Biological deterioration is found principally in the form of insects and fungi.
While this activity can result in the complete destruction of an object, it pales by comparison to use and the abuse by humans. And by contrast to human intervention, biological deterioration is an often preventable form of damage. Since a tree is naturally part of ecosystems, it must decompose. Natural decay contributes to the supply of nutrients for other plants and animals, including the offspring of a decomposing tree. However, when decay processes become evident in historic objects, there is justifiable cause for alarm.