Navegando por Assunto "Serra do Cachimbo - PA"

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Inventário de aranhas (Arachnida, Araneae) em quatro fitofisionomias da serra do cachimbo, Novo Progresso, Pará, Brasil
(Universidade Federal do Pará, 2005-03-04) RICETTI, Janael; BONALDO, Alexandre Bragio; http://lattes.cnpq.br/8721994758453503
A inventory of the spider fauna was carried out at Serra do Cachimbo, inside the "Campo de Provas Brigadeiro Velloso", Novo Progresso municipality, Pará state, Brasil. Two expeditions were made, during both dry (August and September, 2003) and wet (March and April, 2004) seasons. Three collectors participated in each expedition. The sampling effort, represented by 240 samples, was divided through the following methods: beating tray and sweeping net (96 samples); nocturnal hand search (96 samples) and concentrated litter sorted by a combination of hand search and Winkler extractors (48 samples). The spiders assemblages from four vegetation types (open rainforest, Formiga river's riparian forest, arboreal savanna and white sand vegetation) were compared. A total of 4964 spiders were obtained, from which 2724 adults, resulting in 397 recognized morpho-species in 37 families. The most abundant families were Theridiidae, Salticidae and Araneidae and the ones with more species were Salticidae, Araneidae e Theridiidae. The singletons represented 40% of the total species richness and only two species presented more than 100 individuals. The estimated richness species curves reached from 473 (bootstrap) to 674 (jackknife2) species. The higher alpha-diversity (Shannon-Wiener index) was observed in open rainforest, followed by Formiga river's riparian forest, white sand vegetation and arboreal savanna. the higher beta-diversity (Jaccard and Morisita-Horn indexes) was observed between Open rainforest and white sand vegetation and the lowest one was between open rainforest, arboreal savanna and Formiga river's riparian forest. The dry season presented more species than the wet season. However, no such difference was detected in white sand vegetation. A principal component analysis revealed that some species are linked to arboreal vegetations and others are linked to the open vegetation in white sand. Those differences in diversity and taxonomic composition between the various vegetations can be explained by drifts in availability of food items (preys), space resources (refugees and substratum to web attachment), as well as micro-climatic factors (temperature and moisture) of a given vegetation type. The most experienced conectar sampled more species than any other collector and all less experienced collectors sampled similar number of species. The differences in abundance among samples obtained by each conectar were not significant. The night hand sampling was the most efficient technique regarding the detection of differences in species richness among vegetation types. The methods beating tray/sweep net and litter sampling do not showed any significant difference in relation to species richness.
Acesso aberto (Open Access)
Uso de hábitats por mamíferos terrestres de médio e grande porte na Serra do Cachimbo, PA
(Universidade Federal do Pará, 2005) PIMENTA, Flávio Eduardo; NUNES, Andréa Ferreira Portela; http://lattes.cnpq.br/2425593054826164
Neotropical mammals of medium-large size still are poorly studied. In the Amazonia the gaps in the scientific knowledge on this group occur mainly for the difficulty of accomplishment of more complete studies during short periods of time and limited financial resources. To minimize these problems, indirect methods to study them have been used as an alternative to the traditional methods and therefore they had been applied in this work. With the intention to detect how the local community of medium-large size mammals makes use the habitats, comparing the frequency of the use of different vegetation formations reached by the means of count tracks, 1 intended to contribute for the conservation and identification of areas of high biological value for the studied species. The wealth of species and the relative frequency of habitat use had been analyzed of comparative form between White-Sand Vegetation (Campina), Open Arboreal Savannah (Campo Cerrado), Dense Arboreal Savannah (Cerradão) and Forest habitats (Floresta Ombrófila) through three visits to the study area. 1 registered 33 species, distributed in 8 orders, 18 families and 29 genera. The vegetation formations in the study area had not differed in terms of the species presence, with exception of the primate fauna, which is particular of forest formations. However, with relation to the habitat use, distinct trends in the frequency of use of each vegetation formation for the different species had been demonstrated. The majority of species registered for the method of detention of tracks seems to suffer the effect from seasonal variation of the rain regimen. Moreover they seem to depend more on the forest formations. This is clearly when it is demonstrated to a bigger diversity and use of forest habitats by the studied species. However, with exception of arboreal species, they are versatile in the occupation of the different types of habitats. Thus, Serra do Cachimbo presents rich and diversified fauna perhaps due the fact of this region to present distinct vegetational elements, favoring species with preferences for savanoid and forest formations.