There are three kinds of roots. All roots start out as feeder roots or rootlets. They grow or elongate by adding cells at their tips, and absorb N, P, & K, etc. Feeder roots grow up to be trunk roots, which are pipelines that convey up to the leaf surfaces what the feeders absorb. Anchor roots are big, old, trunk roots which serve to hold the tree in the soil. Trunk and Anchor roots also serve as reservoirs during the off-season. Feeder roots are more important to us Professional Bonsaiists than the other two because we substitute our own kinds of anchoring mechanisms, and we don’t want trunk roots wandering far-apot (or, far-afield, either). If you have lots of feeders, you don’t hardly need any anchors or trunks. As a rule, you remove any trunks and anchors which will not affect the remaining feeders. It is paramount that you follow the trunk/anchor roots from their fattest point out to their ends to see that- for sure- all those little feeder roots ARE NOT connected to the ends of the trunk/anchor roots. If they are, then you have to remove a lot less big roots, for obvious reasons.
