Differences in β-thujaplicin content of wood between plantation- and naturally grown Thujopsis dolabrata var. hondae (hinokiasunaro) trees in Shimokita Peninsula, Aomori, Japan

Abstract

Abstract β-Thujaplicin (hinokitiol) is an important extractive of Thujopsis dolabrata var. hondae (hinokiasunaro) that confers high durability to its wood. We investigated differences in β-thujaplicin content in wood from plantation- and naturally grown trees of T. dolabrata var. hondae, and also examined growth rate and wood density. A total of 29 trees were collected from two natural forests and a plantation forest in the Shimokita Peninsula, Aomori, Japan. β-Thujaplicin content was determined for each heartwood sample by gas chromatography. The content ranged from 0.29 to 3.67 mg/g (oven-dry weight basis). β-thujaplicin content of plantation-grown trees was significantly higher than for naturally grown trees, though with a large variation. The effect of radial growth rate on β-thujaplicin content was minimal. We conclude that T. dolabrata var. hondae wood from both plantation and natural forest has similar durability. The coefficient of variation of β-thujaplicin content in each stand was higher than for other wood properties. This degree of tree-to-tree variation in the trait suggests that promising production with more durable wood could be achieved by selecting T. dolabrata var. hondae trees containing a high content of β-thujaplicin for plantations.

Keywords

• Between-tree variation
• Heartwood extractives
• Natural durability
• Thujopsis dolabrata var. hondae
• β-Thujaplicin