Comparison of Whole-Tree Wood Property Maps for 13- and 22-Year-Old Loblolly Pine

Laurence Schimleck,Christian Mora,Finto Antony,Joseph Dahlen

doi:10.3390/f9060287

Laurence Schimleck, Christian Mora + Show 2 more

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https://doi.org/10.3390/f9060287

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Journal: Forests	Publication Date: May 24, 2018
Citations: 20	License type: CC BY 4.0

Affiliation: Oregon State University, University of Georgia

Abstract

Maps developed using Akima’s interpolation method were used to compare patterns of within-tree variation for Pinus taeda L. (loblolly pine) wood properties in plantation-grown trees aged 13 and 22 years. Air-dry density, microfibril angle (MFA) and modulus of elasticity (MOE) maps represented the average of 18 sampled trees in each age class. Near infrared (NIR) spectroscopy models calibrated using SilviScan provided data for the analysis. Zones of high density, low MFA and high MOE wood increased markedly in size in maps of the older trees. The proportion of wood meeting the visually graded No. 1 (11 GPa) and No. 2 (9.7 GPa) MOE design values for southern pine lumber increased from 44 to 74% and from 58 to 83% respectively demonstrating the impact of age on end-product quality. Air-dry density increased from pith to bark at all heights but lacked a significant trend vertically, while radial and longitudinal trends were observed for MFA and MOE. Changes were consistent with the asymptotic progression of properties associated with full maturity in older trees.

Highlights

The study of wood property variation within trees has been an important area of research for many years
The air-dry density map for the 13-year-old trees showed an increase in density from pith to bark at all heights
Latewood density for P. taeda reaches a plateau at about age 12 while percent latewood takes longer to reach its maximum [17]

Summary

Introduction

The study of wood property variation within trees has been an important area of research for many years. Don (Monterey or radiata pine) and Pinus taeda L. Research has generally been limited to studying pith-to-bark variation, either at breast height for trees sampled nondestructively, or at multiple heights for a small number of destructively sampled trees owing to the large number of samples that must be analyzed to achieve a reasonable level of resolution. This can be challenging given the costs of analyses [2,3,4]. Most studies of whole-tree variation have focused on density as it can be determined with X-ray densitometry, while studies of variability of wood chemistry related parameters such as cellulose and lignin are very limited [1]

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