Ramification: Division or distribution into branches; a manner or pattern of branching; the action or process, or an act, of branching; the state of being branched.*
The word ramification was originally used to refer to the branching habit of plants into smaller and smaller sections (i.e. trunks to branches to twigs). Today, the word is more often used to refer to the ‘consequences or results of an action,’ which is a meaning that evolved from the original meaning.
So, now you can say that one of the ramifications of pruning your shrubs is to increase ramification.
*OED Online. Oxford University Press.