What is the term for decay found at the base or lower trunk of a tree?

The correct term for decay found at the base or lower trunk of a tree is "basal rot." This type of decay often occurs in the area where the trunk meets the soil, which is frequently subjected to moisture and other environmental stressors that can lead to fungal infections or other forms of deterioration. Basal rot can significantly affect the structural integrity of a tree, making it susceptible to uprooting or breakage.

Other types of rot, such as heart rot, occur deeper within the trunk and are typically not located at the base but instead affect the inner wood of the tree. Crown rot suggests decay that occurs at the upper sections of the tree or in the crown area, while trunk decay is a general term that may refer to any decay along the trunk but does not specifically identify the basal location. Understanding these distinctions is crucial for identifying and managing tree health and safety effectively.