Frequency of location of failure (%) by tree group. Failure location percentage also divided into failures occurring at ground level (trunk) plus below (root) and failures occurring above ground (trunk above ground level and branch).
| Location of failure | Q. agrifolia | Hardwoods | Eucalyptus | Conifers | Q. lobata | Other oaks |
|---|---|---|---|---|---|---|
| Trunk (%) | 28.9 | 30.6 | 28.1 | 23.6 | 33.8 | 31.3 |
| Branch (%) | 26.4 | 34.2 | 53.0 | 55.0 | 35.1 | 33.8 |
| Root (%) | 44.6 | 35.2 | 18.9 | 21.4 | 31.1 | 35.0 |
| Ground level and below (%) | 54.0 | 45.0 | 24.0 | 25.0 | 35.0 | 45.0 |
| Above ground level (%) | 46.0 | 55.0 | 76.0 | 75.0 | 65.0 | 55.0 |