> How does growing crops work when it's dark 6 months a year?

Have you noticed that all broadleaved trees and shrubs lose their leaves for half the year in temperate zones already?

Did you not wonder why that is?

They'll be fine. Annual crops are fine. Wildlife is fine if it's got somewhere to migrate to.

Tough for wildlife when there's nowhere to migrate to, though. But what's burning desert in summer might be just about tolerable hot tropics in winter.

The problem is that current tropical species can't handle the alternation of the seasons. You don't get seasons at the equator. Spring/summer/autumn/winter is a temperate-zones thing. Near the equator the sun rises and sets at the same time every day, and there are at best 2 seasons: the dry season, when it never rains, and the wet season, when it rains a lot all the time.

>How does growing crops work when it's dark 6 months a year?

Just fine. If the temperature would cooperate.

The land of the midnight sun actually has great yields for the few crops that tolerate the cool temperatures (low ground greens and vegetables basically, not staple grains or fruit). But because the season is so short temperature wise nobody really farms that stuff commercially up there.