Effects of environmental variables on the composition of ants (Hymenoptera: Formicidae) in Amazonian foothills forest

Abiotic factors can negatively or positively affect the structure of communities; studying these factors is important to identify the causes that structure ant communities; taking into account this situation and that in the Amazon foothills region, particularly in the Putumayo department, few studies have been carried out and there is insufficient knowledge about the ecology of many species, this research was aimed to evaluate the effect of environmental variables in the assembly of ants, evaluating the hypothesis: the assembly of forest and grassland ants reflect changes in environmental variables (ambient temperature, soil temperature and relative humidity). In the municipality of Orito, in a secondary forest of the Amazon foothills and its grassland matrix, a 100 m transect was traced, locating 10 stations 10 m apart, in these, ants were sampled with: pitfall traps, corner baits: arboreal, epigeal and hypogeal, leaf litter extraction and manual capture. With the averages of the environmental variables in each station and the diversity and richness data per month of sampling, the Poisson regression analysis was performed and with the data of the morphospecies and the averages of the measured variables, the principal component analysis was performed. The results indicated that, the ants assemblages did not reflect the changes of the variables, some species responded to these patterns. Therefore, to understand the dynamics of the functioning of the ecosystems of the Amazonian foothills, it is necessary to study the biology of each species; However, it was determined that, the habitats studied share generalist species and contain exclusive species that contribute to the diversity of ants in the Amazonian foothills, consequently the sites must be conserved.

Download Full-text

Leaf geometric morphometrics among populations of Dalbergia ecastaphyllum (L.) Taub.

Bioscience Journal ◽

10.14393/bj-v35n6a2019-39814 ◽

2019 ◽

Vol 35 (6) ◽

Author(s):

Daniel Vieira de Morais ◽

Lorena Andrade Nunes ◽

Vandira Pereira da Mata ◽

Maria Angélica Pereira de Carvalho Costa ◽

Geni da Silva Sodré ◽

...

Keyword(s):

Principal Component Analysis ◽

Geometric Morphometrics ◽

Cross Validation ◽

Abiotic Factors ◽

Principal Component ◽

Canonical Variate ◽

Validation Test ◽

Significant Difference ◽

Variate Analysis ◽

Geographical Distances

Leaves are plant structures that express important traits of the environment where they live. Leaf description has allowed identification of plant species as well as investigation of abiotic factors effects on their development, such as gases, light, temperature, and herbivory. This study described populations of Dalbergia ecastaphyllum through leaf geometric morphometrics in Brazil. We evaluated 200 leaves from four populations. The principal component analysis (PCA) showed that the first four principal components were responsible for 97.81% of variation. The non-parametric multivariate analysis of variance (NPMANOVA) indicated significant difference between samples (p = 0.0001). The Mentel test showed no correlation between geographical distances and shape. The canonical variate analysis (CVA) indicated that the first two variables were responsible for 96.77 % of total variation, while the cross-validation test showed an average of 83.33%. D. ecastaphyllum leaves are elliptical and ovate.

Download Full-text

Anurans of a disturbed area in Jarú, Rondônia, Brazil

Check List ◽

10.15560/8.1.083 ◽

2012 ◽

Vol 8 (1) ◽

pp. 083 ◽

Cited By ~ 1

Author(s):

Liliana Piatti ◽

Paulo Matthes Orlandi de Amaro ◽

Jhonatas Fernando de Jesus Araújo ◽

Vitor Quadros Altamore Sanches ◽

Paulo Sérgio Bernarde

Keyword(s):

Secondary Forest ◽

Amazon Forest ◽

Pitfall Traps ◽

Disturbed Area ◽

Disturbed Areas ◽

Species Being

This paper presents a checklist of anurans species and their distribution in a disturbed area in the municipality of Jarú, Rondônia state, Brazil. Nineteen species belonging to eight families were sampled with pitfall traps and time constrained searches. About 70% of the species were found in a secondary forest and 40% were found only in this environment, while about 57% were found in pastures, with 26% of species being registered only in this habitat. Our results were similar to those of previous studies in other disturbed areas of Rondônia. Species that can be found in different habits were unevenly distributed, with forested environments harboring more species. Despite its nearness to Cerrado and the large number of open areas available, most species found are typical of the Amazon forest.

Download Full-text

Diversity and spatial distribution of black flies (Diptera: Simuliidae) in the Ijuí river drainage basin, Rio Grande do Sul, Brazil

EntomoBrasilis ◽

10.12741/ebrasilis.v12i2.845 ◽

2019 ◽

Vol 12 (2) ◽

pp. 47-56

Author(s):

Tieli Cláudia Menzel ◽

Sirlei Maria Hentges ◽

David Augusto Reynalte Tataje ◽

Milton Norberto Strieder

Keyword(s):

River Basin ◽

Indicator Species ◽

Drainage Basin ◽

Abiotic Factors ◽

Principal Component ◽

Rio Grande ◽

Anthropogenic Pressure ◽

Black Flies ◽

Rio Grande Do Sul ◽

Significant Difference

Abstract. In southern Brazil there are several problems regarding the hematophageal activity of black flies, and the information on the distribution of species are still insufficient. In this study, our main goals were to recognize Simuliidae species and to analyze abiotic factors regarding the distribution of immature stages (larva and pupa) in streams from the Ijuí River basin, Northwest of Rio Grande do Sul, Brazil. We sampled simulids specimens in 27 study sites, covering three regions (high, intermediate and low altitude). Concomitantly, we recorded abiotic factors in the studied sites, such as: temperature, electrical conductivity, dissolved oxygen, atmospheric pressure, pH, altitude and stream width. For data analysis, we performed Kruskal-Wallis, ANOVA, Principal Component Analysis (PCA), Analysis of Indicator Species and Canonical Correspondence (CCA). A total of 10 species of black Flies was recorded. Simulium pertinax Kollar, Simulium incrustatum Lutz and Simulium orbitale Lutz were the most frequent. There was no significant difference in richness and density of the species between the different regions studied, except for Simulium jujuyense Paterson & Shannon. The sampled environments were segregated according to the location within the basin, and only S. jujuyense was considered an indicator species of the upper region. These results can be explained by the homogeneous conditions of the Ijuí River basin, which have suffered anthropogenic pressure mainly due to agricultural activities, resulting in losses in local aquatic biodiversity. Also, it may indicate that the control must be conducted considering the basin as a whole, and not only as isolated stretches of the streams.Diversidade e distribuição espacial de borrachudos (Diptera: Simuliidae) na bacia hidrográfica do rio Ijuí, Rio Grande do Sul, BrasilResumo. No sul do Brasil existem problemas com atividade hematofágica de borrachudos e as informações referentes à distribuição das espécies ainda são insuficientes. O presente estudo visa reconhecer as espécies de Simuliidae e analisar fatores abióticos quanto a distribuição dos estágios imaturos (larva e pupa) em riachos da Bacia do Rio Ijuí, no Noroeste do Rio Grande do Sul, Brasil. Foram coletados simulídeos em 27 pontos de estudo, cobrindo três regiões da bacia (alta, intermediária e baixa altitude). Concomitantemente, foi feito o registro de fatores abióticos nos trechos estudados, tais como: temperatura, condutividade elétrica, oxigênio dissolvido, pressão atmosférica, pH, altitude e largura do riacho. Foram realizadas análises de Kruskal-Wallis ou ANOVA, Análise de Componentes Principais (PCA), Análise de Espécie Indicadora e de Correspondência Canônica (CCA). Foi registrado um total de 10 espécies de Simuliidae. Simulium pertinax Kollar, Simulium incrustatum Lutz e Simulium orbitale Lutz foram as mais frequentes. Não ocorreu diferença na riqueza e na densidade das espécies entre as diferentes regiões estudadas, exceto para Simulium jujuyense Paterson & Shannon. Os ambientes nos pontos de amostragem foram segregados de acordo com a sua localização na bacia, e apenas S. jujuyense foi considerada uma espécie indicadora da região alta. Tais resultados podem ser explicados pelas condições homogêneas da Bacia do Rio Ijuí, que vêm sofrendo pressão antropogênica principalmente devido às atividades agrícolas, resultando em perdas na biodiversidade aquática local. Também, indicam que o controle deve ser realizado considerando a bacia como um todo e não apenas em trechos isolados dos riachos.

Download Full-text

Spatial-temporal analysis of the diet of a non-native fish in the Santa Cruz Reservoir, Brazilian semi-arid

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x10416 ◽

2018 ◽

Vol 30 (0) ◽

Author(s):

Jônnata Fernandes de Oliveira ◽

Jean Carlos Dantas de Oliveira ◽

José Luís Costa Novaes ◽

Antonia Elissandra Freire de Souza ◽

Marla Melise Oliveira de Sousa ◽

...

Keyword(s):

Environmental Variables ◽

Abiotic Factors ◽

Temporal Analysis ◽

Arid Environment ◽

Temporal Variations ◽

Environmental Data ◽

Animal Origin ◽

Santa Cruz ◽

Main Item ◽

Semi Arid

Abstract Aim The diet of Plagioscion squamosissimus present in the Santa Cruz Reservoir, Rio Grande do Norte, Brazil, was investigated, evaluating the influences of spatial and temporal variations and abiotic factors in the utilization of food resources. Methods The samplings were performed quarterly between February 2011 and November 2014. Of the 525 specimens captured, 375 presented food items in the stomachs. The diet was determined using: (i) Feeding Index (IAi); (ii) and the graphical interpretation of the food strategy through non-metric multidimensional scaling (NMDS) analyzes, the differences in diet being tested from Permutational Multivariate Analyzes of Variance (PERMANOVA). To verify if environmental variables influence the Canonical Correspondence Analyzes (CCA) were used, using the data from the IAi the environmental data, being the significance of the axes tested through Monte Carlo simulations. Results The species feed mainly on items of animal origin, vegetable being a resource ingested accidentally. The diet was composed of shrimp, fish, insect, mollusk and vegetable, the latter rarely found. The shrimp was the main item (92.57%) and the insects (7.24%) accessory items. Spatial and temporal ordering demonstrated that the species didn’t present variation in diet composition, as well as a low association between diet and environmental variables. Conclusion P. squamosissimus is characterized as carcinophagous, due to the predominance of shrimp in its diet, evidencing that the species is adapted to the conditions offered by the Brazilian semi-arid environment.

Download Full-text

Epigaeic ant (Hymenoptera: Formicidae) communities in urban parks located in Atlantic Forest biome

Check List ◽

10.15560/12.5.1967 ◽

2016 ◽

Vol 12 (5) ◽

pp. 1967 ◽

Cited By ~ 2

Author(s):

Débora R. de Souza-Campana ◽

Otávio G. M. da Silva ◽

Leonardo Menino ◽

Maria Santina de C. Morini

Keyword(s):

Atlantic Forest ◽

Native Species ◽

Urban Parks ◽

Biological Indicators ◽

Public Access ◽

Ant Communities ◽

Generalist Species ◽

Wasmannia Auropunctata ◽

Line Transects ◽

Forest Biome

Urban parks offer refuge for numerous animal species, and some of these parks represent the remaining fragments of native forests. We evaluate the diversity and composition of epigaeic ant species (Hymenoptera: Formicidae) in urban parks located within the Atlantic Forest biome (Centenial Park, Leon Feffer Park and Villa Lobos Park). For our collections, we placed pitfall traps along 100-m line transects in areas both accessible and inaccessible to the public. A total of 46 species distributed in seven subfamilies were collected. The number of species did not differ among park areas, but the ant communities themselves differed. Native species, such as Strumigenys denticulata and S. louisianae, were collected in the most preserved natural areas in the parks. Generalist species composed the richest guild and were primarily found in areas with public access. Wasmannia auropunctata, Brachymyrmex heeri, Solenopsis sp. 2, and Solenopsis sp. 3 were classified with high value as biological indicators.

Download Full-text

Analysis of Soil-Vegetation Interrelationships in a South-Southern Secondary Forest of Nigeria

International Journal of Forestry Research ◽

10.1155/2012/469326 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

D. D. Eni ◽

A. I. Iwara ◽

R. A. Offiong

Keyword(s):

Organic Matter ◽

Correlation Analysis ◽

Canonical Correlation Analysis ◽

State Government ◽

Canonical Correlation ◽

Secondary Forest ◽

Principal Component ◽

Tree Density ◽

Tree Size ◽

Canonical Variate

Soil-vegetation interrelationships in a secondary forest of South-Southern Nigeria were studied using principal component analysis (PCA) and canonical correlation analysis (CCA). The grid system of vegetation sampling was employed to randomly collect vegetation and soil data from fifteen quadrats of 10 m × 10 m. PCA result showed that exchangeable sodium, organic matter, cation exchange capacity, exchangeable calcium, and sand content were the major soil properties sustaining the regenerative capacity and luxuriant characteristics of the secondary forest, while tree size and tree density constituted the main vegetation parameters protecting and enriching the soil for its continuous support to the vegetation after decades of anthropogenic disturbance (food crop cultivation and illegal logging activities) before its acquisition and subsequent preservation by the Cross River State government in 2003. In addition, canonical correlation analysis showed result similar to PCA, as it indicated a pattern of relationship between soil and vegetation. The only retained canonical variate revealed a positive interrelationship between organic matter and tree size as well as an inverse relationship between organic matter and tree density. These extracted soil and vegetation variables are indeed significantly important in explaining soil-vegetation interrelationships in the highly regenerative secondary forest.

Download Full-text

Spatial modelling of soil organic carbon stocks with combined principal component analysis and geographically weighted regression

The Journal of Agricultural Science ◽

10.1017/s0021859618000709 ◽

2018 ◽

Vol 156 (6) ◽

pp. 774-784 ◽

Cited By ~ 2

Author(s):

Long Guo ◽

Mei Luo ◽

Chengsi Zhangyang ◽

Chen Zeng ◽

Shanqin Wang ◽

...

Keyword(s):

Principal Component Analysis ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Geographically Weighted Regression ◽

Environmental Variables ◽

Prediction Models ◽

Principal Component ◽

Weighted Regression ◽

Auxiliary Variables ◽

Soc Stocks

AbstractWith the development of remote sensing and geostatistical technology, complex environmental variables are increasingly easily quantified and applied in modelling soil organic carbon (SOC). However, this emphasizes data redundancy and multicollinearity problems adding to the difficulty in selecting dominant influential auxiliary variables and uncertainty in estimating SOC stocks. The current paper considers the spatial characteristics of SOC density (SOCD) to construct prediction models of SOCD on the basis of reducing the data dimensionality and complexity using the principal component analysis (PCA) method. A total of 260 topsoil samples were collected from Chahe town, China. Eight environmental variables (elevation, aspect, slope, normalized difference vegetation index, normalized difference moisture index, nearest distance to construction area and road, and land use degree comprehensive index) were pre-analysed by PCA and then extracted as the main principal component variables to construct prediction models. Two geostatistical approaches (ordinary kriging and ordinary co-kriging) and two regression approaches (ordinary least squares and geographically weighted regression (GWR)) were used to estimate SOCD. Results showed that PCA played an important role in reducing the redundancy and multicollinearity of the auxiliary variables and GWR achieved the highest prediction accuracy in these four models. GWR considered not only the spatial characteristics of SOCD but also the related valuable information of the auxiliary attributes. In summary, PCA-GWR is a promising spatial method used here to predict SOC stocks.

Download Full-text

Environmental Analysis of GOES-R Proving Ground Convection-Initiation Forecasting Algorithms

Journal of Applied Meteorology and Climatology ◽

10.1175/jamc-d-14-0190.1 ◽

2015 ◽

Vol 54 (7) ◽

pp. 1637-1662 ◽

Cited By ~ 1

Author(s):

Jason M. Apke ◽

Daniel Nietfeld ◽

Mark R. Anderson

Keyword(s):

Environmental Variables ◽

Environmental Influences ◽

Principal Component ◽

University Of Alabama ◽

Algorithm Performance ◽

University Of Wisconsin ◽

Improve Algorithm ◽

Convection Initiation ◽

The University

AbstractEnhanced temporal and spatial resolution of the Geostationary Operational Environmental Satellite–R Series (GOES-R) will allow for the use of cloud-top-cooling-based convection-initiation (CI) forecasting algorithms. Two such algorithms have been created on the current generation of GOES: the University of Wisconsin cloud-top-cooling algorithm (UWCTC) and the University of Alabama in Huntsville’s satellite convection analysis and tracking algorithm (SATCAST). Preliminary analyses of algorithm products have led to speculation over preconvective environmental influences on algorithm performance. An objective validation approach is developed to separate algorithm products into positive and false indications. Seventeen preconvective environmental variables are examined for the positive and false indications to improve algorithm output. The total dataset consists of two time periods in the late convective season of 2012 and the early convective season of 2013. Data are examined for environmental relationships using principal component analysis (PCA) and quadratic discriminant analysis (QDA). Data fusion by QDA is tested for SATCAST and UWCTC on five separate case-study days to determine whether application of environmental variables improves satellite-based CI forecasting. PCA and significance testing revealed that positive indications favored environments with greater vertically integrated instability (CAPE), less stability (CIN), and more low-level convergence. QDA improved both algorithms on all five case studies using significantly different variables. This study provides an examination of environmental influences on the performance of GOES-R Proving Ground CI forecasting algorithms and shows that integration of QDA in the cloud-top-cooling-based algorithms using environmental variables will ultimately generate a more skillful product.

Download Full-text

A Comparison of Pitfall Traps with Bait Traps for Studying Leaf Litter Ant Communities

Journal of Economic Entomology ◽

10.1603/0022-0493-94.3.761 ◽

2001 ◽

Vol 94 (3) ◽

pp. 761-765 ◽

Cited By ~ 21

Author(s):

Changlu Wang ◽

John Strazanac ◽

Linda Butler

Keyword(s):

Leaf Litter ◽

Pitfall Traps ◽

Ant Communities ◽

Bait Traps

Download Full-text

Dietary Variation in a Freshwater Fish Species: Relative Contributions of Biotic Interactions, Abiotic Factors, and Spatial Structure

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-284 ◽

1994 ◽

Vol 51 (12) ◽

pp. 2856-2865 ◽

Cited By ~ 59

Author(s):

Pierre Magnan ◽

Marco A. Rodríguez ◽

Pierre Legendre ◽

Sylvain Lacasse

Keyword(s):

Spatial Structure ◽

Freshwater Fish ◽

Fish Species ◽

Environmental Variables ◽

Brook Trout ◽

Diet Composition ◽

Abiotic Factors ◽

Biotic Interactions ◽

Relative Contribution ◽

Dietary Variation

We used multivariate analyses to examine which variables among the environmental and spatial components can best account for dietary variation in a freshwater fish, brook trout, Salvelinus fontinalis. The diet composition of brook trout was quantified in 37 lakes of the Laurentian Shield, Québec, Canada. Among the 25 measured environmental variables, fish species composition, sampling date, macrophyte abundance, and trout body length were the best predictors of diet composition. The total variation in diet composition was partitioned into four components: pure environmental 21.6%, pure spatial 23.2%, shared 19.9%, and unexplained 35.3%. A significant spatial trend in diet composition existed even after accounting for the main effects measured by the environmental variables. The two sets of spatial variables, when combined with the environmental descriptors, extracted different components of the dietary variation. The study allowed us to (1) highlight the role of spatial structure in diet variation of brook trout, (2) determine the relative contribution of both environmental and spatial components, and (3) generate testable hypotheses concerning mechanisms underlying the observed structure. Dependent variables other than diet composition, such as the density of different species at different sampling sites, can be used within the same statistical framework in studies of community ecology.

Download Full-text