Splintholz

Splintholz, or sapwood, refers to the outer, living portion of a tree’s wood. It lies between the cambium and the heartwood and is responsible for the transport of water and nutrients from the roots to the leaves. In most species, sapwood is lighter in color than heartwood and has a higher moisture content. The tissue consists mainly of xylem vessels or tracheids, along with ray parenchyma cells that store nutrients; it contains living cells, hence it is able to transport resources and repair damage.

Because sapwood is active tissue, it is more susceptible to fungi, decay organisms, and insect attack than heartwood. It is also more permeable to moisture and less dimensionally stable when drying. In timber production and woodworking, Splintholz is often distinguished from Herzholz; it is typically softer and less durable. In some applications the sapwood is unwanted for outdoor or long-term durability and is therefore removed or treated with preservatives. In other contexts, sapwood can be used for pulp, particleboard, or low-cost timber, and remains acceptable for interior uses where durability is not critical.

The proportion and appearance of sapwood vary by species and age. In many conifers, sapwood forms a broad outer layer of nearly all rings, while in many hardwoods the sapwood may be pale and distinct from the darker heartwood. The term is used primarily in German-speaking contexts, with sapwood corresponding to the English term.