2017-04-18
Desert is a land subtype with no special meaning. It doesn't grant the land an intrinsic mana ability. Other cards may care about which lands are Deserts.
2017-07-14
Dunes of the Dead's second ability doesn't allow you to sacrifice it whenever you'd like. You must find another way to get Dunes of the Dead into the graveyard.
2017-07-14
If you sacrifice Dunes of the Dead to pay the activation cost of an ability, you'll create the Zombie token before that activated ability resolves.