Certified Arborist Practice Test

The presence of forking branches is a common indicator of a codominant stem defect. In trees with codominant stems, two or more trunks emerge from a single base, often resulting in a fork right above the ground. This configuration can lead to structural weaknesses because the branches share a similar size and weight, potentially causing them to compete for resources. As the tree matures, this can lead to issues such as included bark, which is the bark that grows between the trunks rather than on the outside, and can increase the risk of failure or splitting, particularly under heavy winds or loaded conditions. The other options do not typically signify a codominant stem defect in the same way. Deep bark furrows might indicate environmental stress or health issues, while a split in the trunk is more commonly associated with physical damage or decay rather than codominance. Unusual leaf size often points to nutritional imbalances or other health-related concerns, but does not provide the structural cues that suggest the presence of codominant stems. Thus, forking branches specifically highlight the structural characteristics associated with codominant stem defects.