Tree inspection process

6. Identification of hazards and intervention/response times

The Tree and Woodland Officers is responsible for identifying and assessing hazards and recording the results. A simple system has been adopted for the trees entered on to the database. These recorded trees/defects are either classed as urgent, routine or monitor. Urgent trees are carried out as soon as operationally possible, but no longer than 7 days. Routine trees are to be done within 3 to 6 months. 

Depending on classification these are then issued to either our in-house arboriculture team or a contractor to complete within a prescribed time frame. Once the work is completed, the job is then removed from the urgent or routine list and added to the works completed list as it will be deemed that the tree is now in an acceptable condition.

Trees can also be recorded as an action to ‘monitor’. This means that the defect is not at a stage where intervention is required but the Inspector wanted to note that the defect has been seen and will be monitored in the future.

Monitor Trees requiring no remedial work low risk
Routine Trees requiring remedial work within 3 to 6 months medium risk
Urgent Trees requiring remedial work within 7 days high risk

Many trees can be potentially hazardous. Using visual tree assessment (after Mattheck et al 1994) the Tree and Woodland Officers or Arboricultural consultant can reasonably assess the conditions most likely to lead to injury or damage to people or property. These are physical or physiological conditions that might lead to a breakup or collapse of the tree.

They are identified and recorded during the inspection process and remedial work specified where required. In practice only visible defects are likely to be identified. Other techniques are available if further investigation beyond visual tree assessment is required to assess the structural integrity of standing trees, such as increment borers, decay detecting drills, resist-graph or ultrasound type equipment. However, it must be noted that these will not be used as a matter of course. The use of such equipment can enable the Tree Officer to make a more informed decision about trees of amenity, or high value wildlife conservation value, or that are politically sensitive.