OK, when you get back can you answer a couple of questions?
-- How big is this island?
-- Is the ice all sea-ice (no land underneath) or is some of it on top of land? The latter would make more sense.
-- You say "arid" at the beginning and then "lush forests"; this sounds like the climate is a bit complicated. Were you thinking ice shading through tundra to boreal forest, like northern Canada, or what?