Sapwood
Definition
The outer living wood of a tree, typically lighter in colour than the dark heartwood. Species have characteristic sapwood ring counts (a range). If sapwood is present on a timber, the felling date can be estimated from the number of sapwood rings remaining. If bark is present, felling is exactly dated.
- Location
- Outer living wood of a tree
- Appearance
- Lighter than heartwood
- Use with sapwood only
- Estimates a felling date range
- Use with bark present
- Exact felling date
Common questions
Why does the presence of bark make dating more precise than sapwood rings alone?+
Bark represents the very last growth layer formed before the tree was cut, so if it is intact the outermost ring can be matched directly to a calendar year, whereas sapwood alone only gives a range because some outer rings may have been lost to weathering or processing.
How is a species-specific sapwood ring count used when bark is missing?+
Each species has a typical range for how many rings its sapwood contains before turning to heartwood, so an examiner counts the surviving sapwood rings and adds the species' expected range to estimate how many additional years of growth were likely present before felling.
What forensic questions does dendrochronological dating of sapwood help answer?+
It is used to estimate when a wooden item such as a tool handle, coffin timber, or structural beam was felled, which can help corroborate or challenge a claimed construction date or timeline in cases involving timber evidence.
Related terms
- Annual Ring
- A single year's growth increment visible as a concentric band in a transverse wood section. In most temperate trees, each ring consists...
- Crossdating
- The matching of ring-width patterns between two or more samples to determine their relative or absolute temporal relationship. The master method of...
- Floating Chronology
- A ring-width sequence whose pattern is internally consistent but whose absolute calendar position is unknown because it cannot yet be crossdated to...
- Master Chronology
- A continuous, absolutely dated ring-width sequence built by overlapping many individual samples, living trees linked to old timbers and subfossil wood. Regional...
- Missing Ring
- A year in which growth was so suppressed, by extreme drought, frost, or injury, that no visible ring was deposited. Missing rings...