Annual Rings
Concentric rings visible in a tree trunk cross-section, each representing one year of growth with lighter earlywood and darker latewood, whose width indicates growing conditions.
In-Depth Explanation
Annual rings provide a record of a tree's life and growing conditions. Wide rings indicate favorable years with ample moisture and warmth, while narrow rings signal drought or stress. The pattern of earlywood and latewood within each ring affects lumber density, strength, and appearance, with tight rings producing denser stronger wood. Ring orientation in sawn lumber matters: boards with rings perpendicular to the face (quarter sawn) are more stable than those with rings parallel (flat sawn). Counting annual rings reveals the tree age, while ring patterns are used in dendrochronology to date old structures and study historical climate.
Usage Example
The old-growth beam had over 30 annual rings per inch, incredibly tight grain that made the wood extremely hard and strong.