Trees submitted as nominees for the Big Tree Registry must be measured with circumference in inches, and height and crown spread to the nearest foot. The total of these measurements is the points awarded to a particular tree.
Measure, to the nearest inch, the distance around the tree at a point 4½ feet up from the ground to get the circumference. A flexible tape measure is a good tool to use. When a tree has deep convolutions or indentations, measure without pressing into the indentations.
• Tree with a double stem that forks below 4½ feet above the ground, measure at the narrowest place below the fork.
• Tree that has forks at ground level, measure the largest stem at 4½ feet.
• When the base of a tree is "heaved" (tree roots exposed usually due to the effects of erosion, along with tree movement and growth patterns), the measuring point begins where the root mass ends and the tree trunk begins.
• Tree growing on a slope, measure 4½ feet above the midpoint of the different ground levels.
Height is the hardest measurement to obtain. The most reliable method uses a hand level or hypsometer. If these instruments are unavailable, use a ruler and follow the instructions below.
- On a 12-inch ruler, mark the 1-inch and 10-inch lines with tape.
- Work in pairs to measure height.
- Person A stands at the base of the tree.
- Person B, while holding the ruler up in front of their eyes at arm length, moves back until the base of the tree is exactly at 0 inches and the top of the tree is exactly at 10 inches.
- Person B sights out from the ruler’s 1-inch mark to a point on the trunk above the base.
- Person A marks this spot on the trunk with tape.
- Measure the distance from the base of the tree to the 1-inch mark (X) on the tree.
- Multiply by 10 to get an approximate height of the tree.
3. Crown spread
- The trees are under 100 points and within 3 points.
- The trees over 100 points and their difference is within 3 percent of the total.
Measurements of tree: