Resolve Sporemound's trigger, creating a 1/1 Saproling token.
Resolve Amulet of Vigor's trigger, untapping the land.
Activate the land by tapping it, adding ({1} magic symbol) .
Activate Perilous Forays by sacrificing the token and paying ({1} magic symbol) , searching your library for a land with a basic land type and putting it onto the battlefield tapped.
Repeat from step 2.
Results
Near-infinite death triggers.
Near-infinite ETB.
Near-infinite landfall triggers.
Near-infinite LTB.
Near-infinite sacrifice triggers.
Put all lands with a basic land type from your library onto the battlefield tapped.