Potentials for Controlling Bark Percentage of the Commercial Tree Species of British Columbia

1981 ◽  
Vol 57 (4) ◽  
pp. 156-161 ◽  
Author(s):  
J. Harry G. Smith ◽  
A. Kozak

Diameters inside and outside bark from 13 sections were used to define variation in bark percentages for 33 844 trees representing 28 major groups of the commercial tree species of British Columbia. The range of age, height, dbh, and dbh/height associated with each group was determined. Statistical significance of effects of these factors and of up to 12 inventory zones was determined for double bark thickness as a percentage of dbh. Bole bark volumes were compared with wood volumes for trees exceeding two standard deviations of bark percentage at breast height. Thick barked trees were more common and a few have equal portions of wood and bark. Our description of the characteristics of the trees with least or most bark should help guide tree improvement programs. Identification of the extent to which stand factors can influence average bark characteristics may help timber managers grow trees of desired bark proportions.

1982 ◽  
Vol 58 (3) ◽  
pp. 143-145 ◽  
Author(s):  
Julien P. Demaerschalk ◽  
Stephen A. Y. Omule

A means of estimating tree diameter at breast height from stump measurements has many applications. In this paper, metric equations are derived for estimating diameters at breast height from measured stump heights for all commercial tree species in British Columbia by age class and biogeoclimatic zones. The model found best was the same one as used by Alemdag and Honer (1977) for eleven tree species from eastern and central Canada. This prediction system can be incorporated into any local volume equation to derive a tree volume prediction model based on stump diameter and stump height.


1992 ◽  
Vol 68 (5) ◽  
pp. 623-627 ◽  
Author(s):  
Antal Kozak ◽  
Stephen A. Y. Omule

Equations were derived for estimating stump volume, stump inside bark diameter at any given height from ground and diameter at breast height from measured stump height and stump inside bark diameter. The equations were tested on 33 British Columbia commercial tree species groups and the results of four species groups are presented in this paper. This prediction system will play an important role in "waste" or "residue" surveys in British Columbia and in reconstructing the initial stand conditions by estimating diameter at breast height.


1981 ◽  
Vol 57 (3) ◽  
pp. 112-115 ◽  
Author(s):  
A. Kozak ◽  
R. C. Yang

Volume and thickness of bark were studied for 32 species groups of British Columbia. Over 32,000 trees constituted the data base to derive bark volume equations. Because of its simplicity and good predictive power, the equation of Vb = a'HTbDBHcBTd is recommended for bark volume prediction. The possibility to develop bark taper equations and to estimate bark thickness at any given height above breast height were also investigated.


2020 ◽  
Vol 3 (1) ◽  
pp. 66
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer

The wood of Scots pine (Pinus sylvestris L.) shows good properties as building and construction timber but also as furniture or pulp and paper, and thus, is one of the most commercially important European tree species. Scots pine are mostly harvested and processed with a high degree of mechanization. In Northeast Germany (federal states of Brandenburg and Berlin), 36% of harvested Scots pine have a diameter at breast height (DBH) between 7 and 19.9 cm. As a typical industrial wood assortment, a large proportion of the resulting small-sized logs are used in the wood industry to produce boards. Although bark is considered a by-product or waste product of the industry, no actual study has quantified the bark thickness, bark volume, bark mass and bark damage of such Scots pine logs. Therefore, the bark characteristics from 50 logs from 10 different piles were analyzed. Bark volume was quantified using the water displacement method, bark mass by weighing, bark thickness with a precision caliper and bark damage by tape measurements. The diameters of the analyzed 150 log discs were normally distributed and the mean value was 12.9 cm. The results showed average bark damages from 12.0%, which were mostly caused during the felling and processing of logs with the harvester. No significant correlation was found between double bark thickness (mean: 3.0 mm) and the diameter; whereas fresh bark volume (mean: 5.6%) and dry bark mass (mean: 3.3%) were significantly affected by the diameter. As shown for spruce by other authors, bark characteristics may change over time and therefore, should be measured regularly. Moreover, it was shown that bark parameters are site dependent. Thus, quantifying bark characteristics for economically important tree species at both the local and national scale is of great relevance. More detailed analyzes are described by Berendt et al. (2021) [1].


2007 ◽  
Vol 37 (10) ◽  
pp. 1886-1893 ◽  
Author(s):  
Xiaobo Li ◽  
Dudley A. Huber ◽  
Gregory L. Powell ◽  
Timothy L. White ◽  
Gary F. Peter

The importance of integrating measures of juvenile corewood mechanical properties, modulus of elasticity in particular, with growth and disease resistance in tree improvement programs has increased. We investigated the utility of in-tree velocity stiffness measurements to estimate the genetic control of corewood stiffness and to select for trees with superior growth and stiffness in a progeny trial of 139 families of slash pine, Pinus elliottii Engelm. grown on six sites. Narrow-sense heritability estimates across all six sites for in-tree acoustic velocity stiffness at 8 years (0.42) were higher than observed for height (0.36) and diameter at breast height (DBH) (0.28) at 5 years. The overall type B genetic correlation across sites for velocity stiffness was 0.68, comparable to those found for DBH and volume growth, indicating that family rankings were moderately repeatable across all sites for these traits. No significant genetic correlations were observed between velocity stiffness, DBH, and volume growth. In contrast, a significant, but small, favorable genetic correlation was found between height and velocity stiffness. Twenty percent of the families had positive breeding values for both velocity stiffness and growth. The low cost, high heritability and nearly independent segregation of the genes involved with in-tree velocity stiffness and growth traits indicate that acoustic methods can be integrated into tree improvement programs to breed for improved corewood stiffness along with growth in slash pine.


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.


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.


2019 ◽  
Vol 10 (2) ◽  
pp. 125-135
Author(s):  
Jusuf Musić ◽  
Velid Halilović ◽  
Jelena Knežević ◽  
Admir Avdagić ◽  
Aida Ibrahimspahić ◽  
...  

Background and Purpose: Bark thickness and its share in the volume of roundwood are the most important characteristics of the bark, particularly in the process of timber harvesting, and during scaling of processed logs. Therefore it is very important to have at disposal relatively accurate data regarding these characteristics of bark for particular tree species. The main goal of this paper is to investigate the thickness of the bark and its share in the volume of roundwood of Norway spruce. Materials and Methods: The research was carried out in the area of the Canton 10 of the Federation of Bosnia and Herzegovina and it encompassed 393 trees of Norway spruce from 10 cm to 115 cm of thickness at breast height. Measuring of the mean diameter and double thickness of bark was conducted by section method. In total, 4,647 diameters and bark thicknesses were measured in different relative lengths of stems or in average 10.6 measurements per one stem. Results: As an optimal model for the evaluation of double thickness of the bark of Norway spruce depending on mean diameter of roundwood the function with designated determination coefficient of 0.7142 was selected. The obtained results have confirmed the previously defined relations of investigate characteristics, which are as following: a) with the increase of mean diameter of roundwood (section) double bark thickness is increased from 9.26 mm (thickness class 12.5 cm) to 31.65 mm (thickness class 92.5 cm); b) with the increase of mean diameter of roundwood the share of bark in its volume decreased from 14.26% (thickness class 12.5 cm) to 6.73% (thickness class 92.5 cm). Conclusions: By the actual method of estimating bark thickness or the share of bark in the volume of roundwood of Norway spruce in the forestry of the Federation of Bosnia and Herzegovina a significant error was created which increases with the increase of mean diameter. The obtained results point to the necessity of investigation of these bark characteristics in Bosnia and Herzegovina and represent an inevitable starting point for making adequate tables of bark thickness and its percentage share in the volume of roundwood of Norway spruce.


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