I found this on a climate change skeptic site but it is an important lecture whatever your opinion on that issue.
The presenter was haunted by the decision to kill 40,000 elephants in his home country of Zimbabwe to preserve grasslands from being overgrazed. Since then he has dedicated himself to finding other ways of preventing desertification.
He believes he has found one as he describes.
I always knew "overgrazing was bad", but it appears to be more about how to do the grazing, rather than whether or not to graze.
I wish he'd presented how to plan the grazing, for that seems to be the key.