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Insects are the most diverse animal taxon on Earth and play a key role in ecosystem functioning. However, they are often neglected by ecological surveys owing to the difficulties involved in monitoring this small and hyper-diverse taxon. With technological advances in biomonitoring and analytical methods, these shortcomings may finally be addressed. Here, we performed passive acoustic monitoring at 141 sites (eight habitats) to investigate insect acoustic activity in the Viruá National Park, Brazil. We first describe the frequency range occupied by three soniferous insect groups (cicadas, crickets and katydids) to calculate the acoustic evenness index (AEI). Then, we assess how AEI varies spatially and temporally among habitat types, and finally we investigate the relationship between vegetation structure variables and AEI for each insect category. Overall, crickets occupied lower and narrower frequency bands than cicadas and katydids. AEI values varied among insect categories and across space and time. The highest acoustic activity occurred before sunrise and the lowest acoustic activity was recorded in pastures. Canopy cover was positively associated with cricket acoustic activity but not with katydids. Our findings contribute to a better understanding of the role of time, habitat and vegetation structure in shaping insect activity within diverse Amazonian ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

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This paper starts by presenting an empirical finding in the U.S. stock market: Between 2001 and 2021, high productivity was achieved when the Shannon evenness-measuring the inverse of concentration-dropped. Conversely, when the Shannon evenness soared, productivity plunged. The same inverse relationship between evenness and productivity has been observed in several ecosystems. This suggests explaining this result by adopting the business ecosystem perspective, i.e., regarding the tangle of interactions between companies as an ecological network, in which companies play the role of species. A useful strategy to model such ecological communities is through ensembles of synthetic communities of pairwise interacting species, whose dynamics is described by the Lotka-Volterra generalized equations. Each community is specified by a random interaction matrix whose elements are drawn from a uniform distribution centered around 0. It is shown that the inverse relationship between productivity and evenness can be generated by varying the strength of the interaction between companies. When the strength increases, productivity increases and simultaneously the market evenness decreases. Conversely, when the strength decreases, productivity decreases and evenness increases. This strength can be interpreted as reflecting the looseness of monetary policy, thus providing a link between interest rates and market structure.

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Given the importance of species diversity as a tool for assessing recovery during forest regeneration and active restoration, robust approaches for assessing changes in tree species diversity over time are urgently needed. We assessed changes in tree species diversity during natural regeneration over 12-20 years in eight 1-ha monitoring plots in NE Costa Rica, six second-growth forests and two old-growth reference forests. We used diversity profiles to show successional trajectories in measures of observed, asymptotic and standardized tree diversity and evenness as well as sample completeness. We randomly subsampled 1-ha plot data to evaluate how well smaller spatial subsamples would have captured temporal trajectories. Annual surveys in eight 1-ha plots were missing substantial numbers of rare or infrequent species. Older second-growth sites showed consistent declines in tree diversity, whereas younger sites showed fluctuating patterns or increases. Subsample areas of 0.5 ha or greater were sufficient to infer the diversity of abundant species, but smaller subsamples failed to capture temporal trajectories of species richness and yielded positively biased estimates of evenness. In tropical forest regions with high levels of diversity, species diversity from small sample plots should be assessed using methods that incorporate abundance information and that standardize for sample coverage. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.

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Reef fish play an important role in the community dynamics of coral reefs and maintaining healthy reefs. This study aimed to (1) assess coral recovery at reefs around Racha Yai Island after the 2010 mass coral bleaching event and (2) compare the fish community indices (Shannon diversity, evenness) and fish trophic functional groups between low (Patok Bay) and high (Khonkae Bay) environmental disturbance sites during 2013-2019. The fish surveys and the percent live coral covers from both bays during 2013-2019 were collected using the fish visual census method and a permanent quadrat method along 50-m transect lines. Our results showed that the percentage of live coral cover at both bays increased by 6-8%. At Khonkae Bay, there were 69 reef fish species and 10,684 individual fish belonging to 5 orders, with 27 families and 54 genera observed from 7 orders: Perciformes (91.03%), Tetraodontiformes (5.54%), Syngnathiformes (1.24%), Beloniformes (0.26%), Beryciformes (1.25%), Scorpaeniformes (0.70%), and Aulopiformes (0.06%). Fish community indices at Khonkae Bay increased during 2013-2019 and were composed of species richness (3.65-10.53), the Shannon index (0.65-3.49), and species evenness (0.49-0.91). At Patok Bay, there were 60 reef fish species and 10,362 individual fish belonging to 3 orders, with 22 families and 50 genera observed from 4 orders: Perciformes (93.04%), Tetraodontiformes (5.92%), Syngnathiformes (0.55%), and Anguilliformes (0.53%). Fish community indices at Patok Bay increased during 2014-2019 and were composed of species richness (4.69-8.62), the Shannon index (1.36-3.30), and species evenness (4.92-8.62). Our results suggested that the 2010 mass coral bleaching event had large impacts on both the coral and reef fish community at both low and high environmental disturbance sites with good recovery over nine years.

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Reef fish play an important role in the community dynamics of coral reefs and maintaining healthy reefs. This study aimed to (1) assess coral recovery at reefs around Racha Yai Island after the 2010 mass coral bleaching event and (2) compare the fish community indices (Shannon diversity, evenness) and fish trophic functional groups between low (Patok Bay) and high (Khonkae Bay) environmental disturbance sites during 2013-2019. The fish surveys and the percent live coral covers from both bays during 2013-2019 were collected using the fish visual census method and a permanent quadrat method along 50-m transect lines. Our results showed that the percentage of live coral cover at both bays increased by 6-8%. At Khonkae Bay, there were 69 reef fish species and 10,684 individual fish belonging to 5 orders, with 27 families and 54 genera observed from 7 orders: Perciformes (91.03%), Tetraodontiformes (5.54%), Syngnathiformes (1.24%), Beloniformes (0.26%), Beryciformes (1.25%), Scorpaeniformes (0.70%), and Aulopiformes (0.06%). Fish community indices at Khonkae Bay increased during 2013-2019 and were composed of species richness (3.65-10.53), the Shannon index (0.65-3.49), and species evenness (0.49-0.91). At Patok Bay, there were 60 reef fish species and 10,362 individual fish belonging to 3 orders, with 22 families and 50 genera observed from 4 orders: Perciformes (93.04%), Tetraodontiformes (5.92%), Syngnathiformes (0.55%), and Anguilliformes (0.53%). Fish community indices at Patok Bay increased during 2014-2019 and were composed of species richness (4.69-8.62), the Shannon index (1.36-3.30), and species evenness (4.92-8.62). Our results suggested that the 2010 mass coral bleaching event had large impacts on both the coral and reef fish community at both low and high environmental disturbance sites with good recovery over nine years.(AU)

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Avaliou-se o uso da análise fractal como ferramenta na determinação de padrões na escala de pastejo em pastagens naturais submetidas a diferentes manejos. Os tratamentos testados em Santa Maria foram: pastejo com queima, pastejo sem queima, exclusão com queima, exclusão sem queima. Em Bagé, os tratamentos avaliados foram: pastagem natural e pastagem natural com introdução de azevém, trevo-branco e cornichão. A caracterização da composição florística da pastagem foi realizada pelo método Botanal. A diversidade da pastagem foi calculada pelos índices de Shannon (H') e equitabilidade. A informação da dimensão fractal foi calculada pela regressão entre H'(ε) e o logaritmo natural de ε, sendo a inclinação da linha a informação da dimensão fractal. Os índices de Shannon e equitabilidade demonstraram dependência em relação à área amostral, onde a maior diversidade florística e a homogeneidade da frequência de distribuição de plantas entre espécies foram observadas no intervalo amostral de 0,87 e 1,03m2. A dimensão fractal pode ser uma ferramenta na determinação de padrões na comunidade vegetal na escala reduzida de pastejo. A limitação do emprego dessa técnica para escalas reduzidas é a necessidade de um número maior de repetições.(AU)

The use of fractal analysis was evaluated as a tool in the determination of grazing patterns in natural grasslands submitted to different managements. The treatments tested in Santa Maria were grazing with burning, grazing without burning, exclusion with burning and exclusion without burning. In Bagé, the evaluated treatments were natural pasture and introduction of ryegrass, white clover and birdsfoot trefoil in a natural grassland. The characterization of the floristic composition of the pasture was performed by the BOTANAL method. The pasture diversity was calculated by Shannon (H') and Evenness (J) indexes. The fractal dimension information was calculated by regression between H'(ε) and ε natural algorithm, with the line's slope being the fractal dimension information. Shannon and Evenness indexes showed dependence on the sample area, where the highest floristic diversity and homogeneity of the distribution frequency of plants between species were observed in the sample range of 0.87 to 1.03m2. The fractal dimension can be a tool in determining patterns in the plant community on the reduced grazing scale. The limitation of the use of this technique for reduced scales is the need for a greater number of repetitions.(AU)

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Avaliou-se o uso da análise fractal como ferramenta na determinação de padrões na escala de pastejo em pastagens naturais submetidas a diferentes manejos. Os tratamentos testados em Santa Maria foram: pastejo com queima, pastejo sem queima, exclusão com queima, exclusão sem queima. Em Bagé, os tratamentos avaliados foram: pastagem natural e pastagem natural com introdução de azevém, trevo-branco e cornichão. A caracterização da composição florística da pastagem foi realizada pelo método Botanal. A diversidade da pastagem foi calculada pelos índices de Shannon (H') e equitabilidade. A informação da dimensão fractal foi calculada pela regressão entre H'(ε) e o logaritmo natural de ε, sendo a inclinação da linha a informação da dimensão fractal. Os índices de Shannon e equitabilidade demonstraram dependência em relação à área amostral, onde a maior diversidade florística e a homogeneidade da frequência de distribuição de plantas entre espécies foram observadas no intervalo amostral de 0,87 e 1,03m2. A dimensão fractal pode ser uma ferramenta na determinação de padrões na comunidade vegetal na escala reduzida de pastejo. A limitação do emprego dessa técnica para escalas reduzidas é a necessidade de um número maior de repetições.(AU)

The use of fractal analysis was evaluated as a tool in the determination of grazing patterns in natural grasslands submitted to different managements. The treatments tested in Santa Maria were grazing with burning, grazing without burning, exclusion with burning and exclusion without burning. In Bagé, the evaluated treatments were natural pasture and introduction of ryegrass, white clover and birdsfoot trefoil in a natural grassland. The characterization of the floristic composition of the pasture was performed by the BOTANAL method. The pasture diversity was calculated by Shannon (H') and Evenness (J) indexes. The fractal dimension information was calculated by regression between H'(ε) and ε natural algorithm, with the line's slope being the fractal dimension information. Shannon and Evenness indexes showed dependence on the sample area, where the highest floristic diversity and homogeneity of the distribution frequency of plants between species were observed in the sample range of 0.87 to 1.03m2. The fractal dimension can be a tool in determining patterns in the plant community on the reduced grazing scale. The limitation of the use of this technique for reduced scales is the need for a greater number of repetitions.(AU)

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Habitat loss or degradation due to land cover change is regarded as one of the main drivers of amphibian decline; therefore, it is imperative to assess the effects of land-cover change on this group of vertebrates. In this study, we analyze changes in alpha and beta diversity of amphibian communities found in five land-cover types: mountain cloud forest, tropical evergreen forest, shade coffee, milpa huasteca, and grazing areas; six samples sites were established for each land-cover type, separated at least one km away. The study was conducted in the northwest part of the state of Hidalgo, in a transition zone between the Sierra Madre Oriental and the Gulf of Mexico, which is a region rich in amphibian species. The results indicate that alpha diversity decreases with loss of canopy cover, this being high in mountain cloud forest, tropical evergreen forest, and Shade coffee, and low in milpa huasteca and grazing areas. The land-cover type with the highest species evenness was found in milpa huasteca and the lowest in. The highest beta diversity was observed among tropical evergreen forest and grazing areas. Mountain cloud forest contains both exclusive species and the highest number of species currently regarded as threatened by national and international conservation assessment systems. In order to preserve amphibian diversity in the study area it is vital to protect the last remnants of native vegetation, especially mountain cloud forest, but also including Shade coffee, since the latter habitat harbors amphibian diversity similar to that found in native forests. Finally, implementation of policies that both reduce Grazing areas and increase their productivity is also necessary, since these highly modified areas turn out to be the ones that affect amphibian diversity the most.

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Abstract The application of gap dynamics theory appears to be a promising option for tropical forest management and conservation. In the present study of a tree species-rich and old-growth Ecuadorian Neotropical forest, we assessed the spatial distribution of gaps and gap size in relation to: i) tree number at the gap edge, ii) number of tree species at the gap edge, iii) number of tree species per stem at the gap edge, iv) species similarity, v) species evenness at the gap edge, vi) size differentiation at the gap edge, vii) gap isolation and viii) species mingling at the gap edge. Our results demonstrated that the spatial distribution of gaps was random. Various gap attributes were strongly associated with gap size. The number of tree species per stem at the gap edge was negatively correlated to the gap size. Gap sizes up to 50 m2were mostly sufficient to generate tree species-rich forest stands. Assuming that our results were representative for an old-growth neotropical rainforest in Ecuador, our study remarks the following management recommendations: 1) Rainforests have a very complex spatial and diversity structure and logging activities should preferably be omitted because of adverse effects. 2) If logging is inevitable, this should mimic a random choice of trees and tree species, to prevent special selection of tree dimension and species; and a random distribution of trees to be logged, to produce gaps smaller than 50 m2and never larger than 400 m2. Additionally, we suggest cutting not more than 5 % of the tree biomass per 10-20 years period, to preclude stronger alterations of ecosystem processes, and the reduction of existing dead wood from the ecosystem. Rev. Biol. Trop. 66(1): 149-163. Epub 2018 March 01.

Resumen Aplicar la teoría de la dinámica de parches parece ser una opción prometedora para el manejo y conservación de los bosques tropicales. En el presente estudio se analizó la distribución espacial y el tamaño de los parches en relación con: i) el número de árboles en el borde del parche, ii) el número de especies arbóreas en el parche iii) número de especies arbóreas por tronco en el borde del parche, iv) similitud de las especies, v) uniformidad de las especies en el borde del parche, vi) separación del tamaño en el borde del parche, vii) aislamiento del parche y viii) borde del parche. Nuestros resultados demostraron que la distribución espacial de los parches fue aleatoria. Varios atributos de la vegetación se asociaron fuertemente con el tamaño del parche. El número de especies de árboles por fuste en el borde del parche se correlacionó negativamente con el tamaño del parche. Asumiendo que, nuestros resultados fueron representativos de un bosque neotropical en el Ecuador, nuestro estudio respalda las siguientes recomendaciones: 1) Este tipo de bosque húmedo tiene una diversidad espacial y estructural muy compleja; por lo tanto, las actividades de explotación forestal deberían omitirse, ya que afectarán negativamente sus estructuras. 2) Si la tala es inevitable, entonces deberían imitarse las estructuras naturales descritas en este estudio. Es decir, i) una selección aleatoria de especies de árboles a cosechar, con el fin de evitar la selección específica por dimensiones del arbolado o por especies, ii) en la distribución aleatoria de árboles debe tomarse en cuenta que los parches sean menores a 50 m2y jamás mayores a 400 m2. Adicionalmente, se recomienda no cortar más del 5 % de la biomasa arbórea en cada período de corta de entre 10 a 20 años, para evitar alteraciones mayores en los procesos del ecosistema y la reducción de madera muerta existente en estos ecosistemas.

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The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia), middle stretch (Olaria), just above the falls (Paiquerê) and downstream (Foz). Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff paranae Eigenmann,1914 (78% of the total) was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to problems related to the conservation and management of the basin.(AU)

A construção de reservatórios é considerada importante fonte de impactos para a fauna de peixes, levando a alterações significativas na estrutura da assembleia. Considerando isso, esse artigo objetiva descrever a estrutura da assembleia de peixes do rio Goioerê, determinando sua distribuição longitudinal e padrões na dominância das espécies. A avaliação da variação longitudinal na diversidade e abundância da assembleia de peixes neste rio foi conduzida em julho e outubro de 2004 e janeiro e maio de 2005. As coletas foram realizadas próximas as nascentes (Gurucaia), no segmento médio (Olaria), logo acima do salto Paiquerê (Paiquerê) e na foz do rio (Foz). Foram registradas 44 espécies. A assembleia de peixes de Gurucaia diferiu significativamente de Olaria, Paiquerê e Foz. A assembleia de Olaria diferiu significativamente de Foz. Gurucaia apresentou a menor diversidade e abundância de espécies. Astyanax aff. paranae Eigenmann,1914 (78% do total) foi dominante nesta localidade. Em Olaria e Paiquerê foi encontrada grande similaridade na riqueza de espécies, no entanto, em Olaria registrou-se a maior abundância de indivíduos. Astyanax aff. paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 foram as três espécies dominantes de topo e compreenderam cerca de 71% do total de peixes capturados. Na localidade Paiquerê, A. altiparanae, Hypostomus aff. ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 compuseram 58% das capturas. Trinta e uma espécies foram registradas na Foz, que apresentou a maior riqueza. As espécies mais abundantes foram Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A. altiparanae, as quais contribuíram com 50% das capturas totais neste ambiente. Estes resultados registram a biodiversidade de peixes e como esta comunidade se estrutura longitudinalmente no rio Goioerê, além de demonstrar a importância desse tipo de avaliação para a compreensão dos padrões das comunidades de peixes e para a busca de soluções para problemas relacionados à conservação e o manejo desta bacia.(AU)

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O objetivo do trabalho foi realizar o levantamento fitossociológico da comunidade arbustivo-arbórea em área de Cerrado sentido restrito na Área de Proteção de Manancial Mestre D'Armas, em Planaltina, Distrito Federal. Para isso foram instaladas 10 parcelas aleatórias de 1.000 m2 (20 x 50 m) e identificados e medidos todos os indivíduos lenhosos (Db30 cm) 5 cm. Os valores de riqueza (75 espécies/51 gêneros/34 famílias), de diversidade de Shannon (3,39) e de equabilidade (0,85) estão na faixa de variação encontrados em outros estudos realizados no Brasil Central e refletem alta diversidade na área estudada. Foram registrados 960 indivíduos/ha e uma área basal total de 8,61 m2/ha. As dez espécies mais importantes (Miconia burchellii, Qualea parviflora, Roupala montana, Kielmeyera coriaceae, Annona crassiflora, Miconia ferruginea, Vochysia thyrsoidea, Miconia albicans, Erythoxylum suberosum e Rapanea guianensis) corresponderam 59% da densidade total, 50% do IVI total e 61% da área basal da comunidade. Assim, essas são as espécies que representam a estrutura principal do Cerrado sentido restrito no presente trabalho. Miconia burchellii ocorreu com a maior densidade (180 ind.ha-1) já registrada para a espécie no Brasil Central. Os resultados contribuem para aumentar o conhecimento sobre a fisionomia Cerrado sentido restrito e indicam que o fragmento está em bom estado de conservação, de acordo com o índice de diversidade. Essa área é importante no contexto do Distrito Federal, uma vez que forma elos entre os fragmentos remanescentes, o Parque Nacional de Brasília e a Estação Ecológica de Águas Emendadas.

This study aimed to describe the floristic composition, diversity and community structure of woody community in Cerrado sensu stricto in the Área de Proteção de Manancial Mestre D'Armas, Distrito Federal, Brazil. Ten random plots (20 x 50 m) were installed and identified and measured all the individuals with diameter (Dh30 cm) 5 cm. The results showed richness (75 species/51 genus/34 family), Shannon diversity (3.39 nats. nats.ind-1) and evenness (0.85) reflect high diversity in the studied area and similar to the range of variation found in other studies in Central Brazil. In this study were registered 960 individuals/ha and 8.61 m2/ha of basal area. The ten most important species (Miconia burchellii, Qualea parviflora, Roupala montana, Kielmeyera coriaceae, Annona crassiflora, Miconia ferruginea, Vochysia thyrsoidea, Miconia albicans, Erythoxylum suberosum and Rapanea guianensis) accounted for 59% of the total density, 50% of the IVI and 61% of the basal area of the community. So, these are the species that represent the main structure of Cerrado stricto sensu in that area. Miconia burchellii occurred with the highest density (180 ind.ha-1) ever recorded for the species in Central Brazil. The results contribute to increase the knowledge about the physiognomy Cerrado stricto sensu and indicate that the fragment is in good condition, and it is important in the context of the Federal District, once that form links between the remaining fragments, the Parque Nacional de Brasília and the Estação Ecológica de Águas Emendadas.

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The construction of reservoirs is considered an important source of impacts on the fish fauna, severely altering the structure of the assemblage. This paper aimed to describe the structure of the fish assemblage of the Goioerê River, determining its longitudinal distribution and patterns of species dominance. The evaluation of its longitudinal variation in the diversity and abundance of the fish assemblage was conducted in July and October 2004 and January and May 2005. The collections were carried out near the headwaters (Gurucaia), middle stretch (Olaria), just above the falls (Paiquerê) and downstream (Foz). Forty-four species were captured. The Gurucaia fish assemblages differed significantly from Olaria, Paiquerê and Foz. The Olaria assemblages differed significantly from the Foz. Gurucaia showed the lowest diversity and abundance of species. Astyanax aff paranae Eigenmann,1914 (78% of the total) was found to be dominant at this site. Almost the same species richness was found at Olaria and Paiquerê, although Olaria had the greatest abundance of individuals. Astyanax aff paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 were the top three dominants and comprised over 71% of the total number of fish caught. At Paiquerê, Astyanax altiparanae, Hypostomus aff ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 composed 58% of the catches. Thirty-one species were recorded at Foz, which presented the greatest richness. The most abundant species were Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A.altiparanae, which contributed to 50% of the total catches in this environment.These results record the fish biodiversity and how the community is longitudinally structured in the Goioerê River, and also demonstrate how this type of evaluation is important to understanding the fish community patterns and finding solutions to problems related to the conservation and management of the basin.

A construção de reservatórios é considerada importante fonte de impactos para a fauna de peixes, levando a alterações significativas na estrutura da assembleia. Considerando isso, esse artigo objetiva descrever a estrutura da assembleia de peixes do rio Goioerê, determinando sua distribuição longitudinal e padrões na dominância das espécies. A avaliação da variação longitudinal na diversidade e abundância da assembleia de peixes neste rio foi conduzida em julho e outubro de 2004 e janeiro e maio de 2005. As coletas foram realizadas próximas as nascentes (Gurucaia), no segmento médio (Olaria), logo acima do salto Paiquerê (Paiquerê) e na foz do rio (Foz). Foram registradas 44 espécies. A assembleia de peixes de Gurucaia diferiu significativamente de Olaria, Paiquerê e Foz. A assembleia de Olaria diferiu significativamente de Foz. Gurucaia apresentou a menor diversidade e abundância de espécies. Astyanax aff. paranae Eigenmann,1914 (78% do total) foi dominante nesta localidade. Em Olaria e Paiquerê foi encontrada grande similaridade na riqueza de espécies, no entanto, em Olaria registrou-se a maior abundância de indivíduos. Astyanax aff. paranae, Cyphocharax modestus (Fernández-Yépez, 1948) and Astyanax altiparanae Garutti & Britski, 2000 foram as três espécies dominantes de topo e compreenderam cerca de 71% do total de peixes capturados. Na localidade Paiquerê, A. altiparanae, Hypostomus aff. ancistroides (Ihering, 1911) and Loricariichthys platymetopon Isbrücker & Nijssen, 1979 compuseram 58% das capturas. Trinta e uma espécies foram registradas na Foz, que apresentou a maior riqueza. As espécies mais abundantes foram Apareiodon affinis (Steindachner, 1879), Galeocharax knerii (Steindachner, 1879) and A. altiparanae, as quais contribuíram com 50% das capturas totais neste ambiente. Estes resultados registram a biodiversidade de peixes e como esta comunidade se estrutura longitudinalmente no rio Goioerê, além de demonstrar a importância desse tipo de avaliação para a compreensão dos padrões das comunidades de peixes e para a busca de soluções para problemas relacionados à conservação e o manejo desta bacia.

Assuntos

RESUMO

O presente estudo investiga a fauna de califorídeos na Reserva Biológica do Tinguá usando como meios os índices faunísticos. Realizaram-se coletas mensais com armadilhas contendo sardinha expostas por 48 horas, nos pontos: A- borda da mata; B- 1000 metros para interior da mata; C- 500 metros para interior da mata. Objetivou-se estudar a entomofauna califorídica em ambiente florestal através de índices faunísticos. Foram coletadas 26 espécies de califorídeos ao longo do experimento. Definiram-se espécies Singletons, Doubletons, Uniques e Duplicates, intermediárias e comuns; calcularam-se riqueza e projeção da riqueza (estimadores Chao 1 e 2, Jackknife 1 e 2, Ace, Ice e Bootstrap); diversidade (Índice Shannon-Wiener); equidade (Índice Pielou) e similaridade dos pontos (quociente Sorensen e porcentagem de similaridade Southwood). Os pontos A e B mostraram o mesmo número de espécies de califorídeos (23), maior que C (16), diferindo apenas nas espécies raras, intermediárias e comuns. Em A foi registrado grande número de espécies consideradas intermediárias. Em B o número de espécies raras, intermediárias e comuns foi similar. Em C, o número de espécies raras foi menor que de intermediárias e comuns. Jackknife 2 no ponto B gerou a maior riqueza, indicando possibilidade de serem coletadas mais cinco espécies na reserva além das coletadas neste estudo, e em A e C mais três espécies. Ace e Bootstrap apresentaram-se seguros para estimativa de riqueza de Calliphoridae. A diversidade foi maior em B. A equidade foi semelhante nos pontos. B e C foram mais semelhantes em relação às espécies (dendograma): Laneela nigripes e Mesembrinella bellardiana, principais destes dois pontos aparecem agrupadas; Chrysomya albiceps, Chrysomya megacephala e Hemilucilia semidiaphana, principais espécies em A aparecem unidas.

The present study investigates the calliphorid fauna in the Biological Reserve of Tinguá using faunistic indices. Monthly samplings were carried out using traps containing sardines that were exposed for 48 hours at the sites: A, at the border of the forest; B, 1,000 m towards the interior of the forest; and C, 500 m towards the interior of the forest. The objective was to study the Calliphoridae fauna in forest environments using faunal indices. During the course of the experiment, 26 calliphorid species were collected. The species Singletons, Doubletons, Uniques, Duplicates, intermediate and common were defined. Richness and richness estimation (estimators Chao 1 and 2, Jackknife 1 and 2, Ace, Ice and Bootstrap), diversity (Shannon-Wiener index), evenness (Pielou's index), and similarity of the sites (using the Sorensen coefficient and the Southwood percent similarity) were calculated. Sites A and B had the same number of species of Calliphoridae (23), representing a greater richness than site C (16). The sites differed only in their rare, intermediate and common species composition. The greatest number of intermediate species was found at A. At B, the numbers of rare, intermediate and common species were similar. At C, there were fewer rare species than intermediate and common ones. Jackknife 2 at site B produced a higher value, however, indicating that it was possible to collect five other species in the reserve and three more species at A and C. Diversity was greatest at B, but evenness was similar at the sites. B and C showed a greater level of similarity in species composition (dendogram); L. nigripes and Mesembrinella bellardiana, which are the most important species at these two sites, appeared grouped together. Chrysomya albiceps, Chrysomya megacephala and Hemilucilia semidiaphana, the main species at Site A, also appear together.

RESUMO

The benthic fauna plays an important role in the trophic web and the nutrient flow of limnetic environments. This work aimed to study the diversity and abundance of the benthic invertebrates in four watercourses in the central region of the state of Rio Grande do Sul, Brazil. Sampling was done seasonally at each site, with a long-handled net at the margins (banks) and streambed, from November 2001 through September 2002. Margalef richness, Shannon diversity and Pielou evenness indices were applied to the data analysis. A total of 58 families and three other major taxa (Hirudinea, Oligochaeta and Copepoda) of invertebrates were identified. The highest values of diversity and abundance were recorded at the margins of the rivers, in the same pattern found in other tropical and subtropical regions. This is the first inventory of benthic invertebrates from central region of Rio Grande do Sul, which will be important for future studies of the diversity and conservation of this fauna, because human alterations of the environment have already begun.

A fauna bentônica tem um importante papel nos ambientes límnicos, fazendo parte da cadeia trófica e participando do fluxo de nutrientes. O objetivo deste trabalho foi estudar a diversidade e a abundância dos invertebrados bentônicos em quatro cursos de água da região central do Estado do Rio Grande do Sul, Brasil. Amostragens foram realizadas sazonalmente com uma rede de mão (puçá) nas margens e nos leitos dos arroios em cada local de coleta, entre Novembro de 2001 e Setembro de 2002. Para analisar os dados foram aplicados os índices de riqueza de Margalef, diversidade de Shannon e uniformidade de Pielou. Um total de 58 famílias e três outros grandes taxa (Hirudinea, Oligochaeta e Copepoda) de invertebrados foram identificados. Os maiores valores de diversidade e abundância foram encontrados nas margens dos arroios, seguindo um padrão verificado para regiões tropicais e subtropicais. Este é o primeiro inventário de invertebrados bentônicos da região central do Estado Rio Grande do Sul, e servirá de base para futuros estudos sobre a diversidade e a conservação dessa fauna frente às alterações antrópicas no ambiente.

Assuntos