Paulina Barbosa - Academia.edu (original) (raw)
Papers by Paulina Barbosa
Brazilian Journal of Biology, 2010
In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (So... more In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (South-East Brazil), this study compares previous and recent data obtained from limnological investigations over three decades. Plankton species composition and density together with environmental data from 1978, 1983, and during 1999 to 2006 showed changes driven by seasonal climatic forces or by anthropogenic causes. Changes in diversity are shown as a consequence of alternation of rainy and dry periods and introduction of exotic fish species. Finally, suggestions are made for improving conservation efforts in the area, through planned actions and monitoring programmes.
Environment, Development and Sustainability, 2020
The investigation of land use changes by anthropic processes, spatially and temporally, is a fund... more The investigation of land use changes by anthropic processes, spatially and temporally, is a fundamental tool to establish correlations between landscape patterns and processes and management of the buffer zone of Conservation Units. This study aimed to analyze the forest fragmentation and land use dynamics in the buffer zone of the Rio Doce State Park (PERD), located in Minas Gerais, Brazil, for the year 2015. Its buffer zone was delimited to a radius of 10 km, covering a total area of 128.893,36 ha. Land use classification was based on Landsat 8 image, orbit 217, point 73 and 74, and two types of ecosystems were identified: natural and anthropic. In the thematic mapping, the pressure of the anthropic use over the natural was notified, as well as the high number of forest fragments, which is a negative impact on the resilience required for the conservation of biodiversity and the local Atlantic forest. The fragments have different shapes and sizes and are distributed throughout the buffer zone of the PERD. There is a need to adopt conservation strategies, such as environmental education, reforestation techniques, recovery of degraded areas and ecological corridors. Even with a worrying current scenario, this finding makes it possible to establish an optimistic point for biodiversity conservation, associated with a tendency to reduce the forces of direct changes on natural systems.
Aim: This study aimed to examine and compare the different patterns of diel vertical migration (D... more Aim: This study aimed to examine and compare the different patterns of diel vertical migration (DVM) in two tropical freshwater ecosystems: Carioca Lake (PERD, MG), dominated by piscivorous fishes and Nado reservoir (Belo Horizonte, MG), dominated by planktivorous/omnivorous fishes. Methods: The vertical distribution of the zooplankton was examined at noon and midnight, in April 2003 in both systems, using a Schindler-Patalas trap. Results: In Nado reservoir, the larvae of the invertebrate predator Chaoborus, remained in the hypolimnion during the day and ascended into the surface waters at night. The same migratory behavior was observed for the population of the copepod Thermocyclops inversus, the dominant zooplankter, as well as for the rotifers. In Carioca Lake, the Chaoborus larvae did not migrate, and individuals were found occupying the entire water column in daytime as well as at night. The population of the copepod T. minutus, a potential prey of Chaoborus larvae, and most rotifers also did not migrate in Carioca Lake. Conclusions: In Nado reservoir, where planktivorous and omnivorous fishes dominate, the zooplankton was forced to adopt the diurnal vertical migration (DVM), a phenomenon that propagated through the different trophic levels. In Carioca Lake, in the virtual absence of vertebrate predators of zooplankton, no migration in the planktonic community was observed.
Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 2006
Journal of Plankton Research, Nov 21, 2017
Previous laboratory experiments have indicated that Chaoborus larvae may be confused when exposed... more Previous laboratory experiments have indicated that Chaoborus larvae may be confused when exposed to a single prey species at a high density, resulting in decreased attack efficiency. Here, we hypothesized that a prey less vulnerable to Chaoborus larvae, such as Physocypria schubarti ostracods, could affect the predatory performance of Chaoborus on a more vulnerable prey, such as Ceriodaphnia silvestrii neonates. We predicted that fewer neonates would be ingested by Chaoborus larvae in the presence of ostracods at high densities due to the decreased attack efficiency caused by the confusion effect. This hypothesis was tested by combining predation assays and direct visual observations of live organisms. There was a significant decrease in the consumption of neonates when they were offered together with ostracods at high densities; however, this was not related to the ingestion of ostracods as an alternative prey or to decreased attack efficiency on neonates caused by the confusion. The energy wasted due to the numerous attacks on the ostracods ("fake prey") possibly led the chaoborids to exhaustion, reducing their predatory performance on neonates. In ecological terms, high densities of ostracods in the water column may theoretically minimize the strong impact of Chaoborus sp. larvae on more vulnerable prey.
Ethnoscientia
Estudos etnobotânicos podem subsidiar projetos de bioprospecção e conservação de plantas nativas ... more Estudos etnobotânicos podem subsidiar projetos de bioprospecção e conservação de plantas nativas com propriedades medicinais, pois, através da utilização dos recursos vegetais como medicamentos, a própria população pode tornar efetiva a sua proteção. Nesse sentido, o objetivo deste trabalho foi estudar o conhecimento popular de moradores de São Thomé das Letras, MG, na bacia do Alto Rio Grande, sobre as espécies vegetais medicinais nativas da região. O público-alvo para o levantamento etnobotânico foram moradores da área urbana e rural do município e de seu entorno, que detêm algum conhecimento especial a respeito de plantas medicinais nativas da região. Foram realizadas entrevistas semiestruturadas com 20 informantes e turnês guiadas com seis deles, em Cerrado sentido restrito, Cerrado Rupestre, campos, fragmentos de floresta estacional semidecidual e beiras de estrada, além de quintais com espécies nativas cultivadas. Ao todo foram citadas 87 espécies, pertencentes a 46 famílias b...
Environmental Monitoring and Assessment
It is necessary to understand the importance of landscapes that comprise the environment across a... more It is necessary to understand the importance of landscapes that comprise the environment across a broad range of time and space and that each part of these landscapes responds to changes in environmental factors and land use. This study employs a multiscale modeling approach in the Rio Doce State Park (PERD), located in Minas Gerais, Brazil, based on a previous study on land use change in this region over the last 30 years (1985-2015), with an aim of predicting possible scenarios for the next 15 years (2015-2030). The results indicate that the municipalities and buffer zones within the PERD will suffer from increased human disturbance in all four land use types present in the region (Urban, Agriculture, Pasture, and Forestry). Correspondingly , areas of natural environment (Forest and Water) will shrink due to an increase in forest fragmentation , causing the loss of permanent ecological reserves , thereby endangering the biodiversity of these areas. Cooperation between the local community and private companies is therefore necessary to improve regional environmental conservation, encourage advanced sustainable development, and improve the quality of life for residents within each municipality near the State Park.
Fundamental and Applied Limnology / Archiv für Hydrobiologie
Aiming to evaluate the importance of egg banks from a tropical lake for the active Daphnia laevis... more Aiming to evaluate the importance of egg banks from a tropical lake for the active Daphnia laevis dynamics, we investigated ephippia down to a 28-cm sediment depth, and used data obtained by traps to compare with the in situ production and hatching rates of fresh ephippia. All the ephippia from the sediment were opened for inspection of the presence of resting eggs, and those found were incubated to verify hatching. Ephippia density degradation rate was tested by putting isolated ephippia immersed in the sediment lake for 75 days, and found to exponentially decrease with increasing sediment depth. Higher densities were recorded in 2017 (maximum of 1.43 ephippia per cm2) than in 2016 (maximum of 0.8 ephippia per cm2). The empty ephippia rates were high in all sediment depths ranging from 83% to 100%. In contrast, the hatching rates in situ of fresh ephippia were high, suggesting that those that sink are mostly unviable or empty, forming an unusual egg bank in the sediment. In the lab...
Acta Limnologica Brasiliensia
Aim Temperature and light have been recognized as important factors for ephippia hatching in temp... more Aim Temperature and light have been recognized as important factors for ephippia hatching in temperate and tropical freshwater systems. Oddly some authors suggested that decapsulation of resting eggs would be a pro when it comes to ex situ hatching studies, exposing those eggs to a greater amount of light. This study aimed to compare the difference in the hatching rate between resting eggs decapsulated and intact ephippia of Daphnia laevis, a zooplankton that occurs at lakes, in tropical freshwaters (Cladocera). Methods The ephippia used in this work were collected at the sediment of a reservoir, in Belo Horizonte city (Minas Gerais, Brazil). We set up the laboratory experiment with two distinct groups: intact ephippia and decapsulated resting eggs. For that, we manually decapsulated 120 ephippia and kept 120 others intact (six replicas with 20 ephippia each), then incubated them all with culture water at 22ºC (12h photoperiod) for 30 days with daily monitoring. Results The results ...
Annales de Limnologie - International Journal of Limnology
Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, ... more Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, because different predators consume different sized prey, cladocerans may display differing life-history responses depending on predator type. Although most studies use the genus Daphnia to evaluate phenotypic plasticity in cladocerans, other genera might also respond to predator infochemicals. In this study, we compared life-history responses of Daphnia similis and Moina macrocopa to infochemicals released by a vertebrate (fish) and an invertebrate (Chaoborus) predator. As expected, some life-history parameters were altered depending on the type of predator. Overall, fish infochemicals increased the size at primipara, clutch size, net reproductive rate and longevity in both cladocerans. We argue that increased body lengths in the presence of fish promote bigger clutch sizes. Conversely, responses to Chaoborus were weaker, affecting only the net reproductive rates and longevity. Non-daph...
Journal of Environmental Planning and Management
This article uses a multiscale approach for assessing landscape changes in one of the world&#... more This article uses a multiscale approach for assessing landscape changes in one of the world's biodiversity hotspots in Brazil, the Rio Doce State Park (PERD). In this article, we assess land use changes over a 30 year period. Our results show that, while inside the park landscape changes were minimal, in the park buffer zone human induced changes are steadily rising due to an increase in eucalyptus plantations and urban sprawl that grew by 4% and 1.9%, respectively. Agricultural land has been reduced by 6.35%, but there are trends that a form of welcome forest transition has been occurring. We report an increase in native forests from 40,588 ha in 1985 to 45,690 ha in 2015. The analysis of human impacts in the study area delivers very different results when varying the pixel size from 25 ha to 900 m 2. The former shows a very high level of human influence while the latter reveals small but vital patches of native forest offering hopeful opportunities for sustainable natural resource management in this critical biome. Our work stresses the importance of better targeted policy making and sympathetic land use management of buffer zones of protected areas. Currently, such zones suffer from many development pressures and often experience contradictory policy frameworks which encourage a clash between biodiversity conservation and intensive agro husbandry production. Highlights: We characterize land use transitions in a hotspot of biodiversity in Brazil. Analysis at finer resolution show that there is still hope for forest recovery. For instilling sustainable forest transitions there is the need for fresh governance.
Limnology and Oceanography: Methods
International Review of Hydrobiology, 2016
The study of the structure and dynamics of cladoceran egg banks in South America began only 15 ye... more The study of the structure and dynamics of cladoceran egg banks in South America began only 15 years ago and the amount of knowledge, in addition to being scarce, is widely spread over partially national journals, theses, and books, and thus partially unavailable. We conducted a review of the literature published for this region, focusing mainly on the methodological approaches that have been applied and describe the main findings already published. The different methodological approaches make data comparability difficult. However, a total of 77 egg morphotypes were identified in the published studies. Among the variety of methods used, we suggest to adopt as the standard procedure: 1) pre isolation of eggs from the sediments by the " Sugar Flotation Method;'' 2) identification, enumeration, and sorting of egg morphotypes present in the sample; 3) individual hatching of each egg morphotype; 4) adult individual identification to the species level according to available keys; and 5) linking identified eggs to identified species' adults. The absence of identification keys constitutes a challenge. Therefore, collaborative research with the aim of generating pictorial taxonomical support for Neotropical resting eggs are encouraged. We believe the adoption of the suggested protocol might facilitate this issue. An extremely low hatching success was reported for most studies and the factors triggering the break of dormancy in the resting eggs coming from permanent systems remain unknown. In conclusion, resting egg studies are a novel and promising field in South America, but with many challenges that need to be addressed.
Nauplius, 2016
Cladoceran males are not very frequent in natural populations, since they are only produced in st... more Cladoceran males are not very frequent in natural populations, since they are only produced in stress situations. Th us, only a few species have had the male morphology described. Nevertheless, whenever data concerning the morphology of males is available, they are used as a tool to resolve taxonomic problems. In this study, the morphology of Coronatella paulinae Sousa, Elmoor-Loureiro and Santos, 2015 (Cladocera: Chydoridae) was described and compared to other species within the genus. Coronatella paulinae shares the diagnostic morphological traits typically att ributed to the genus: (1) gonopores opening ventrally, subapically to the postabdominal claw; (2) marginal setulae arranged in groups on the postanal margin; (3) Inner Distal Lobe (IDL) armed with three setae, of which one is the male seta. Th e absence of lateral aesthetascs on male antennules might also be an important diagnostic character for the genus, since they are present in other Aloninae groups. Coronatella paulinae males present a unique combination of morphological traits on the postabdomen, which distinguish them from
Cadernos Do Leme, Mar 10, 2011
... materiais voltados para as realidades locais de cada aldeia, elaborados por professores indíg... more ... materiais voltados para as realidades locais de cada aldeia, elaborados por professores indígenas, na ... Page 6. SABERES AMBIENTAIS NA EDUCAÇÃO INTERCULTURAL – Marco Túlio da Silva Ferreira & Paulina M. Maia Barbosa Cadernos do LEME, Campina Grande, vol. ...
Ensaio Pesquisa em Educação em Ciências (Belo Horizonte), 2004
Resumo: Procuramos neste estudo levantar as concepções de jovens escolarizados sobre a conservaçã... more Resumo: Procuramos neste estudo levantar as concepções de jovens escolarizados sobre a conservação de primatas a partir de suas vivências em duas instituições não-formais de ensino: Fundação Zoo-botânica de Belo Horizonte (FZB-BH) e Reserva Particular do Patrimônio Nacional Feliciano Miguel Abdala (RPPN-FMA). Os dados foram levantados por meio de entrevistas semi-estruturadas, realizadas com estudantes entre 14 e 18 anos. Os resultados obtidos mostraram que os entrevistados da FZB-BH associam aquela área quase sempre às atividades de lazer, enquanto a RPPN-FMA foi vista como uma unidade voltada à realização de pesquisas. Os entrevistados nesta última instituição apresentaram um maior nível de informação a respeito dos aspectos da ecologia e comportamento dos primatas, contrariamente aos da FZB-BH, o que pode ser explicado, entre outros, pelas atividades sistematizadas de educação ambiental desenvolvidas pela unidade de conservação em questão. A educação ambiental nestas instituições...
Anais da Academia Brasileira de Ciências, 2016
Temperature and light are acknowledged as important factors for hatching of resting eggs. The kno... more Temperature and light are acknowledged as important factors for hatching of resting eggs. The knowledge of how they affect hatching rates of this type of egg is important for the comprehension of the consequences of warming waters in recolonization of aquatic ecosystems dependent on dormant populations. This study aimed at comparing the influence of different temperature and light conditions on hatching rates of Daphnia ambigua andDaphnia laevis resting eggs from tropical environments. The ephippia were collected in the sediment of three aquatic ecosystems, in southeastern Brazil. For each lake, the resting eggs were exposed to temperatures of 20, 24, 28 and 32 °C, under light (12 h photoperiod) and dark conditions. The results showed that the absence of light and high temperatures have a negative influence on the hatching rates. Statistical differences for hatching rates were also found when comparing the studied ecosystems (ranging from 0.6 to 31%), indicating the importance of lo...
Pesquisa em Educação Ambiental, 2013
&... more <p>O Parque Estadual do Rio Doce (PERD) foi a primeira unidade de conservação criada em Minas Gerais e é uma das maiores áreas remanescentes de Mata Atlântica no país. O objetivo deste estudo foi investigar em São José do Goiabal, município circunvizinho ao parque, a percepção dos moradores sobre o PERD analisando, através de entrevistas semi-estruturadas, a influência de diferentes variáveis. Os dados mostraram que gênero, classe social e idade não determinam a frequência de visitação. A caça a animais silvestres mostrou-se como prática comum, reconhecida pela população e motivada principalmente pelo lazer e apreciação da carne. O desenvolvimento de projetos de Educação Ambiental envolvendo alunos da rede básica de educação é o fator que mais influencia no conhecimento e valorização do PERD. Tais constatações sugerem a necessidade da implantação de programas de educação ambiental voltados principalmente para crianças e jovens, tornando-os parceiros dos propósitos de conservação da biodiversidade na região.</p>
Brazilian Journal of Biology, 2015
The Ibirité reservoir is an urban and eutrophic environment, with regular occurrences of cyanobac... more The Ibirité reservoir is an urban and eutrophic environment, with regular occurrences of cyanobacteria blooms. The reservoir is warm monomict and remains stratified most of the year, circulating in the dry season (winter). During the hydrological cycle of October/07 to October/08 there were four scenarios with different environmental conditions, which influenced the structure of the zooplankton community, as confirmed in a previous study. Changes in the zooplankton community structure between the scenarios were studied, aiming at analyzing the stability and persistence of this community. The Spearman’s coefficient of correlation was used to measure the stability; the persistence was evaluated through a cluster analysis and changes in community composition were estimated by the "temporal" β diversity index. Considering the distribution patterns of abundance, the community was stable only in the transition between scenarios 1 and 2 (n = 30, r = 0.71, p = 0.00001), when there...
Brazilian Journal of Biology, 2010
In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (So... more In order to verify changes in physical, chemical and biological features of Dom Helvécio Lake (South-East Brazil), this study compares previous and recent data obtained from limnological investigations over three decades. Plankton species composition and density together with environmental data from 1978, 1983, and during 1999 to 2006 showed changes driven by seasonal climatic forces or by anthropogenic causes. Changes in diversity are shown as a consequence of alternation of rainy and dry periods and introduction of exotic fish species. Finally, suggestions are made for improving conservation efforts in the area, through planned actions and monitoring programmes.
Environment, Development and Sustainability, 2020
The investigation of land use changes by anthropic processes, spatially and temporally, is a fund... more The investigation of land use changes by anthropic processes, spatially and temporally, is a fundamental tool to establish correlations between landscape patterns and processes and management of the buffer zone of Conservation Units. This study aimed to analyze the forest fragmentation and land use dynamics in the buffer zone of the Rio Doce State Park (PERD), located in Minas Gerais, Brazil, for the year 2015. Its buffer zone was delimited to a radius of 10 km, covering a total area of 128.893,36 ha. Land use classification was based on Landsat 8 image, orbit 217, point 73 and 74, and two types of ecosystems were identified: natural and anthropic. In the thematic mapping, the pressure of the anthropic use over the natural was notified, as well as the high number of forest fragments, which is a negative impact on the resilience required for the conservation of biodiversity and the local Atlantic forest. The fragments have different shapes and sizes and are distributed throughout the buffer zone of the PERD. There is a need to adopt conservation strategies, such as environmental education, reforestation techniques, recovery of degraded areas and ecological corridors. Even with a worrying current scenario, this finding makes it possible to establish an optimistic point for biodiversity conservation, associated with a tendency to reduce the forces of direct changes on natural systems.
Aim: This study aimed to examine and compare the different patterns of diel vertical migration (D... more Aim: This study aimed to examine and compare the different patterns of diel vertical migration (DVM) in two tropical freshwater ecosystems: Carioca Lake (PERD, MG), dominated by piscivorous fishes and Nado reservoir (Belo Horizonte, MG), dominated by planktivorous/omnivorous fishes. Methods: The vertical distribution of the zooplankton was examined at noon and midnight, in April 2003 in both systems, using a Schindler-Patalas trap. Results: In Nado reservoir, the larvae of the invertebrate predator Chaoborus, remained in the hypolimnion during the day and ascended into the surface waters at night. The same migratory behavior was observed for the population of the copepod Thermocyclops inversus, the dominant zooplankter, as well as for the rotifers. In Carioca Lake, the Chaoborus larvae did not migrate, and individuals were found occupying the entire water column in daytime as well as at night. The population of the copepod T. minutus, a potential prey of Chaoborus larvae, and most rotifers also did not migrate in Carioca Lake. Conclusions: In Nado reservoir, where planktivorous and omnivorous fishes dominate, the zooplankton was forced to adopt the diurnal vertical migration (DVM), a phenomenon that propagated through the different trophic levels. In Carioca Lake, in the virtual absence of vertebrate predators of zooplankton, no migration in the planktonic community was observed.
Internationale Vereinigung für theoretische und angewandte Limnologie: Verhandlungen, 2006
Journal of Plankton Research, Nov 21, 2017
Previous laboratory experiments have indicated that Chaoborus larvae may be confused when exposed... more Previous laboratory experiments have indicated that Chaoborus larvae may be confused when exposed to a single prey species at a high density, resulting in decreased attack efficiency. Here, we hypothesized that a prey less vulnerable to Chaoborus larvae, such as Physocypria schubarti ostracods, could affect the predatory performance of Chaoborus on a more vulnerable prey, such as Ceriodaphnia silvestrii neonates. We predicted that fewer neonates would be ingested by Chaoborus larvae in the presence of ostracods at high densities due to the decreased attack efficiency caused by the confusion effect. This hypothesis was tested by combining predation assays and direct visual observations of live organisms. There was a significant decrease in the consumption of neonates when they were offered together with ostracods at high densities; however, this was not related to the ingestion of ostracods as an alternative prey or to decreased attack efficiency on neonates caused by the confusion. The energy wasted due to the numerous attacks on the ostracods ("fake prey") possibly led the chaoborids to exhaustion, reducing their predatory performance on neonates. In ecological terms, high densities of ostracods in the water column may theoretically minimize the strong impact of Chaoborus sp. larvae on more vulnerable prey.
Ethnoscientia
Estudos etnobotânicos podem subsidiar projetos de bioprospecção e conservação de plantas nativas ... more Estudos etnobotânicos podem subsidiar projetos de bioprospecção e conservação de plantas nativas com propriedades medicinais, pois, através da utilização dos recursos vegetais como medicamentos, a própria população pode tornar efetiva a sua proteção. Nesse sentido, o objetivo deste trabalho foi estudar o conhecimento popular de moradores de São Thomé das Letras, MG, na bacia do Alto Rio Grande, sobre as espécies vegetais medicinais nativas da região. O público-alvo para o levantamento etnobotânico foram moradores da área urbana e rural do município e de seu entorno, que detêm algum conhecimento especial a respeito de plantas medicinais nativas da região. Foram realizadas entrevistas semiestruturadas com 20 informantes e turnês guiadas com seis deles, em Cerrado sentido restrito, Cerrado Rupestre, campos, fragmentos de floresta estacional semidecidual e beiras de estrada, além de quintais com espécies nativas cultivadas. Ao todo foram citadas 87 espécies, pertencentes a 46 famílias b...
Environmental Monitoring and Assessment
It is necessary to understand the importance of landscapes that comprise the environment across a... more It is necessary to understand the importance of landscapes that comprise the environment across a broad range of time and space and that each part of these landscapes responds to changes in environmental factors and land use. This study employs a multiscale modeling approach in the Rio Doce State Park (PERD), located in Minas Gerais, Brazil, based on a previous study on land use change in this region over the last 30 years (1985-2015), with an aim of predicting possible scenarios for the next 15 years (2015-2030). The results indicate that the municipalities and buffer zones within the PERD will suffer from increased human disturbance in all four land use types present in the region (Urban, Agriculture, Pasture, and Forestry). Correspondingly , areas of natural environment (Forest and Water) will shrink due to an increase in forest fragmentation , causing the loss of permanent ecological reserves , thereby endangering the biodiversity of these areas. Cooperation between the local community and private companies is therefore necessary to improve regional environmental conservation, encourage advanced sustainable development, and improve the quality of life for residents within each municipality near the State Park.
Fundamental and Applied Limnology / Archiv für Hydrobiologie
Aiming to evaluate the importance of egg banks from a tropical lake for the active Daphnia laevis... more Aiming to evaluate the importance of egg banks from a tropical lake for the active Daphnia laevis dynamics, we investigated ephippia down to a 28-cm sediment depth, and used data obtained by traps to compare with the in situ production and hatching rates of fresh ephippia. All the ephippia from the sediment were opened for inspection of the presence of resting eggs, and those found were incubated to verify hatching. Ephippia density degradation rate was tested by putting isolated ephippia immersed in the sediment lake for 75 days, and found to exponentially decrease with increasing sediment depth. Higher densities were recorded in 2017 (maximum of 1.43 ephippia per cm2) than in 2016 (maximum of 0.8 ephippia per cm2). The empty ephippia rates were high in all sediment depths ranging from 83% to 100%. In contrast, the hatching rates in situ of fresh ephippia were high, suggesting that those that sink are mostly unviable or empty, forming an unusual egg bank in the sediment. In the lab...
Acta Limnologica Brasiliensia
Aim Temperature and light have been recognized as important factors for ephippia hatching in temp... more Aim Temperature and light have been recognized as important factors for ephippia hatching in temperate and tropical freshwater systems. Oddly some authors suggested that decapsulation of resting eggs would be a pro when it comes to ex situ hatching studies, exposing those eggs to a greater amount of light. This study aimed to compare the difference in the hatching rate between resting eggs decapsulated and intact ephippia of Daphnia laevis, a zooplankton that occurs at lakes, in tropical freshwaters (Cladocera). Methods The ephippia used in this work were collected at the sediment of a reservoir, in Belo Horizonte city (Minas Gerais, Brazil). We set up the laboratory experiment with two distinct groups: intact ephippia and decapsulated resting eggs. For that, we manually decapsulated 120 ephippia and kept 120 others intact (six replicas with 20 ephippia each), then incubated them all with culture water at 22ºC (12h photoperiod) for 30 days with daily monitoring. Results The results ...
Annales de Limnologie - International Journal of Limnology
Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, ... more Cladocerans serve as prey for several aquatic predators like fish and Chaoborus larvae. However, because different predators consume different sized prey, cladocerans may display differing life-history responses depending on predator type. Although most studies use the genus Daphnia to evaluate phenotypic plasticity in cladocerans, other genera might also respond to predator infochemicals. In this study, we compared life-history responses of Daphnia similis and Moina macrocopa to infochemicals released by a vertebrate (fish) and an invertebrate (Chaoborus) predator. As expected, some life-history parameters were altered depending on the type of predator. Overall, fish infochemicals increased the size at primipara, clutch size, net reproductive rate and longevity in both cladocerans. We argue that increased body lengths in the presence of fish promote bigger clutch sizes. Conversely, responses to Chaoborus were weaker, affecting only the net reproductive rates and longevity. Non-daph...
Journal of Environmental Planning and Management
This article uses a multiscale approach for assessing landscape changes in one of the world&#... more This article uses a multiscale approach for assessing landscape changes in one of the world's biodiversity hotspots in Brazil, the Rio Doce State Park (PERD). In this article, we assess land use changes over a 30 year period. Our results show that, while inside the park landscape changes were minimal, in the park buffer zone human induced changes are steadily rising due to an increase in eucalyptus plantations and urban sprawl that grew by 4% and 1.9%, respectively. Agricultural land has been reduced by 6.35%, but there are trends that a form of welcome forest transition has been occurring. We report an increase in native forests from 40,588 ha in 1985 to 45,690 ha in 2015. The analysis of human impacts in the study area delivers very different results when varying the pixel size from 25 ha to 900 m 2. The former shows a very high level of human influence while the latter reveals small but vital patches of native forest offering hopeful opportunities for sustainable natural resource management in this critical biome. Our work stresses the importance of better targeted policy making and sympathetic land use management of buffer zones of protected areas. Currently, such zones suffer from many development pressures and often experience contradictory policy frameworks which encourage a clash between biodiversity conservation and intensive agro husbandry production. Highlights: We characterize land use transitions in a hotspot of biodiversity in Brazil. Analysis at finer resolution show that there is still hope for forest recovery. For instilling sustainable forest transitions there is the need for fresh governance.
Limnology and Oceanography: Methods
International Review of Hydrobiology, 2016
The study of the structure and dynamics of cladoceran egg banks in South America began only 15 ye... more The study of the structure and dynamics of cladoceran egg banks in South America began only 15 years ago and the amount of knowledge, in addition to being scarce, is widely spread over partially national journals, theses, and books, and thus partially unavailable. We conducted a review of the literature published for this region, focusing mainly on the methodological approaches that have been applied and describe the main findings already published. The different methodological approaches make data comparability difficult. However, a total of 77 egg morphotypes were identified in the published studies. Among the variety of methods used, we suggest to adopt as the standard procedure: 1) pre isolation of eggs from the sediments by the " Sugar Flotation Method;'' 2) identification, enumeration, and sorting of egg morphotypes present in the sample; 3) individual hatching of each egg morphotype; 4) adult individual identification to the species level according to available keys; and 5) linking identified eggs to identified species' adults. The absence of identification keys constitutes a challenge. Therefore, collaborative research with the aim of generating pictorial taxonomical support for Neotropical resting eggs are encouraged. We believe the adoption of the suggested protocol might facilitate this issue. An extremely low hatching success was reported for most studies and the factors triggering the break of dormancy in the resting eggs coming from permanent systems remain unknown. In conclusion, resting egg studies are a novel and promising field in South America, but with many challenges that need to be addressed.
Nauplius, 2016
Cladoceran males are not very frequent in natural populations, since they are only produced in st... more Cladoceran males are not very frequent in natural populations, since they are only produced in stress situations. Th us, only a few species have had the male morphology described. Nevertheless, whenever data concerning the morphology of males is available, they are used as a tool to resolve taxonomic problems. In this study, the morphology of Coronatella paulinae Sousa, Elmoor-Loureiro and Santos, 2015 (Cladocera: Chydoridae) was described and compared to other species within the genus. Coronatella paulinae shares the diagnostic morphological traits typically att ributed to the genus: (1) gonopores opening ventrally, subapically to the postabdominal claw; (2) marginal setulae arranged in groups on the postanal margin; (3) Inner Distal Lobe (IDL) armed with three setae, of which one is the male seta. Th e absence of lateral aesthetascs on male antennules might also be an important diagnostic character for the genus, since they are present in other Aloninae groups. Coronatella paulinae males present a unique combination of morphological traits on the postabdomen, which distinguish them from
Cadernos Do Leme, Mar 10, 2011
... materiais voltados para as realidades locais de cada aldeia, elaborados por professores indíg... more ... materiais voltados para as realidades locais de cada aldeia, elaborados por professores indígenas, na ... Page 6. SABERES AMBIENTAIS NA EDUCAÇÃO INTERCULTURAL – Marco Túlio da Silva Ferreira & Paulina M. Maia Barbosa Cadernos do LEME, Campina Grande, vol. ...
Ensaio Pesquisa em Educação em Ciências (Belo Horizonte), 2004
Resumo: Procuramos neste estudo levantar as concepções de jovens escolarizados sobre a conservaçã... more Resumo: Procuramos neste estudo levantar as concepções de jovens escolarizados sobre a conservação de primatas a partir de suas vivências em duas instituições não-formais de ensino: Fundação Zoo-botânica de Belo Horizonte (FZB-BH) e Reserva Particular do Patrimônio Nacional Feliciano Miguel Abdala (RPPN-FMA). Os dados foram levantados por meio de entrevistas semi-estruturadas, realizadas com estudantes entre 14 e 18 anos. Os resultados obtidos mostraram que os entrevistados da FZB-BH associam aquela área quase sempre às atividades de lazer, enquanto a RPPN-FMA foi vista como uma unidade voltada à realização de pesquisas. Os entrevistados nesta última instituição apresentaram um maior nível de informação a respeito dos aspectos da ecologia e comportamento dos primatas, contrariamente aos da FZB-BH, o que pode ser explicado, entre outros, pelas atividades sistematizadas de educação ambiental desenvolvidas pela unidade de conservação em questão. A educação ambiental nestas instituições...
Anais da Academia Brasileira de Ciências, 2016
Temperature and light are acknowledged as important factors for hatching of resting eggs. The kno... more Temperature and light are acknowledged as important factors for hatching of resting eggs. The knowledge of how they affect hatching rates of this type of egg is important for the comprehension of the consequences of warming waters in recolonization of aquatic ecosystems dependent on dormant populations. This study aimed at comparing the influence of different temperature and light conditions on hatching rates of Daphnia ambigua andDaphnia laevis resting eggs from tropical environments. The ephippia were collected in the sediment of three aquatic ecosystems, in southeastern Brazil. For each lake, the resting eggs were exposed to temperatures of 20, 24, 28 and 32 °C, under light (12 h photoperiod) and dark conditions. The results showed that the absence of light and high temperatures have a negative influence on the hatching rates. Statistical differences for hatching rates were also found when comparing the studied ecosystems (ranging from 0.6 to 31%), indicating the importance of lo...
Pesquisa em Educação Ambiental, 2013
&... more <p>O Parque Estadual do Rio Doce (PERD) foi a primeira unidade de conservação criada em Minas Gerais e é uma das maiores áreas remanescentes de Mata Atlântica no país. O objetivo deste estudo foi investigar em São José do Goiabal, município circunvizinho ao parque, a percepção dos moradores sobre o PERD analisando, através de entrevistas semi-estruturadas, a influência de diferentes variáveis. Os dados mostraram que gênero, classe social e idade não determinam a frequência de visitação. A caça a animais silvestres mostrou-se como prática comum, reconhecida pela população e motivada principalmente pelo lazer e apreciação da carne. O desenvolvimento de projetos de Educação Ambiental envolvendo alunos da rede básica de educação é o fator que mais influencia no conhecimento e valorização do PERD. Tais constatações sugerem a necessidade da implantação de programas de educação ambiental voltados principalmente para crianças e jovens, tornando-os parceiros dos propósitos de conservação da biodiversidade na região.</p>
Brazilian Journal of Biology, 2015
The Ibirité reservoir is an urban and eutrophic environment, with regular occurrences of cyanobac... more The Ibirité reservoir is an urban and eutrophic environment, with regular occurrences of cyanobacteria blooms. The reservoir is warm monomict and remains stratified most of the year, circulating in the dry season (winter). During the hydrological cycle of October/07 to October/08 there were four scenarios with different environmental conditions, which influenced the structure of the zooplankton community, as confirmed in a previous study. Changes in the zooplankton community structure between the scenarios were studied, aiming at analyzing the stability and persistence of this community. The Spearman’s coefficient of correlation was used to measure the stability; the persistence was evaluated through a cluster analysis and changes in community composition were estimated by the "temporal" β diversity index. Considering the distribution patterns of abundance, the community was stable only in the transition between scenarios 1 and 2 (n = 30, r = 0.71, p = 0.00001), when there...