Navegando por Assunto "Microclima"

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Acesso aberto (Open Access)
Ecologia de culicídeos vetores de febre amarela silvestre em relação ao microclima na Floresta Nacional de Caxiuanã-Melgaço-PA
(Universidade Federal do Pará, 2007) PINTO, Claudeth de Souza; MASCARENHAS, Bento Melo; http://lattes.cnpq.br/3279744837272788; CONFALONIERI, Ulisses Eugênio Cavalcante; http://lattes.cnpq.br/0960107425984526
The species vectors of yellow fever are distributed, in the Americas, in the genera Haemagogus and Sabethes. The culicidae have their blood-sucking activities influenced both by endogenous and exogenous factors, such as the responses to microclimatic factors. The micoclimate and the stratification of the mosquito hosts are the main determinants for the occupation of ecological niches by culicids in the tropical forests. This study was developed in the micrometeorological tower of the Caxiuanã National Forest, in the municipality of Melgaço, State of Pará, Brazil. The aims were to analyse the vertical distribution of the species vectors of yellow fever in relation to microclimate in the dense upland forest, from July 2005 to April 2006, at ground level and in platforms at 8m, 16m and 30 meters. Collections were made for 12-hour periods, both at night and during the day, with the use of human attractors. Temperature and humidity records were made at all heights where the collections were made and the precipitation was measured at the top of the tower. A total of 25,498 specimens of culicids were collected, among which 1028 were from the genus Haemagogus and 502 from Sabethes, captured during daytime. The species of Sabethes and Haemagogus janthinomys were found mostly at the canopy level, especially at the heights of 16 and 30 meters, while Haemagogus leucocelaenus was more frequent in the ground. The rainiest months were associated to the greatest number of specimens of the different species but this was not statistically significant. However, there was a significant relationship between temperature, relative humidity and the number of yellow fever vectors collected.
Acesso aberto (Open Access)
O efeito da topografia e microclima na florística e estrutura de árvores e na produção de liteira em uma floresta ombrófila densa na Amazônia Oriental
(Universidade Federal do Pará, 2012) FERREIRA, Laura Suéllen Lisboa; JARDIM, Mário Augusto Gonçalves; http://lattes.cnpq.br/9596100367613471; CATTANIO, José Henrique; http://lattes.cnpq.br/1518769773387350
The object this study was to study the effect of topography and microclimate (temperature and precipitation) in the floristic and structure of trees and litter production in a tropical rain forest in the National Forest Caxiuanã. In the grade of 25 km2PPBio, three areas were chosen (A, B and C) where plots were established 10 x 100 m, following the same topographic profile (lowland, intermediate and planteau). These plots, we identified all trees with DBH ≥ 10 cm for the realization of phytossociologic, taking into account the parameters of absolute and relative density, frequency and dominance, thus calculating the index value of importance (IVI). Micrometeorological temperature data were obtained from connected data logger Hobo Pro v2 and precipitation data were collected by the automatic station of IBAMA. We found 124 species in 33 plant families. The richest families in number of species were Sapotaceae (17), Chrysobalanaceae (10), Lecythidaceae (10) and Caesalpiniaceae (8). The most abundant families in number of individuals were Sapotaceae (65), Chrysobalanaceae (52) and Caesalpiniaceae (40). The area showed little floristic diversity evidenced by the low Shannon Diversity Index (H’= 3.16) and high uniformity in the proportions individuals/species within the plant community, given the degree of evenness of Pileou (J’= 0,94). There were no significant differences in richness and diversity of trees in relation to the plateus, intermediate ans lowland, as well as the density of species and basal area individuals. No there was a clear separation in the composition of tree species (DBH ≥ 10 cm) between the plots sampled in the plateau topographic condition, intermediate and lowland. The family with the higest IVI was Sapotaceae for the topography of lowland and intermediate, and Lecythidaceae for the plateau and species with higher IVI for three topographies were Lecythis idatiomon, Rinoria guianensis and Eschweilera coriacea. The average production of total litter in the nine plots was 758.59 kg ha-1. There was no significant difference in the production of litter in relation to topography and medium temperature and maximum temperature, but in relation to rainfall and minimum temperature there was differences. The leaf fraction (73,55%) was the most representative in the composition of litter, followed by branches (24,98%), fruits (3,88%) and flowers (3,85%). The flower production and fruits showed no significant relationship with the topography. No relationship was found in flower production with rainfall and temperature, but the fruits production showed significant differences with precipitacion and maximum temperature and minimum. The topography does not influence the floristic and structure of trees and litter production in the nine studied plots, but the variation in precipitation and temperature had a strong influence on litter production total and fruit production.
Acesso aberto (Open Access)
Variabilidade quantitativa de população microbiana associada às condições microclimáticas observadas em solo de floresta tropical úmida
(2011-12) RODRIGUES, Hernani José Brazão; SÁ, Leonardo Deane de Abreu; RUIVO, Maria de Lourdes Pinheiro; COSTA, Antonio Carlos Lôla da; SILVA, Rommel Benicio Costa da; MOURA, Quêzia Leandro de; MELO, Ivan Fiuza de
This study is a proposal for a scientific contribution to the understanding of the interrelationships between density population of soil microorganisms associated with seasonal microclimatic variability in tropical rainforest, also considering a case study of extreme event. Some organisms, especially soil microorganisms are very sensitive to small variations in microclimate (sun light, temperature, soil moisture, wind, sensible heat, latent heat, etc). Surely these conditioning factors are important for understanding the spatial distribution of these living things in natural ecosystems, inhabited by a variety of microorganisms (mushroom and bacteria) that were studied for their distribution and density, using the technique of "Pour Plate" count of "Petri plates" following the methodology utilized for De-Polli and Guerra, described by Clark. This study was conducted in two experimental areas PPBio (natural rainforest area) and ESECAFLOR (one acre covered area to simulate drought) in Caxiuanã-PA, with continuous measurements of microclimatic variables such as temperature, humidity and rainfall, and the evaluation of spatial and temporal distribution patterns of the species abundance and richness, to establish a monitoring procedure of soil fungi and bacteria associated with climate variability in the national forest Caxiuanã. The experimental areas are predominantly Yellow Latossol soils. Microbiological analysis showed that fungi developed better during the dry season and bacteria during rainy season, and their populations decrease with depth, except in a changed environment. Correlation values between seasonal variation of fungi and bacteria population and varying temperature and soil humidity were satisfactorily for any season in both sites.