What are some problems associated with topping or heading back a tree?

Topping or heading back a tree results in large wounds where branches have been cut away, and these wounds do not heal effectively. The exposure of the inner wood can attract insects and pathogens, making the tree more susceptible to infestations and diseases. Large cuts create open areas that take a long time to seal, leaving the tree vulnerable to secondary issues such as decay and infection.

The other options do not accurately represent the problems associated with topping. Improved sunlight access is a misconception, as topping often leads to uneven canopies and does not enhance light penetration effectively. Increased leaf surface area is typically not a benefit of topping, as the overall health of the tree is compromised, and the regrowth may not result in a stronger or more efficient leaf area. Reduced disease resistance is indeed a consequence of the tree's stress and wounds, but the more immediate concern with topping is the attraction of insects due to the large wounds created.