The bird Clark's nutcracker, for example, hides up to 100, 000 seeds per year, up to 30 kilometers away from the seed source, and has a very close symbiotic(共生的) relationship with several pine species, most 32 notably the whitebark pine.

The reason for constructing the buildings from wood is probably that ideally proportioned straight and slender timber was available in large quantities in Scandinavia's vast pine forests.