What type of tree condition can significantly increase risk factors?

Trees with visible decay or girdling roots significantly increase risk factors because these conditions can undermine the structural integrity and overall health of the tree. When decay is present, it indicates that the wood tissue is compromised, leading to a reduced ability to withstand structural stresses such as wind and heavy snow loads.

Girdling roots, on the other hand, can restrict the tree's ability to absorb water and nutrients, making it more susceptible to diseases and other stressors that can weaken it further. These physiological stresses can lead to failures, particularly in adverse weather conditions, thereby elevating the risk of the tree falling or breaking, posing threats to surrounding people and property.

In contrast, healthy and well-watered trees are generally more resilient, young trees are still developing and may not pose the same immediate risks, and deep-rooted species are often better suited for stability in their environments.