Average Crown Spread

Average crown spread is obtained by measuring the longest and shortest extent of the crown and averaging the figures. Crown spread is taken independent of trunk position.  Endeavour to measure to the tips of the limbs, not to “notches” in the crown shape.  Two measurements of the crown spread are taken (in metres), at right angles to one another.

When measuring the spread of  trees with high canopies, a clinometer may be used to establish the outer edge of the canopy. Walk to where you estimate the outer canopy edge is, sight through the clinometer at 90 degrees and adjust your position until the canopy aligns with your vertical sighting. Place your tape here and repeat on the opposite side of the canopy to obtain one of your measurements. Repeat at right angles to your first measurement to obtain your second. 

Record both measurements in your notes. These will be automatically averaged on the tree registration spreadsheet when you submit your data.

For additional information on measuring trees go to www.nativetreesociety.org/

This site includes many diagrams and excellent discussion on the science of tree measuring.