Navegando por Assunto "Floresta de manguezal"

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Acesso aberto (Open Access)
Dieta de Micoureus demerarae (Thomas) (Mammalia, Didelphidae) associada às florestas contíguas de mangue e terra firme em Bragança, Pará, Brasil
(2006-12) FERNANDES, Marcus Emanuel Barroncas; ANDRADE, Fernanda Atanaena Gonçalves de; SILVA JÚNIOR, José de Sousa e
The diet of Micoureus demerarae (Thomas, 1905) was studied in mangrove and terra firme stands by using stomachal and faecal samples. The number of captured individuals was inversely proportional to availability of fruits and insects, being Coleoptera and Hemiptera the most consumed arthropod orders and Passifloraceae and Arecaceae the most ingested fruits. Thus, either fruits variability or their high yield during the dry season seem to explain the increase of captured animals in the terra firme stands, where they originally come from. The food items suggest that this species has an omnivorous diet, independently of the seasonality or distribution of available resources.
Acesso aberto (Open Access)
Parâmetros demográficos de Micoureus demerarae (Didelphidae, Marsupialia) em áreas contíguas de manguezal e terra firme, Bragança, Pará, Brasil
(2007-06) ANDRADE, Fernanda Atanaena Gonçalves de; FERNANDES, Marcus Emanuel Barroncas; BRITO, Stélio Ângelo da Costa
This study investigated some aspects of the population dynamics of Micoureus demerarae (Thomas, 1905), such as: density, recruitment, and survivorship in two contiguous ecosystems, mangal and terra firme at the Fazenda das Salinas in the northeast of the state of Pará. One transect in each system was used for fieldwork. Data collection was carried out from November 2002 to September 2003. The following population parameters were estimated: density, recruitment, and survivorship. The results defined an open population with an even distribution for individuals from mangal and a clumped one for individuals from terra firme, and the evident seasonality with higher proportion of males in the terra firme. The reproductive period was the most important parameter to the population fluctuation in the beginning of the dry season. The environmental impacts over the population dynamics parameters of M. demerarae seem to be determinant for the maintenance of these populations.
Acesso aberto (Open Access)
Variabilidade sazonal da condutância estomática em um ecossistema de manguezal amazônico e suas relações com variáveis meteorológicas
(2011-06) RODRIGUES, Hernani José Brazão; COSTA, Rafael Ferreira da; RIBEIRO, João Batista Miranda; SOUZA FILHO, José Danilo da Costa; RUIVO, Maria de Lourdes Pinheiro; SILVA JUNIOR, João de Athaydes
This work investigated the variations of stomatal conductance (gs) in the rainy and dry seasons and its dependence relations with meteorological variables measured in an Amazonian mangrove ecosystem. Data were originated from the ECOBIOMA project, part of the Large Scale Biosphere-Atmosphere Experiment in Amazon (LBA). Stomatal conductance followed the tendency of the radiation balance variation, reaching maximum values during the day and minimum values at night. The conductance showed greater fluctuations in the rainy season, with mean value of gs = 0.015 m s-1, however smaller in magnitude than in the dry season. During the dry season, the mean value was gs = 0.027 m s-1, with lower range, varying between 0.010 and 0.042 m s-1. The meteorological variables used for establishing the dependence relations with the daily variability of stomatal conductance were the following; specific moisture deficit (δq), vapor pressure deficit (PVD), net radiation (Rn) and wind velocity (Vv). The PVD showed the best correlation with gs, with R2 = 0.99 for both periods. In spite of the importance of Vv in the gaseous changes between the vegetation and the atmosphere, it presented the smallest influence in the mean variation of the gs, with R2 = 0,44 for the rainy and R2 =0,51 for the dry period.