Integrated system of equations for estimating stem volume, density, and biomass for Australian redcedar (Toona ciliata) plantations

2017 ◽  
Vol 47 (5) ◽  
pp. 681-689 ◽  
Author(s):  
Natalino Calegario ◽  
Timothy G. Gregoire ◽  
Tatiane Antunes da Silva ◽  
Mario Tomazello Filho ◽  
Joyce A. Alves

A system of equations is proposed to assess the stem wood density variation of Toona ciliata M. Roem. growing in Brazilian plantations. As a taper function, a third-degree polynomial was fitted and the stem radius squared (r2), the dependent variable, was estimated as a function of diameter at breast height (dbh), total height (ht), and radius (r) at height (h). A nonlinear function was fitted to estimate wood density variation, having as the independent variable the ratio of r to h. The stem mass was estimated by integrating the product of stem volume and wood density. Stem measurements from a group of 72 trees of T. ciliata were used to fit the taper equation. A group of six trees was selected and a wood density database was created using X-ray technology. Both the taper and the nonlinear functions performed well in estimating the radius and the wood density. The within-tree wood density systematically increased from pith to bark and from the base to the top of the tree. With the density varying from base to top, the estimated mass of the stem, compared with the mass estimated using wood density value at dbh, had a bias of 4.2%. When the density variations from base to top and from pith to bark of the tree were considered, the estimated mass had a bias of 1.5%.

2021 ◽  
pp. 1-12
Author(s):  
Damon Vaughan ◽  
David Auty ◽  
Thomas Kolb ◽  
Joseph Dahlen ◽  
Andrew J. Sánchez Meador ◽  
...  

In the southwestern United States, land managers are implementing large-scale forest restoration projects involving treatments designed to improve forest health, protect ecosystem services, and reduce the risk of catastrophic wildfire in overstocked ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests. A better understanding of wood properties is necessary to improve the currently limited markets for the woody byproducts generated by these treatments. Therefore, our objective was to investigate variations in ponderosa pine wood density across the northern Arizona landscape. We sampled trees from 18 naturally regenerated stands and used X-ray densitometry to quantify the radial and axial variation within and among trees. We modeled within-stem wood density patterns using generalized additive models, and investigated the effects of climatic variation using response function analyses. Additionally, we tested the effects of site-level predictors on whole-tree wood density. We found high variability in radial wood density profiles among trees in our stands compared with that observed in studies of other species grown in plantations — perhaps due to high genetic variation within naturally regenerated stands. Wood density was negatively correlated with precipitation at annual and most quarterly intervals, except for a positive correlation with late-summer monsoon precipitation. The high wood density variation we found among trees highlights the need for further investigation of controls over wood properties in natural nonplantation forests.


2015 ◽  
Vol 2 (1) ◽  
pp. 625
Author(s):  
Rizki Maharani ◽  
Andrian Fernandes

<p>S. leprosula and S. parvifolia are widely developed as source of high quality wood. The quality of wood could be affected by nutrient elements. It is important to measure the nutrients contained in tree stem including wood density and fiber length due to their influence in tree growth. This research aims to know correlation between wood density and fiber length with distribution of essential macro-nutrients; N, P and K on stem base of S. leprosula and S. parvifolia trees. Wood density measurement followed DIN 2135 standard method, fiber length measurement followed FPL method, and nutrient measurement used AAS method. Further, the observation data was analyzed using SPSS 16 software. Wood density and fiber length on stem bases of both of tree species tended to increase radially from section nearby the pith to section nearby the bark respectively. Wood density of S. leprosula ranged from 0.333-0.362 with 1.279-1.343 µm in fiber length, while wood density of S. parvifolia ranged from 0.285-0.346 with 1.497-1.805 µm in fiber length. Distribution of nutrient N, P and K of stem base from pith to bark also tended to increase. On S. leprosula, nutrient elements N, P, K had significant correlation with wood density and fiber length. On S parvifolia, nutrient elements N, P, K had a significant correlation with wood density. Meanwhile, nutrient elements N, P, K had a non significant correlation with fiber length.</p><p><br /><strong>Keywords</strong> : Shorea leprosula, Shorea parvifolia, base of the stem, wood quality distribution, nutrient distribution.</p>


FLORESTA ◽  
2020 ◽  
Vol 50 (3) ◽  
pp. 1518
Author(s):  
Marcos Behling ◽  
Henrique Soares Koehler ◽  
Alexandre Behling

A system of equations widely used in Forest Engineering by the international community of researchers consists of a combination of a volumetric function and a taper function, with the purpose of making volume estimates compatible. When using the volume function and the taper function in a system, the result of the volume estimated by the two functions should be compatible, meaning that the volume estimated by the volumetric function should not differ from the volume obtained by integrating the taper function. Thus, the purpose of this paper was to develop and present the procedures of a system of equations to make volume estimates from both volume and taper equations compatible, and then compare it to the traditional approach, which is used in forestry companies. The procedures proposed were applied to a data set on the Acacia mearnsii De Wild. (black wattle) at sites where the plantation of this species is concentrated in the state of Rio Grande do Sul. The data set included 343 trees ranging from 5 to 10.75 years of age. It was noted that the lack of volume compatibility, in absolute terms, grows exponentially with the size of the tree. The quality of the estimates using the system of compatible equations did not differ from those obtained from the traditional model, therefore, the former is preferable. Furthermore, it was noted that the residuals from the volume and taper equations are correlated, which suggests that the system of equations be fitted simultaneously.


1987 ◽  
Vol 17 (7) ◽  
pp. 675-682 ◽  
Author(s):  
A. Corriveau ◽  
J. Beaulieu ◽  
F. Mothe

During genetic sampling of white spruce in 1984, increment cores were taken from 80 populations in order to study wood density variation within species in natural Quebec forests. Results show that wood density differences exist between populations and that wood density is negatively correlated with the width of the growth rings; however, some trees and some populations exhibit both high wood density and rapid growth. A moderate positive link was found between juvenile and mature wood densities at both the individual and population levels. Therefore, breeding programs for the improvement of wood density could be based on selections made on juvenile wood.


2010 ◽  
Vol 34 (2) ◽  
pp. 84-90 ◽  
Author(s):  
Michael J. Aspinwall ◽  
Bailian Li ◽  
Steven E. McKeand ◽  
Fikret Isik ◽  
Marcia L. Gumpertz

Abstract Models were developed for predicting whole-stem α-cellulose yield, lignin content, and wood density in 14- and 20-year-old loblolly pine across three different sites. Also, the relationships between juvenile-, transition-, and mature-wood α-cellulose yield, lignin content, and wood density at breast-height and overall whole-stem wood property values were examined. Whole-stem wood property weighted averages were calculated by taking 12-mm core samples at breast height and at 2.4-m incremental heights up each tree, and breast-height wood property values were then used to predict whole-stem weighted averages. Despite large differences in growth across sites and both ages, whole-stem models based on whole cores taken at breast height were not significantly different among sites, and coefficients of determination (R2) were 0.87, 0.74, and 0.78 for α-cellulose, lignin, and wood density, respectively. Generally, whole-stem prediction models based on sections of wood at breast height were not significantly different among sites and were less effective than cores as predictors, explaining between 39 and 82% of the variation in whole-stem wood traits. The results of this study indicate that the relationship between breast height and whole-stem wood chemical properties (and density) is predictable and consistent across sites in both juvenile and mature loblolly pine.


2007 ◽  
Vol 37 (5) ◽  
pp. 895-906 ◽  
Author(s):  
Nuno António ◽  
Margarida Tomé ◽  
José Tomé ◽  
Paula Soares ◽  
Luís Fontes

The objective of this study was to develop a system of compatible equations to estimate eucalyptus ( Eucalyptus globulus Labill.) tree aboveground biomass and biomass of tree components for forest biomass prediction across regional boundaries. Data came from 441 trees sampled on several sites (99 and 14 plots in planted and coppice regenerated stands, respectively) representative of the eucalyptus expansion area in Portugal. The system of equations, simultaneously fitted using seemingly unrelated regression, was based on the allometric model for the biomass of stem wood, stem bark, leaves, and branches. Total aboveground biomass was expressed as the sum of the biomass of the respective tree components. The study allowed the following conclusions: (i) there is a significant increase in the predictive ability of the models that include height (stem components) or crown length (crown components) as an additional predictor to diameter at 1.30 m; (ii) there is a clear effect of the stage of development of the stand on tree allometry, with a decreasing pattern of the allometric constants; (iii) no effect of stand density, site index or climate on tree allometry was found; and (iv) for practical purposes, the same system of equations can be used for planted and coppice regenerated stands.


1990 ◽  
Vol 17 (6) ◽  
pp. 615 ◽  
Author(s):  
DW Sheriff ◽  
DA Rook

In Pinus radiata a negative relationship has usually been found between stem volume and wood density. Clones previously found to produce wood of high or low density were used to investigate interrelationships between above-ground partitioning coefficients, carbon gain, and wood density. Cuttings had been propagated c. 5 years earlier, and were 5 m high when the experiment started. Potential carbon gain of the tree was manipulated by using two light environments; one with a light level c. 1.5 times the other. Measurements were of changes in stem, branch, and needle biomass during the 305-day experiment, of rates of photosynthesis, and of wood density by β-ray densitometry and microscopy; densities determined by the two techniques were the same. For all but two trees, wood densities of a stem and its branches were the same; for the other two, stem density was 13% less than that of their branches. Trees in the high light treatment accumulated more above-ground biomass, but there was no simple relationship between wood density and either above-ground growth or photosynthesis. With one exception, partitioning of photosynthate to stem was constant. In most cases, proportionately less photosynthate (30-80%) was allocated to below-ground biomass in the low light treatment than in the high light treatment (60-80%).


2019 ◽  
Vol 40 (2) ◽  
pp. 731
Author(s):  
Natan Teles Cruz ◽  
Braulio Maia de Lana Sousa ◽  
Jailson Lara Fagundes ◽  
Alfredo Acosta Backes ◽  
José Dantas Gusmão Filho ◽  
...  

This study was undertaken to examine the herbage accumulation dynamics and structural characteristics of digit grass subjected to different defoliation frequencies in the period of January 2015 to February 2016. Four defoliation frequencies [very high (25 cm), high (35 cm), medium (45 cm), and low (55 cm)] were evaluated in two periods of the year [greater insolation (September to March) and lesser insolation (April to August)]. The experiment was set up as a randomized-block design with four replicates. Overall, the decreasing defoliation frequencies increased the cutting interval; leaf area index; total-herbage, stem, and dead-herbage accumulation rates; and percentages of stems and dead herbage. This reduction in defoliation frequency also resulted in a lower leaf accumulation rate and percentage of leaves. In overall terms, digit grass showed higher total-herbage, leaf, and stem accumulation rates; percentages of stems and dead herbage; stem volume density; and tiller density in the period of greater insolation. In the period of lesser insolation, however, digit grass exhibited a lower dead-herbage accumulation rate and a lower percentage of dead herbage. Less frequent defoliations increase the herbage accumulation rates of digit grass, but result in a less desirable morphological composition.


2020 ◽  
Vol 66 (No. 7) ◽  
pp. 299-308
Author(s):  
Ivan Sopushynskyy ◽  
Ruslan Maksymchuk ◽  
Yaroslav Kopolovets ◽  
Sezgin Ayan

The aim of this paper is to present the intraspecific differentiation of the curly silver fir (Abies alba Mill.) by the wood structure growing in the Ukrainian Carpathians. To find the morphological distinctions by using the silvicultural and biometric methods, 50 silver fir trees with anomalous wavy-relief stemwood formations were investigated. The trees aged from 94 to 132 years were characterised by the diameter at breast height of 32–59 cm. The length of the wave-grained stemwood varied from 6 to 11.5 m. The amplitude of the wood fibre waves varied from 4.4 to 24.1 mm. The smallest values of the amplitude of the wave-grained wood corresponded to the smaller wavelengths. The significant differences in the wood density and annual growth between the silver fir trees with the straight-grained and wave-grained stem wood were determined. The number of annual rings in 1 cm of the curly silver fir was 27.1% lower and 22.7% higher than the same characteristics for the straight-grained stem wood. The obtained linear equation described the relationship between the number of annual rings in 1 cm and the basic wood density of the silver fir with the straight-grained wood. The aesthetic features of the curly silver fir stem wood were discussed in the subject area of a new niche of exclusive wood products.


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