Where ever there is wind and sand in any amount you will find linear dunes.
In Michigan’s upper peninsula they’re covered with vegetation but the dunes are there in parallel lines along the lake Superior shore.
“Where ever there is wind and sand in any amount you will find linear dunes.”
Yes, there are multiple causes for the production of linear dunes. The scale of those being discussed in Southern Africa are extensive in areal size because they are a result of the interactions between the Hadley and Mid-Latitude cells. You can see the relationship by examining the location of their convergence zone overhead of these linear dunes. The Congo jungles and the Kalihara Desert exist because of these cells.