ATR-FTIR Study of Alaska Yellow Cedar Extractives and Relationship with Their Natural Durability

Shahlinney Lipeh,Mark E Mankowski,Jeffrey J Morrell,Laurence Schimleck,Armando G Mcdonald

doi:10.3390/f12121692

Abstract

New approaches for assessing wood durability are needed to help categorize decay resistance as timber utilization shifts towards plantations or native forest regrowth that may be less durable than original native forest resources. This study evaluated attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy combined with principal component analysis (PCA) for distinguishing between groups of Alaska yellow cedar (Cupressus nootkatensis) wood for susceptibility to two decay fungi (Gloeophyllum trabeum and Rhodonia placenta) and the eastern subterranean termite (Reticulitermes flavipes). Alaska yellow cedar durability varied with test organisms, but the majority of samples were highly resistant to fungal and termite attack. Weight losses and extractives yield using sequential extractions (toluene:ethanol > ethanol > hot water) showed moderate to weak relationships. PCA analysis revealed limited ability to distinguish amongst levels of wood durability to all tested organisms. The absence of non-resistant samples may have influenced the ability of the chemometric methods to accurately categorize durability.

Highlights

The heartwood of some tree species exhibits exceptional resistance to fungal and insect attack, but this property can be highly variable between and even within individual trees [1]. These variations are becoming more important with the shift from harvesting old-growth forests to short rotation plantation trees and native forest regrowth
Wood from plantation and regrowth forests are generally proving to be more susceptible to degradation compared to old growth trees due to a decrease in the presence of toxic chemicals or extractives [2,3]
The boards varied from quarter to flat sawn, did not include the pith, and were obtained from old growth (>100 years old) native forest trees grown on the

Summary

Introduction

The heartwood of some tree species exhibits exceptional resistance to fungal and insect attack, but this property can be highly variable between and even within individual trees [1] These variations are becoming more important with the shift from harvesting old-growth forests to short rotation plantation trees and native forest regrowth. Durability gradients are believed to be caused by biological detoxification, natural oxidation of heartwood extractives, and continued polymerization of extractives to produce less toxic compounds [9,10,11]. This makes durability classification a complex process

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