Sapwood

Sapwood is the young, physiologically active wood below the cambium in the root of a tree. His capillaries disperse water and nutrient salts in the tree crown and save sugar and starch in the parenchyma. With increasing age, the Splintgewebe loses vitality and turns in some tree species in heartwood. This process is called heartwood. Contrary to frequent representations to heartwood and sapwood hardly differ in density and strength.

Sapwood are trees with delayed heartwood formation, there are no color and moisture differences between heartwood and sapwood. These include, for example, birch, alder and maple. Its wood has over the entire cross section Splintcharakter.

For the timber sapwood has no natural durability. For exterior wood use of the splint is therefore in the processing of either removed or its durability increased by introduction of chemical wood preservatives. An example of this application are wooden poles.

In oaks and some other tree species occur frequently bright, concentric zones apparently unverkernten wood within the heartwood on ( snap ring ). This feature is often mistakenly referred to as enclosed sapwood. However, it presents no sapwood, but flawed verkerntes wood. The cause of damage to the parenchyma apply during the heartwood formation due to severe frosts in combination with Starkastbrüchen in winter. Disadvantage of the sapwood is the danger of infestation by fungi that cause blue stain and prefer the sapwood of conifers. However, these fungi do not impair the mechanical properties, but only the visual quality.

Hygroscopic properties of the sapwood

The moisture content of freshly harvested timber is generally between about 40 and 60 weight percent (M. - %). You can, in extreme cases, for example in the sapwood of the tree, up to 67 M. - % reach. The wood contains so in the case twice as much water as solid components.