Agenda - Environmental Policy Board - 05/21/2018

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Measuring Crown Width The crown width of a tree refers to the average diameter of a tree's crown. You can approximate a tree's crown width by using a standard measuring tape. To measure crown width (Figure 3): • One group member will stand at the edge of the canopy with one end of the tape measure • A second member walks with the opposite end of the tape measure to the tree's trunk. They then turn 90 degrees with the tape hugging the stem around the corner and continue that path to the edge of the canopy. o Record this distance to the nearest foot. Average Crown Spread Figure 3 - Measuring Crown Width Condition Rating When assessing the condition of a tree, each team member present should evaluate the tree independently. Once everyone has had a chance to determine their ratings, the team should discuss how each person rated the tree. If condition ratings vary dramatically between team members, take time to discuss and resolve the differences. For each tree surveyed, two separate condition ratings will be determined, one for the crown and one for the stem. Numeric values for the crown and stem ratings are not lumped together or averaged. Each rating is determined by using a zero -to -four point scale. Every tree begins with four points, and receives reductions in quarter point increments as the crown and as the stem are evaluated. Foliage (leaves) is not evaluated in this rating system. Rating the Crown Condition Stag Heading Stagheading is a condition where an entire main branch is dead, from the tip of the branch all the way back to the main stem of another major branch (Figure 4). Up to 1 point may be deducted, based on the size of the dead branch and the percentage of crown affected. Larger branches that affect more of the crown will receive deductions near 1, whereas smaller dead branches that make up only a small portion of the crown will receive minor deductions. 14