Don't think so --- they can stop things spawing in certain areas, but I don't beleive they affect the amount of objects spawned -- could be wrong though .....
Supercell neutered my beloved Zaps.... Oh well, adapt and survive... Now BAMing in a league near you, with max rage...
Bring on the BAMfury! !!!!
They do. If trees tries to spawn in certain areas (like right next to buildings), the system will prevent it from spawning and that tree won't try to spawn somewhere else