Other elemental spells may be enhanced or weakened by the terrain. Spell keys might be available to reach off-plane sources of information, but other uses seem improbable. Wizardly spell keys are natural objects. Alterations require blown leaves. Conjuration-Summonings require a bit of food that the animal will like.
Divinations are in silver ore.
Enchantments and charms require quartz crystals. Cloud-evocations require a treebranch struck by lightning. Necromancy requires a bone. Referees might not want players to realize that they have entered the Happy Hunting Grounds. Depending on the site of arrival, visitors might simply recognize a world where animals live as happily as we sometimes pretend they do.