puutuma

Puutuma is a Finnish noun used primarily in forestry and wood-processing contexts to refer to the central portion of a tree or a piece of timber, commonly identified with the heartwood. The term is formed from puu (wood) and tuma (core or nucleus) and has appeared in Finnish technical writings since the early 20th century. In practical use, puutuma is often contrasted with the outer layers such as sapwood and bark, which have different properties and behaviors during drying, finishing, and processing.

In historical and traditional woodcraft literature, puutuma can denote the natural core region of a log that remains after the outer layers are considered or removed for specific uses. In modern forestry and wood science, the property distinctions of puutuma are typically described using standard terms like heartwood and sapwood. Consequently, puutuma is less common in everyday language and is more likely to be encountered in older texts, dialectal references, or discussions of traditional woodworking methods.

Properties associated with puutuma, such as higher density and improved decay resistance relative to surrounding wood, can influence decisions in drying schedules, treatment requirements, and durability considerations for timber products. Understanding the concept, even when referred to by the more widely used terms heartwood and sapwood, helps in assessing wood quality and performance in various applications.

See also: heartwood, sapwood, timber processing.