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1.
Environ Monit Assess ; 193(10): 686, 2021 Oct 02.
Article in English | MEDLINE | ID: mdl-34599687

ABSTRACT

Biological inventories combined with the estimation of species richness represent a useful tool for the analysis of the pattern of species distribution in different regions. This study aimed to (i) comparatively evaluate the performance of non-parametric richness estimators for invertebrate inventories in reservoirs between ecoregions and (ii) to assess whether the efficiency (bias, precision and accuracy indices) of the estimators is altered when applied to sites from different ecoregions. The study was conducted in the ecoregions Central Pediplano of the Borborema Plateau (Paraíba River basin) and Northern Sertaneja Depression (Piranhas-Assu River basin), semiarid region of Brazil. Six reservoirs were selected and benthic macroinvertebrates were sampled at 141 sites distributed along the littoral zone, in 4 periods (June, September, December 2014 and March 2015). The organisms were identified to the family level, except for Chironomidae, identified to the genus level. We comparatively analyzed six non-parametric richness estimators: Jackknife 1, Jackknife 2, Chao1, Chao 2, ICE, and Bootstrap, and three performance indicators: bias, precision, and accuracy. ICE and Jackknife 2 had more stable results for total species richness, but with different performance between ecoregions for bias, precision, and accuracy. Variation in performance of the estimators may be associated with differences in species richness and frequency between ecoregions. ICE and Jackknife 2 proved to be the best estimators for biological inventories of aquatic invertebrates in reservoirs in studies comparing data from different ecoregions, due to accuracy and precision, while Bootstrap is the least indicated, given greater bias and less accuracy and precision.


Subject(s)
Chironomidae , Environmental Monitoring , Animals , Brazil , Invertebrates , Rivers
2.
BMC Ecol ; 17(1): 45, 2017 Dec 22.
Article in English | MEDLINE | ID: mdl-29273049

ABSTRACT

BACKGROUND: The species pool concept was formulated over the past several decades and has since played an important role in explaining multi-scale ecological patterns. Previous statistical methods were developed to identify species pools based on broad-scale species range maps or community similarity computed from data collected from many areas. No statistical method is available for estimating species pools for a single local community (sampling area size may be very small as ≤ 1 km2). In this study, based on limited local abundance information, we developed a simple method to estimate the area size and richness of a species pool for a local ecological community. The method involves two steps. In the first step, parameters from a truncated negative trinomial model characterizing the distributional aggregation of all species (i.e., non-random species distribution) in the local community were estimated. In the second step, we assume that the unseen species in the local community are most likely the rare species, only found in the remaining part of the species pool, and vice versa, if the remaining portion of the pool was surveyed and was contrasted with the sampled area. Therefore, we can estimate the area size of the pool, as long as an abundance threshold for defining rare species is given. Since the size of the pool is dependent on the rarity threshold, to unanimously determine the pool size, we developed an optimal method to delineate the rarity threshold based on the balance of the changing rates of species absence probabilities in the sampled and unsampled areas of the pool. RESULTS: For a 50 ha (0.5 km2) forest plot in the Barro Colorado Island of central Panama, our model predicted that the local, if not regional, species pool for the 0.5 km2 forest plot was nearly the entire island. Accordingly, tree species richness in this pool was estimated as around 360. When the sampling size was smaller, the upper bound of the 95% confidence interval could reach 418, which was very close to the flora record of tree richness for the island. A numerical test further demonstrated the power and reliability of the proposed method, as the true values of area size and species richness for the hypothetical species pool have been well covered by the 95% confidence intervals of the true values. CONCLUSIONS: Our method fills the knowledge gap on estimating species pools for a single local ecological assemblage with little information. The method is statistically robust and independent of sampling size, as proved by both empirical and numerical tests.


Subject(s)
Ecosystem , Trees/classification , Ecology , Forests , Models, Biological , Panama , Population Dynamics
3.
Anal Bioanal Chem ; 409(11): 3017-3024, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28251293

ABSTRACT

This work presents a new method for forward variable selection and calibration and its evaluation for manganese determination in steel by laser-induced breakdown spectroscopy (LIBS). A compact and low-cost LIBS instrument was used, based on a microchip laser and a grating mini-spectrometer containing a non-intensified, non-gated, and non-cooled linear sensor array. Sixty steel samples were analyzed, with known manganese concentrations from 0.106 to 1.696 wt%. The spectra (1757 variables between 200 and 850 nm) were acquired under the continuous application of laser pulses at 100 Hz and using 80, 400, and 1000 ms integration times. The new method generated a mathematic combination of the selected variables and the results were calibrated against the manganese content by linear or quadratic regression. The best results were obtained using the spectra from all integration times together, with 31 selected variables and root mean square errors of cross-validation and prediction of 0.015 and 0.033, respectively. Compared to Jack-knife partial least squares regression, the new method presented lower prediction errors and numbers of selected variables, with the advantages of no data pretreatment and a simpler mathematic calculation. Graphical abstract New method for forward variable selection and calibration applied to manganese determination in steel by laser induced breakdown spectroscopy.

4.
Rev. biol. trop ; Rev. biol. trop;64(2): 821-836, abr.-jun. 2016. tab, ilus
Article in Spanish | LILACS | ID: biblio-843316

ABSTRACT

ResumenLa captura de la jaiba azul (Callinectes sapidus) es una de las principales del Estado de Tamaulipas, México, tanto por su volumen y precio de venta, como por la generación de empleo, pero se cuenta con escasa información de sus características biológicas. El objetivo del presente estudio fue evaluar los parámetros de crecimiento de la jaiba azul, estableciendo el método más adecuado para realizarlo. Se estimó la frecuencia de tallas de 17 814 jaibas de muestreos realizados de enero a junio 2009, provenientes de la captura comercial de trece localidades, comprendidas en cuatro lagunas costeras: Laguna El Barril, Laguna Madre, Laguna de Morales y Laguna de San Andrés. Los parámetros de crecimiento se estimaron usando los métodos indirectos ELEFAN, PROJMAT y SLCA en combinación con la técnica jackknife para establecer la incertidumbre de las estimaciones inherentes a cada método. Los parámetros de crecimiento L∞ y k se unificaron para efectos comparativos mediante el índice de crecimiento phi prima (Φ’). Con una moda de 110 mm, el intervalo de longitud de caparazón varió entre 60 y 205 mm. Los valores de los parámetros de crecimiento variaron de acuerdo al método utilizado. Utilizando SLCA, L∞ varió entre 259 y 260 mm y k osciló entre 0.749 y 0.750/año; con PROJMAT, L∞ registró valores entre 205 y 260 mm y k fluctuó entre 0.550 y 0.740/año, y con ELEFAN, L∞ osciló entre 156 y 215 mm y k varió entre 0.479 y 0.848/año. Las estimaciones mediante jackknife detectaron nula variabilidad en Φ’ entre localidades y diferencias significativas entre métodos. Los rangos de valores de Φ’ estimados por SLCA y PROJMAT (4.70 a 4.71 y 4.66 a 4.70, respectivamente) se ubicaron en el rango reportado por la literatura (4.201-4.798), mientras que ELEFAN aportó valores significativamente menores (3.87 a 4.27). Los métodos SLCA y PROJMAT en combinación con la técnica jackknife, resultaron ser los más adecuados para estimar los parámetros de crecimiento de C. sapidus.


AbstractThe capture blue crab (Callinectes sapidus) is one of the major fisheries of the state of Tamaulipas, Mexico; both in volume and selling price, as well as employment generation, but there is little information on its biological characteristics. The aim of this study was to evaluate the growth parameters of the blue crab, establishing the most appropriate method. We estimated the length frequency of 17 814 crabs from commercial catch of thirteen locations, including four coastal lagoons. The lagoons were El Barril, Madre, Morales and San Andrés from Tamaulipas, State. Growth parameters were evaluated using indirect methods ELEFAN, PROJMAT and SLCA in combination with the jackknife technique to establish the uncertainty of estimates inherent in each method. The growth parameters L∞ and k were consolidated for purposes of comparison with the growth index phi prime (Φ’). With a mode of 110 mm, the interval carapace length varied between 60 and 205 mm. The values of the growth parameters varied according to the method used. Using SLCA, L∞ varied between 259 and 260 mm and k ranged between 0.749 and 0.750 /year; with PROJMAT, L∞ recorded values between 205 and 260 mm, k fluctuated between 0.550 and 0.740/year, and with ELEFAN, L∞ ranged between 156 and 215 mm and k varied between 0.479 and 0.848/year. Estimates by jackknife detected no variability in Φ’ between locations and significant differences between methods. The ranges of values of Φ’ and PROJMAT estimated SLCA (4.70 to 4.71 and 4.66 to 4.70, respectively) were in the range reported in the literature (4.201-4.798), while lower values ELEFAN contributed significantly (3.87 to 4.27). The SLCA and PROJMAT methods in combination with the jackknife technique, proved to be the most suitable to estimate the growth parameters of C. sapidus. Rev. Biol. Trop. 64 (2): 821-836. Epub 2016 June 01.


Subject(s)
Animals , Male , Female , Decapoda/growth & development , Seasons , Decapoda/anatomy & histology , Fisheries , Mexico , Models, Biological
5.
Rev. biol. trop ; Rev. biol. trop;61(3): 1301-1312, sep. 2013. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-688477

ABSTRACT

Several methods are now avail- able to estimate fish individual growth based upon the distribution of body lengths in a population. Comparative analyses of length-based methods have been undertaken mainly for marine species; nevertheless, limited information is available for inland species. Tilapia is one of the most important freshwater fisheries and its growth parameters have been estimated by several authors, usually using one length-based method. Thus, the main objectives of this study were: a) to estimate growth parameters of O. aureus from Chapala lake, Mexico, using three length-based methods ELEFAN, PROJMAT and SLCA; b) to quantify the effect of input data variations in growth parameters estimates by the jackknife technique; and c) to compare the new estimates with those previously reported, through the standard growth index f’. We collected and analyzed a total of 1 973 specimens from commercial landings from January to December 2010. The three length-base methods used in the present study resulted in parameter estimates within the range of those reported in other studies. Results derived from jackknife analysis revealed lowest values in the error percentage and coefficient of variation for L∞ when applying ELEFAN, while PROJMAT showed lowest values in the precision estimators for K, which was very similar to ELEFAN. Estimates of the comparative growth index f’ were also very similar to those reported for the same species when studied in different reservoirs. Considering our results, we suggest the use of ELEFAN rather than SLCA due to its accuracy to estimate growth parameters for O. aureus.


Una de las pesquerías de aguas continentales más importantes en México es la pesca de la tilapia Oreochromis aureus. Con base en el análisis de frecuencia de tallas mediante ELEFAN, SLCA y PROJMAT se estimó el crecimiento en la tilapia en el lago de Chapala, Jalisco, para lo cual se utilizaron 1 973 individuos que fueron recolectados de la captura comercial de enero a diciembre 2010. Se cuantificó la variabilidad de los estimadores y el efecto de las muestras mensuales a través de la técnica de remuestreo jackknife. Los parámetros de crecimiento de L∞ y K se unificaron para efectos comparativos mediante el índice de crecimiento estándar (f’). Con los tres métodos utilizados se estimaron valores de los parámetros de crecimiento que se encuentran dentro del rango reportado en la literatura. La aplicación de jackknife mostró que ELEFAN estimó los mejores resultados, con los valores más bajos en el error porcentual y coeficiente de variación para L∞, en tanto PROJMAT presentó los valores más bajos en los estimadores de precisión para K, la cual fue muy similar a la de ELEFAN. Los intervalos del índice comparativo de crecimiento f’ fueron muy similares a los reportados para la especie en diferentes embalses. Se sugiere el uso de ELEFAN en lugar de SLCA, debido a su precisión para estimar los parámetros de crecimiento de Oreochromis aureus.


Subject(s)
Animals , Tilapia/growth & development , Lakes , Mexico , Reproducibility of Results
6.
Braz. J. Biol. ; 70(3): 483-491, Aug. 2010. ilus
Article in English | VETINDEX | ID: vti-2593

ABSTRACT

In this paper we examine the accuracy and precision of three indices of catch-per-unit-effort (CPUE). We carried out simulations, generating catch data according to six probability distributions (normal, Poisson, lognormal, gamma, delta and negative binomial), three variance structures (constant, proportional to effort and proportional to the squared effort) and their magnitudes (tail weight). The Jackknife approach of the index is recommended, whenever catch is proportional to effort or even under small deviations from proportionality assumption, when a ratio estimator is to be applied and little is known about the underlying behaviour of variables, as is the case for most fishery studies.(AU)


Neste trabalho, examinamos a acurácia e precisão de três índices de captura por unidade de esforço (CPUE). Foram feitas simulações, nas quais foram gerados dados de captura de acordo com seis distribuições de probabilidade (normal, Poisson, lognormal, gama, delta e binomial negativa), três estruturas de variância (constante, proporcional ao esforço e proporcional ao quadrado do esforço), e magnitudes (tail weight). É recomendado o uso do método Jackknife para os índices, sempre que a captura for proporcional ao esforço ou até em casos de pequenos desvios do pressuposto de proporcionalidade, quando se deseja utilizar um estimador de razão e pouco é conhecido sobre o real comportamento das variáveis, como é o caso da maioria dos estudos de pesca.(AU)


Subject(s)
Statistics as Topic/methods , Probability
7.
Braz. j. biol ; Braz. j. biol;70(3)Aug. 2010.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1468052

ABSTRACT

In this paper we examine the accuracy and precision of three indices of catch-per-unit-effort (CPUE). We carried out simulations, generating catch data according to six probability distributions (normal, Poisson, lognormal, gamma, delta and negative binomial), three variance structures (constant, proportional to effort and proportional to the squared effort) and their magnitudes (tail weight). The Jackknife approach of the index is recommended, whenever catch is proportional to effort or even under small deviations from proportionality assumption, when a ratio estimator is to be applied and little is known about the underlying behaviour of variables, as is the case for most fishery studies.


Neste trabalho, examinamos a acurácia e precisão de três índices de captura por unidade de esforço (CPUE). Foram feitas simulações, nas quais foram gerados dados de captura de acordo com seis distribuições de probabilidade (normal, Poisson, lognormal, gama, delta e binomial negativa), três estruturas de variância (constante, proporcional ao esforço e proporcional ao quadrado do esforço), e magnitudes (tail weight). É recomendado o uso do método Jackknife para os índices, sempre que a captura for proporcional ao esforço ou até em casos de pequenos desvios do pressuposto de proporcionalidade, quando se deseja utilizar um estimador de razão e pouco é conhecido sobre o real comportamento das variáveis, como é o caso da maioria dos estudos de pesca.

8.
Braz. j. biol ; Braz. j. biol;70(3): 483-491, Aug. 2010. ilus
Article in English | LILACS | ID: lil-555288

ABSTRACT

In this paper we examine the accuracy and precision of three indices of catch-per-unit-effort (CPUE). We carried out simulations, generating catch data according to six probability distributions (normal, Poisson, lognormal, gamma, delta and negative binomial), three variance structures (constant, proportional to effort and proportional to the squared effort) and their magnitudes (tail weight). The Jackknife approach of the index is recommended, whenever catch is proportional to effort or even under small deviations from proportionality assumption, when a ratio estimator is to be applied and little is known about the underlying behaviour of variables, as is the case for most fishery studies.


Neste trabalho, examinamos a acurácia e precisão de três índices de captura por unidade de esforço (CPUE). Foram feitas simulações, nas quais foram gerados dados de captura de acordo com seis distribuições de probabilidade (normal, Poisson, lognormal, gama, delta e binomial negativa), três estruturas de variância (constante, proporcional ao esforço e proporcional ao quadrado do esforço), e magnitudes (tail weight). É recomendado o uso do método Jackknife para os índices, sempre que a captura for proporcional ao esforço ou até em casos de pequenos desvios do pressuposto de proporcionalidade, quando se deseja utilizar um estimador de razão e pouco é conhecido sobre o real comportamento das variáveis, como é o caso da maioria dos estudos de pesca.


Subject(s)
Animals , Biometry , Fisheries/statistics & numerical data , Models, Statistical , Monte Carlo Method , Probability
9.
Acta amaz ; Acta amaz;39(1): 105-112, mar. 2009. graf, tab
Article in Portuguese | LILACS | ID: lil-515753

ABSTRACT

A análise da produtividade individual de espécies permite descrever o comportamento das mesmas em ecossistemas florestais. O objetivo deste trabalho foi analisar a produtividade de quatro espécies arbóreas em um período de seis anos (2000-2006) em uma área de terra firme na região de Manaus, AM. A produtividade foi estimada indiretamente por meio da utilização de equações alométricas individuais geradas e dados de inventários florestais. Foram selecionadas Pouteria reticulata Eyma (Sapotaceae), Micrandra siphonioides Benth. (Euphorbiaceae), Protium hebetatum Daly (Burseraceae) e Eschweilera wachenheimii Sand (Lecythidaceae) por apresentarem alto índice de valor de importância na área. As equações foram geradas a partir de um arquivo de dados; devido ao reduzido número de indivíduos por espécie foi necessária a utilização de um método não paramétrico, sendo escolhido o "Jackknife". As equações foram aplicadas às árvores das espécies selecionadas localizadas em duas parcelas permanentes com as informações dos inventários florestais dos anos de 2000, 2002, 2004 e 2006. Os resultados mostram indícios de confiabilidade do método, as equações geradas apresentaram altos valores de coeficiente de determinação (R² > 0,93) e baixos valores de erro padrão da estimativa (s y.x < 0,692), evidenciando sua consistência e precisão. As taxas de produtividade foram específicas para cada espécie, entretanto, o padrão de produtividade das espécies E. wachenheimii, P. reticulata e P. hebetatum foram semelhantes, diferindo da M. siphonioides. A maior produtividade se refere à espécie M. siphonioides e a menor à P. hebetatum. A variação da produtividade intra-específica foi superior à variação inter-específica, com P. reticulata apresentando o maior coeficiente de variação.


Individual productivity analysis of species helps describe their comportment in forest ecosystems. The objective of this work was to analyze the productivity of four tree species during a period of six years (2000-2006) in a "terra firme" area near Manaus, Amazonas. The productivity was indirectly estimated by using individual allometric equations along with data from a continuous forest inventory. The following species were selected for this study: Pouteria reticulata Eyma (Sapotaceae), Micrandra siphonioides Benth. (Euphorbiaceae), Protium hebetatum Daly (Burseraceae) and Eschweilera wachenheimii Sand (Lecythidaceae). These were selected because they presented a very high importance value index in the area. The raw data used to developed specific equations were taken from an existing set of data. Samples for each species numbered less than 30 individuals; for this reason, "Jackknife" was used. The "jackknifed" equations were used to estimate aboveground biomass of individuals which occurred in two permanent sample plots measured in 2000, and re-measured in 2002, 2004 and 2006. The "jackknife" method was consistent and reliable, with high and significant determination coefficients (r² > 0,93) and low values of standard error of estimates (sy.x < 0,692). The productivity rates of E. wachenheimii, P. reticulata e P. hebetatum were similar, different from M. siphonioides. The highest productivity was reported for M. siphonioides, and the lowest for P. hebetatum. The intra-specific productivity variability was superior to the inter-specific, with P. reticulata showing the highest variability coefficient.


Subject(s)
Forests
10.
Acta amaz. ; 39(1)2009.
Article in Portuguese | VETINDEX | ID: vti-450427

ABSTRACT

Individual productivity analysis of species helps describe their comportment in forest ecosystems. The objective of this work was to analyze the productivity of four tree species during a period of six years (2000-2006) in a "terra firme" area near Manaus, Amazonas. The productivity was indirectly estimated by using individual allometric equations along with data from a continuous forest inventory. The following species were selected for this study: Pouteria reticulata Eyma (Sapotaceae), Micrandra siphonioides Benth. (Euphorbiaceae), Protium hebetatum Daly (Burseraceae) and Eschweilera wachenheimii Sand (Lecythidaceae). These were selected because they presented a very high importance value index in the area. The raw data used to developed specific equations were taken from an existing set of data. Samples for each species numbered less than 30 individuals; for this reason, "Jackknife" was used. The "jackknifed" equations were used to estimate aboveground biomass of individuals which occurred in two permanent sample plots measured in 2000, and re-measured in 2002, 2004 and 2006. The "jackknife" method was consistent and reliable, with high and significant determination coefficients (r² > 0,93) and low values of standard error of estimates (sy.x 0,692). The productivity rates of E. wachenheimii, P. reticulata e P. hebetatum were similar, different from M. siphonioides. The highest productivity was reported for M. siphonioides, and the lowest for P. hebetatum. The intra-specific productivity variability was superior to the inter-specific, with P. reticulata showing the highest variability coefficient.


A análise da produtividade individual de espécies permite descrever o comportamento das mesmas em ecossistemas florestais. O objetivo deste trabalho foi analisar a produtividade de quatro espécies arbóreas em um período de seis anos (2000-2006) em uma área de terra firme na região de Manaus, AM. A produtividade foi estimada indiretamente por meio da utilização de equações alométricas individuais geradas e dados de inventários florestais. Foram selecionadas Pouteria reticulata Eyma (Sapotaceae), Micrandra siphonioides Benth. (Euphorbiaceae), Protium hebetatum Daly (Burseraceae) e Eschweilera wachenheimii Sand (Lecythidaceae) por apresentarem alto índice de valor de importância na área. As equações foram geradas a partir de um arquivo de dados; devido ao reduzido número de indivíduos por espécie foi necessária a utilização de um método não paramétrico, sendo escolhido o "Jackknife". As equações foram aplicadas às árvores das espécies selecionadas localizadas em duas parcelas permanentes com as informações dos inventários florestais dos anos de 2000, 2002, 2004 e 2006. Os resultados mostram indícios de confiabilidade do método, as equações geradas apresentaram altos valores de coeficiente de determinação (R² > 0,93) e baixos valores de erro padrão da estimativa (s y.x 0,692), evidenciando sua consistência e precisão. As taxas de produtividade foram específicas para cada espécie, entretanto, o padrão de produtividade das espécies E. wachenheimii, P. reticulata e P. hebetatum foram semelhantes, diferindo da M. siphonioides. A maior produtividade se refere à espécie M. siphonioides e a menor à P. hebetatum. A variação da produtividade intra-específica foi superior à variação inter-específica, com P. reticulata apresentando o maior coeficiente de variação.

11.
Ciênc. agrotec., (Impr.) ; 32(5): 1622-1628, set.-out. 2008. ilus, tab
Article in English | LILACS | ID: lil-497016

ABSTRACT

The aim of this study is to evaluate the behavior of the parameters of the degradation model proposed by Mertens & Loften (1980) fitted to the results of a rehearsal of degradability in situ. In the experiment, we evaluate the potentially degradable residue of neutral detergent fiber (NDF) of coastcross grass (Cynodon dactylon x Cynodon nlemfunensis) cut at 60 days, with three replications. The potentially degradable residue of NDF is studied using fifteen incubation times (0; 0.5; 1; 3; 6; 9; 12; 18; 24; 36; 48; 56; 72; 96 and 120 hours). The experimental plot is comprised of a non-lactating cow with a permanent ruminal fistula. It is obtained mean and individual fits for the animals. Variances of parameter estimators is also obtained through both the covariance matrix of the parameters and the jackknife method, then resulting expressions for the estimate of the confidence interval for the parameters of the model. The results shows that the jackknife method presents larger variance estimate for the parameters of the model of Mertens & Loften (1980), resulting in confidence intervals of greater amplitude and less precise parameter estimates for both the individual and mean fits.


Objetiva-se avaliar o comportamento dos parâmetros do modelo de degradação proposto por Mertens & Loften (1980) ajustado aos resultados de um ensaio de degradabilidade in situ. No experimento é avaliado o resíduo potencialmente degradável da fibra em detergente neutro (FDN) da gramínea coastcross (Cynodon dactylon x Cynodon nlemfunensis) cortada aos 60 dias, com três repetições. O resíduo potencialmente degradável da FDN é estudado utilizando quinze tempos de incubação (0; 0,5; 1; 3; 6; 9; 12; 18; 24; 36; 48; 56; 72; 96 e 120 horas). A parcela experimental é constituída por uma vaca não lactante, com fístula ruminal permanente. São obtidos ajustes médios e individuais para os animais. Obtem-se também as variâncias dos estimadores dos parâmetros por meio da matriz de variância e covariância dos parâmetros e pelo método jackknife, propondo-se expressões para a estimação do intervalo de confiança para os parâmetros do modelo. Os resultados mostram que o método de jackknife apresenta maior estimativa de variância para os parâmetros do modelo de Mertens & Loften (1980), resultando em intervalos de confiança de maior amplitude e estimativas dos parâmetros menos precisas, nos ajustes individuais e médios.

12.
Neotrop. entomol ; 37(2): 152-158, Mar.-Apr. 2008. ilus, tab
Article in Portuguese | LILACS | ID: lil-483199

ABSTRACT

Estudou-se a riqueza e abundância de gêneros de Bethylidae coletados em quatro áreas de mata de encosta da Mata Atlântica do Espírito Santo, com estados de preservação diferentes: Santa Maria de Jetibá (SMJ), Domingos Martins (DM), Pancas (P) e Atílio Vivácqua (AV). Foram coletados 2.840 espécimes alocados em 12 gêneros, sendo Lepidosternopsis Ogloblin e Bakeriella Kieffer citados pela primeira vez para esse estado. A riqueza dos táxons foi obtida através do procedimento Jackknife com auxílio do programa EstimateS. Curvas de acumulação de gêneros foram construídas para avaliar o esforço amostral. Os dados se ajustaram à distribuição geométrica e calculou-se o parâmetro k para comparar as localidades. O perfil genérico não foi equivalente em todas as localidades, e todas foram consideradas perturbadas. SMJ e DM apresentaram riqueza de gêneros maior em comparação com P e AV. As diferenças relatadas neste estudo para as áreas amostradas refletem o grau diferente de preservação das matas. Pseudisobrachium Kieffer e Dissomphalus Ashmead foram os gêneros mais abundantes em SMJ, DM e P e Anisepyris Kieffer em AV. Este estudo reforça o fato de Dissomphalus ser mais abundante em florestas tropicais úmidas e que o perfil genérico encontrado em AV assemelha-se a dados publicados para o cerrado.


The generic richness and abundance of Bethylidae collected in four different hillside areas of Atlantic rain forest from Espírito Santo, Brazil were studied. The sites are Santa Maria de Jetibá (SMJ), Domingos Martins (DM), Pancas (P) and Atílio Vivacqua (AV). A total of 2,840 specimens of 12 genera were collected. Lepidosternopsis Ogloblin and Bakeriella Kieffer are first recorded from the State. Richness of taxa was calculated using first-order Jackknife richness with EstimateS program. Genera accumulation curves were ran to evaluate the samples. Abundance data were adjusted to the geometric distribution. Parameter k was used to compare areas. The generic profile was not equal for the sites we studied. The areas were considered disturbed. SMJ and DM presented genera richness bigger than in P and AV. The differences in the sites reflect the different preservation of each environment. Pseudisobrachium Kieffer and Dissomphalus Ashmead are most dominant genera in SMJ, DM and P, and Anisepyris Kieffer in AV. This study emphasizes the fact of Dissomphalus as the most abundant genus in rain forests. The generic profile found in AV is similar to that of some areas of Brazilian savannah.


Subject(s)
Animals , Hymenoptera/classification , Brazil , Demography , Trees
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