Sciencedaily ( aug. 18 , 2010 ) - despite the many cosmetic products , surgical treatments , food supplements , and drugs designed specifically to reverse the biological effects of aging in humans , long-lived aspen clones aren 't so lucky .
The second-biggest forest area , about a third of the total , is in the boreal , or taiga , biome : a belt of spruce , birch , fir and aspen that encircles the far northern hemisphere , mostly in russia , scandinavia , finland , canada and a small part of america .