Tree Evaluation Case Studies – Fort Hunt & Alexandria, VA

Tree Identification
• Species: Red Oak (Quercus rubra)
• DBH: 42 inches
• Approximate height: 100 feet

Site Context & Targets
A mature red oak located on a residential property in Fort Hunt, VA was evaluated due to visible decline in one primary stem and proximity to a structure. One co-dominant leader extended directly over an occupied home, creating a high-consequence scenario should structural failure occur.

• Primary target: Residential structure
• Target occupancy: Frequent / constant

Inspection Method
An initial ground-based inspection identified significant defects associated with one co-dominant leader, warranting further evaluation. Due to the tree’s size, the extent of crown coverage over the home, and the severity of observed symptoms, a Level 3 inspection was performed. The Level 3 inspection involved aerial access using rope-access climbing techniques to allow close, hands-on examination of the affected leader, its attachment, and surrounding wood tissue not fully visible from the ground.

Observed Condition & Defects
During the Level 3 tree evaluation and site inspection, significant defects were confirmed in one co-dominant leader measuring approximately 28 inches in diameter, which comprised approximately 50 percent of the total crown and extended directly over the residence.

Observed conditions included:
• One co-dominant leader (≈28-inch diameter) with poor structural attachment
• Advanced decay present at the co-dominant union of the affected leader
• Fungal fruiting bodies observed beneath loose bark on the affected leader, indicating internal decay
• Loose and sloughing bark exposing compromised wood
• Frass accumulation beneath bark, consistent with insect activity
• Egg cocoons present beneath bark plates
• Major dieback within the affected leader’s crown

The opposing co-dominant leader did not exhibit comparable levels of decline or decay at the time of inspection. Hands-on inspection confirmed advanced internal deterioration within the affected leader at critical load-bearing points.

Evaluation Summary
• Likelihood of failure (affected leader): High
• Likelihood of impacting the target: High
• Potential impact severity: Severe

Given that the compromised leader measured approximately 28 inches in diameter and represented roughly half of the crown mass over the residence, failure of this leader would be expected to result in significant damage.

Recommendation
Due to the extent of decay confirmed in the affected co-dominant leader, its size, crown proportion, and the severity of potential consequences, removal of the tree was recommended in the immediate future. Selective pruning, cabling, or bracing were not considered sufficient to adequately mitigate the structural deficiencies associated with the compromised leader and its attachment.

Professional Notes
This case illustrates how defects isolated to a single co-dominant leader can warrant removal when that leader represents a substantial portion of the crown, has advanced internal decay, and overhangs a high-value target. Advanced inspection methods are critical in confirming defect severity not visible from the ground.

Sean Harman
ISA Certified Arborist®
Certification ID: MA-6197A