Basic Tree Risk Assessment Form
Client _______________________________________________________________ Date ___________________ Time _________________
Address/ Tree location _________________________________________________________ Tree no. ____________ Sheet _____ of _____
Tree species _________________________________________ dbh_____________ Height ___________ Crown spread dia. ____________
Assessor(s) __________________________________________ Time frame_____________ Tools used______________________________
Target Assessment
Target zone
Occupancy
rate
1– rare
Target description
2 – occasional
3 – frequent
4 – constant
1
2
3
4
Site Factors
History of failures _____________________________________________________________ Topography Flat Slope _________% Aspect _____
Site changes None Grade change Site clearing Changed soil hydrology Root cuts Describe _____________________________________
Soil conditions Limited volume Saturated Shallow Compacted Pavement over roots ______% Describe __________________________
Prevailing wind direction ______ Common weather Strong winds Ice Snow Heavy rain Describe ______________________________
Tree Health and Species Profile
Vigor Low Normal High
Foliage None (seasonal)
None (dead) Normal _____ %
Chlorotic _____%
Necrotic _____%
Pests_____________________________________________________ Abiotic ________________________________________________________
Species failure profile Branches Trunk Roots Describe ____________________________________________________________________
Load Factors
Wind exposure Protected Partial Full Wind funneling ________________________ Relative crown size Small Medium Large
Crown density Sparse Normal Dense
Interior branches Few Normal Dense Vines/Mistletoe/Moss _____________________
Recent or planned change in load factors _________________________________________________________________________________________
Tree Defects and Conditions Affecting the Likelihood of Failure
— Crown and Branches —
Unbalanced crown LCR ______%
Cracks ___________________________________ Lightning damage
Dead twigs/branches ____% overall Max. dia. ______
Codominant __________________________________ Included bark
Broken/Hangers Number __________
Max. dia. ______
Weak attachments ___________________ Cavity/Nest hole ____% circ.
Over-extended branches
Previous branch failures _______________
Similar branches present
Pruning history
Dead/Missing bark
Cankers/Galls/Burls
Sapwood damage/decay
Crown cleaned
Thinned
Raised
Conks Heartwood decay ________________________
Reduced
Topped
Lion-tailed
Flush cuts
Other
Response growth
Main concern(s)
Load on defect
N/A
Minor Moderate Significant
Likelihood of failure
Improbable
Possible
Probable
Imminent
— Trunk —
— Roots and Root Collar —
Dead/Missing bark
Abnormal bark texture/color
Collar buried/Not visible Depth________
Stem girdling
Codominant stems
Included bark
Cracks
Dead
Decay Conks/Mushrooms
Sapwood damage/decay Cankers/Galls/Burls Sap ooze
Ooze
Cavity _____% circ.
Lightning damage Heartwood decay Conks/Mushrooms
Cracks
Cut/Damaged roots Distance from trunk _______
Cavity/Nest hole _____ % circ. Depth _______
Poor taper
Root plate lifting
Soil weakness
Lean _____ ° Corrected? ________________________________
Response growth
Response growth
Main concern(s)
Main concern(s)
Load on defect
N/A Minor Moderate Significant
Load on defect
N/A Minor Moderate Significant
Likelihood of failure
Likelihood of failure
Improbable
Possible
Probable
Imminent
Improbable
Possible
Probable
Imminent
Page 1 of 2