Each individual tree can live for 40–150 years above ground, but the root system of the colony is long-lived. Aspens do not thrive in the shade, and it is difficult for seedlings to grow in an already mature aspen stand.

Aspen bark

homepage

Additionally, the bark is photosynthetic, meaning that growth is still possible after the leaves have been dropped. They are able to survive forest fires, because the roots are below the heat of the fire, and new sprouts appear after the fire burns out. Elk, deer, and moose not only eat the leaves but also strip the bark with their front teeth.

Source: http://aspenlogandbeetlekillpinefurniture.com/portfolio/sink-vanity/