If lion hunting was banned the proportional impact on ROI would be highest in Tanzania and Namibia (Table 6). The impact of closure of lion hunting on the proportion of hunting blocks that are viable would be greatest in Tanzania, Zambia, and Zimbabwe (Table 6). If lion hunting were precluded, trophy hunting could become potentially financially unviable across 43,828 km2 in Tanzania, 10,280 km2 in Zambia, 3,310 km2 in Zimbabwe and 2,120 km2 in Mozambique (or 59,538 km2 in total – which is equivalent to ∼4 times the area of Serengeti National Park) (Table 6). Reducing off-takes to 0.5 lions/1,000 km2, however, would only potentially render trophy hunting financially unviable across 7,005 km2 (affecting only Tanzania and Zimbabwe) (Table 6).
http://plosone.org/article/info:doi/10.1371/journal.pone.0029332#article1.body1.sec3.p4

The focus here on presenting the modelled results of implementing a lion hunting ban is misguided. This provides little insight into existing regulatory proposals. There are no proposals for a continent-wide ban of lion hunting and no such ban seems practical or enforceable. More emphasis should be given to the changes with reduced lion hunting, which would better reflect existing proposals.

It would also be useful to inform readers about the size of these area changes in percentage terms, not just absolute terms, or in relation to the size of Serengeti National park. The largest estimated change, associated with a hypothetical ban, represents a change of around 16% of the study area.