I was interested in that expression also. Apparently it's a German colloquialism. I looked up the etymology and found this: "The number is derived from a machinegun used in WWI named MG 08/15.
Because the soldiers had intensive training on this gun the number was referred as a standard procedure."

Now, I like the texture you have on your map. Have you thought about onshore winds and marine humidity? I'm looking at the wide peninsula of the western continent and it appears desert right up to the coast. This may be a question of the scale making it invisible, but I would think a bit of the levantine green would be noticeable. I'm not sure, but would a thin margin hinting at some hardy growth look more natural?