Acta Amazonica 

About: Acta Amazonica is an academic journal published by National Institute of Amazonian Research. The journal publishes majorly in the area(s): Amazon rainforest & Population. It has an ISSN identifier of 0044-5967. It is also open access. Over the lifetime, 2811 publications have been published receiving 40698 citations.

Habitat preferences, diet, feeding strategy and social organization of the black spider monkey (Ateles paniscus paniscus Linnaeus 1758) in Surinam

Abstract: A Socioecological Field Study. This monograph reports on a 26 month socioecological study of black spider monkeys (Ateles paniscus paniscus)in the Raleigh-vallen — Voltzberg Nature Reserve, Surinam. It recognizes the fundamental importance of food to the behavior and the regulation of population density fox this primate. It clarifies the complex temporal and spatial effects of tropical rain forest food sources on the behavior of a group of spider monkeys, concentrating on food category, food plant identity and phenology, and quantity, density and dispersion of the most important food sources. In addition, the present study describes habitat choice, optimal feeding strategy and sexual behavior of the spider monkey, and discusses implications of diet for social behavior. This study is also fundamental to conservation. Specialized in eating mature fruits, the spider monkey is a very important dispersal agent for many trees and lianes, particularly canopy species. However, the spider monkey is probably the most vulnerable monkey species in Surinam and it is disappearing rapidly throughout the remainder of its range. Unfortunately, it is large and noisy and can be easily tracked and hunted. It is largely restricted to undisturbed high forest, and consequently habitat destruction has more effect on it than on most other species. Together with its slow reproductive rate (a female gives birth only once every four or five years), this means that the species is poorly adapted to recover from exploitation. In order to implement proper measures for conservation, data on forest type preferences, diet and social behavior of the species, or on closely related species, in undisturbed areas, such as the one described in this monograph, are essential tools for assessing the potential of proposed protected areas.

Variação espacial e temporal da precipitação no estado do Pará.

Abstract: Estudos sobre a climatologia das precipitacoes no Estado do Para sao essenciais para o planejamento das atividades agricolas. A variacao da precipitacao anual e sazonal no Estado do Para foi analisada com base em series historicas de 23 anos (1976-1998) de dados diarios de chuva. A analise foi realizada para 31 localidades do Estado do Para, sendo os resultados representados em mapas com a utilizacao de tecnicas de sistemas de informacoes geograficas (SIG). A variabilidade da precipitacao anual e sazonal foi caracterizada com base no coeficiente de variacao e no indice de variabilidade interanual relativo. A variacao desses coeficientes para a precipitacao anual no Estado do Para foi de 15 a 30%. As caracteristicas mensais da estacao chuvosa, em termos de inicio, fim e duracao, foram determinadas utilizando-se o criterio proposto por KASSAM (1979). A variacao entre as datas de plantio precoces e tardias corresponderam aos decendios identificados pelos dias julianos 309319 e 353363, respectivamente.

High spatial resolution land use and land cover mapping of the Brazilian Legal Amazon in 2008 using Landsat-5/TM and MODIS data

Abstract: Understanding spatial patterns of land use and land cover is essential for studies addressing biodiversity, climate change and environmental modeling as well as for the design and monitoring of land use policies. The aim of this study was to create a detailed map of land use land cover of the deforested areas of the Brazilian Legal Amazon up to 2008. Deforestation data from and uses were mapped with Landsat-5/TM images analysed with techniques, such as linear spectral mixture model, threshold slicing and visual interpretation, aided by temporal information extracted from NDVI MODIS time series. The result is a high spatial resolution of land use and land cover map of the entire Brazilian Legal Amazon for the year 2008 and corresponding calculation of area occupied by different land use classes. The results showed that the four classes of Pasture covered 62% of the deforested areas of the Brazilian Legal Amazon, followed by Secondary Vegetation with 21%. The area occupied by Annual Agriculture covered less than 5% of deforested areas; the remaining areas were distributed among six other land use classes. The maps generated from this project - called TerraClass - are available at INPE's web site (http://www.inpe.br/cra/projetos_pesquisas/terraclass2008.php).

Phytogeographic support tor the theory of Pleistocene forest refuges in the Amazon Basin, based on evidence from distribution patterns in Caryocaraceae, Chrysobalanaceae, Dichapetalaceae and Lecythidaceae

Abstract: In recent years it has generally been accepted that Amazonia was subject to long dry periods in the late Pleistocene and post-Pleistocene which induced forest cover to a few limited areas or refuges. It has been proposed that the subsequent genetic isolation into separate populations is a mnjor factor in the evolution of the species diversity within the lowland forest of Amazonia. Most of the previous evidence for this theory is based on studies of animals, for example: lizards, butterflies, and birds. Here data are presented to confirm the theory of forest refuges using evidence from phytogeography. Distribution patterns of the lowland species of the woody plant families Caryocaraceae, Chrysobalanaceae, Dichapetalaceae and Lecythidaceae are discussed and concur with the possibility of forest refuges. A map is given of the refuge areas that seem most likely, based on evidence from species distribution of the above plant families. The refuges proposed here correspond closely with the refuge areas proposed by Haffer and Brown rather than the extremely reduced areas proposed by Vanzolini.

Effects of forest fragmentation on amazonian understory bird communities

Abstract: Data form an intensive mist-netting mark-recapture program in the central Amazon demostrate significant changes in the undesrtory avian community in isolate patches of 1 and 10 ha of terra firme forest. Following isolation, capture rates increase significantly as birds fleeing the felled forest entered the. newly formed forest fragments. Movement to and from the reserve is restricted, as witnessed by an increase in recapture percentages following isolation. Species of birds that axe. obligate army ant followers disappeared at the time the surrounding habitat was removed from 1 - and 10 - ha areas. The complex mixed-species insectivorous flocks typical of Amazonian forests deteriorated within 2 years of isolation of 1 - and 10 - ha forest fragments. Several species of mid-story insectivores changed their foraging behavior after isolation of small forest reserves.