When is a "Level 3" tree risk assessment deemed necessary?

A "Level 3" tree risk assessment is necessary when a detailed analysis and extensive investigation are required. This level of assessment is often called for in situations where the initial evaluations indicate potential risks that require further scrutiny. For example, if a tree shows symptoms of decay or structural defects and is located near a target area, an in-depth examination is essential.

This entails various methods of investigation including, but not limited to, examining internal tree structures using tools like resistographs, or analyzing the tree's surroundings for factors that could contribute to instability. Level 3 assessments help in making informed decisions about whether a tree should be retained, pruned, or removed, based on a comprehensive understanding of its condition and the risks it presents.

The other options provide scenarios that do not trigger a Level 3 assessment. For instance, a Level 3 assessment would not be necessary when no immediate hazards are detected or when minimal information is available, as these situations generally require less intensive evaluation methods. Assessing soil quality specifically also does not constitute a Level 3 assessment, which focuses more on the tree's health and structure rather than solely on the soil environment.