scholarly journals MODELOS DE AFILAMENTO PARA Pinus elliottii EM DIFERENTES IDADES, NA REGIÃO DE CAÇADOR, SC

FLORESTA ◽  
2013 ◽  
Vol 43 (3) ◽  
pp. 439 ◽  
Author(s):  
Saulo Jorge Téo ◽  
Alan Marcon ◽  
Tiago Ehlers ◽  
Júlio César Bianchi ◽  
Adriano Peloso ◽  
...  
Keyword(s):  
Pinus Elliottii ◽  
Degree Polynomial ◽  
Stem Form ◽  
Taper Function ◽  
Different Ages ◽  
Polynomial Models ◽  
Old Trees ◽  
Taper Models ◽  
Best Estimates

Os objetivos deste trabalho foram ajustar e selecionar modelos de afilamento para estimar diâmetros a várias alturas e volume total, com e sem casca, de árvores de Pinus elliottii Engelm., na região de Caçador, SC, para estudar a forma dos fustes das árvores de diferentes idades. Ao todo, 78 árvores, com idades de 10, 18 e 27 anos, foram abatidas, cubadas rigorosamente e tiveram os seus volumes obtidos por meio do método de Smalian. Os modelos de afilamento testados foram os Polinômios de 2º e de 5º Graus e o Polinômio de Potências Fracionárias de Hradetzky. A função de afilamento que apresentou melhor desempenho para estimar o diâmetro com e sem casca ao longo do fuste das árvores foram baseadas no Polinômio de Potências Fracionárias de Hradetzky, para as idades de 10, 18 e 27 anos. O Polinômio de 2º Grau propiciou as melhores estimativas de volume total com casca para as idades de 10 e 27 anos e de volume total sem casca para as idades de 18 e 27 anos. Já o Polinômio de Potências Fracionárias apresentou melhores estimativas de volume com casca para 18 anos e de volume sem casca para árvores de 10 anos. Os fustes das árvores de Pinus elliottii apresentam melhor forma nas idades mais avançadas. AbstractTaper models for Pinus elliottii, at different ages, in the region of Caçador - SC. The research aims to fit and select taper models in order to estimate diameters at different heights and total volumes, inside and outside bark, of Pinus elliottii Engelm. trees, in the region of Caçador - SC, Brazil, as well as to analyze  behavior of stem form for trees at different ages. Altogether, 78 trees at 10, 18 and 27 years of age, had been cut and their volumes obtained by Smalian method. The taper models tested were the 2nd and 5th Degree Polynomial and the Hradetzky Polynomial of Fractioned Potencies. The best performance taper function for estimate diameters inside and outside bark throughout the stem were based on the Hradetzky Polynomial of Fractioned Potencies, for 10, 18 and 27 years of age. The 2nd Degree Polynomial provided the best estimates of outside bark volume for 10 and 27 years of age, and of inside bark volume for 18 and 27 years of age, although the Hradetzky Polynomial presented the best estimates of outside bark volume for 18 years of age and of inside bark volume for 10 years old trees. The stems of the Pinus elliottii trees present better form for the oldest tress.Keywords: Polynomial models; profile models; stem form.

scholarly journals MODELOS DE AFILAMENTO E FORMA DOS FUSTES DE EUCALIPTO, EM DIFERENTES QUALIDADES DE SÍTIO

Nativa ◽  
2018 ◽  
Vol 6 ◽  
pp. 832
Author(s):  
Saulo Jorge Téo ◽  
Eder Pereira Miguel ◽  
Rodrigo Geroni Mendes Nascimento
Keyword(s):  
Polynomial Function ◽  
Initial Density ◽  
Eucalyptus Grandis ◽  
Degree Polynomial ◽  
Stem Form ◽  
Site Class ◽  
Volume Calculation ◽  
Taper Function ◽  
Site Classes ◽  
Taper Models

Este trabalho teve como objetivo ajustar e selecionar modelos de afilamento para estimar diâmetros, volume por seção e volume acumulado com casca, ao longo do tronco de árvores de Eucalyptus grandis Hill ex. Maiden, em Rio Verde – GO, para estudar a forma dos fustes das árvores em diferentes classes de sítio. Foram cubadas rigorosamente pelo método de Smalian, 812 árvores em um povoamento florestal cuja densidade inicial foi de 1.111 árvores por hectare, com idade de 80 meses. Os modelos de afilamento testados foram os Polinômios de 2º e de 5º Graus e o Polinômio de Potências Fracionárias e Inteiras de Hradetzky. A função de afilamento mais acurada para estimar os diâmetros e volumes por seção, ao longo do fuste das árvores foi o Polinômio de Hradetzky, para todas as classes de sítio testadas. No entanto, para estimar os volumes acumulados, a função de afilamento de melhor desempenho foi o Polinômio de 5º Grau para as classes de sítio II e III, e o Polinômio de Hradetzky, para a classe de sítio I. Os fustes das árvores de Eucalyptus grandis apresentam melhor forma nos sítios de melhor qualidade, enquanto na pior classe de sítio, apresentam maior conicidade.Palavras-chave: modelos polinomiais, perfil do fuste, Eucalyptus grandis. TAPER MODELS AND STEM FORM OF EUCALYPTUS, IN DIFFERENT SITE QUALITIES ABSTRACT:The objective of this paper was fitting and selecting taper models to estimate diameters, volume section and accumulated volume outside bark, throughout stem of Eucalyptus grandis Hill ex. Maiden trees, in Rio Verde – GO, Brazil, as well as, study the stem form of the trees at different site classes. Altogether, it was measured by Smalian volume calculation procedure, 812 trees of a forest stand with initial density of 1,111 trees per hectare and age of 80 months. The taper models tested was the 2º and 5º Degree Polynomial and the Hradetzky Polynomial of Fractioned and Entire Potencies. The most accurate taper function for estimating diameters and volume section outside bark, throughout stem was Hradetzky Polynomial function, for all site classes tested. However, to estimate accumulated volume outside bark, the best performance was the 5º Degree Polynomial taper function for II and III site classes, and the Hradetzky Polynomial, for the site class I. The stems of the Eucalyptus grandis trees present better form in the sites with better quality, whereas in the poorest site class the stems are more conical.Keywords: polynomial models, stem profile, Eucalyptus grandis.

scholarly journals Stand Stability of Pure and Mixed-Eucalyptus Forests of Different Tree Species in a Typhoon-Prone Area

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 458
Author(s):  
Haiyan Deng ◽  
Linlin Shen ◽  
Jiaqi Yang ◽  
Xiaoyong Mo
Keyword(s):  
Tree Species ◽  
Forest Restoration ◽  
Large Scale ◽  
Stand Structure ◽  
Pinus Elliottii ◽  
Stem Form ◽  
Tree Species Composition ◽  
Eucalyptus Plantation ◽  
Mixed Plantation ◽  
Preservation Rate

Background and Objectives: The stable stand structure of mixed plantations is the basis of giving full play to forest ecological function and benefit. However, the monocultural Eucalyptus plantations with large-scale and successive planting that caused ecological problems such as reduced species diversity and loss of soil nutrients have presented to be unstable and vulnerable, especially in typhoon-prone areas. The objective of this study was to evaluate the nonspatial structure difference and the stand stability of pure and mixed-Eucalyptus forests, to find out the best mixed pattern of Eucalyptus forests with the most stability in typhoon-prone areas. Materials and Methods: In this study, we randomly investigated eight plots of 30 m × 30 m in pure and mixed-Eucalyptus (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill) plantations of different tree species (Neolamarckia cadamba (Roxb.) Bosser, Acacia mangium Willd., and Pinus elliottii var. Elliottii Engelm. × P. caribaea Morelet) on growth status, characterized and compared the distribution of nonspatial structure of the monoculture and mixtures, and evaluated the stand quality and stability from eight indexes of the nonspatial structure, including preservation rate, stand density, height, diameter, stem form, degree of stem inclination, tree-species composition, and age structure. Results: Eucalyptus surviving in the mixed plantation of Eucalyptus and A. mangium (EA) and in the mixed plantation of Eucalyptus and P. elliottii × P. caribaea (EP) were 5.0% and 7.6% greater than those in pure Eucalyptus plantation (EE), respectively, while only the stand preservation rate of EA was greater (+2.9%) than that of the pure Eucalyptus plantation. The proportions of all mixtures in the height class greater than 7 m were fewer than that of EE. The proportions of EA and mixed plantation of Eucalyptus and N. cadamba (EN) in the diameter class greater than 7 m were 10.6% and 7.8%, respectively, more than that of EE. EN had the highest ratio of branching visibly (41.0%), EA had the highest ratio of inclined stems (8.1%), and EP had the most straight and complete stem form (68.7%). The stand stability of the mixed plantation of Eucalyptus and A. mangium presented to be optimal, as its subordinate function value (0.76) and state value (ω = 0.61) of real stand were the largest. Conclusions: A. mangium is a superior tree species to mix with Eucalyptus for a more stable stand structure in the early growth stage to approach an evident and immense stability and resistance, which is of great significance for the forest restoration of Eucalyptus in response to extreme climate and forest management.

scholarly journals DETERMINAÇÃO DAS PROPRIEDADES ENERGÉTICAS DA MADEIRA E DO CARVÃO VEGETAL PRODUZIDO A PARTIR DE Eucalyptus benthamii

FLORESTA ◽  
2014 ◽  
Vol 45 (1) ◽  
pp. 57 ◽  
Author(s):  
Daniela Letícia Nones ◽  
Martha Andreia Brand ◽  
Alexsandro Bayestorff Da Cunha ◽  
Adriel Furtado De Carvalho ◽  
Solange Maria Krug Weise
Keyword(s):  
Chemical Analysis ◽  
Specific Gravity ◽  
Calorific Value ◽  
Biomass Energy ◽  
Energetic Properties ◽  
Different Ages ◽  
End Use ◽  
Immediate Analysis ◽  
Old Trees ◽  
Volumetric Yield

Este trabalho teve como objetivo caracterizar energeticamente a madeira e o carvão vegetal obtidos a partir da espécie Eucalyptus benthamii Maiden & Cambage para duas diferentes idades, 5 e 13 anos. Para a madeira de cada idade, foram confeccionados 48 corpos de prova, com aproximadamente 2 x 2 x 2 cm, que foram utilizados para determinação da massa específica, poder calorífico superior, análise química imediata e carbonização. Após a carbonização, as propriedades energéticas do carvão vegetal foram avaliadas a partir da massa específica aparente, rendimento gravimétrico e volumétrico, poder calorífico superior e análise química imediata. Tanto para a madeira quanto para o carvão vegetal houve influência da idade. A madeira com 13 anos apresentou maior massa específica básica e maior poder calorífico. Porém as diferenças nas propriedades físicas e energéticas da madeira das duas idades não justificam a manutenção da floresta até os 13 anos de idade, quando seu uso final é a geração de energia na forma de carvão. Em relação ao carvão, aquele produzido com madeira de 13 anos apresentou maior rendimento, enquanto o carvão vegetal de 5 anos apresentou melhor qualidade final para uso energético.Palavras-chave: Energia de biomassa; propriedades energéticas; eucalipto. AbstractDetermination of energetic properties of wood and charcoal produced from Eucalyptus benthamii. This research aimed to characterize the energetic properties of wood and charcoal obtained from Eucalyptus benthamii for two different ages, 5 and 13 years. For each timber age, we prepared 48 specimens, approximately 2 x 2 x 2 cm, used to determine specific gravity, calorific value, immediate analysis and carbonization. After carbonization, we evaluated the energetic properties of the charcoal in relation to density, gravimetric and volumetric yield, calorific value and immediate chemical analysis. As the wood as charcoal were influenced by age. The 13 years old timber revealed higher specific gravity and higher calorific value. However, the differences in the physical and energetic properties of the wood of the two ages do not justify maintaining the forest until the age of 13, as its end use is generation of energy as coal. The charcoal produced from 13 years old trees had the highest yield, while the charcoal from 5 years old trees had better quality to energy usage.Keywords: Biomass energy; energy properties; Eucalyptus.

What factors should be accounted for when developing a generalized taper function for black wattle trees?

2020 ◽  
Vol 50 (11) ◽  
pp. 1113-1123
Author(s):  
Mateus Niroh Inoue Sanquetta ◽  
John Paul McTague ◽  
Henrique Ferraço Scolforo ◽  
Alexandre Behling ◽  
Carlos Roberto Sanquetta ◽  
...  
Keyword(s):  
Solid Wood ◽  
Auxiliary Variables ◽  
Stem Form ◽  
Mixed Effect ◽  
Individual Tree ◽  
Taper Function ◽  
Black Wattle ◽  
Taper Equation ◽  
Total Tree ◽  
Mixed Effect Modeling

Taper functions have been widely used for various purposes. Several functions were developed and successfully applied; however, most of these functions fail to account for the influence of stand-level and individual-tree effects of variation on the stem profile. Hence, we aimed in this study to assess how these factors influence the stem profile of black wattle (Acacia mearnsii De Wild.) trees in southern Brazil. There is a notable necessity for developing a domestic market for black wattle solid wood. The database was composed of 218 black wattle trees at age 10 years distributed across the state of Rio Grande do Sul, Brazil. A dimensionally compatible taper equation combined with the mixed-effect modeling approach was used. Additionally, auxiliary variables were included to build a generalized taper function that explains stem form variations. In general, all variables showed a significant influence on the stem profile, except the crown ratio. The inclusion of relative spacing and tree hierarchical position in the taper function resulted in higher accuracy when estimating stem diameters and total tree volume. This study indicates that accounting for attributes at the stand and individual-tree levels may improve stem profile predictions, as well as the biological soundness of the taper function.

Stem Form Changes in Unthinned Slash and Loblolly Pine Stands Following Midrotation Fertilization

1988 ◽  
Vol 12 (2) ◽  
pp. 90-97 ◽  
Author(s):  
Steven B. Jack ◽  
Earl L. Stone ◽  
Benee F. Swindel
Keyword(s):  
Loblolly Pine ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Stem Analysis ◽  
Stem Form ◽  
Cross Sectional ◽  
Pine Stands ◽  
Volume Equation ◽  
Volume Equations ◽  
Fertilization Experiments

Abstract Trees from fertilization experiments in four slash pine (Pinus elliottii Engelm. var. elliottii) and two loblolly pine (P. taeda L.) stands were subjected to stem analysis. The stands were unthinned and were between 13 and 25 years old at time of treatment. Profiles of radial width and cross-sectional area were examined to determine whether fertilization changed stem form. Proportionally greater growth on the upper stems of fertilized trees in the years immediately after treatment led to underestimating response with conventional volume equations. After 5 or more years, however, form was little changed and a single volume equation was appropriate for both fertilized and unfertilized trees.² South. J. Appl. For. 12(2):90-97.

scholarly journals MODELOS POLINOMIAIS PARA REPRESENTAR O PERFIL E O VOLUME DO FUSTE DE Eucalyptus urophylla NA REGIÃO NORTE DO ESTADO DE GOIÁS

FLORESTA ◽  
2011 ◽  
Vol 41 (2) ◽  
Author(s):  
Eder Pereira Miguel ◽  
Sebastião do Amaral Machado ◽  
Afonso Figueiredo Filho ◽  
Julio Eduardo Arce
Keyword(s):  
Standard Error ◽  
Raw Material ◽  
Eucalyptus Urophylla ◽  
Forest Stands ◽  
Timber Volume ◽  
Multiple Products ◽  
Absolute Volume ◽  
Taper Function ◽  
Polynomial Models ◽  
Volume Estimates

A possibilidade de estimar o volume madeirável de um determinado empreendimento florestal e paralelamente a isso fazer a predição de múltiplos produtos advindos do mesmo, viabilizam significativos ganhos na administração dos povoamentos florestais. É claro e evidente que a estimativa precisa do volume de um povoamento florestal cada vez mais vem se tornando prática indispensável nas empresas ligadas ao setor madeireiro, e a possibilidade de agregar valores nas florestas, sejam plantadas ou nativas, é possível uma vez que haja meios de diversificar os produtos madeireiros, nos casos em que o resíduo da elaboração de um produto torna-se matéria-prima para elaboração de outro. Esta pesquisa teve como objetivo avaliar a acuracidade dos modelos polinomiais propostos por Schöepfer (1966), Kozak et al. (1969) e Hradetzky (1976), para estimativa de diâmetros e volumes ao longo do fuste de Eucalyptus urophylla, em plantio localizado no município de Niquelândia, no estado do Goiás. A base de dados foi composta por 48 árvores cubadas rigorosamente pelo método de Smalian. A avaliação da precisão dos modelos foi feita através da análise de resíduos, Erro Padrão Residual (Syx) e Coeficiente de Determinação (R²). O modelo que gerou as melhores estatísticas para a estimativa dos diâmetros ao longo do fuste foi o modelo proposto por Hradetzky (1976). Já para a estimativa do volume total com e sem casca, o polinômio do 5° grau proposto por Schöepfer (1966) foi um pouco superior.Palavras-chave: Modelagem; função de afilamento; volumetria. AbstractPolynomial models to represent profile and volume of Eucalyptus urophylla stem in north region of Goias State, Brazil. Timber volume estimates of a certain forest due to its multiple products prediction may increase incomes from forest stands management. It is already clear that precise volume survey of a forest is essential to timber companies in order to increase commercial value to forests (native or planted ones), even by diversification of products, transforming residues into raw material. This research has as its main aim to evaluate accuracy of polynomial models proposed by Schöpfer (1966), Kozak et al. (1969) and Hradetzky (1976) to estimate diameter and volume along Eucalyptus urophylla stem, in the region of Niquelândia, Goiás State. The database was composed by 48 trees that had their absolute volume calculate by the Smalian method. The models precision was evaluated by analysis of residuals, the Standard error of estimate (Syx) and the determination coefficient (R²). The model that produced the best statistics for diameter estimation along the stem was the model proposed by Hradetzky (1976), as well as the 5th degree model proposed by Schöepfer (1966) proved to be superior to estimate total volume.Keywords: Modeling; taper function; volumetry.

Acoustic and bending properties in Pinus elliottii beams obtained from trees of different ages

2012 ◽  
Vol 59 (2) ◽  
pp. 127-132 ◽  
Author(s):  
Raquel Gonçalves ◽  
Cinthya Bertoldo Pedroso ◽  
Marcus Vinicius Massak
Keyword(s):  
Pinus Elliottii ◽  
Bending Properties ◽  
Different Ages

Influence of species proportion and timing of establishment on stem quality in mixed red alder – Douglas-fir plantations

2004 ◽  
Vol 34 (4) ◽  
pp. 863-873 ◽  
Author(s):  
Amy T Grotta ◽  
Barbara L Gartner ◽  
Steven R Radosevich
Keyword(s):  
Stand Structure ◽  
Stand Density ◽  
Douglas Fir ◽  
Stem Form ◽  
Mixed Stands ◽  
Red Alder ◽  
Stem Quality ◽  
Multiple Stems ◽  
Old Trees ◽  
Species Proportion

The relationships among stand structure, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) branch characteristics, and red alder (Alnus rubra (Bong.)) stem form attributes were explored for 10- to 15-year-old trees growing in mixed Douglas-fir – red alder plantations. Treatments included a range of species proportions, and red alder was either planted simultaneously with Douglas-fir or after 5 years. Both replacement effects (total stand density held constant) and additive effects (stand density doubled) of competition were considered. When the two species were planted simultaneously and red alder proportion was low, red alder trees had low crown bases and much stem defect (lean, sweep, and multiple stems). Douglas-fir grew slowly when the two species were planted simultaneously. When red alder planting was delayed, species proportion did not affect red alder stem form, and height to the base of the Douglas-fir live crown decreased with increasing red alder proportion. Doubling Douglas-fir density increased the height to the base of the Douglas-fir live crown; however, doubling stand density by adding red alder did not affect Douglas-fir crown height. Douglas-fir lumber coming from mixed stands may be inferior because of the changes in knot characteristics associated with these different patterns of crown recession. In stands with a low proportion of red alder, red alder product recovery may be compromised because of the stem defects described above.

scholarly journals Analiza regresji z programem R – przykład użycia w badaniach politologicznych

2020 ◽  
Vol 2020 (55) ◽  
pp. 396-405
Author(s):  
Mateusz Wajzer ◽  
Monika Cugier-Syguła
Keyword(s):  
Political Science ◽  
Voter Turnout ◽  
Regression Models ◽  
Degree Polynomial ◽  
Postgraduate Students ◽  
Statistical Procedures ◽  
R Program ◽  
Polynomial Models ◽  
The Creation ◽  
Second Degree

The aim of the article is to present the basic functionalities of the R program for the creation of regression models describing political phenomena. A database of voter turnout during the 2014 U.S. Congress elections categorised according to voters’ age was used for the analyses. The statistical procedures (linear and second-degree polynomial models) applied were discussed in detail, with paths to their respective commands being provided. The article is addressed primarily to postgraduate students in political science and related disciplines, as well as to researchers who have never used the R program before.

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