Okay so this might be very popular. But often biomes mix up and end up in weird generated enviroments.
(I forgot how to put screenshots in so here is a descryption of them):
A Roofed Forest biome and Snowy Mountain biome next to eachother, mix up in game caused a Dark Oak tree to be planted on the mountain side covered in snow)
Click the more button for screenshots. Also, do not comment on really old issues with random talking. This isn't a forum.