Nature Spells

All nature spells require the pre-existing resource that the spell manipulates (within reason) the DM can change the effectiveness of your nature spell if you lack a sufficient supply of any given resource. Meaning you cannot summon a tidal wave from a pool of water or an avalanche from the open sky. Unlike other schools of magic, Nature Magic depends heavily on the setting (It is not a summoning school) a magically overgrown tree on an arid plain will wilt and die without water.