I have an environmental degradation mechanic planned for this game. Most biomes provide resources, but if these resources are abused too much, yield may drop, and, in extreme cases, the ecosystem will collapse and that location will stop being the biome it used to be, and the resources it used to provide are never available again. I'm saving the use of synthesizers for contaminated areas (or, override tracks for offense or defense in these areas--haven't started these yet).
This is what other biomes, such as the tropical rainforest, could turn into if a faction of monsters abuses its resources so badly that the ecosystem is destabilized. The keystone species are extinct. The biome is now a wasteland. Even if the monsters who did this are gone (an enemy monster faction which is expansionist and very harsh on environments is planned to act as the primary antagonist for this game), the biome is now in a corrupted state and won't be returning to the way it was before.