(Saltcrusted Rainforest isn't a spell.)

At the beginning of your end step, if you didn't cast any spells this turn, Saltcrusted Rainforest deals 1 damage to you.

All creatures have Mountainwalk.

, Pay 1 life, Sacrifice Saltcrusted Rainforest: Search your library for a Forest or Plains card and put it onto the battlefield, then shuffle your library.