It's not a heat or distribution map. It just a height map set to a specific altitude. The plants are probably set to spawn on certain terrains at certain alitudes.
No it's not, Concha will spawn in ravines and it doesn't matter if that's a ravine in a desert or among mountains, yes the colour of the blue is affected by the underlying terrain but that's just a side effect of the terrain. If you go to a body with an icy pole you will often find no bio there even though it is the same height as the desert on another part of the planet. All you are doing is either confusing things or trolling, I can't work out which at the moment!