What is the purpose of using decay detection tools in tree risk assessment?

Using decay detection tools in tree risk assessment is essential for identifying internal defects that may not be immediately visible from external observations. These tools, such as resistographs or sonic tomography, are designed to penetrate the tree's bark and foliage to evaluate the condition of the wood inside. Since many of the serious weaknesses affecting a tree's structural integrity arise from internal decay—often caused by fungi or other pathogens—having the ability to detect these conditions is vital.

Identifying internal defects allows assessors to make informed decisions about the tree's safety, health, and management options. By utilizing these tools, tree care professionals can determine the extent of decay and the potential for failure, thereby preventing hazardous conditions that could result from falling branches or the entire tree.

The other options do not align with the primary role of decay detection tools. While identifying external health indicators, measuring growth rates, or assessing soil drainage may be components of a comprehensive tree risk assessment, they do not specifically address the internal assessments that decay detection tools are designed for.