There are three main benefits for pruning (also known as tree trimming or tree cutting) your trees: personal safety, health of the tree, and tree appearance. It is often recommended for personal and property safety reasons to reduce the risk of falling limbs and branches. In addition it is important to remove branches that may be resting on utility lines or near rooftops.
For the tree’s overall health, proper tree pruning helps stimulate new growth and the healing of wounds. It is necessary for the continued health of the tree to remove dead, weakened, diseased, and insect-infested limbs. It can also encourage greater fruit production.
And finally it improves the appearance of trees in your landscape. This is not only beneficial for the look of your property, but can also help increase the overall value! Limbs too close to rooftops can encourage moss and other fungi to grow and reduce the life of the roof. They also can allow various tree climbing animals access to your roof and potentially your home.
This is a brief description for tree pruning, for more details check with your local university or government agricultural office for specific standards in your area, including those of the American National Standards Institute (ANSI).