That's interesting. The few people I know that live in Alaska or who have purchased local produce have said the opposite. That the strawberries were very large and very bland.
I assume some things get sweeter and some are more bland depending on if they burn their own sugar to grow?
But having been raised in central Alberta, which is fairly far north (lattitude 53), I tend to agree with this about flavour and northern climates. Higher lattitudes seem to produce more intense or nuanced berry flavours. One thing I've heard mentioned is that cool nights are important for berry flavour development; here in Ontario in the high humid summer heat (great lakes basin) it doesn't really cool down much at night.
Things like carrot flavours are likely explained more by the mineral composition of the soils, which haven't been farmed as much and are younger soils.