We should really have something like this, maybe not for every biome but for every region so we can discuss what would reasonably evolve.
If the very tall pufftower stands 2 m above every other flora in the biome and they do not compete within the race to much they would probably evolve to be smaller, saving energy can be quite an important aspect in natural sellection.
Feel free to make an "adopt a biome" topics like this yourself. The more people get involved the better the project becomes.