Skivkärna

Skivkärna refers to the central part of a tree trunk, specifically the innermost section. It is the oldest wood in the tree and is often denser and darker than the surrounding sapwood. The term is derived from the Swedish words "skiva" meaning disk or slice, and "kärna" meaning core. This anatomical region is characterized by cells that have undergone lignification and are filled with extractives, which can include tannins, resins, and oils. These extractives often contribute to the wood's color and are responsible for its increased resistance to decay and insect attack.

In contrast to sapwood, which is living tissue responsible for water transport, heartwood is typically dead. This makes heartwood more stable and less prone to shrinkage and swelling. The formation of heartwood is a natural process as the tree ages, and it plays a crucial role in structural support. The specific properties and appearance of skivkärna can vary significantly depending on the tree species. For example, oak heartwood is known for its durability and is often used in furniture and flooring, while pine heartwood may be less dense but still offers some resistance to rot. Understanding the characteristics of skivkärna is important in forestry and woodworking for determining wood quality and appropriate uses.