Although not a preferred method but sometimes necessary for immature trees with root problems. If signs of girdling roots (roots wrapping around the trunk of the tree) are caught early enough, root pruning can increase chances of survival of young trees. Girdling roots are caused by improper growing techniques at the nursery, being planted to deep or volcano mulching (mulch being stacked up against the trunk). Girdling roots can eventually "choke" the tree. As the tree and the roots grow into each other, the restriction of the vascular area found just under the bark limits water and nutrient uptake from the roots into the tree. Removing such roots and bringing the soil down to the trunk flair (where the trunk of the tree ends and the roots start) can decrease trunk decay, stop new girdling roots from forming, and prevent the tree from getting choked by its own roots.