Which of the following statements about pruning material is true?

Pruning material can indeed prevent diseases and pests from spreading, making this statement accurate. By removing dead or diseased branches, pruning helps to improve the overall health of the tree and can stop the transmission of diseases to healthy parts of the tree or to nearby plants. Pruning can also enhance air circulation within the tree, reducing moisture levels that favor disease growth, and it can remove habitats for pests.

The other statements do not hold the same truth. While healthy trees are ideal candidates for pruning, it is not exclusive to them, as even some unhealthy trees may benefit from careful pruning. Additionally, natural pruning does occur in the wild without human intervention, so it can be necessary in some contexts, even if not directly managed. Lastly, while aesthetic improvements are a benefit of pruning, its primary role is tied to health and structure rather than just appearance.