CO2 fertilization effect also thought to be responsible for change from open grasslands to thicket in Southern Africa.
http://e360.yale.edu/feature/the_surprising_role_of_co2_in_changes_on_the_african_savanna/2663/
Namibia, a generally arid, thinly populated country to the northwest of South Africa, has been particularly hard hit; about 26 million hectares (64 million acres) of the country has been invaded by undesirable woody plants, which smother grazing areas. Because trees use more rain than grasses, they also significantly reduce groundwater recharge and runoff into rivers. The loss of grasslands is one reason the country’s beef production is now 50 to 70 percent below 1950s levels, according to some estimates. Bush encroachment costs Namibia’s small economy as much as $170 million per year.
http://e360.yale.edu/feature/the_surprising_role_of_co2_in_changes_on_the_african_savanna/2663/
