Short season, cold climate will produce narrow growth rings to be sure.
When cell division is producing more/new wood cells, they push in between eachother before their development finishes.
In this sense, spruce and birch are no different. Give a substantially improved mechanical property to the wood.
Any sort of wood working and wood carving is so much easier.
That interstitial growth, in turn for spruce, produces the world's best pulp for paper.
Two sources: Scandanavia and the central interior of British Columbia.
The mills in Prince George, BC use peroxide bleaching and produce more than 4,500 air dried tons per day.