Root Failures

Summary data for root failures 12/08/11.

This data does not include data from the wind event of 11/30/11-12/02/11

The database contains 5264 reports. 1790 are root failures.

	% of all failures	% of root failures
Quercus	23%	26%
Pinus	18%	20%
Eucalyptus	12%	11%
Cupressus	9%	10%
Fraxinus	3%	3%
Acacia	3%	4%
Ulmus	3%	2%
Liquidambar	2.6%	0.2%
Cedrus	2%	1%
Sequoia	2%	2%
Pyrus	2%	1%

Mean age: 65 years

Mean height: 53 ft.

Mean DBH: 26 inches

Pruning at point of failure from 1591 reports

Root pruning: 113 (7%)

No pruning: 1478 (93%)

Pruning of whole tree from 1499 reports

Some pruning (all types): 698 (47%)

No pruning: 732 (49%)

Other: (4%)

Structural defects (not decay) Up to three choices are permitted in this field. the following lists the number of times a defect was chosen from 1582 reports.

None: 306, Lean: 238, Dense crown: 201, Failed portion dead: 174, Kinked/girdling roots: 173, Other: 159, Onesided: 137, Multiple trunks: 117, Heavy lateral limbs:112, Top heavy: 80.

Decay

Some: 866 (48%)

None: 761 (43%)

Unknown or not reported: 163 (9%)

Restricted roots

Raised planter or bed: 81, Container or boxed tree: 17, Root bariers: 72, Root cutting: 184, N/A or data missing: 1436

Soil from 1642 reports

Good condition: 18%, Compacted: 12%, Saturated: 57%, Dry: 6%, Shallow: 4%, Other: 3%.

Wind from 1567 reports

Less than 5mph: 16%, 5-25 mph: 26%, more than 25 mph: 58%

Precipitation from 1621 reports

Some: 76%, None 24%