Measuring a Big Tree

While a basic identification, a photo of the tree, and noting its locality are good, please try to take the time to measure the tree, the following measurements are essential:

Trunk Circumference
The trunk circumference is measured at 1.3 to 1.4 metres above the ground. When taking this measurement:

• Ignore any lumps or burls on the trunk.
• Measure tightly around the stem for accuracy.
• If there are branches below 1.3 metres, measure them separately at right angles to the trunk at 1.4 metres.

Crown Diameter
The crown diameter refers to the width of the tree’s canopy. To measure this:

• Measure the projected crown diameter along both north-south and east-west directions for a more accurate representation.
  (The best time of day to measure the crown diameter using the tree's shade would be midday when the sun is directly overhead. During this time:
  Minimised Distortion: The sun casts the least amount of shadow distortion, meaning the shape and size of the tree's crown will be more accurately represented by its shadow.
  More Accurate Diameter: With the sun overhead, the shadow is more circular, reflecting the true crown diameter in both the north-south and east-west directions.
  If midday isn't possible, try measuring when the sun is as high as possible in the sky to reduce the distortion caused by long shadows. Avoid early morning or late afternoon when shadows are elongated, which can make the crown diameter appear larger or distorted.)

Tree Height
Measuring the tree's height is often the most challenging aspect because trees are rarely on level ground. However, height is crucial, as it greatly influences the tree size index. To measure the height:

• Try measuring the tree from various directions to get an accurate reading.
• Ideally, a clinometer should be used, which calculates height based on the angle measured from a known distance.
• Alternatively, several Android apps are available that can perform the same measurement using your smartphone.

By following these steps, you’ll be able to provide a more detailed and informative account of the tree’s size and structure.

Posted on September 22, 2024 05:26 PM by shauns