Distribution of extractives in Sitka spruce (Picea sitchensis) grown in the northern UK

Abstract

The distribution of acetone soluble extractives in Sitka spruce (Picea sitchensis) grown in Northern Britain was determined. Neither yield class, latitude, longitude nor thinning were found to have an impact on the total amount of acetone soluble extractives. More extractives were present in heartwood compared to sapwood but there were no significant differences in extractive content with stem height. A spectroscopic method capable of medium to high throughput of samples was developed to assess the relative amounts of aliphatic, carbonyl and aromatic functional groups in wood extractives. Heartwood contained a higher relative amount of aromatics than sapwood. Again no significant influence of site factors or stem height was found in terms of extractive composition. The low and stable extractive content of Sitka spruce contributes to its outstanding pulping properties and makes the wood ideally suited for applications like interior cladding or shavings for animal bedding where volatile extractives are of concern.