The Biome Map Tab.
This tab gives a preview of the biomes generated by the elevation,
rainfall, drainage and savagery maps. Any maps that are selected on the
Map Parameters Tab to be generated by PerfectWorldDF will get it's
source from the map tabs in PerfectWorldDF. Any maps that are not
selected to be generated by PW and have pre-set data from the
world_gen.txt file will use the pre-set data as the source.