Certified Arborist Practice Exam

Brown rot decay this tissue but leave behind lignin. This reduces the bending strength of a tree:

1. Open wound, frass, fruiting bodies, discolored bark, basal mushroom

2. Mitigation

3. False

4. Root collar excavation

The correct answer is: Open wound, frass, fruiting bodies, discolored bark, basal mushroom

The correct choice highlights the symptoms and indicators of brown rot decay in trees. Brown rot primarily affects the cellulose in wood, leading to the deterioration of the structural integrity of the tree. The remaining lignin, which is a crucial component providing rigidity, remains relatively intact, which contributes to the unique features associated with this type of decay. Open wounds are entry points for decay fungi; frass can indicate insect activity, often associated with wood decay; fruiting bodies may appear where the fungus is actively decomposing wood; discolored bark is a common symptom of an underlying issue; and basal mushrooms can signal decay at the base of the tree. All these signs help arborists recognize the presence of brown rot and assess the weakening structure of the tree. In contrast, mitigation focuses on ways to prevent or reduce damage, which does not directly relate to identifying the decay type in this scenario. The option indicating 'false' suggests a misunderstanding, as brown rot does indeed leave lignin but compromises tree strength. Root collar excavation is a technique for managing problems around the root zone but does not directly correspond to the symptoms or identification of brown rot decay.