Influence of tree height and diameter on wood basic density, cellulose and fibre characteristics in Melia dubia Cav. families

2020 ◽  
Vol 17 (2) ◽  
pp. 138-144
Author(s):  
Ravindra Kumar Dhaka ◽  
R. P. Gunaga ◽  
S. K. Sinha ◽  
N. S. Thakur ◽  
M. J. Dobriyal
Author(s):  
Gabriel Marcos Vieira Oliveira ◽  
José Márcio de Mello ◽  
Carlos Rogério de Mello ◽  
José Roberto Soares Scolforo ◽  
Eder Pereira Miguel ◽  
...  

Nativa ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 615-624
Author(s):  
Humberto Fauller De Siqueira ◽  
Evelym Poliana Santos Patrício ◽  
Michael Douglas Roque Lima ◽  
José Benedito Guimarães Junior ◽  
Angélica de Cássia Oliveira Carneiro ◽  
...  

Estudos que visem ampliar o conhecimento das madeiras oriundas do cerrado podem contribuir com o correto manejo das espécies. O objetivo deste estudo foi avaliar a qualidade da madeira e do carvão vegetal de três espécies do cerrado (Tachigali vulgaris, Myracrodruon urundeuva e Amburana cearensis) para fins energéticos. Foram amostradas duas árvores por espécie e, destas, foram retirados discos da base, a 25, 50, 75 e 100% da altura total. Para a madeira, determinou-se longitudinalmente a densidade básica, composição química, estoque de carbono, poderes caloríficos superior (PCS) e inferior (PCI) e densidade energética. As carbonizações da madeira foram realizadas em forno elétrico, com temperatura final de 450 ºC e taxa de aquecimento de 1,67 ºC.min-1. A posição longitudinal de amostragem não influenciou a densidade da madeira. A madeira de M. urundeuva apresentou maior densidade básica e PCS, bem como menor teor de materiais voláteis. O carvão da espécie T. vulgaris apresentou a menor densidade aparente (298 kg.m-3) e baixo teor de cinzas (1,14%), porém elevado teor de carbono fixo e PCS. O carvão vegetal da espécie M. urundeuva se destacou com elevada densidade relativa aparente (475 kg.m-3). A ordem das melhores espécies é: M. urundeuva, A. cearensis e T. vulgaris. Palavras-chave: energia renovável; espécies nativas; potencial energético; qualidade do carvão.   ASSESSMENT OF THREE NATIVE WOODS FROM CERRADO OF GOIÁS FOR THE ENERGY PURPOSES   ABSTRACT: Studies aimed at expanding the knowledge of woods from cerrado can contribute to the correct management of the species. The aim of this study was to evaluate the quality of wood and charcoal of three species from cerrado (Tachigali vulgaris, Myracrodruon urundeuva, and Amburana cearensis) for energy purposes. Two trees per species were sampled and, from these, disks were removed from the base, at 25, 50, 75, and 100% of the total height. For wood, the properties basic density, chemical analysis, carbon stock, higher (HHV) and lower (LHV) heating values were determined longitudinally. Carbonizations were carried out in a muffle furnace with a final temperature of 450 ºC and heating rate of 1.67 ºC.min-1. There was no effect of longitudinal position under the wood basic density. Myracrodruon urundeuva wood had the highest basic density and HHV, as well as the lowest content of volatile matters. The Tachigali vulgaris charcoal had the lowest bulk density (298 kg.m-3) and low ash content (1.14%), but a high content of fixed carbon and HHV. Charcoal of the species M. urundeuva stood out with high apparent relative density (475 kg.m-3). The order of the best species is M. urundeuva, A. cearensis, and T. vulgaris. Keywords: renewable energy; native species; energy potential; charcoal quality.


Author(s):  
Yanhua Zhang ◽  
Shengzuo Fang ◽  
Ye Tian ◽  
Linlin Wang ◽  
Yi Lv

AbstractPoplar is raw material for various panel, paper and fiber products. The 12 sample trees of clone Nanlin-895 from four spacings were destructively harvested after thirteen growing seasons to assess the influence of spacing on radial growth and wood properties. Spacing significantly affected tree-ring width and wood basic density (p < 0.05) but not fiber traits. The highest diameter and wood basic density at breast height (1.3 m) was in 6 m × 6 m and 3 m × 8 m spacings, respectively. However, no significant differences in tree-ring width, wood basic density and fiber traits were observed among the four sampling directions in discs taken at 1.3 m for each spacing. Growth rings from the pith and tree heights had significant effects on wood basic density and fiber anatomical characteristics, highlighting obvious temporal-spatial variations. Pearson correlation analysis showed a significantly negative relationship of tree-ring width to wood basic density, fiber length and fiber width, but a significantly positive relationship to hemicellulose. There was no relationship with cellulose and lignin contents. Based on a comprehensive assessment by the TOPSIS method, the 6 m × 6 m spacing is recommended for producing wood fiber at similar sites in the future.


2010 ◽  
Vol 18 (6) ◽  
pp. 465-472 ◽  
Author(s):  
Cristóbal Galleguillos-Hart ◽  
M. Paulina Fernández ◽  
Andrés Guesalaga

2020 ◽  
Vol 83 (3) ◽  
pp. 172-179
Author(s):  
H. Nickolas ◽  
D. Williams ◽  
G. Downes ◽  
P. A. Harrison ◽  
R. E. Vaillancourt ◽  
...  

FLORESTA ◽  
2010 ◽  
Vol 40 (4) ◽  
Author(s):  
Péricles Silveira

O objetivo principal desta pesquisa foi estimar pelo método da derivação do volume comercial, e comparar com a estimativa realizada por uma equação previamente selecionada para biomassa, o estoque de biomassa e carbono em um fragmento de Floresta Ombrófila Densa localizado nos municípios de Presidente Nereu Ramos e Apiúna, no estado de Santa Catarina. Com as informações de biomassa total, biomassa comercial, densidade básica da madeira, volume comercial e teores de carbono determinou-se o fator de expansão médio, por espécie e por classes de DAP. Estimou-se também, conforme o método de estimativa, a quantidade de dióxido de carbono removido da atmosfera e o valor monetário da floresta. Estes resultados mostraram que as estimativas encontradas pelo método da derivação de volume comercial em estoque de biomassa e carbono, apesar de até o momento ter sido pouco explorado, são confiáveis por estarem próximas às estimativas encontradas pela equação para biomassa assim como dos trabalhos realizados atualmente em florestas de formação natural.Palavras-chave:  Biomassa; carbono; fator de expansão de biomassa; modelos para biomassa e carbono. AbstractAbove ground biomass and carbon stock estimation through the commercial volume derivation in a Dense Ombrophyllous Forest fragment. The objective of this research was to estimate biomass and carbon amounts through the commercial volume derivation in an Atlantic Rain Forest fragment located in Presidente Nereu Ramos and Apiúna counties, Santa Catarina State, Brazil, and compare the results with a previously selected equation. Using the total biomass, commercial biomass, wood basic density, commercial volume, and carbon content, the average expansion factor by species and DBH classes was calculated. It was also estimated the CO2 amount absorbed from the atmosphere and the monetary value of the forest. The results showed that the estimations obtained through the commercial volume derivation method, although not common, are reliable when compared to the selected biomass equation and the results from other studies carried out in native forests.Keywords: Biomass; carbon; biomass expansion factor; biomass and carbon models.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ezekiel Edward Mwakalukwa ◽  
Henrik Meilby ◽  
Thorsten Treue

Tools to accurately estimate tree volume and biomass are scarce for most forest types in East Africa, including Tanzania. Based on a sample of 142 trees and 57 shrubs from a 6,065 ha area of dry miombo woodland in Iringa rural district in Tanzania, regression models were developed for volume and biomass of three important species,Brachystegia spiciformisBenth. (n = 40),Combretum molleG. Don (n = 41), andDalbergia arbutifoliaBaker (n = 37) separately, and for broader samples of trees (28 species,n = 72), shrubs (16 species,n = 32), and trees and shrubs combined (44 species,n = 104). Applied independent variables were log-transformed diameter, height, and wood basic density, and in each case a range of different models were tested. The general tendency among the final models is that the fit improved when height and wood basic density were included. Also the precision and accuracy of the predictions tended to increase from general to species-specific models. Except for a few volume and biomass models developed for shrubs, all models hadR2values of 96–99%. Thus, the models appear robust and should be applicable to forests with similar site conditions, species, and diameter ranges.


2018 ◽  
Vol 42 (2) ◽  
Author(s):  
Antonio José Vinha Zanuncio ◽  
Amélia Guimarães Carvalho ◽  
Angélica de Cassia Oliveira Carneiro ◽  
Mario Tomazello Filho ◽  
Paulina Valenzuela ◽  
...  

ABSTRACT Eucalyptus wood from adult trees is used for several purposes; however, the wood of younger trees has limited use. This study aims to characterize and propose uses of two-year-old eucalyptus wood. Six two-year-old Eucalyptus grandis × Eucalyptus urophylla clones have been selected and their anatomical, ultrastructural, physical and mechanical wood characteristics evaluated. The wood of Clone A shows more robust fibers with better microfibril arrangement, resulting in better mechanical properties, and therefore, a better performance for structural use. Clone F showed a low variation of wood basic density in the radial direction, facilitating its machinability, and with the Clone B, showed a lower anisotropy, and therefore, the wood is recommended for locations with high variations of humidity. The heterogeneity of the wood characteristics of the evaluated clones confirms the need for further studies, to choose those most adequate to each use.


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