Western Tree Failure Database/California Tree Failure Report Program

A Twenty Year Look 2000/2010/2020

Data Summary comparisons: 2000,2010,2020

  200020102020
Total Reports 258748876284
Top genera (% of total)Pinus20.618.316.9
 Quercus19.121.523.4
 Eucalyptus14.612.412.5
 Cupressus12.99.88.6
Top species (% of total)Pinus radiata13.510.38.8
 Cupressus macrocarpa11.99.17.9
 Quercus agrifolia9.510.711.5
 Eucalyptus globulus5.35.45.6
Location of failure
(% of total)
trunk283028.7
 branch363636.7
 root363434.6
Mean age 636161.5
Mean DBH 30"29"29
Mean height 56'55'55
Most frequently reported defects (excluding decay)
% of total
heavy lateral limb1918.818.7
 Codominant/multiple trunk1415.615.6
 dense crown1010.310.6
Site category (% of total)residential28.334.933.3
 park402928.3
 street111415.9
Site use (% of total)high46.148.754
 medium26.724.722.9
 low181815.7
 undeveloped88.67.4
Tree occurring (% of total)alone35.239.539.7
 in a group55.951.250.8
 altered stand8.699.1
Stand type (% of total)natural21.124.623.3
 planted72.367.269.3
 mixed6.68.17.3
Hardwood (% of total) 60.664.267.2
Conifer (% of total) 39.435.832.8
Origins (county) of reports (% of total)San Francisco33.521.718.5
 Alameda10.714.312.7
 San Mateo8.611.612.2
 Santa Clara7.88.810.1
 Yolo4.22.52.1
 Contra Costa4.23.84.8
 Sonoma3.62.82.6
 Los Angeles3.42.84.4
 San Joaquin3.42.62.1
 Ventura2.11.82.0
 Napa2.44.34.1
 Marin2.03.33.4
 Stanislaus1.42.80.6
 Santa Cruz0.52.32.3
 Mariposa2.42.11.7
Mean costs of failure (includes property damage and cleanup)*All (trunk, branch
and root)
$2506.00$3477.00$3417.40
 trunk$3798.00$3562.00$3461.20
 branch$604.00$3516.00$3373.54
 root$3198.00$3351.00$3425.49

* Costs are estimates and in about 38% of cases they are not reported.