It also reduces weight on heavy limbs and helps retain the tree's natural shape. Crown raising removes lower branches to provide clearance for buildings, vehicles, etc. Crown reduction reduces the size of a tree by pruning back leaders and branch terminals to lateral branches large enough to assume the treetop, or terminal, role. This depends on tree size, species, age and pruning objectives. A tree can recover from several small pruning wounds better than one large wound.
Young trees can tolerate pruning better than old ones.
Mature trees should require little pruning. The older and larger the tree, the less energy it has in reserve to close wounds and fight decay and insect attacks. Yes, if you have the proper equipment and knowledge. Provided they are healthy, trees are innately capable of closing the wounds caused by correctly done pruning. The proper place to remove a branch is just beyond the branch collar at the branch's point of attachment.