Silisca, Great River Dragon

When Silisca, Great River Dragon enters the battlefield, you may deal {x} damage to up to two target permanents you don't control, where {x} is the number of islands you control.
{2}{g/u} Tap target permanent. Draw a card.
{g/u}{g/u} Deal {x} damage to each creature, where {x} is the number of forests you control.