Table 3.

Probability of failure (1 to 3 points).

Low: Some minor defects present (1 point)
  • minor branch dieback

  • minor defects or wounds


Moderate: One to several moderate defects present (2 points)
  • stem decay or cavity within safe shell decay

  • weak union with in-rolled bark

  • defects(s) affecting less than 50% of tree’s circumference

  • leaning tree (away from target area; greater than 45-degree angle) without new root lifting


High: Multiple or significant defects present (3 points)
  • stem decay or cavity at shell safety limits

  • multiple cracks or a single crack that goes completely through the stem

  • weak union with crack or decay

  • defect(s) affecting more than 50% of tree’s circumference, with decay present

  • leaning tree (toward target area; greater than 45-degree angle) with recent root lifting or soil mounding

  • dead or lodged branches; dead trees