IMPORTANCE OF MICROHABITATS IN THE OCCURRENCE OF EPHEMEROPTERA AND TRICHOPTERA SPECIES IN AN ISLA... more IMPORTANCE OF MICROHABITATS IN THE OCCURRENCE OF EPHEMEROPTERA AND TRICHOPTERA SPECIES IN AN ISLAND IN RIO XINGU. This work described the abundance, richness and composition of genera and the functional food groups (GFA) of Ephemeroptera and Trichoptera (ET), in different microhabitats of a fluvial island, in Volta Grande of the Xingu River, Brazilian Amazon. Aquatic insects were collected from 30 samples located in puddles situated in the interior of the island (rocks as substrate); and another 30 samples located in the coastal margin of the island (pebble as substrate). The different facets of diversity (abundance, richness and composition of genera and GFA) were compared between puddle samples with rock substrate and those from the coastal region with pebble substrate. In total, 56 individuals were collected, distributed in 15 genera ET. The greatest estimated genera richness and the largest number of individuals occurred in the rocks of the puddle environments. The composition o...
Understanding the processes that influence species diversity is still a challenge in ecological
s... more Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confus õ es National Parks, where 36 areas were sampled in differ- ent seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower dur- ing the dry season, indicating a strong influence of seasonality, a pattern also found for envi- ronmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmen- tal factors were more important in explaining variations in composition. Climate change pre- dictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments.
Large scale palm oil plantations for the production of vegetable oil are among the most harmful a... more Large scale palm oil plantations for the production of vegetable oil are among the most harmful agricultural activities to biodiversity, especially given their rapid expansion, worldwide. Many cases of species loss have already been recorded in Asian countries, although research is still incipient in the Amazon basin, and the environmental impacts of these monocultures on freshwater ecosystems in the Neotropical region are still poorly understood. The present study evaluated the e ff ects of oil palm plantations on the physical structure of stream habitats and the resulting changes in the taxonomic and functional composition of aquatic insect communities. A total of 2100 specimens of the orders Ephemeroptera, Plecoptera and Trichoptera were collected during the present study, representing 40 genera and 16 families. The hypothesis tested was that the taxonomic and functional diversity of the orders Ephemeroptera, Plecoptera and Trichoptera (Insecta) decreases in streams surrounded by oil palm plantations in comparison with those embedded in forested areas. In the plantation streams, the taxonomic richness and composition, and the functional richness are modi fi ed signi fi cantly. Functional composition appeared unaltered despite reduced canopy cover associated with oil palm streams. These e ff ects emphasize the importance of the riparian vegetation for the protection of the aquatic communities found in oil palm plantations. The maintenance of the riparian vegetation may mitigate the impacts of plan- tations, contributing to the conservation of insect communities and associated biodiversity.
A new species of Miroculis is described based on all developmental stages (nymph, and male and fe... more A new species of Miroculis is described based on all developmental stages (nymph, and male and female imagos). Miroc- ulis yulieae sp. nov. is recorded from the transitional area of Cerrado-Amazonia, Brazil.
Thediversityoflakes,riversandstreamsoffloodplainsustainsgreattaxonomicandfunctionaldiversity.The... more Thediversityoflakes,riversandstreamsoffloodplainsustainsgreattaxonomicandfunctionaldiversity.The BananalfloodplainislocatedmainlyintheStateofMatoGrosso,inthesouthernregionoftheCerradoBiomeandnorthof the Cerrado–Amazonia transition zone, two very diverse ecosystems. In the present study, to test the hypothesis that composition, richness and functional groups would differ between regions (south and north), as well as between environments (lentic and lotic), always being greater in the northern area and in lotic environments, immature Ephemeroptera individuals were collected from 12 aquatic environments, 6 streams and 6 lakes, in the northern and southern regions of the plains. Composition differed only between regions; the richness of genera and the number of functionalfeedinggroupswashigherinthenorthernregion,anddidnotdifferbetweenenvironments.Thegreaterdiversity in the northern region may be because of its location in the ecotone of two highly diverse ecosystems, whereas the similarity between the lentic and lotic environments may be because of the homogenisation temporarily caused by floods during the flood period, increasing fluvial connectivity. Knowledge of the diversity patterns in these inhospitable regions spatially minimises knowledge gaps and provides empirical evidence of the importance of areas such as the Cerrado– Amazon transition for conservation, as shown in the present study.
We tested if linear spatial distance between two sites, environmental variables or river distance... more We tested if linear spatial distance between two sites, environmental variables or river distance, are important drivers of aquatic insect assemblages composition in impounded rivers, located at the transition between Cerrado/ Amazonia. Regarding the scale of the study, we believe that flying adults have no dispersal limitation. Hence, our hypothesis is that species composition is structured mainly by environmental variables. We tested our hypothesis with partial Mantel. The model, which included environmental variables was the one that better explained the species composition in impounded rivers. We believe that the strong relationship between assemblages and environment is due to aspects related to acquisition of shelter and food resources.
Effect of the abiotic factors on Brachymetra albinervis albinervis (Heteroptera: Gerridae). We an... more Effect of the abiotic factors on Brachymetra albinervis albinervis (Heteroptera: Gerridae). 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. RESUMO. Analisou-se a influência de fatores abióticos, distribuição longitudinal e temporal sobre a abundância de Brachymetra albinervis albinervis Amyot & Serville, 1843. Foram avaliados três sítios de um riacho de Cerrado: nascente, intermediário e foz, mensalmente durante um ano (junho de 2011 a maio de 2012). As variáveis abióticas aferidas foram: oxigênio dissolvido, temperatura da água, pH, condutividade elétrica, largura e profundidade do riacho. Em cada sítio, mensalmente coletou-se em transecção de 100 m lineares. Foram coletados 111 espécimes. A foz apresentou menor abundância quando comparada aos outros locais (F (2, 9) 13,721, p = 0,001). A abundância não variou entre os períodos do ano (chuva, vazante, seca ou início da chuva). Assim, a alteração na abundância de B. a. albinervis analisada ao longo de um ano foi influenciada pelos trechos do córrego, e essa variação foi atribuída a alterações ambientais no sítio foz que apresentou menor abundância e consequentemente é o que apresenta menor integridade ambiental. Esses resultados contribuem para o conhecimento ecológico dessa espécie e discute sobre a mudança da ocorrência da espécie em função da alteração dos ambientes aquáticos.
Our goal was to investigate whether the loss of riparian forests alters the structure of assembla... more Our goal was to investigate whether the loss of riparian forests alters the structure of assemblages and populations of dragonflies and damselflies. We tested the hypothesis that the composition of the odonate assemblages found upstream from dams are significantly different from those found downstream of these barriers. To test the hypothesis, we investigated stream sectors upstream and downstream of three dams located at the extreme of the southern Amazon basin, in the Brazilian state of Mato Grosso. We collected 111 adult odonates, 45 upstream and 69 downstream, representing 18 species, 12 upstream and 10 downstream. The most abundant species was Epipleoneura williamsoni Santos, 1957 (n = 41, 36.9%), followed by Epipleoneura metallica Rácenis, 1955 (n = 20, 18%) and Hetaerina curvicauda Garrison, 1990 (n = 17, 15.3%). Statistical ordination separated the different sectors, with the greatest dissimilarity being found between the upstream and downstream I (DS I), and our hypothesis was further supported by the fact that six of the 18 species recorded in the study did not occur in the upstream sector. As this process may lead to the local extinction of part of the biodiversity of the Amazon–Cerrado transition, even before it is fully understood, we would recommend that the observed pattern be verified through the analysis of other taxonomic groups and on a more ample spatial scale.
Aquatic insects are widely distributed, and are especially diverse and abundant in tropical strea... more Aquatic insects are widely distributed, and are especially diverse and abundant in tropical streams, where they play an important role in the food chain due to their diversity of feeding strategies, and the potential for the transfer of energy between aquatic and terrestrial environments. The intimate relationship found between these insects and environmental variables means that they are often used as bioindicatorss in environmental studies. We tested the hypothesis that the loss of environmental integrity in tropical streams will lead to a loss of species and a decline in the abundance of mayflies (Leptophlebiidae), in addition to a change in species composition, and the dynamics of population. Collect immature leptophlebiids in 18 streams representing different DEGREES of conservation, in the Brazilian Cerrado. The environmental integrity of the sites was assessed using a Habitat Integrity Index (HII), which generates values of zero (degraded) to one (preserved), based on soil use, the extension and conservation of riparian forest, as well as morphological features of the stream. A total of 4945 immature leptophlebiids were collected and identified as belonging to 16 species or morphospecies. On an average, a reduction of 0.1 in the value of the HII led to the loss of five specimens and one species. The composition of the communities varied systematically along the environmental gradient, with more sensitive species being found only when the index was above a threshold of 0.6. The importance of the riparian vegetation for the aquatic biota, especially its role in the mitigation of impacts from the surrounding matrix, supports the universal conservation of this type of habitat.
Investigated how the loss of environmental integrity affects damselfly
species composition in ... more Investigated how the loss of environmental integrity affects damselfly
species composition in nine sites with different levels of environmental integrity in a
Cerrado-Amazon transition region known as “arc of deforestation” in Mato Grosso State,
Brazil. We also tested the influence of environmental variables on species composition.
Methods: We collected in transects of 100 m and used ordination (PCoA) and
simple linear regression. Results: Species composition was strongly influenced by the
environmental quality of sites, and the best model to explain species composition included
variables related to channel morphology. Conclusions: These results are connected to the
environmental homogenization and loss of environmental integrity as a result of extensive
agricultural practices which alter stream communities of dragonflies in this region.
We demonstrate that the distribution of the functional feeding groups of aquatic insects is relat... more We demonstrate that the distribution of the functional feeding groups of aquatic insects is related to hierarchical patch dynamics. Patches are sites with unique environmental and functional characteristics that are discontinuously distributed in time and space within a lotic system. This distribution predicts that the occurrence of species will be based predominantly on their environmental requirements. We sampled three streams within the same drainage basin in the Brazilian Cerrado savanna, focusing on waterfalls and associated habitats (upstream, downstream), representing different functional zones. We collected 2,636 specimens representing six functional feeding groups (FFGs): brushers, collector–gatherers, collector–filterers, shredders, predators, and scrapers. The frequency of occurrence of these groups varied significantly among environments. This variation appeared to be related to the distinct characteristics of the different habitat patches, which led us to infer that the hierarchical patch dynamics model can best explain the distribution of functional feeding groups in minor lotic environments, such as waterfalls.
Edge effect on the litter layer in a cerradão area of Eastern Mato Grosso, Brazil. ... more Edge effect on the litter layer in a cerradão area of Eastern Mato Grosso, Brazil. Vegetation
fragmentation causes edge effect, changing the microclimate, the species composition, and their biotic and abiotic
interactions. The litter layer is crucial for nutrient cycling in forests. This study aimed to check the influence of
vegetation edge on attributes of the litter layer in a cerradão area, testing the hypothesis that distance from the
edge is directly related to biomass and leaf proportion in the litter layer. Samples were collected from the litter
layer in 95m transects in 5 cerradão areas of eastern Mato Grosso, Brazil. We estimated a total of 6,724.44 kg/
ha -1 of litter, out of which 72.2% are leaves, 27.8% are branches, 0.07% is fruits, and 0.004% is flowers. Distance from the edge presented a positive and significant relation to thickness, dry weight, volume, and leaf fraction
mass of the litter. This information contributes to the understanding of a poorly studied component in cerradão
areas, showing that the fragmentation of these areas changes the structure of litter layer, and this may cause
losses to ecosystem functions and services, with possible future reflexes on the species diversity
IMPORTANCE OF MICROHABITATS IN THE OCCURRENCE OF EPHEMEROPTERA AND TRICHOPTERA SPECIES IN AN ISLA... more IMPORTANCE OF MICROHABITATS IN THE OCCURRENCE OF EPHEMEROPTERA AND TRICHOPTERA SPECIES IN AN ISLAND IN RIO XINGU. This work described the abundance, richness and composition of genera and the functional food groups (GFA) of Ephemeroptera and Trichoptera (ET), in different microhabitats of a fluvial island, in Volta Grande of the Xingu River, Brazilian Amazon. Aquatic insects were collected from 30 samples located in puddles situated in the interior of the island (rocks as substrate); and another 30 samples located in the coastal margin of the island (pebble as substrate). The different facets of diversity (abundance, richness and composition of genera and GFA) were compared between puddle samples with rock substrate and those from the coastal region with pebble substrate. In total, 56 individuals were collected, distributed in 15 genera ET. The greatest estimated genera richness and the largest number of individuals occurred in the rocks of the puddle environments. The composition o...
Understanding the processes that influence species diversity is still a challenge in ecological
s... more Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confus õ es National Parks, where 36 areas were sampled in differ- ent seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower dur- ing the dry season, indicating a strong influence of seasonality, a pattern also found for envi- ronmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmen- tal factors were more important in explaining variations in composition. Climate change pre- dictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments.
Large scale palm oil plantations for the production of vegetable oil are among the most harmful a... more Large scale palm oil plantations for the production of vegetable oil are among the most harmful agricultural activities to biodiversity, especially given their rapid expansion, worldwide. Many cases of species loss have already been recorded in Asian countries, although research is still incipient in the Amazon basin, and the environmental impacts of these monocultures on freshwater ecosystems in the Neotropical region are still poorly understood. The present study evaluated the e ff ects of oil palm plantations on the physical structure of stream habitats and the resulting changes in the taxonomic and functional composition of aquatic insect communities. A total of 2100 specimens of the orders Ephemeroptera, Plecoptera and Trichoptera were collected during the present study, representing 40 genera and 16 families. The hypothesis tested was that the taxonomic and functional diversity of the orders Ephemeroptera, Plecoptera and Trichoptera (Insecta) decreases in streams surrounded by oil palm plantations in comparison with those embedded in forested areas. In the plantation streams, the taxonomic richness and composition, and the functional richness are modi fi ed signi fi cantly. Functional composition appeared unaltered despite reduced canopy cover associated with oil palm streams. These e ff ects emphasize the importance of the riparian vegetation for the protection of the aquatic communities found in oil palm plantations. The maintenance of the riparian vegetation may mitigate the impacts of plan- tations, contributing to the conservation of insect communities and associated biodiversity.
A new species of Miroculis is described based on all developmental stages (nymph, and male and fe... more A new species of Miroculis is described based on all developmental stages (nymph, and male and female imagos). Miroc- ulis yulieae sp. nov. is recorded from the transitional area of Cerrado-Amazonia, Brazil.
Thediversityoflakes,riversandstreamsoffloodplainsustainsgreattaxonomicandfunctionaldiversity.The... more Thediversityoflakes,riversandstreamsoffloodplainsustainsgreattaxonomicandfunctionaldiversity.The BananalfloodplainislocatedmainlyintheStateofMatoGrosso,inthesouthernregionoftheCerradoBiomeandnorthof the Cerrado–Amazonia transition zone, two very diverse ecosystems. In the present study, to test the hypothesis that composition, richness and functional groups would differ between regions (south and north), as well as between environments (lentic and lotic), always being greater in the northern area and in lotic environments, immature Ephemeroptera individuals were collected from 12 aquatic environments, 6 streams and 6 lakes, in the northern and southern regions of the plains. Composition differed only between regions; the richness of genera and the number of functionalfeedinggroupswashigherinthenorthernregion,anddidnotdifferbetweenenvironments.Thegreaterdiversity in the northern region may be because of its location in the ecotone of two highly diverse ecosystems, whereas the similarity between the lentic and lotic environments may be because of the homogenisation temporarily caused by floods during the flood period, increasing fluvial connectivity. Knowledge of the diversity patterns in these inhospitable regions spatially minimises knowledge gaps and provides empirical evidence of the importance of areas such as the Cerrado– Amazon transition for conservation, as shown in the present study.
We tested if linear spatial distance between two sites, environmental variables or river distance... more We tested if linear spatial distance between two sites, environmental variables or river distance, are important drivers of aquatic insect assemblages composition in impounded rivers, located at the transition between Cerrado/ Amazonia. Regarding the scale of the study, we believe that flying adults have no dispersal limitation. Hence, our hypothesis is that species composition is structured mainly by environmental variables. We tested our hypothesis with partial Mantel. The model, which included environmental variables was the one that better explained the species composition in impounded rivers. We believe that the strong relationship between assemblages and environment is due to aspects related to acquisition of shelter and food resources.
Effect of the abiotic factors on Brachymetra albinervis albinervis (Heteroptera: Gerridae). We an... more Effect of the abiotic factors on Brachymetra albinervis albinervis (Heteroptera: Gerridae). 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. RESUMO. Analisou-se a influência de fatores abióticos, distribuição longitudinal e temporal sobre a abundância de Brachymetra albinervis albinervis Amyot & Serville, 1843. Foram avaliados três sítios de um riacho de Cerrado: nascente, intermediário e foz, mensalmente durante um ano (junho de 2011 a maio de 2012). As variáveis abióticas aferidas foram: oxigênio dissolvido, temperatura da água, pH, condutividade elétrica, largura e profundidade do riacho. Em cada sítio, mensalmente coletou-se em transecção de 100 m lineares. Foram coletados 111 espécimes. A foz apresentou menor abundância quando comparada aos outros locais (F (2, 9) 13,721, p = 0,001). A abundância não variou entre os períodos do ano (chuva, vazante, seca ou início da chuva). Assim, a alteração na abundância de B. a. albinervis analisada ao longo de um ano foi influenciada pelos trechos do córrego, e essa variação foi atribuída a alterações ambientais no sítio foz que apresentou menor abundância e consequentemente é o que apresenta menor integridade ambiental. Esses resultados contribuem para o conhecimento ecológico dessa espécie e discute sobre a mudança da ocorrência da espécie em função da alteração dos ambientes aquáticos.
Our goal was to investigate whether the loss of riparian forests alters the structure of assembla... more Our goal was to investigate whether the loss of riparian forests alters the structure of assemblages and populations of dragonflies and damselflies. We tested the hypothesis that the composition of the odonate assemblages found upstream from dams are significantly different from those found downstream of these barriers. To test the hypothesis, we investigated stream sectors upstream and downstream of three dams located at the extreme of the southern Amazon basin, in the Brazilian state of Mato Grosso. We collected 111 adult odonates, 45 upstream and 69 downstream, representing 18 species, 12 upstream and 10 downstream. The most abundant species was Epipleoneura williamsoni Santos, 1957 (n = 41, 36.9%), followed by Epipleoneura metallica Rácenis, 1955 (n = 20, 18%) and Hetaerina curvicauda Garrison, 1990 (n = 17, 15.3%). Statistical ordination separated the different sectors, with the greatest dissimilarity being found between the upstream and downstream I (DS I), and our hypothesis was further supported by the fact that six of the 18 species recorded in the study did not occur in the upstream sector. As this process may lead to the local extinction of part of the biodiversity of the Amazon–Cerrado transition, even before it is fully understood, we would recommend that the observed pattern be verified through the analysis of other taxonomic groups and on a more ample spatial scale.
Aquatic insects are widely distributed, and are especially diverse and abundant in tropical strea... more Aquatic insects are widely distributed, and are especially diverse and abundant in tropical streams, where they play an important role in the food chain due to their diversity of feeding strategies, and the potential for the transfer of energy between aquatic and terrestrial environments. The intimate relationship found between these insects and environmental variables means that they are often used as bioindicatorss in environmental studies. We tested the hypothesis that the loss of environmental integrity in tropical streams will lead to a loss of species and a decline in the abundance of mayflies (Leptophlebiidae), in addition to a change in species composition, and the dynamics of population. Collect immature leptophlebiids in 18 streams representing different DEGREES of conservation, in the Brazilian Cerrado. The environmental integrity of the sites was assessed using a Habitat Integrity Index (HII), which generates values of zero (degraded) to one (preserved), based on soil use, the extension and conservation of riparian forest, as well as morphological features of the stream. A total of 4945 immature leptophlebiids were collected and identified as belonging to 16 species or morphospecies. On an average, a reduction of 0.1 in the value of the HII led to the loss of five specimens and one species. The composition of the communities varied systematically along the environmental gradient, with more sensitive species being found only when the index was above a threshold of 0.6. The importance of the riparian vegetation for the aquatic biota, especially its role in the mitigation of impacts from the surrounding matrix, supports the universal conservation of this type of habitat.
Investigated how the loss of environmental integrity affects damselfly
species composition in ... more Investigated how the loss of environmental integrity affects damselfly
species composition in nine sites with different levels of environmental integrity in a
Cerrado-Amazon transition region known as “arc of deforestation” in Mato Grosso State,
Brazil. We also tested the influence of environmental variables on species composition.
Methods: We collected in transects of 100 m and used ordination (PCoA) and
simple linear regression. Results: Species composition was strongly influenced by the
environmental quality of sites, and the best model to explain species composition included
variables related to channel morphology. Conclusions: These results are connected to the
environmental homogenization and loss of environmental integrity as a result of extensive
agricultural practices which alter stream communities of dragonflies in this region.
We demonstrate that the distribution of the functional feeding groups of aquatic insects is relat... more We demonstrate that the distribution of the functional feeding groups of aquatic insects is related to hierarchical patch dynamics. Patches are sites with unique environmental and functional characteristics that are discontinuously distributed in time and space within a lotic system. This distribution predicts that the occurrence of species will be based predominantly on their environmental requirements. We sampled three streams within the same drainage basin in the Brazilian Cerrado savanna, focusing on waterfalls and associated habitats (upstream, downstream), representing different functional zones. We collected 2,636 specimens representing six functional feeding groups (FFGs): brushers, collector–gatherers, collector–filterers, shredders, predators, and scrapers. The frequency of occurrence of these groups varied significantly among environments. This variation appeared to be related to the distinct characteristics of the different habitat patches, which led us to infer that the hierarchical patch dynamics model can best explain the distribution of functional feeding groups in minor lotic environments, such as waterfalls.
Edge effect on the litter layer in a cerradão area of Eastern Mato Grosso, Brazil. ... more Edge effect on the litter layer in a cerradão area of Eastern Mato Grosso, Brazil. Vegetation
fragmentation causes edge effect, changing the microclimate, the species composition, and their biotic and abiotic
interactions. The litter layer is crucial for nutrient cycling in forests. This study aimed to check the influence of
vegetation edge on attributes of the litter layer in a cerradão area, testing the hypothesis that distance from the
edge is directly related to biomass and leaf proportion in the litter layer. Samples were collected from the litter
layer in 95m transects in 5 cerradão areas of eastern Mato Grosso, Brazil. We estimated a total of 6,724.44 kg/
ha -1 of litter, out of which 72.2% are leaves, 27.8% are branches, 0.07% is fruits, and 0.004% is flowers. Distance from the edge presented a positive and significant relation to thickness, dry weight, volume, and leaf fraction
mass of the litter. This information contributes to the understanding of a poorly studied component in cerradão
areas, showing that the fragmentation of these areas changes the structure of litter layer, and this may cause
losses to ecosystem functions and services, with possible future reflexes on the species diversity
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Papers by Leandro Brasil
studies. However, there are two main theories to discuss this topic, the niche theory and the
neutral theory. Our objective was to understand the importance of environmental and spatial
processes in structuring bird communities within the hydrological seasons in dry forest
areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da
Capivara and Serra das Confus õ es National Parks, where 36 areas were sampled in differ-
ent seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We
found with our results that bird species richness is higher in the rainy season and lower dur-
ing the dry season, indicating a strong influence of seasonality, a pattern also found for envi-
ronmental heterogeneity. Richness was explained by local environmental factors, while
species composition was explained by environmental and spatial factors. The environmen-
tal factors were more important in explaining variations in composition. Climate change pre-
dictions have currently pointed out frequent drought events and a rise in global temperature
by 2050, which would lead to changes in species behavior and to increasing desertification
in some regions, including the Caatinga. In addition, the high deforestation rates and the low
level of representativeness of the Caatinga in the conservation units negatively affects bird
communities. This scenario has demonstrated how climatic factors affect individuals, and,
therefore, should be the starting point for conservation initiatives to be developed in xeric
environments.
activities to biodiversity, especially given their rapid expansion, worldwide. Many cases of species loss have
already been recorded in Asian countries, although research is still incipient in the Amazon basin, and the
environmental impacts of these monocultures on freshwater ecosystems in the Neotropical region are still poorly
understood. The present study evaluated the e ff ects of oil palm plantations on the physical structure of stream
habitats and the resulting changes in the taxonomic and functional composition of aquatic insect communities. A
total of 2100 specimens of the orders Ephemeroptera, Plecoptera and Trichoptera were collected during the
present study, representing 40 genera and 16 families. The hypothesis tested was that the taxonomic and
functional diversity of the orders Ephemeroptera, Plecoptera and Trichoptera (Insecta) decreases in streams
surrounded by oil palm plantations in comparison with those embedded in forested areas. In the plantation
streams, the taxonomic richness and composition, and the functional richness are modi fi ed signi fi cantly.
Functional composition appeared unaltered despite reduced canopy cover associated with oil palm streams.
These e ff ects emphasize the importance of the riparian vegetation for the protection of the aquatic communities
found in oil palm plantations. The maintenance of the riparian vegetation may mitigate the impacts of plan-
tations, contributing to the conservation of insect communities and associated biodiversity.
ulis yulieae sp. nov. is recorded from the transitional area of Cerrado-Amazonia, Brazil.
species composition in nine sites with different levels of environmental integrity in a
Cerrado-Amazon transition region known as “arc of deforestation” in Mato Grosso State,
Brazil. We also tested the influence of environmental variables on species composition.
Methods: We collected in transects of 100 m and used ordination (PCoA) and
simple linear regression. Results: Species composition was strongly influenced by the
environmental quality of sites, and the best model to explain species composition included
variables related to channel morphology. Conclusions: These results are connected to the
environmental homogenization and loss of environmental integrity as a result of extensive
agricultural practices which alter stream communities of dragonflies in this region.
fragmentation causes edge effect, changing the microclimate, the species composition, and their biotic and abiotic
interactions. The litter layer is crucial for nutrient cycling in forests. This study aimed to check the influence of
vegetation edge on attributes of the litter layer in a cerradão area, testing the hypothesis that distance from the
edge is directly related to biomass and leaf proportion in the litter layer. Samples were collected from the litter
layer in 95m transects in 5 cerradão areas of eastern Mato Grosso, Brazil. We estimated a total of 6,724.44 kg/
ha -1 of litter, out of which 72.2% are leaves, 27.8% are branches, 0.07% is fruits, and 0.004% is flowers. Distance from the edge presented a positive and significant relation to thickness, dry weight, volume, and leaf fraction
mass of the litter. This information contributes to the understanding of a poorly studied component in cerradão
areas, showing that the fragmentation of these areas changes the structure of litter layer, and this may cause
losses to ecosystem functions and services, with possible future reflexes on the species diversity
studies. However, there are two main theories to discuss this topic, the niche theory and the
neutral theory. Our objective was to understand the importance of environmental and spatial
processes in structuring bird communities within the hydrological seasons in dry forest
areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da
Capivara and Serra das Confus õ es National Parks, where 36 areas were sampled in differ-
ent seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We
found with our results that bird species richness is higher in the rainy season and lower dur-
ing the dry season, indicating a strong influence of seasonality, a pattern also found for envi-
ronmental heterogeneity. Richness was explained by local environmental factors, while
species composition was explained by environmental and spatial factors. The environmen-
tal factors were more important in explaining variations in composition. Climate change pre-
dictions have currently pointed out frequent drought events and a rise in global temperature
by 2050, which would lead to changes in species behavior and to increasing desertification
in some regions, including the Caatinga. In addition, the high deforestation rates and the low
level of representativeness of the Caatinga in the conservation units negatively affects bird
communities. This scenario has demonstrated how climatic factors affect individuals, and,
therefore, should be the starting point for conservation initiatives to be developed in xeric
environments.
activities to biodiversity, especially given their rapid expansion, worldwide. Many cases of species loss have
already been recorded in Asian countries, although research is still incipient in the Amazon basin, and the
environmental impacts of these monocultures on freshwater ecosystems in the Neotropical region are still poorly
understood. The present study evaluated the e ff ects of oil palm plantations on the physical structure of stream
habitats and the resulting changes in the taxonomic and functional composition of aquatic insect communities. A
total of 2100 specimens of the orders Ephemeroptera, Plecoptera and Trichoptera were collected during the
present study, representing 40 genera and 16 families. The hypothesis tested was that the taxonomic and
functional diversity of the orders Ephemeroptera, Plecoptera and Trichoptera (Insecta) decreases in streams
surrounded by oil palm plantations in comparison with those embedded in forested areas. In the plantation
streams, the taxonomic richness and composition, and the functional richness are modi fi ed signi fi cantly.
Functional composition appeared unaltered despite reduced canopy cover associated with oil palm streams.
These e ff ects emphasize the importance of the riparian vegetation for the protection of the aquatic communities
found in oil palm plantations. The maintenance of the riparian vegetation may mitigate the impacts of plan-
tations, contributing to the conservation of insect communities and associated biodiversity.
ulis yulieae sp. nov. is recorded from the transitional area of Cerrado-Amazonia, Brazil.
species composition in nine sites with different levels of environmental integrity in a
Cerrado-Amazon transition region known as “arc of deforestation” in Mato Grosso State,
Brazil. We also tested the influence of environmental variables on species composition.
Methods: We collected in transects of 100 m and used ordination (PCoA) and
simple linear regression. Results: Species composition was strongly influenced by the
environmental quality of sites, and the best model to explain species composition included
variables related to channel morphology. Conclusions: These results are connected to the
environmental homogenization and loss of environmental integrity as a result of extensive
agricultural practices which alter stream communities of dragonflies in this region.
fragmentation causes edge effect, changing the microclimate, the species composition, and their biotic and abiotic
interactions. The litter layer is crucial for nutrient cycling in forests. This study aimed to check the influence of
vegetation edge on attributes of the litter layer in a cerradão area, testing the hypothesis that distance from the
edge is directly related to biomass and leaf proportion in the litter layer. Samples were collected from the litter
layer in 95m transects in 5 cerradão areas of eastern Mato Grosso, Brazil. We estimated a total of 6,724.44 kg/
ha -1 of litter, out of which 72.2% are leaves, 27.8% are branches, 0.07% is fruits, and 0.004% is flowers. Distance from the edge presented a positive and significant relation to thickness, dry weight, volume, and leaf fraction
mass of the litter. This information contributes to the understanding of a poorly studied component in cerradão
areas, showing that the fragmentation of these areas changes the structure of litter layer, and this may cause
losses to ecosystem functions and services, with possible future reflexes on the species diversity