At a recent TED talk Allan Savory spoke on How to Green the Deserts and reverse climate change.
Basically Allan concludes that life stock moved in a migratory manner is the way to go. I sort of agree with this logic, but he's a little too quick to dismiss the benefits of fire. Chris Helzer talks a lot in his book, and on his blog, about the benefits of combining fire with live stock grazing. He found that animal grazers tended to favor eating forbs (wildflowers) and would leave prairies rich with grasses but almost devoid of wildflowers. Not that grasses are a bad thing, but so much more plant diversity can be had by including wildfires into the mix. Keep the animals anywhere long enough and they'll eat the grasses too, but most of them favor forbs first and then go onto grasses second. Wildfires do release carbon into the atmosphere, but Allan is forgetting about the root mass that can be as much as 10 times the green of the plant. Wildfires are a natural process too, and many wildflowers and even tree seeds benefit from the extreme temperatures they bring.
Allan's conclusions also goes against some of the methods used by John D. Liu who promotes restrictive grazing to let the land heal for 3 to 5 years, and Geoff Lawton who promote the benefits of permaculture which often includes nonnative plants, but more often than not they're at least food plants or nitrogen fixing. The issue with permaculture is occasionally invasive species are used and that has a negative effect on the local biodiversity. The areas that Allan seems to be looking at are perhaps flatter terrine so there's less ability to manipulate the land besides digging out ditches.
All very interesting topics. A balance between biodiversity and food production needs to be found.