I extensively root-pruned a 60 year old camphor laurel (Cinnamomum camphora) while landscaping 4 years ago. Last winter here was severe dieback on the quarter of the crown on the side I root-pruned. If I remove the affected limbs, can I expect the balance of the tree to stay healthy - or would a tree this age be expected to enter long-term decline?

Alan, Brisbane , Australia

I read that this tree is considered an invasive nuisance in Queensland. The tree develops an extensive root system with large buttress roots.
Depending on the size and number of roots cut, and how they were cut, the tree will lose some top as a direct result. Since I don't know how (size, number, wound quality) the tree roots were pruned, I don't know how much the tree was damaged. In the absence of disease, I would expect the tree to reach some equilibrium between root loss and top loss. I would be concerned about tree stability in any situation where wind is high and buttress root loss is severe. I guess that it's a wait and see situation. Age of tree is only relative to all other factors, I think, in predicting decline. If the tree was vigorous before, and if it adjusts within a couple of years, then it may live long. But although many trees do live many years after root damage, often they are weakened and succumb to root disease and decay. In general, if the tree was already in decline, that makes it worse.