scholarly journals ECOLOGICAL AND FUNCTIONAL CLUSTERING OF FORESTAL SPECIES IN THE SOUTH WESTERN AMAZONIA

2016 ◽  
Vol 40 (6) ◽  
pp. 1083-1090
Author(s):  
Elias Lourenço Vasconcelos Neto ◽  
Celso Azevedo ◽  
Luciano Ribas ◽  
Marcus Neves d'Oliveira

ABSTRACT The aim of this study was to perform ecological and functional clustering of tree species in southwestern Amazon. Developed from data from 95 permanent plots of 1 ha each, all individuals with diameter at breast height (DBH) ≥10 cm were measured. The species grouping was performed in three stages: (1) cluster analysis, using the variables: diameter annual periodic increment -(IPADAP) considering three competition levels (high, medium and low) and the 95th percentile of the diameters (P95) cumulative frequency distribution (Ward hierarchical method); (2) Discriminant analysis, using the variables P95 and IPADAP by Fisher's method and (3) subjective stage, considering the species ecological characteristics. The Ward and Fisher methods used for discriminant and cluster analyses were effective for species grouping resulting on the formation of 10 groups. Variables: IPADAP and and P95 were efficient on the formed groups discrimination.. Variations in the growth rates for the overall mean data were reduced wen calculated for each group of species.

1996 ◽  
Vol 8 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Ken Bartley

This paper discusses the need for nationally based analytical models of the medieval period. The use of cluster analysis as a method for classifying demesne farms, by the crops they grew and their livestock management, is explained. Successful implementation of cluster analysis requires both the existence of a large base sample, to permit isolation of specific groupings within the data, and access to considerable processing time. The paper concludes by demonstrating how discriminant analysis can provide an efficient and systematic way of classifying even a single manor within a national frame of reference.


2010 ◽  
Vol 10 (5) ◽  
pp. 710-720 ◽  
Author(s):  
J. L. Solanas ◽  
M. R. Cussó

Multivariate Consumption Profiling (MCP) is a methodology to analyse the readings made by Intelligent Meter (IM) systems. Even in advanced water companies with well supported IM, full statistical analyses are not performed, since no efficient methods are available to deal with all the data items. Multivariate Analysis has been proposed as a convenient way to synthesise all IM information. MCP uses Factor Analysis, Cluster Analysis and Discriminant Analysis to analyse data variability by categories and levels, in a cyclical improvement process. MCP obtains a conceptual schema of a reference population on a set of classifying tables, one for each category. These tables are quantitative concepts to evaluate consumption, meter sizing, leakage and undermetering for populations and groupings and individual cases. They give structuring items to enhance “traditional” statistics. All the relevant data from each new meter reading can be matched to the classifying tables. A set of indexes is computed and thresholds are used to select those cases with the desired profiles. The paper gives an example of a MCP conceptual schema for five categories, three variables, and five levels, and obtains its classifying tables. It shows the use of case profiles to implement actions in accordance with the operative objectives.


2020 ◽  
Vol 16 (8) ◽  
pp. 1079-1087
Author(s):  
Jorgelina Z. Heredia ◽  
Carlos A. Moldes ◽  
Raúl A. Gil ◽  
José M. Camiña

Background: The elemental composition of maize grains depends on the soil, land and environment characteristics where the crop grows. These effects are important to evaluate the availability of nutrients with complex dynamics, such as the concentration of macro and micronutrients in soils, which can vary according to different topographies. There is available scarce information about the influence of topographic characteristics (upland and lowland) where culture is developed with the mineral composition of crop products, in the present case, maize seeds. On the other hand, the study of the topographic effect on crops using multivariate analysis tools has not been reported. Objective: This paper assesses the effect of topographic conditions on plants, analyzing the mineral profiles in maize seeds obtained in two land conditions: uplands and lowlands. Materials and Methods: The mineral profile was studied by microwave plasma atomic emission spectrometry. Samples were collected from lowlands and uplands of cultivable lands of the north-east of La Pampa province, Argentina. Results: Differentiation of maize seeds collected from both topographical areas was achieved by principal components analysis (PCA), cluster analysis (CA) and linear discriminant analysis (LDA). PCA model based on mineral profile allowed to differentiate seeds from upland and lowlands by the influence of Cr and Mg variables. A significant accumulation of Cr and Mg in seeds from lowlands was observed. Cluster analysis confirmed such grouping but also, linear discriminant analysis achieved a correct classification of both the crops, showing the effect of topography on elemental profile. Conclusions: Multi-elemental analysis combined with chemometric tools proved useful to assess the effect of topographic characteristics on crops.


2015 ◽  
Vol 39 (6) ◽  
pp. 985-994 ◽  
Author(s):  
Markus Gastauer ◽  
Marcos Eduardo Guerra Sobral ◽  
João Augusto Alves Meira-Neto

According to its owners, the Forest of Seu Nico (FSN) from the Viçosa municipality, Minas Gerais, Brazil, never has been logged and is therefore considered a primary forest. Nevertheless, the forest patch suffered impacts due to selective wood and non-timber extraction, fragmentation and isolation. Aim of this study was to test if the FSN, despite impacts, preserved characteristics of primary forests, which are elevated percentages of non-pioneer (>90%), animal-dispersed (>80 %), understory (>50%) and endemic species (~40%). For that, all trees with diameter at breast height equal or major than 3.2 cm within a plot of 100 x 100 m were identified. With 218 tree species found within this hectare, the FSN's species richness is outstanding for the region. The percentages of non-pioneer (92 %), animal-dispersed (85 %), understory (55 %) and endemic species (39.2 %) from the FSN fulfill the criteria proposed for primary forest. Therefore, we conclude that the FSN maintained its characteristics as a primary forest which highlights its importance for the conservation of biotic resources in the region, where similar fragments are lacking or not described yet.


2018 ◽  
Vol 29 (14) ◽  
pp. 1375-1383
Author(s):  
Hector P Rodriguez ◽  
Summer Starling ◽  
Zosha Kandel ◽  
Robert Weech-Maldonado ◽  
Nicholas J Moss ◽  
...  

Local health departments (LHDs) and their organizational partners play a critical role in controlling sexually transmitted diseases (STDs) in the United States. We examine variation in the differentiation, integration, and concentration (DIC) of STD services and develop a taxonomy describing the scope and organization of local STD services. LHD STD programs (n = 115) in Alabama (AL) and California (CA) responded to surveys assessing STD services available in 2014. K-means cluster analysis identified LHD groupings based on DIC variation. Discriminant analysis validated cluster solutions. Differences in organizational partnerships and scope of STD services were compared by taxonomy category. Multivariable regression models estimated the association of the STD services organization taxonomy and five-year (2010–2014) gonorrhea incidence rates, controlling for county-level sociodemographics and resources. A three-cluster solution was identified: (1) low DIC (n = 74), (2) moderate DIC (n = 31), and (3) high DIC (n = 10). In discriminant analysis, 95% of jurisdictions were classified into the same types as originally assigned through K-means cluster analysis. High DIC jurisdictions were more likely (p < 0.001) to partner with most organizations than moderate and low DIC jurisdictions, and more likely (p < 0.001) to conduct STD needs assessment, comprehensive sex education, and targeted screening. In contrast, contact tracing, case management, and investigations were conducted similarly across jurisdictions. In adjusted analyses, there were no differences in gonorrhea incidence rates by category. Jurisdictions in CA and AL can be characterized into three distinct clusters based on the DIC of STD services. Taxonomic analyses may aid in improving the reach and effectiveness of STD services.


2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Agus Alim Hakim ◽  
M Mukhlis Kamal ◽  
Nurlisa A Butet ◽  
Ridwan Affandi

Freshwater eel (Anguilla spp.) is a catadromus fish that migrates from freshwater into seawater for spawning and return to freshwater during larvae stage to grow. The objective of this study was to determine species composition of tropical freshwater eels based on morphology collected from several rivers flowing in to the Palabuhan Ratu Bay. Young, adult, and glass eels were caught in August 2014 until Desember 2014. Glass eels were only caught in Cimandiri River. Freshwater eels were classified by ano-dorsal length (AD) divided by total length (TL), cluster analysis, and discriminant analysis based on morphometric data. The results showed different AD/TL of young and adult, i.e., 1.93±0.51 for A. bicolor bicolor, and 16.99±0.65 for A. marmorata, and three different AD/TL of glass eels i.e.,1.72±1.05 for A. bicolor bicolor6.60±1.79 for A. nebulosa nebulosa, and 15.07±1.04 for A. marmorata. Cluster analysis showed three groups of population  characters of young and adult eels i.e.  A. bicolor bicolor (2 groups) and A. marmorata (1 group). Discriminant analysis showed three groups of glass eels population i.e., A. bicolor bicolor, A. nebulosa nebulosa, and A. marmorata. Morphological identification showed that young and adult eels in Cibareno  and Citepus rivers had two species i.e., A. bicolor bicolor and A. marmorata. Glass eels from Cimandiri river had three species i.e., A. bicolorbicolor, A. nebulosanebulosa, and A. marmorata. A. bicolor bicolor was found in each rivers and as a dominant species in Palabuhan Ratu Bay.Keywords: A. bicolor bicolor, A. marmorata, A. nebulosa nebulosa, species composition


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yan Li ◽  
Ji Zhang ◽  
Tao Li ◽  
Tianwei Yang ◽  
Yuanzhong Wang ◽  
...  

Nowadays, wild-grown edible mushrooms which are natural, nutritious, and healthy get more and more popular by large consumers. In this paper, UV spectra of different Boletaceae mushrooms with the aid of partial least squares discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) were shown to be a practical and rapid method for discrimination purpose. The specimens of Boletus edulis, Boletus ferrugineus, Boletus tomentipes, Leccinum rugosiceps, and Xerocomus sp. were described based on the UV spectra. From the results, all the specimens were characterized by strong absorption at the wavelengths of 274 and 284 nm and showed the shoulder at 296 nm. However, changes could be seen in the peak heights at the same wavelength for different samples. After analyzing by chemometrics, visual discrimination among samples was presented and the relationships among them were also obtained. This study showed that UV spectroscopy combined with chemometrics methods could be used successfully as a simple and effective approach for characterization of these five wild-grown edible mushrooms at species and genus levels. Meanwhile, this rapid and simple methodology could also provide reference for the discrimination of edible mushrooms.


2021 ◽  
Vol 67 (2) ◽  
pp. 119-124
Author(s):  
Erik C Berg ◽  
Eric A Simmons ◽  
Todd A Morgan ◽  
Stanley J Zarnoch

Abstract Alaska forest managers seek information on how timber harvesting practices change the creation of postharvest woody residues. To predict residue volumes, researchers investigated how residue ratios—growing-stock residue volume per mill-delivered volume—related to readily available data on logging site and tree attributes in Alaska. Residue ratios were not related to logging site-level variables but were related to individual tree variables with predictive models. Ratios varied widely by tree species and were predicted to increase with larger stump height and larger small-end used diameters and decline exponentially with increasing diameter breast height (dbh) to approximately 25 inches. Ratios were then predicted to increase progressively in larger dbh trees. Results from this study update previous findings in other US Northwest states and can be used to produce or improve residue prediction tools for Alaska land managers.


1959 ◽  
Vol 26 (1) ◽  
pp. 95-100
Author(s):  
I. R. Whiteman

Abstract A model is made up of elastoplastic elements, all of which have the same value of Young’s modulus E, but which have different values of yield stress. It is shown that the dimensionless tangent modulus graph Et/E represents the cumulative frequency distribution of those elements which are in the elastic region. From the frequency distribution, the equations for the stress-strain diagram and the hysteresis loop can be written.


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