Previous issue date: 2003-12-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Communities of termites in the Atlantic forest of Northeast Brazil were studied at four forest remnants, northern of the River São Francisco, namely: Reserva Biológica de Pedra Talhada (RPT), State of Alagoas; Horto Dois Irmãos (HDI), State of Pernambuco; Reserva Biológica Guaribas (RBG) and Mata do Buraquinho (MAB), both in the State of Paraíba. Several aspects of the ecology and natural history of these insects were analysed, with emphases on (i) their taxonomic and functional structures and seasonal influence on the diversity and richness of species at all localities (RPT, HDI, RGB, MAB); (ii) the abundance and biomass of populations in the RPT, HDI, and MAB; (iii) the participation of three species of Nasutitermes on removal of wood from the necromass in the HDI and MAB; (iv) the seasonal effects on abundance and biomass of termites on leaf litter, wood, soil, and tree trunks in the RBG; and (v) the abundance and spatial distribution of conspicuous nests at two sites with different successional stages in the RBG. In total, 61 species of termites were found, most of them of the family Termitidae (78,7%), followed by the families Kalotermitidae (14,7%) and Rhinotermitidae (6,6%). Ten species are reported here for the first time as occurring in the Atlantic forest. Among the identified species, 23 also occur in the Amazonian forest, showing that both biomes have similar termite fauna. The taxonomic and functional structures of the communities collected throughout the dry and rain seasons were quite similar, suggesting that the survey protocolo of termite biodiversity can be applied at any period of the year without altering drastically the communities structure. The abundance varied from 4951 to 5663 termites/m2 and biomas varied from 8,05 to 10,64g (fresh weight)/ m2. The termites were found mainly in the soil, 0-20 cm depth, and in dead wood. Two species were most abundant, Embiratermes parvirostris and Nasutitermes corniger. The average of wood consumption in laboratory of N. corniger, N. ephratae and N. macrocephalus was 9,43 mg (dry weight)  g of termite (fresh weight) -1  day-1. These three species alone remove from the HDI and MAB areas ca.67 and 73 g of wood  ha-1  year-1, respectively, which mean 2,9% and 3,3% of the total animal production of dead wood, respectively. However, 25 species of termites in the MAB and 21 in the HDI utilize wood as their nutrient source, suggesting that termites participation on removal of wood could be higher than 15% of the annual production. The quantitative sampling performed in the leaf litter, nests, soil, and tree trunks revealed large xv abundance and biomass of specimens of the subfamily Nasutitermitinae and of individuals of humus feeding group. The seasonal influence on the fauna of termites was only perceptible in nests and tree trunks, which appears to be related to the effects of one season on the production of wringed brood, foraging activity, and production of plant necromass. Eight termite species are conspicuous nest-builders in the studied areas, noticeably the abundant constructions built Microcerotermes exiguus and N. corniger. The spatial distribution of nests by each species and feeding groups was in the most cases at random, suggesting that competition does not represent an important determining factor of the spatial distribution pattern of nests. The analyses of abundance, taxonomic composition, and feeding groups of nest-builders species showed to be an additional tool for the evaluation of the habitat quality, indicating a more mature stage in the successional process. / As comunidades de cupins de Mata Atlântica do Nordeste Brasileiro foram estudadas em quatroremanescentes localizados ao Norte do Rio São Francisco: Reserva Biológica de Pedra Talhada(RPT), Alagoas; Horto Dois Irmãos (HDI), Pernambuco; Reserva Biológica Guaribas (RBG),Paraíba e Mata do Buraquinho (MAB), Paraíba. Vários aspectos da ecologia e história naturaldestes insetos foram analisados, entre eles destacam-se: (i) as estruturas taxonômicas e funcionaise a influência da sazonalidade sobre a diversidade e riqueza de espécies na RPT, RBG, HDI eMAB; (ii) a abundância e biomassa das populações na RPT, HDI e MAB; (iii) a participação detrês espécies de Nasutitermes na remoção de madeira da necromassa no HDI e MAB; (iv) osefeitos estacionais sobre a abundância e biomassa de cupins do folhiço, madeira, solo e troncosna RBG; e (v) a abundância e distribuição espacial de ninhos conspícuos em duas áreas comdiferentes estádios de sucessão da vegetação na RBG. No total, 61 espécies de cupins foramencontradas, sendo a maioria da família Termitidae (78,7%), seguida pelas famíliasKalotermitidae (14,7) e Rhinotermitidae (6,6%). Dez espécies representaram novas ocorrênciaspara a Mata Atlântica. Entre as espécies identificadas, 23 também ocorrem na FlorestaAmazônica, evidenciando a similaridade da fauna de cupins desses biomas. As estruturastaxonômicas e funcionais das comunidades coletadas nas estações seca e chuvosa foram bastantesimilares, sugerindo que os protocolos de levantamento de biodiversidade termítica podem seraplicados em qualquer período do ano sem alterar drasticamente a estrutura da comunidade. Aabundância variou de 4950,9 a 5662,5 cupins/m2 e a biomassa de 8,05 a 10,64g (peso fresco)/m2.Os cupins foram encontrados principalmente no solo, entre 0-20cm de profundidade, e emmadeira morta. Duas espécies destacaram-se pela abundância: Embiratermes parvirostris eNasutitermes corniger. O consumo médio de madeiras em laboratório por Nasutitermes corniger,N. ephratae e N. macrocephalus foi 9,43 mg (peso seco)  g de cupim (peso fresco)-1  dia-1.Apenas essas três espécies removem no HDI e MAB 66,92 e 72,85 kg madeira  ha-1  ano-1,respectivamente, correspondendo a 2,9 e 3,3% do total da produção anual de madeira danecromassa. No entanto, 25 espécies de cupins na MAB e 21 no HDI utilizam a madeira comofonte de nutriente, sugerindo que a participação dos cupins na remoção de madeira pode sersuperior a 15% da produção anual. As amostragens quantitativas no folhiço, ninhos, solo etroncos revelam a grande abundância e biomassa da subfamília Nasutitermitinae e do grupoalimentar dos consumidores de húmus. A influência estacional sobre a fauna de cupins só foiperceptível nos ninhos e nos troncos, e esteve aparentemente relacionada com os efeitos dedeterminada estação sobre a produção da ninhada de alados, atividade de forrageamento eprodução da necromassa vegetal. Oito espécies de cupins são construtoras de ninhos conspícuosnas áreas estudadas, mas destacam-se, pela abundância de suas construções, Microcerotermesexiguus e N. corniger. A distribuição espacial dos ninhos por espécies e grupos alimentares foi,na maioria dos casos, aleatória, sugerindo que a competição não representa um fator importantena determinação do padrão de distribuição espacial dos ninhos. As análises de abundância,composição taxonômica e grupos alimentares das espécies construtoras de ninhos mostrou-secomo ferramenta adicional na avaliação da qualidade do habitat, indicando um estádio maismaturo no processo sucessional.

Transformer ageing is inevitable and it is a challenge for utilities to manage a large fleet of ageing transformers. This means the need for monitoring transformer condition. One of the most widely used methods is oil sampling and testing. Databases of oil test records hence manifest as a great source of information for facilitating transformer ageing assessment and asset management. In this work, databases from three UK utilities including about 4,600 transformers and 65,000 oil test entries were processed, cleaned and analysed. The procedures used could help asset managers in how to approach databases, such as the need for addressing oil contamination, measurement procedure change and oil treatment discontinuities. An early degradation phenomenon was detected in multiple databases/utilities, which was investigated and found to be caused by the adoption of hydrotreatment oil refining technique in the late 1980s. Asset managers may need to monitor more frequently the affected units and restructure long term plans. The work subsequently focused on population analyses which indicated higher voltage transformers (275 kV and 400 kV) are tested more frequently and for more parameters compared with lower voltage units (33 kV and 132 kV). Acidity is the parameter that shows the highest correlation with transformer in-service age. In addition, the influence of the length of oil test records on population ageing trends was studied. It is found that it is possible to have a representative population ageing trend even with a short period (e.g. two years) of oil test results if the transformer age profile is representative of the whole transformer population. Leading from population analyses, seasonal influence on moisture was investigated which implies the importance of incorporating oil sampling temperature for better interpretation of moisture as well as indirectly breakdown voltage records. A condition mismatch between dielectric dissipation factor and resistivity was also discovered which could mean the need for revising the current IEC 60422 oil maintenance guide. Finally, insulation condition ranking was performed through principal component analysis (PCA) and analytic hierarchy process (AHP). These two techniques were demonstrated to be not just capable alternatives to traditional empirical formula but also allow fast, objective interpretation in PCA case, as well as flexible and comprehensive (objective and subjective incorporations) analysis in AHP case.