Volume and Taper Equations for P. taeda (L.) and E. grandis (Hill ex. Maiden)

Rachid-Casnati, Cecilia; Mason, Euan G.; Woollons, R. C.; Resquín, Fernando

doi:10.31285/agro.18.464

Cited by 16 publications

(7 citation statements)

References 20 publications

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“…A comparison of statistics of fit of wood including bark volume equations from three studies (the study reported here, Casnati and Muhairwe) provides the following results. The Eucalyptus grandis volume equation(Casnati et al 2014) with its RMSE value of 0.0422 m 3 was comparably more precise than the Eucalyptus globoidea model developed herein (RMSE values 0.1439786 m 3 ). The Eucalyptus globoidea MAB value was higher than the lowest (0.0245 m 3 ) reported for Eucalyptus grandis.…”

mentioning

confidence: 57%

“…Model efficiency was the best for Eucalyptus globoidea based on EF value (0.971). The Eucalyptus globoidea taper equation was a less precise model as it had a larger RMSE value (2.474088 cm) compared to Rachid's model (0.8937 cm)(Casnati et al 2014). The MAB value of 1.647877 cm was also higher than the lowest (0.6747 cm) reported for Eucalyptus grandis.…”

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confidence: 71%

“…There are a few publications about Eucalyptus species taper and volume equations. Rachid's study compared several taper and volume equations with emphasis on testing the suitability of compatible taper equations(Casnati et al 2014). Among two species one of them is Eucalyptus grandis W.Hill Muhairwe (1999).…”

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confidence: 99%

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Developing fully compatible taper and volume equations for all stem components of Eucalyptus globoidea Blakely trees in New Zealand

Boczniewicz

Mason

Morgenroth

2022

NZJFS

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Background: Individual-tree taper and volume equations are essential for forest management. They provide estimates of volume that are incorporated into plot-level volume equations and also into growth and yield models to estimate volumes per hectare in forest crops. Moreover, taper equations allow forest managers to estimate dimensions of logs that can be cut from stems in their forests when they have measured diameters at breast height and heights of trees in inventories. Compatible taper and volume equations have the property that the same individual tree volume can be estimated either from the tree volume equation or by integrating the taper equation. Durable eucalypt species such as Eucalyptus globoidea Blakely, however, have especially valuable heartwood and so managers require estimates of the volumes and shapes of heartwood zones within trees. Simple overall wood taper and volume equations would therefore be inadequate. Methods: 74 Eucalyptus globoidea trees were destructively sampled in 8 different trial plots throughout New Zealand. Tree ages were 7 to 29 years old, the DBHs were 11 to 67.6 cm and the heights were 7.2 to 35.4 m. All trees were felled and lengths and taper diameters outside bark were measured. To measure taper diameters of heartwood and sapwood, discs were cut at irregular intervals along the stems. Heartwood and sapwood components were identified by applying methyl orange dye and quantified using image analysis. In this study we extended compatibility so that sums of estimated volumes of separate components of stems, bark, sapwood and heartwood, would equal overall tree volume estimates. In addition, taper equations were made for outside bark, inside bark and heartwood that were compatible with their respective volume equations. Parameters of five volume equations for whole stem, whole wood, bark, sapwood, and heartwood were simultaneously estimated. Compatible taper equations for whole stem, stem wood and heartwood were estimated so that they were compatible with the volume equations, thereby creating a fully compatible system. Results: Root mean squared error (RMSE) of volume models were 0.1248298 m3 for heartwood, 0.05496807 m3 for sapwood, 0.1539625 m3 for wood inside bark, 0.1108201 m3 for bark and 0.1439786 m3 for wood including bark. RMSE of taper models was 2.572765 cm for heartwood, 2.348552 cm for wood inside bark and 2.474088 cm for wood including bark. Conclusions: A compatible system of multiple taper and volume equations can be fitted through the simultaneous fitting of parameters with minimal bias and precision levels of ± 0.055-0.154 m3 for volume equations and ± 2.35 to 2.57 cm for taper equations. Leave-one-out cross-validation of the fitted models yielded very similar levels of precision and bias to those encountered when fitting models with the entire dataset.

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confidence: 57%

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confidence: 71%

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Developing fully compatible taper and volume equations for all stem components of Eucalyptus globoidea Blakely trees in New Zealand

Boczniewicz

Mason

Morgenroth

2022

NZJFS

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“…in 2002, 2005, 2007, 2008, 2009, 2011, 2015, 2018, 2019, and 2021. Total individual volume under bark (Vi, m 3 .tree) was estimated applying equation 1 [48], and the total volume per hectare (Vht, m 3 .ha -1 ) was calculated as the sum of individual volumes of each plot, related to one hectare. 𝑉𝑖 = 0.00003242 * 𝐷𝐵𝐻 .…”

Section: Growth and Competitionmentioning

confidence: 99%

Impact of Thinning on the Yield and Quality of <em>Eucalyptus grandis</em> Wood at Harvest Time

Resquin,

Baez,

de Freitas

et al. 2024

Preprint

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To understand how the thinning strategies impacts on wood quality and quantity for different purposes is of interest, considering that the management of plantations is carried out with parameters that have yet to be validated for different growth conditions. This work evaluated contrasting thinning regimes applied early at two moments of the crop cycle. With an initial population of 840 trees.ha-1, two thinning with populations ranging from 700 to 400, and from 400 to 100 trees.ha-1 were applied at 1.5 and 7.3 years, respectively. Growth analyses were carried out from the ages of 1.5 to 20.8 years considering: total height, diameter at breast height, individual volume, total and commercial volume per hectare, mean annual increase and current annual increase. At final age, contrasting populations of 100, 250 and 400 trees.ha-1 were sampled to assess wood density, and mechanical properties (bending and compression on small scale clear samples). The values of individual growth and wood properties are related to a Stand Density Index to understand the effect of competition on those values. The results allow us to identify the thinning schemes that record the most significant individual and per-hectare growth (both in thinning and clear felling) and the optimal harvest time under specific growth conditions. We assessed the proportions of commercial logs for sawmill and pulp uses, providing valuable inputs for a subsequent economic analysis of thinning regimes seeking for the most convenient combination of wood products. Wood's physical and mechanical properties assessed were barely affected by contrasting levels of competition between trees, therefore the decision of the silvicultural system to implement will depend on production and economic criteria.

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“…El análisis de los residuales que resultaron del ajuste del modelo de volumen de En general, el sistema S2 registró la más alta precisión tanto en la estimación del volumen comercial, como del ahusamiento. Los estadísticos de validación de los modelos que conforman el S2, así como la tendencia lineal que forma la relación entre los datos observados contra los estimados prueban que los estimadores de los parámetros del sistema S2 son eficientes (Rachid et al, 2014).…”

Section: Modelounclassified

Ecuaciones de razón de volumen para Pinus oocarpa Schiede ex Schltdl. del estado de Nayarit, México

Hernández,

Simental-Serrano,

Hernández-Díaz

et al. 2023

RMCF

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Las ecuaciones de razón de volumen son una opción viable para estimar con precisión el volumen comercial maderable de las especies forestales. El objetivo del presente estudio fue evaluar el ajuste de tres modelos de volumen comercial asociados a la razón de la altura y tres de ahusamiento para conformar un sistema de ecuaciones de volumen comercial-ahusamiento para Pinus oocarpa en el estado de Nayarit. Los datos provienen de la medición de 76 árboles para ajustar los modelos y 20 para validarlos. El ajuste se hizo con PROC MODEL, y se aplicaron regresiones aparentemente no relacionadas (SUR) en el software estadístico SAS 9.2. Los estadísticos de ajuste fueron el Coeficiente de Determinación Ajustado, Raíz del Cuadrado Medio del Error, Coeficiente de Variación y Criterio de Información de Akaike; los de validación fueron el sesgo promedio, error absoluto promedio, porcentaje de la diferencia agregada, Coeficiente de Determinación, Raíz del Cuadrado Medio del Error y los valores del parámetro de la pendiente de la regresión lineal entre datos observados y estimados. El Coeficiente de Determinación y la Raíz del Cuadrado Medio del Error que resultaron del ajuste del mejor modelo de volumen comercial fueron 0.9727 y 0.0651, mientras que los del mejor modelo de ahusamiento fueron 0.9579 y 2.7797. En conclusión, el proceso de validación permitió seleccionar al sistema de ecuaciones de volumen comercial y ahusamiento S2 como el mejor para estimar el volumen y el diámetro a cualquier altura del fuste para P. oocarpa.

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Volume and Taper Equations for P. taeda (L.) and E. grandis (Hill ex. Maiden)

Cited by 16 publications

References 20 publications

Developing fully compatible taper and volume equations for all stem components of Eucalyptus globoidea Blakely trees in New Zealand

Developing fully compatible taper and volume equations for all stem components of Eucalyptus globoidea Blakely trees in New Zealand

Impact of Thinning on the Yield and Quality of <em>Eucalyptus grandis</em> Wood at Harvest Time

Ecuaciones de razón de volumen para Pinus oocarpa Schiede ex Schltdl. del estado de Nayarit, México

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