In instances where the tree continues to live and is healthy, in most cases, the bark around the scar will continue to grow, gradually thickening and growing out and into the void where the earlier bark had been removed. Eventually, the two sides of the overgrowth bark will meet together and combine, leaving only a faint vertical line and some additional creasing in the bark around it to signify where the scar had been.
Here is a scar tree supposedly saved when it was relocated from Stanwell to Rockhampton Cultural Centre in Queensland.
How long does this process take? Probably not that long. A good measure is the scar tree cut on 17 November 1824, not by an aborigine, but by William Hovell, now 192 years old. In that time the scar has almost entirely sealed over, and the heartwood of the tree in which the inscription was cut, has rotted away completely. Another few decades and if the tree stays healthy, there will be only the faintest trace of where the scar once was.
The Age article shows an example of well preserved scar trees at Boort, that the local Aboriginal community consider a major part of their culture and heritage. They are, however, preserved in their present dead state,because the lake was artificially flooded as part of an irrigation scheme, which killed the trees and prevented further overgrowth of bark. As they were also in a protected piece of public land, and there was no demand for their timber until, sitting as it is in permanent water, it became commercially valueless, they did not get cut down or burnt.
At least a program to identify and record them, and monitor their condition (not just the Boort trees, but all the surviving scar trees in the country) would at least let us know what we are going to lose.