Which of the following would NOT be a reliable sign of health in a tree?

The presence of carpenter ants is not a reliable sign of health in a tree. While carpenter ants themselves are not necessarily harmful to healthy trees, their presence typically indicates some form of decay or damage. Carpenter ants tend to inhabit wood that has been previously degraded, often by moisture or rot, which suggests that the tree may be in a compromised state. Healthy trees usually do not attract carpenter ants, so their presence is more indicative of underlying issues rather than the vitality of the tree.

In contrast, firm attachment of bark, bright and lush leaves, and robust trunk diameter are all positive indicators of overall tree health. A tree with tightly attached bark is generally free from significant issues such as cankers or decay, while bright and lush leaves typically indicate good photosynthetic activity and overall vigor. A robust trunk diameter reflects a tree's ability to grow and thrive, showcasing its health and stability.