In the original box set it was clear that there were only two ways of doing magic. Defiling, and preserving. Both methods drew energy from plant life, but defiling was more destructive, destroying even the ability of soil to grow plant life.
In the later Dark Sun products, other sources of magical energy became available. I have criticized this in the past, but people seem to like these energy sources. Here is what I wrote, so I do not have to repeat it again.
Lets restore the defiling and preserving mechanic by making wizards that use alternative power sources choose between defiling or preserving. Let me explain how.
Magic touches on plant life, no matter how you draw energy. If you draw from the Black or Gray or Tyr Storm, the medium is still plant life from which the energy is drawn though. If a wizard does so recklessly, energy from the Black, Gray or Tyr Storm can destroy plant life. Effectively, its defiling. Or they can choose to be careful, in which case it is preserving.
This is a necessary innovation to fix what was done to the setting. Nor is it a radical change; it simply harmonizes the various power sources along the lines of the preserver/defiler dichotomy that is central to the Dark Sun setting theme.