Navegando por Autor "CABETTE, Helena Soares Ramos"

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Acesso aberto (Open Access)
Baetidae (Insecta, Ephemeroptera) em córregos do cerrado matogrossense sob diferentes níveis de preservação ambiental
(2011-09) SOUZA, Hilton Marcelo de Lima; CABETTE, Helena Soares Ramos; JUEN, Leandro
The effect of different stream environmental preservation levels, in 1st to 4th orders, over the richness, abundance, similarity in the composition and the potential of Baetidae (Ephemeroptera) species as bioindicators were investigated in a Cerrado region located in the state of Mato Grosso, Brazil. A total of twenty species/morphospecies were catalogued from the 1752 samples of nymphs, resulting in a new record for two species in Brazil. Values of Habitat Integrity Index (HII) were categorized among damaged, modified, and preserved environments. Species richness was different between sites, being greater in disturbed habitats. Total abundance was higher among preserved and altered environments, and differed significantly from the degraded areas. The NMDS analysis indicates that, in preserved and modified sites, the similarity in the composition of species differs from degraded areas. Four species showed a positive relationship with increasing values of HII. Baetidae showed environmental indicator species with different levels of preservation, with Zelusia principalis Lugo-Ortiz & McCafferty, 1998 and Baetodes sp. being indicators of preserved environments and Aturbina nigra Salles, Boldrini & Shimano, 2011, Callibaetis sp. 2, Camelobaetidius aff. janae, Paracloeodes binodulus Lugo-Ortiz & McCafferty, 1996 and Waltzoyphius roberti Thomas & Peru, 2002 as indicators of modified environments. The knowledge on the ecology of species advances in terms of providing subsidies for the biomonitoring of basins and the use of indicator species.
Acesso aberto (Open Access)
Composição e riqueza de Odonata (Insecta) em riachos com diferentes níveis de conservação em um ecótone Cerrado-Floresta Amazônica
(Instituto Nacional de Pesquisas da Amazônia, 2014-06) JUEN, Leandro; OLIVEIRA JUNIOR, José Max Barbosa de; SHIMANO, Yulie; MENDES, Thiago Pereira; CABETTE, Helena Soares Ramos
The removal or substitution of riparian vegetation causes disturbance in physical environment, seasonal water flow and water chemical quality. These modifications can cause decrease in species richness by local extinctions. The aim of this study was to examine the effect of disturbance in the physical environmental on the richness and species composition of Odonata adults in streams with different levels of conservation in the river Suiá-Missu basin, Mato Grosso, Brazil. Modifications in the aquatic systems affected the Odonata community, probably because their ecophysiological and behavioral requirements of adults and larvae. Anisoptera species, which require sunny environments because of their body size, had higher species richness in environments with low plant cover. On the other hand, Zygoptera species, which generally inhabit streams with dense vegetation, presented a decrease in richness in disturbed environments, as a result high sunlight radiation and/or variations in temperature. Hence, in both suborders, environmental perturbations do not need to be severe to change species composition, indicating that ecosystem services could be lost, even with only partial alterations in physical environment.
Acesso aberto (Open Access)
Diversidade de presas e predadores (Insecta) em mesohabitats de córregos de Cerrado
(Museu de Ciências Naturais, 2018-12) GIEHL, Núbia França da Silva; RESENDE, Bethânia Oliveira de; SILVA, Karina Dias; NOGUEIRA, Denis Silva; CABETTE, Helena Soares Ramos; ROGES, Paulo F. S. S.
Tropical streams feature high variety of habitats and environmental gradients, which reflect on the greater richness of aquatic insects. In this way, we evaluate if the diversity of aquatic insects of prey and predator categories is influenced by the type of substrates or by longitudinal portions in Cerrado streams. Our hypothesis is that prey and predator diversity will be determined by the type of substrate, assuming that the substrate serves as a source for foraging and / or refuge. In addition, the folhiço substrate will present greater abundance and richness due to the availability of shelter and food provided by this type of substrate. There will be differences in prey and predator composition among substrates, since some species have associations with the substrate type. The portions of the stream will have no effect on the diversity of prey and predator, since in streams of up to third order does not present considerable changes in physical characteristics. The study was carried out in nascent (1st order), intermediate (2nd) and estuary (3rd), in two streams, during dry and rainy periods. Five subsamples of sand, gravel, rocks or boulders were collected, backwaters, rapids and roots (substrate). The substrate influenced all prey and predator responses (abundance, richness and composition), but the environment (longitudinal portions) did not influence the abundance and predator composition. The influence of substrates on the diversity of prey and predators evidences the importance of riparian vegetation as a source of allochthonous material in bedside streams.
Acesso aberto (Open Access)
Efeito de fatores abióticos sobre Brachymetra albinervis albinervis (Heteroptera: Gerridae)
(Universidade Federal do Pará, 2015-12) GIEHL, Núbia França Da Silva; BRASIL, Leandro Schlemmer; FONSECA, Paula Viana Barros; SILVA, Karina Dias da; CABETTE, Helena Soares Ramos
We analyzed the influence of abiotic factors, longitudinal and temporal distribution on the abundance of Brachymetra albinervis albinervis Amyot & Serville, 1843. Three sites of Cerrado stream were assessed: headwater, intermediary and river mouth, monthly for a year (June 2011 to May 2012). At each site, the following abiotic variables were monthly measured in a linear 100 meters transect: dissolved oxygen, water temperature, pH, electrical conductivity, width and depth of the stream. Were collected 111 specimens. The river mouth presented lower abundance when compared with others sites (F(2,9) = 13.721, p = 0.001). The periods of the year (rain, ebb, dry or early rains), there was no differences in the abundance. Thus, the abundance of B. a. albinervis analyzed for one year showed variation only in the streams longitudinal distribution, which was attributed to the effect of environmental changes in the river mouth, where presented lower abundance and less environmental integrity. These results contribute to the ecological knowledge of this species and discusses the change in the occurrence and abundance this species due to alteration in aquatic environments.
Acesso aberto (Open Access)
Effects of changes in the riparian forest on the butterfly community (Insecta: Lepidoptera) in Cerrado areas
(Universidade Federal do Pará, 2017-03) CABETTE, Helena Soares Ramos; SOUZA, Jaqueline Rodrigues; FEITOZA, Yulie Shimano; JUEN, Leandro
Preserved riparian vegetation usually has greater environmental complexity than the riparian vegetation modified by human actions. These systems may have a greater availability and diversity of food resources for the species. Our objective was to evaluate the effect of changes on the structure of the riparian forest on species richness, beta diversity and composition of butterfly species in the Cerrado of Mato Grosso. We tested the hypotheses that: (i) higher species richness and (ii) beta diversity would be recorded in more preserved environments; and (iii) species composition would be more homogeneous in disturbed habitats. For hypothesis testing, the riparian vegetation of eight streams were sampled in four periods of the year in a fixed transect of 100 m along the shores. The richness of butterfly species is lower in disturbed than in preserved areas. However, species richness is not affected by habitat integrity. Beta diversity differed among sites, such that preserved sites have greater beta diversity, showing greater variation in species composition. In addition, beta diversity was positively affected by environmental heterogeneity. A total of 23 of the 84 species sampled occurred only in the changed environment, 42 were exclusive to preserved sites and 19 occurred in both environments. The environmental change caused by riparian forest removal drastically affects the butterfly community. Therefore, riparian vegetation is extremely important for butterfly preservation in the Cerrado and may be a true biodiversity oasis, especially during the dry periods, when the biome undergoes water stress and resource supply is more limited.
Acesso aberto (Open Access)
Effects of environmental factors on community structure of Leptophlebiidae (Insecta, Ephemeroptera) in Cerrado streams, Brazil
(2013-09) BRASIL, Leandro Schlemmer; SHIMANO, Yulie; BATISTA, Joana Darc; CABETTE, Helena Soares Ramos
We analyzed the effects of environmental factors on abundance, species richness, and functional group richness of Leptophlebiidae in 16 sampling points along four Cerrado streams. Across three periods of 2005, we collected 5,492 larvae from 14 species in stream bed substrate. These species belong to three functional feeding groups: scrapers, filtering collectors and shredders. The abundance and species richness were not affected by water quality, but habitat quality related to presence of riparian vegetation had positive effects on the abundance of shredders. Our results add important information on the natural history of the species and functional groups of aquatic insects and also provide relevant data for the monitoring and conservation of streams in the Brazilian Cerrado.
Acesso aberto (Open Access)
Emergence trap for the collection of exuviae and adult of Odonata
(Universidade Federal do Rio de Janeiro, 2020) RESENDE, Bethânia Oliveira de; FERREIRA, Victor Rennan Santos; JUEN, Leandro; CABETTE, Helena Soares Ramos
Odonates have aquatic larval stages and terrestrial adults. The extreme change in habitat occupation during their life cycle means that combined collection methods, capable of providing data for both larvae and adults, are scarce and are often inefficient. Given this, we applied a method for the collection of specimens of both life phases using emergence traps. During fieldwork, 78 emergence events were recorded for 15 species. We also briefly discuss the emergence pattern of the recorded species. We believe the information obtained here provide an important contribution to the understanding of the ecology and basic biology of Neotropical odonate species, as well as helping to solve the taxonomic problems associated with the identification of larvae.
Acesso aberto (Open Access)
Estrutura e composição da comunidade de Trichoptera (Insecta) de rios e áreas alagadas da bacia do rio Suiá-Miçú, Mato Grosso, Brasil
(2011-09) NOGUEIRA, Denis Silva; CABETTE, Helena Soares Ramos; JUEN, Leandro
The composition, abundance and species diversity of Trichoptera immatures was studied in 12 tributaries of Suiá-Miçú River Basin, a mosaic of wetlands, streams and rivers tributary of the Xingu River in the Cerrado-Amazonian Forest transition zone in Mato Grosso, Brazil. The varying sizes, flow types and conservation levels of the tributaries were sampled through three periods between 2007 and 2008 by the use of fixed transects along the environments margins. A total of 867 larvae was collected (divided in seven families, 17 genera, 49 species/morphospecies) with the most abundant and rich families being Hydropsychidae and Leptoceridae and the most abundant species Leptonema sparsum (n = 370). There has been loss of species richness in impacted, large and lentic environments. Composition variations related to the flow, the vegetation type and the interaction between conservation levels and flow was detected. Conservation levels, width and the quantitative habitat integrity index (HII) did not influence the Trichoptera composition. These results may encourage further investigation of impact effects on aquatic insect compositions and pattern of distribution in the transition area between the Cerrado and the Amazonian Forest.
Acesso aberto (Open Access)
Setting boundaries: Environmental and spatial effects on Odonata larvae distribution (Insecta)
(2015-03) MENDES, Thiago Pereira; CABETTE, Helena Soares Ramos; JUEN, Leandro
Environmental characteristics and spatial distances between sites have been used to explain species distribution in the environment, through Neutral (space) and Niche theory (environment) predictions. We evaluated the effects of spatial and environmental factors on Odonata larvae distribution along the Suiá-Missú River Basin, state of Mato Grosso. We tested the hypotheses that (1) the environment is the main factor structuring the community due to its ecophysiological requirements; and (2) the pattern, if present, is clearer for Zygoptera. Samples were made in 12 sites on the Suiá-Missú River Basin in three seasons (2007/2008), with a total of 1.382 Odonata larvae, comprising 10 families, 51 genera and 100 morphospecies. The Anisoptera were more abundant than Zygoptera, comprising 81% of all specimens. The environment affected Zygoptera (R=0.291; p=0.007) and was the main factor structuring the assembly. Thus, Niche theory was confirmed. The absence of this effect on Anisoptera may be due to the ecophysiological adaptations that enable it to occupy different habitats. Zygoptera larvae are indicators of changes in habitat structure. The effects of environmental variables on larvae ecology emphasize the strong relationship between these organisms and environmental integrity.